update vendor

vendor/github.com/cznic/mathutil/LICENSE

+Copyright (c) 2014 The mathutil Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the names of the authors nor the names of the
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/cznic/mathutil/bits.go

+// Copyright (c) 2014 The mathutil Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mathutil
+
+import (
+	"math/big"
+)
+
+// BitLenByte returns the bit width of the non zero part of n.
+func BitLenByte(n byte) int {
+	return log2[n] + 1
+}
+
+// BitLenUint16 returns the bit width of the non zero part of n.
+func BitLenUint16(n uint16) int {
+	if b := n >> 8; b != 0 {
+		return log2[b] + 8 + 1
+	}
+
+	return log2[n] + 1
+}
+
+// BitLenUint32 returns the bit width of the non zero part of n.
+func BitLenUint32(n uint32) int {
+	if b := n >> 24; b != 0 {
+		return log2[b] + 24 + 1
+	}
+
+	if b := n >> 16; b != 0 {
+		return log2[b] + 16 + 1
+	}
+
+	if b := n >> 8; b != 0 {
+		return log2[b] + 8 + 1
+	}
+
+	return log2[n] + 1
+}
+
+// BitLen returns the bit width of the non zero part of n.
+func BitLen(n int) int { // Should handle correctly [future] 64 bit Go ints
+	if IntBits == 64 {
+		return BitLenUint64(uint64(n))
+	}
+
+	if b := byte(n >> 24); b != 0 {
+		return log2[b] + 24 + 1
+	}
+
+	if b := byte(n >> 16); b != 0 {
+		return log2[b] + 16 + 1
+	}
+
+	if b := byte(n >> 8); b != 0 {
+		return log2[b] + 8 + 1
+	}
+
+	return log2[byte(n)] + 1
+}
+
+// BitLenUint returns the bit width of the non zero part of n.
+func BitLenUint(n uint) int { // Should handle correctly [future] 64 bit Go uints
+	if IntBits == 64 {
+		return BitLenUint64(uint64(n))
+	}
+
+	if b := n >> 24; b != 0 {
+		return log2[b] + 24 + 1
+	}
+
+	if b := n >> 16; b != 0 {
+		return log2[b] + 16 + 1
+	}
+
+	if b := n >> 8; b != 0 {
+		return log2[b] + 8 + 1
+	}
+
+	return log2[n] + 1
+}
+
+// BitLenUint64 returns the bit width of the non zero part of n.
+func BitLenUint64(n uint64) int {
+	if b := n >> 56; b != 0 {
+		return log2[b] + 56 + 1
+	}
+
+	if b := n >> 48; b != 0 {
+		return log2[b] + 48 + 1
+	}
+
+	if b := n >> 40; b != 0 {
+		return log2[b] + 40 + 1
+	}
+
+	if b := n >> 32; b != 0 {
+		return log2[b] + 32 + 1
+	}
+
+	if b := n >> 24; b != 0 {
+		return log2[b] + 24 + 1
+	}
+
+	if b := n >> 16; b != 0 {
+		return log2[b] + 16 + 1
+	}
+
+	if b := n >> 8; b != 0 {
+		return log2[b] + 8 + 1
+	}
+
+	return log2[n] + 1
+}
+
+// BitLenUintptr returns the bit width of the non zero part of n.
+func BitLenUintptr(n uintptr) int {
+	if b := n >> 56; b != 0 {
+		return log2[b] + 56 + 1
+	}
+
+	if b := n >> 48; b != 0 {
+		return log2[b] + 48 + 1
+	}
+
+	if b := n >> 40; b != 0 {
+		return log2[b] + 40 + 1
+	}
+
+	if b := n >> 32; b != 0 {
+		return log2[b] + 32 + 1
+	}
+
+	if b := n >> 24; b != 0 {
+		return log2[b] + 24 + 1
+	}
+
+	if b := n >> 16; b != 0 {
+		return log2[b] + 16 + 1
+	}
+
+	if b := n >> 8; b != 0 {
+		return log2[b] + 8 + 1
+	}
+
+	return log2[n] + 1
+}
+
+// PopCountByte returns population count of n (number of bits set in n).
+func PopCountByte(n byte) int {
+	return int(popcnt[byte(n)])
+}
+
+// PopCountUint16 returns population count of n (number of bits set in n).
+func PopCountUint16(n uint16) int {
+	return int(popcnt[byte(n>>8)]) + int(popcnt[byte(n)])
+}
+
+// PopCountUint32 returns population count of n (number of bits set in n).
+func PopCountUint32(n uint32) int {
+	return int(popcnt[byte(n>>24)]) + int(popcnt[byte(n>>16)]) +
+		int(popcnt[byte(n>>8)]) + int(popcnt[byte(n)])
+}
+
+// PopCount returns population count of n (number of bits set in n).
+func PopCount(n int) int { // Should handle correctly [future] 64 bit Go ints
+	if IntBits == 64 {
+		return PopCountUint64(uint64(n))
+	}
+
+	return PopCountUint32(uint32(n))
+}
+
+// PopCountUint returns population count of n (number of bits set in n).
+func PopCountUint(n uint) int { // Should handle correctly [future] 64 bit Go uints
+	if IntBits == 64 {
+		return PopCountUint64(uint64(n))
+	}
+
+	return PopCountUint32(uint32(n))
+}
+
+// PopCountUintptr returns population count of n (number of bits set in n).
+func PopCountUintptr(n uintptr) int {
+	if UintPtrBits == 64 {
+		return PopCountUint64(uint64(n))
+	}
+
+	return PopCountUint32(uint32(n))
+}
+
+// PopCountUint64 returns population count of n (number of bits set in n).
+func PopCountUint64(n uint64) int {
+	return int(popcnt[byte(n>>56)]) + int(popcnt[byte(n>>48)]) +
+		int(popcnt[byte(n>>40)]) + int(popcnt[byte(n>>32)]) +
+		int(popcnt[byte(n>>24)]) + int(popcnt[byte(n>>16)]) +
+		int(popcnt[byte(n>>8)]) + int(popcnt[byte(n)])
+}
+
+// PopCountBigInt returns population count of |n| (number of bits set in |n|).
+func PopCountBigInt(n *big.Int) (r int) {
+	for _, v := range n.Bits() {
+		r += PopCountUintptr(uintptr(v))
+	}
+	return
+}

vendor/github.com/cznic/mathutil/envelope.go

+// Copyright (c) 2014 The mathutil Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mathutil
+
+import (
+	"math"
+)
+
+// Approximation type determines approximation methods used by e.g. Envelope.
+type Approximation int
+
+// Specific approximation method tags
+const (
+	_          Approximation = iota
+	Linear                   // As named
+	Sinusoidal               // Smooth for all derivations
+)
+
+// Envelope is an utility for defining simple curves using a small (usually)
+// set of data points.  Envelope returns a value defined by x, points and
+// approximation.  The value of x must be in [0,1) otherwise the result is
+// undefined or the function may panic. Points are interpreted as dividing the
+// [0,1) interval in len(points)-1 sections, so len(points) must be > 1 or the
+// function may panic. According to the left and right points closing/adjacent
+// to the section the resulting value is interpolated using the chosen
+// approximation method.  Unsupported values of approximation are silently
+// interpreted as 'Linear'.
+func Envelope(x float64, points []float64, approximation Approximation) float64 {
+	step := 1 / float64(len(points)-1)
+	fslot := math.Floor(x / step)
+	mod := x - fslot*step
+	slot := int(fslot)
+	l, r := points[slot], points[slot+1]
+	rmod := mod / step
+	switch approximation {
+	case Sinusoidal:
+		k := (math.Sin(math.Pi*(rmod-0.5)) + 1) / 2
+		return l + (r-l)*k
+	case Linear:
+		fallthrough
+	default:
+		return l + (r-l)*rmod
+	}
+}

vendor/github.com/cznic/mathutil/mathutil.go

+// Copyright (c) 2014 The mathutil Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package mathutil provides utilities supplementing the standard 'math' and
+// 'math/rand' packages.
+//
+// Compatibility issues
+//
+// 2013-12-13: The following functions have been REMOVED
+//
+// 	func Uint64ToBigInt(n uint64) *big.Int
+// 	func Uint64FromBigInt(n *big.Int) (uint64, bool)
+//
+// 2013-05-13: The following functions are now DEPRECATED
+//
+// 	func Uint64ToBigInt(n uint64) *big.Int
+// 	func Uint64FromBigInt(n *big.Int) (uint64, bool)
+//
+// These functions will be REMOVED with Go release 1.1+1.
+//
+// 2013-01-21: The following functions have been REMOVED
+//
+// 	func MaxInt() int
+// 	func MinInt() int
+// 	func MaxUint() uint
+// 	func UintPtrBits() int
+//
+// They are now replaced by untyped constants
+//
+// 	MaxInt
+// 	MinInt
+// 	MaxUint
+// 	UintPtrBits
+//
+// Additionally one more untyped constant was added
+//
+// 	IntBits
+//
+// This change breaks any existing code depending on the above removed
+// functions.  They should have not been published in the first place, that was
+// unfortunate. Instead, defining such architecture and/or implementation
+// specific integer limits and bit widths as untyped constants improves
+// performance and allows for static dead code elimination if it depends on
+// these values. Thanks to minux for pointing it out in the mail list
+// (https://groups.google.com/d/msg/golang-nuts/tlPpLW6aJw8/NT3mpToH-a4J).
+//
+// 2012-12-12: The following functions will be DEPRECATED with Go release
+// 1.0.3+1 and REMOVED with Go release 1.0.3+2, b/c of
+// http://code.google.com/p/go/source/detail?r=954a79ee3ea8
+//
+// 	func Uint64ToBigInt(n uint64) *big.Int
+// 	func Uint64FromBigInt(n *big.Int) (uint64, bool)
+package mathutil
+
+import (
+	"math"
+	"math/big"
+)
+
+// Architecture and/or implementation specific integer limits and bit widths.
+const (
+	MaxInt      = 1<<(IntBits-1) - 1
+	MinInt      = -MaxInt - 1
+	MaxUint     = 1<<IntBits - 1
+	IntBits     = 1 << (^uint(0)>>32&1 + ^uint(0)>>16&1 + ^uint(0)>>8&1 + 3)
+	UintPtrBits = 1 << (^uintptr(0)>>32&1 + ^uintptr(0)>>16&1 + ^uintptr(0)>>8&1 + 3)
+)
+
+var (
+	_1 = big.NewInt(1)
+	_2 = big.NewInt(2)
+)
+
+// GCDByte returns the greatest common divisor of a and b. Based on:
+// http://en.wikipedia.org/wiki/Euclidean_algorithm#Implementations
+func GCDByte(a, b byte) byte {
+	for b != 0 {
+		a, b = b, a%b
+	}
+	return a
+}
+
+// GCDUint16 returns the greatest common divisor of a and b.
+func GCDUint16(a, b uint16) uint16 {
+	for b != 0 {
+		a, b = b, a%b
+	}
+	return a
+}
+
+// GCD returns the greatest common divisor of a and b.
+func GCDUint32(a, b uint32) uint32 {
+	for b != 0 {
+		a, b = b, a%b
+	}
+	return a
+}
+
+// GCD64 returns the greatest common divisor of a and b.
+func GCDUint64(a, b uint64) uint64 {
+	for b != 0 {
+		a, b = b, a%b
+	}
+	return a
+}
+
+// ISqrt returns floor(sqrt(n)). Typical run time is few hundreds of ns.
+func ISqrt(n uint32) (x uint32) {
+	if n == 0 {
+		return
+	}
+
+	if n >= math.MaxUint16*math.MaxUint16 {
+		return math.MaxUint16
+	}
+
+	var px, nx uint32
+	for x = n; ; px, x = x, nx {
+		nx = (x + n/x) / 2
+		if nx == x || nx == px {
+			break
+		}
+	}
+	return
+}
+
+// SqrtUint64 returns floor(sqrt(n)). Typical run time is about 0.5 µs.
+func SqrtUint64(n uint64) (x uint64) {
+	if n == 0 {
+		return
+	}
+
+	if n >= math.MaxUint32*math.MaxUint32 {
+		return math.MaxUint32
+	}
+
+	var px, nx uint64
+	for x = n; ; px, x = x, nx {
+		nx = (x + n/x) / 2
+		if nx == x || nx == px {
+			break
+		}
+	}
+	return
+}
+
+// SqrtBig returns floor(sqrt(n)). It panics on n < 0.
+func SqrtBig(n *big.Int) (x *big.Int) {
+	switch n.Sign() {
+	case -1:
+		panic(-1)
+	case 0:
+		return big.NewInt(0)
+	}
+
+	var px, nx big.Int
+	x = big.NewInt(0)
+	x.SetBit(x, n.BitLen()/2+1, 1)
+	for {
+		nx.Rsh(nx.Add(x, nx.Div(n, x)), 1)
+		if nx.Cmp(x) == 0 || nx.Cmp(&px) == 0 {
+			break
+		}
+		px.Set(x)
+		x.Set(&nx)
+	}
+	return
+}
+
+// Log2Byte returns log base 2 of n. It's the same as index of the highest
+// bit set in n.  For n == 0 -1 is returned.
+func Log2Byte(n byte) int {
+	return log2[n]
+}
+
+// Log2Uint16 returns log base 2 of n. It's the same as index of the highest
+// bit set in n.  For n == 0 -1 is returned.
+func Log2Uint16(n uint16) int {
+	if b := n >> 8; b != 0 {
+		return log2[b] + 8
+	}
+
+	return log2[n]
+}
+
+// Log2Uint32 returns log base 2 of n. It's the same as index of the highest
+// bit set in n.  For n == 0 -1 is returned.
+func Log2Uint32(n uint32) int {
+	if b := n >> 24; b != 0 {
+		return log2[b] + 24
+	}
+
+	if b := n >> 16; b != 0 {
+		return log2[b] + 16
+	}
+
+	if b := n >> 8; b != 0 {
+		return log2[b] + 8
+	}
+
+	return log2[n]
+}
+
+// Log2Uint64 returns log base 2 of n. It's the same as index of the highest
+// bit set in n.  For n == 0 -1 is returned.
+func Log2Uint64(n uint64) int {
+	if b := n >> 56; b != 0 {
+		return log2[b] + 56
+	}
+
+	if b := n >> 48; b != 0 {
+		return log2[b] + 48
+	}
+
+	if b := n >> 40; b != 0 {
+		return log2[b] + 40
+	}
+
+	if b := n >> 32; b != 0 {
+		return log2[b] + 32
+	}
+
+	if b := n >> 24; b != 0 {
+		return log2[b] + 24
+	}
+
+	if b := n >> 16; b != 0 {
+		return log2[b] + 16
+	}
+
+	if b := n >> 8; b != 0 {
+		return log2[b] + 8
+	}
+
+	return log2[n]
+}
+
+// ModPowByte computes (b^e)%m. It panics for m == 0 || b == e == 0.
+//
+// See also: http://en.wikipedia.org/wiki/Modular_exponentiation#Right-to-left_binary_method
+func ModPowByte(b, e, m byte) byte {
+	if b == 0 && e == 0 {
+		panic(0)
+	}
+
+	if m == 1 {
+		return 0
+	}
+
+	r := uint16(1)
+	for b, m := uint16(b), uint16(m); e > 0; b, e = b*b%m, e>>1 {
+		if e&1 == 1 {
+			r = r * b % m
+		}
+	}
+	return byte(r)
+}
+
+// ModPowByte computes (b^e)%m. It panics for m == 0 || b == e == 0.
+func ModPowUint16(b, e, m uint16) uint16 {
+	if b == 0 && e == 0 {
+		panic(0)
+	}
+
+	if m == 1 {
+		return 0
+	}
+
+	r := uint32(1)
+	for b, m := uint32(b), uint32(m); e > 0; b, e = b*b%m, e>>1 {
+		if e&1 == 1 {
+			r = r * b % m
+		}
+	}
+	return uint16(r)
+}
+
+// ModPowUint32 computes (b^e)%m. It panics for m == 0 || b == e == 0.
+func ModPowUint32(b, e, m uint32) uint32 {
+	if b == 0 && e == 0 {
+		panic(0)
+	}
+
+	if m == 1 {
+		return 0
+	}
+
+	r := uint64(1)
+	for b, m := uint64(b), uint64(m); e > 0; b, e = b*b%m, e>>1 {
+		if e&1 == 1 {
+			r = r * b % m
+		}
+	}
+	return uint32(r)
+}
+
+// ModPowUint64 computes (b^e)%m. It panics for m == 0 || b == e == 0.
+func ModPowUint64(b, e, m uint64) (r uint64) {
+	if b == 0 && e == 0 {
+		panic(0)
+	}
+
+	if m == 1 {
+		return 0
+	}
+
+	return modPowBigInt(big.NewInt(0).SetUint64(b), big.NewInt(0).SetUint64(e), big.NewInt(0).SetUint64(m)).Uint64()
+}
+
+func modPowBigInt(b, e, m *big.Int) (r *big.Int) {
+	r = big.NewInt(1)
+	for i, n := 0, e.BitLen(); i < n; i++ {
+		if e.Bit(i) != 0 {
+			r.Mod(r.Mul(r, b), m)
+		}
+		b.Mod(b.Mul(b, b), m)
+	}
+	return
+}
+
+// ModPowBigInt computes (b^e)%m. Returns nil for e < 0. It panics for m == 0 || b == e == 0.
+func ModPowBigInt(b, e, m *big.Int) (r *big.Int) {
+	if b.Sign() == 0 && e.Sign() == 0 {
+		panic(0)
+	}
+
+	if m.Cmp(_1) == 0 {
+		return big.NewInt(0)
+	}
+
+	if e.Sign() < 0 {
+		return
+	}
+
+	return modPowBigInt(big.NewInt(0).Set(b), big.NewInt(0).Set(e), m)
+}
+
+var uint64ToBigIntDelta big.Int
+
+func init() {
+	uint64ToBigIntDelta.SetBit(&uint64ToBigIntDelta, 63, 1)
+}
+
+var uintptrBits int
+
+func init() {
+	x := uint64(math.MaxUint64)
+	uintptrBits = BitLenUintptr(uintptr(x))
+}
+
+// UintptrBits returns the bit width of an uintptr at the executing machine.
+func UintptrBits() int {
+	return uintptrBits
+}
+
+// AddUint128_64 returns the uint128 sum of uint64 a and b.
+func AddUint128_64(a, b uint64) (hi uint64, lo uint64) {
+	lo = a + b
+	if lo < a {
+		hi = 1
+	}
+	return
+}
+
+// MulUint128_64 returns the uint128 bit product of uint64 a and b.
+func MulUint128_64(a, b uint64) (hi, lo uint64) {
+	/*
+		2^(2 W) ahi bhi + 2^W alo bhi + 2^W ahi blo + alo blo
+
+		FEDCBA98 76543210 FEDCBA98 76543210
+		                  ---- alo*blo ----
+		         ---- alo*bhi ----
+		         ---- ahi*blo ----
+		---- ahi*bhi ----
+	*/
+	const w = 32
+	const m = 1<<w - 1
+	ahi, bhi, alo, blo := a>>w, b>>w, a&m, b&m
+	lo = alo * blo
+	mid1 := alo * bhi
+	mid2 := ahi * blo
+	c1, lo := AddUint128_64(lo, mid1<<w)
+	c2, lo := AddUint128_64(lo, mid2<<w)
+	_, hi = AddUint128_64(ahi*bhi, mid1>>w+mid2>>w+uint64(c1+c2))
+	return
+}
+
+// PowerizeBigInt returns (e, p) such that e is the smallest number for which p
+// == b^e is greater or equal n. For n < 0 or b < 2 (0, nil) is returned.
+//
+// NOTE: Run time for large values of n (above about 2^1e6 ~= 1e300000) can be
+// significant and/or unacceptabe.  For any smaller values of n the function
+// typically performs in sub second time.  For "small" values of n (cca bellow
+// 2^1e3 ~= 1e300) the same can be easily below 10 µs.
+//
+// A special (and trivial) case of b == 2 is handled separately and performs
+// much faster.
+func PowerizeBigInt(b, n *big.Int) (e uint32, p *big.Int) {
+	switch {
+	case b.Cmp(_2) < 0 || n.Sign() < 0:
+		return
+	case n.Sign() == 0 || n.Cmp(_1) == 0:
+		return 0, big.NewInt(1)
+	case b.Cmp(_2) == 0:
+		p = big.NewInt(0)
+		e = uint32(n.BitLen() - 1)
+		p.SetBit(p, int(e), 1)
+		if p.Cmp(n) < 0 {
+			p.Mul(p, _2)
+			e++
+		}
+		return
+	}
+
+	bw := b.BitLen()
+	nw := n.BitLen()
+	p = big.NewInt(1)
+	var bb, r big.Int
+	for {
+		switch p.Cmp(n) {
+		case -1:
+			x := uint32((nw - p.BitLen()) / bw)
+			if x == 0 {
+				x = 1
+			}
+			e += x
+			switch x {
+			case 1:
+				p.Mul(p, b)
+			default:
+				r.Set(_1)
+				bb.Set(b)
+				e := x
+				for {
+					if e&1 != 0 {
+						r.Mul(&r, &bb)
+					}
+					if e >>= 1; e == 0 {
+						break
+					}
+
+					bb.Mul(&bb, &bb)
+				}
+				p.Mul(p, &r)
+			}
+		case 0, 1:
+			return
+		}
+	}
+}
+
+// PowerizeUint32BigInt returns (e, p) such that e is the smallest number for
+// which p == b^e is greater or equal n. For n < 0 or b < 2 (0, nil) is
+// returned.
+//
+// More info: see PowerizeBigInt.
+func PowerizeUint32BigInt(b uint32, n *big.Int) (e uint32, p *big.Int) {
+	switch {
+	case b < 2 || n.Sign() < 0:
+		return
+	case n.Sign() == 0 || n.Cmp(_1) == 0:
+		return 0, big.NewInt(1)
+	case b == 2:
+		p = big.NewInt(0)
+		e = uint32(n.BitLen() - 1)
+		p.SetBit(p, int(e), 1)
+		if p.Cmp(n) < 0 {
+			p.Mul(p, _2)
+			e++
+		}
+		return
+	}
+
+	var bb big.Int
+	bb.SetInt64(int64(b))
+	return PowerizeBigInt(&bb, n)
+}
+
+/*
+ProbablyPrimeUint32 returns true if n is prime or n is a pseudoprime to base a.
+It implements the Miller-Rabin primality test for one specific value of 'a' and
+k == 1.
+
+Wrt pseudocode shown at
+http://en.wikipedia.org/wiki/Miller-Rabin_primality_test#Algorithm_and_running_time
+
+ Input: n > 3, an odd integer to be tested for primality;
+ Input: k, a parameter that determines the accuracy of the test
+ Output: composite if n is composite, otherwise probably prime
+ write n − 1 as 2^s·d with d odd by factoring powers of 2 from n − 1
+ LOOP: repeat k times:
+    pick a random integer a in the range [2, n − 2]
+    x ← a^d mod n
+    if x = 1 or x = n − 1 then do next LOOP
+    for r = 1 .. s − 1
+       x ← x^2 mod n
+       if x = 1 then return composite
+       if x = n − 1 then do next LOOP
+    return composite
+ return probably prime
+
+... this function behaves like passing 1 for 'k' and additionally a
+fixed/non-random 'a'.  Otherwise it's the same algorithm.
+
+See also: http://mathworld.wolfram.com/Rabin-MillerStrongPseudoprimeTest.html
+*/
+func ProbablyPrimeUint32(n, a uint32) bool {
+	d, s := n-1, 0
+	for ; d&1 == 0; d, s = d>>1, s+1 {
+	}
+	x := uint64(ModPowUint32(a, d, n))
+	if x == 1 || uint32(x) == n-1 {
+		return true
+	}
+
+	for ; s > 1; s-- {
+		if x = x * x % uint64(n); x == 1 {
+			return false
+		}
+
+		if uint32(x) == n-1 {
+			return true
+		}
+	}
+	return false
+}
+
+// ProbablyPrimeUint64_32 returns true if n is prime or n is a pseudoprime to
+// base a. It implements the Miller-Rabin primality test for one specific value
+// of 'a' and k == 1.  See also ProbablyPrimeUint32.
+func ProbablyPrimeUint64_32(n uint64, a uint32) bool {
+	d, s := n-1, 0
+	for ; d&1 == 0; d, s = d>>1, s+1 {
+	}
+	x := ModPowUint64(uint64(a), d, n)
+	if x == 1 || x == n-1 {
+		return true
+	}
+
+	bx, bn := big.NewInt(0).SetUint64(x), big.NewInt(0).SetUint64(n)
+	for ; s > 1; s-- {
+		if x = bx.Mod(bx.Mul(bx, bx), bn).Uint64(); x == 1 {
+			return false
+		}
+
+		if x == n-1 {
+			return true
+		}
+	}
+	return false
+}
+
+// ProbablyPrimeBigInt_32 returns true if n is prime or n is a pseudoprime to
+// base a. It implements the Miller-Rabin primality test for one specific value
+// of 'a' and k == 1.  See also ProbablyPrimeUint32.
+func ProbablyPrimeBigInt_32(n *big.Int, a uint32) bool {
+	var d big.Int
+	d.Set(n)
+	d.Sub(&d, _1) // d <- n-1
+	s := 0
+	for ; d.Bit(s) == 0; s++ {
+	}
+	nMinus1 := big.NewInt(0).Set(&d)
+	d.Rsh(&d, uint(s))
+
+	x := ModPowBigInt(big.NewInt(int64(a)), &d, n)
+	if x.Cmp(_1) == 0 || x.Cmp(nMinus1) == 0 {
+		return true
+	}
+
+	for ; s > 1; s-- {
+		if x = x.Mod(x.Mul(x, x), n); x.Cmp(_1) == 0 {
+			return false
+		}
+
+		if x.Cmp(nMinus1) == 0 {
+			return true
+		}
+	}
+	return false
+}
+
+// ProbablyPrimeBigInt returns true if n is prime or n is a pseudoprime to base
+// a. It implements the Miller-Rabin primality test for one specific value of
+// 'a' and k == 1.  See also ProbablyPrimeUint32.
+func ProbablyPrimeBigInt(n, a *big.Int) bool {
+	var d big.Int
+	d.Set(n)
+	d.Sub(&d, _1) // d <- n-1
+	s := 0
+	for ; d.Bit(s) == 0; s++ {
+	}
+	nMinus1 := big.NewInt(0).Set(&d)
+	d.Rsh(&d, uint(s))
+
+	x := ModPowBigInt(a, &d, n)
+	if x.Cmp(_1) == 0 || x.Cmp(nMinus1) == 0 {
+		return true
+	}
+
+	for ; s > 1; s-- {
+		if x = x.Mod(x.Mul(x, x), n); x.Cmp(_1) == 0 {
+			return false
+		}
+
+		if x.Cmp(nMinus1) == 0 {
+			return true
+		}
+	}
+	return false
+}
+
+// Max returns the larger of a and b.
+func Max(a, b int) int {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+// Min returns the smaller of a and b.
+func Min(a, b int) int {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+// UMax returns the larger of a and b.
+func UMax(a, b uint) uint {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+// UMin returns the smaller of a and b.
+func UMin(a, b uint) uint {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+// MaxByte returns the larger of a and b.
+func MaxByte(a, b byte) byte {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+// MinByte returns the smaller of a and b.
+func MinByte(a, b byte) byte {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+// MaxInt8 returns the larger of a and b.
+func MaxInt8(a, b int8) int8 {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+// MinInt8 returns the smaller of a and b.
+func MinInt8(a, b int8) int8 {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+// MaxUint16 returns the larger of a and b.
+func MaxUint16(a, b uint16) uint16 {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+// MinUint16 returns the smaller of a and b.
+func MinUint16(a, b uint16) uint16 {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+// MaxInt16 returns the larger of a and b.
+func MaxInt16(a, b int16) int16 {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+// MinInt16 returns the smaller of a and b.
+func MinInt16(a, b int16) int16 {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+// MaxUint32 returns the larger of a and b.
+func MaxUint32(a, b uint32) uint32 {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+// MinUint32 returns the smaller of a and b.
+func MinUint32(a, b uint32) uint32 {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+// MaxInt32 returns the larger of a and b.
+func MaxInt32(a, b int32) int32 {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+// MinInt32 returns the smaller of a and b.
+func MinInt32(a, b int32) int32 {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+// MaxUint64 returns the larger of a and b.
+func MaxUint64(a, b uint64) uint64 {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+// MinUint64 returns the smaller of a and b.
+func MinUint64(a, b uint64) uint64 {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+// MaxInt64 returns the larger of a and b.
+func MaxInt64(a, b int64) int64 {
+	if a > b {
+		return a
+	}
+
+	return b
+}
+
+// MinInt64 returns the smaller of a and b.
+func MinInt64(a, b int64) int64 {
+	if a < b {
+		return a
+	}
+
+	return b
+}
+
+// ToBase produces n in base b. For example
+//
+// 	ToBase(2047, 22) -> [1, 5, 4]
+//
+//	1 * 22^0           1
+//	5 * 22^1         110
+//	4 * 22^2        1936
+//	                ----
+//	                2047
+//
+// ToBase panics for bases < 2.
+func ToBase(n *big.Int, b int) []int {
+	var nn big.Int
+	nn.Set(n)
+	if b < 2 {
+		panic("invalid base")
+	}
+
+	k := 1
+	switch nn.Sign() {
+	case -1:
+		nn.Neg(&nn)
+		k = -1
+	case 0:
+		return []int{0}
+	}
+
+	bb := big.NewInt(int64(b))
+	var r []int
+	rem := big.NewInt(0)
+	for nn.Sign() != 0 {
+		nn.QuoRem(&nn, bb, rem)
+		r = append(r, k*int(rem.Int64()))
+	}
+	return r
+}

vendor/github.com/cznic/mathutil/permute.go

+// Copyright (c) 2014 The mathutil Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mathutil
+
+import (
+	"sort"
+)
+
+// Generate the first permutation of data.
+func PermutationFirst(data sort.Interface) {
+	sort.Sort(data)
+}
+
+// Generate the next permutation of data if possible and return true.
+// Return false if there is no more permutation left.
+// Based on the algorithm described here:
+// http://en.wikipedia.org/wiki/Permutation#Generation_in_lexicographic_order
+func PermutationNext(data sort.Interface) bool {
+	var k, l int
+	for k = data.Len() - 2; ; k-- { // 1.
+		if k < 0 {
+			return false
+		}
+
+		if data.Less(k, k+1) {
+			break
+		}
+	}
+	for l = data.Len() - 1; !data.Less(k, l); l-- { // 2.
+	}
+	data.Swap(k, l)                             // 3.
+	for i, j := k+1, data.Len()-1; i < j; i++ { // 4.
+		data.Swap(i, j)
+		j--
+	}
+	return true
+}

vendor/github.com/cznic/mathutil/primes.go

+// Copyright (c) 2014 The mathutil Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mathutil
+
+import (
+	"math"
+)
+
+// IsPrimeUint16 returns true if n is prime. Typical run time is few ns.
+func IsPrimeUint16(n uint16) bool {
+	return n > 0 && primes16[n-1] == 1
+}
+
+// NextPrimeUint16 returns first prime > n and true if successful or an
+// undefined value and false if there is no next prime in the uint16 limits.
+// Typical run time is few ns.
+func NextPrimeUint16(n uint16) (p uint16, ok bool) {
+	return n + uint16(primes16[n]), n < 65521
+}
+
+// IsPrime returns true if n is prime. Typical run time is about 100 ns.
+//
+//TODO rename to IsPrimeUint32
+func IsPrime(n uint32) bool {
+	switch {
+	case n&1 == 0:
+		return n == 2
+	case n%3 == 0:
+		return n == 3
+	case n%5 == 0:
+		return n == 5
+	case n%7 == 0:
+		return n == 7
+	case n%11 == 0:
+		return n == 11
+	case n%13 == 0:
+		return n == 13
+	case n%17 == 0:
+		return n == 17
+	case n%19 == 0:
+		return n == 19
+	case n%23 == 0:
+		return n == 23
+	case n%29 == 0:
+		return n == 29
+	case n%31 == 0:
+		return n == 31
+	case n%37 == 0:
+		return n == 37
+	case n%41 == 0:
+		return n == 41
+	case n%43 == 0:
+		return n == 43
+	case n%47 == 0:
+		return n == 47
+	case n%53 == 0:
+		return n == 53 // Benchmarked optimum
+	case n < 65536:
+		// use table data
+		return IsPrimeUint16(uint16(n))
+	default:
+		mod := ModPowUint32(2, (n+1)/2, n)
+		if mod != 2 && mod != n-2 {
+			return false
+		}
+		blk := &lohi[n>>24]
+		lo, hi := blk.lo, blk.hi
+		for lo <= hi {
+			index := (lo + hi) >> 1
+			liar := liars[index]
+			switch {
+			case n > liar:
+				lo = index + 1
+			case n < liar:
+				hi = index - 1
+			default:
+				return false
+			}
+		}
+		return true
+	}
+}
+
+// IsPrimeUint64 returns true if n is prime. Typical run time is few tens of µs.
+//
+// SPRP bases: http://miller-rabin.appspot.com
+func IsPrimeUint64(n uint64) bool {
+	switch {
+	case n%2 == 0:
+		return n == 2
+	case n%3 == 0:
+		return n == 3
+	case n%5 == 0:
+		return n == 5
+	case n%7 == 0:
+		return n == 7
+	case n%11 == 0:
+		return n == 11
+	case n%13 == 0:
+		return n == 13
+	case n%17 == 0:
+		return n == 17
+	case n%19 == 0:
+		return n == 19
+	case n%23 == 0:
+		return n == 23
+	case n%29 == 0:
+		return n == 29
+	case n%31 == 0:
+		return n == 31
+	case n%37 == 0:
+		return n == 37
+	case n%41 == 0:
+		return n == 41
+	case n%43 == 0:
+		return n == 43
+	case n%47 == 0:
+		return n == 47
+	case n%53 == 0:
+		return n == 53
+	case n%59 == 0:
+		return n == 59
+	case n%61 == 0:
+		return n == 61
+	case n%67 == 0:
+		return n == 67
+	case n%71 == 0:
+		return n == 71
+	case n%73 == 0:
+		return n == 73
+	case n%79 == 0:
+		return n == 79
+	case n%83 == 0:
+		return n == 83
+	case n%89 == 0:
+		return n == 89 // Benchmarked optimum
+	case n <= math.MaxUint16:
+		return IsPrimeUint16(uint16(n))
+	case n <= math.MaxUint32:
+		return ProbablyPrimeUint32(uint32(n), 11000544) &&
+			ProbablyPrimeUint32(uint32(n), 31481107)
+	case n < 105936894253:
+		return ProbablyPrimeUint64_32(n, 2) &&
+			ProbablyPrimeUint64_32(n, 1005905886) &&
+			ProbablyPrimeUint64_32(n, 1340600841)
+	case n < 31858317218647:
+		return ProbablyPrimeUint64_32(n, 2) &&
+			ProbablyPrimeUint64_32(n, 642735) &&
+			ProbablyPrimeUint64_32(n, 553174392) &&
+			ProbablyPrimeUint64_32(n, 3046413974)
+	case n < 3071837692357849:
+		return ProbablyPrimeUint64_32(n, 2) &&
+			ProbablyPrimeUint64_32(n, 75088) &&
+			ProbablyPrimeUint64_32(n, 642735) &&
+			ProbablyPrimeUint64_32(n, 203659041) &&
+			ProbablyPrimeUint64_32(n, 3613982119)
+	default:
+		return ProbablyPrimeUint64_32(n, 2) &&
+			ProbablyPrimeUint64_32(n, 325) &&
+			ProbablyPrimeUint64_32(n, 9375) &&
+			ProbablyPrimeUint64_32(n, 28178) &&
+			ProbablyPrimeUint64_32(n, 450775) &&
+			ProbablyPrimeUint64_32(n, 9780504) &&
+			ProbablyPrimeUint64_32(n, 1795265022)
+	}
+}
+
+// NextPrime returns first prime > n and true if successful or an undefined value and false if there
+// is no next prime in the uint32 limits. Typical run time is about 2 µs.
+//
+//TODO rename to NextPrimeUint32
+func NextPrime(n uint32) (p uint32, ok bool) {
+	switch {
+	case n < 65521:
+		p16, _ := NextPrimeUint16(uint16(n))
+		return uint32(p16), true
+	case n >= math.MaxUint32-4:
+		return
+	}
+
+	n++
+	var d0, d uint32
+	switch mod := n % 6; mod {
+	case 0:
+		d0, d = 1, 4
+	case 1:
+		d = 4
+	case 2, 3, 4:
+		d0, d = 5-mod, 2
+	case 5:
+		d = 2
+	}
+
+	p = n + d0
+	if p < n { // overflow
+		return
+	}
+
+	for {
+		if IsPrime(p) {
+			return p, true
+		}
+
+		p0 := p
+		p += d
+		if p < p0 { // overflow
+			break
+		}
+
+		d ^= 6
+	}
+	return
+}
+
+// NextPrimeUint64 returns first prime > n and true if successful or an undefined value and false if there
+// is no next prime in the uint64 limits. Typical run time is in hundreds of µs.
+func NextPrimeUint64(n uint64) (p uint64, ok bool) {
+	switch {
+	case n < 65521:
+		p16, _ := NextPrimeUint16(uint16(n))
+		return uint64(p16), true
+	case n >= 18446744073709551557: // last uint64 prime
+		return
+	}
+
+	n++
+	var d0, d uint64
+	switch mod := n % 6; mod {
+	case 0:
+		d0, d = 1, 4
+	case 1:
+		d = 4
+	case 2, 3, 4:
+		d0, d = 5-mod, 2
+	case 5:
+		d = 2
+	}
+
+	p = n + d0
+	if p < n { // overflow
+		return
+	}
+
+	for {
+		if ok = IsPrimeUint64(p); ok {
+			break
+		}
+
+		p0 := p
+		p += d
+		if p < p0 { // overflow
+			break
+		}
+
+		d ^= 6
+	}
+	return
+}
+
+// FactorTerm is one term of an integer factorization.
+type FactorTerm struct {
+	Prime uint32 // The divisor
+	Power uint32 // Term == Prime^Power
+}
+
+// FactorTerms represent a factorization of an integer
+type FactorTerms []FactorTerm
+
+// FactorInt returns prime factorization of n > 1 or nil otherwise.
+// Resulting factors are ordered by Prime. Typical run time is few µs.
+func FactorInt(n uint32) (f FactorTerms) {
+	switch {
+	case n < 2:
+		return
+	case IsPrime(n):
+		return []FactorTerm{{n, 1}}
+	}
+
+	f, w := make([]FactorTerm, 9), 0
+	for p := 2; p < len(primes16); p += int(primes16[p]) {
+		if uint(p*p) > uint(n) {
+			break
+		}
+
+		power := uint32(0)
+		for n%uint32(p) == 0 {
+			n /= uint32(p)
+			power++
+		}
+		if power != 0 {
+			f[w] = FactorTerm{uint32(p), power}
+			w++
+		}
+		if n == 1 {
+			break
+		}
+	}
+	if n != 1 {
+		f[w] = FactorTerm{n, 1}
+		w++
+	}
+	return f[:w]
+}
+
+// PrimorialProductsUint32 returns a slice of numbers in [lo, hi] which are a
+// product of max 'max' primorials. The slice is not sorted.
+//
+// See also: http://en.wikipedia.org/wiki/Primorial
+func PrimorialProductsUint32(lo, hi, max uint32) (r []uint32) {
+	lo64, hi64 := int64(lo), int64(hi)
+	if max > 31 { // N/A
+		max = 31
+	}
+
+	var f func(int64, int64, uint32)
+	f = func(n, p int64, emax uint32) {
+		e := uint32(1)
+		for n <= hi64 && e <= emax {
+			n *= p
+			if n >= lo64 && n <= hi64 {
+				r = append(r, uint32(n))
+			}
+			if n < hi64 {
+				p, _ := NextPrime(uint32(p))
+				f(n, int64(p), e)
+			}
+			e++
+		}
+	}
+
+	f(1, 2, max)
+	return
+}

vendor/github.com/cznic/mathutil/rat.go

+// Copyright (c) 2014 The mathutil Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mathutil
+
+// QCmpUint32 compares a/b and c/d and returns:
+//
+//   -1 if a/b <  c/d
+//    0 if a/b == c/d
+//   +1 if a/b >  c/d
+//
+func QCmpUint32(a, b, c, d uint32) int {
+	switch x, y := uint64(a)*uint64(d), uint64(b)*uint64(c); {
+	case x < y:
+		return -1
+	case x == y:
+		return 0
+	default: // x > y
+		return 1
+	}
+}
+
+// QScaleUint32 returns a such that a/b >= c/d.
+func QScaleUint32(b, c, d uint32) (a uint64) {
+	return 1 + (uint64(b)*uint64(c))/uint64(d)
+}

vendor/github.com/cznic/mathutil/rnd.go

+// Copyright (c) 2014 The mathutil Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mathutil
+
+import (
+	"fmt"
+	"math"
+	"math/big"
+)
+
+// FC32 is a full cycle PRNG covering the 32 bit signed integer range.
+// In contrast to full cycle generators shown at e.g. http://en.wikipedia.org/wiki/Full_cycle,
+// this code doesn't produce values at constant delta (mod cycle length).
+// The 32 bit limit is per this implementation, the algorithm used has no intrinsic limit on the cycle size.
+// Properties include:
+//	- Adjustable limits on creation (hi, lo).
+//	- Positionable/randomly accessible (Pos, Seek).
+//	- Repeatable (deterministic).
+//	- Can run forward or backward (Next, Prev).
+//	- For a billion numbers cycle the Next/Prev PRN can be produced in cca 100-150ns.
+//	  That's like 5-10 times slower compared to PRNs generated using the (non FC) rand package.
+type FC32 struct {
+	cycle   int64     // On average: 3 * delta / 2, (HQ: 2 * delta)
+	delta   int64     // hi - lo
+	factors [][]int64 // This trades some space for hopefully a bit of speed (multiple adding vs multiplying).
+	lo      int
+	mods    []int   // pos % set
+	pos     int64   // Within cycle.
+	primes  []int64 // Ordered. ∏ primes == cycle.
+	set     []int64 // Reordered primes (magnitude order bases) according to seed.
+}
+
+// NewFC32 returns a newly created FC32 adjusted for the closed interval [lo, hi] or an Error if any.
+// If hq == true then trade some generation time for improved (pseudo)randomness.
+func NewFC32(lo, hi int, hq bool) (r *FC32, err error) {
+	if lo > hi {
+		return nil, fmt.Errorf("invalid range %d > %d", lo, hi)
+	}
+
+	if uint64(hi)-uint64(lo) > math.MaxUint32 {
+		return nil, fmt.Errorf("range out of int32 limits %d, %d", lo, hi)
+	}
+
+	delta := int64(hi) - int64(lo)
+	// Find the primorial covering whole delta
+	n, set, p := int64(1), []int64{}, uint32(2)
+	if hq {
+		p++
+	}
+	for {
+		set = append(set, int64(p))
+		n *= int64(p)
+		if n > delta {
+			break
+		}
+		p, _ = NextPrime(p)
+	}
+
+	// Adjust the set so n ∊ [delta, 2 * delta] (HQ: [delta, 3 * delta])
+	// while keeping the cardinality of the set (correlates with the statistic "randomness quality")
+	// at max, i.e. discard atmost one member.
+	i := -1 // no candidate prime
+	if n > 2*(delta+1) {
+		for j, p := range set {
+			q := n / p
+			if q < delta+1 {
+				break
+			}
+
+			i = j // mark the highest candidate prime set index
+		}
+	}
+	if i >= 0 { // shrink the inner cycle
+		n = n / set[i]
+		set = delete(set, i)
+	}
+	r = &FC32{
+		cycle:   n,
+		delta:   delta,
+		factors: make([][]int64, len(set)),
+		lo:      lo,
+		mods:    make([]int, len(set)),
+		primes:  set,
+	}
+	r.Seed(1) // the default seed should be always non zero
+	return
+}
+
+// Cycle reports the length of the inner FCPRNG cycle.
+// Cycle is atmost the double (HQ: triple) of the generator period (hi - lo + 1).
+func (r *FC32) Cycle() int64 {
+	return r.cycle
+}
+
+// Next returns the first PRN after Pos.
+func (r *FC32) Next() int {
+	return r.step(1)
+}
+
+// Pos reports the current position within the inner cycle.
+func (r *FC32) Pos() int64 {
+	return r.pos
+}
+
+// Prev return the first PRN before Pos.
+func (r *FC32) Prev() int {
+	return r.step(-1)
+}
+
+// Seed uses the provided seed value to initialize the generator to a deterministic state.
+// A zero seed produces a "canonical" generator with worse randomness than for most non zero seeds.
+// Still, the FC property holds for any seed value.
+func (r *FC32) Seed(seed int64) {
+	u := uint64(seed)
+	r.set = mix(r.primes, &u)
+	n := int64(1)
+	for i, p := range r.set {
+		k := make([]int64, p)
+		v := int64(0)
+		for j := range k {
+			k[j] = v
+			v += n
+		}
+		n *= p
+		r.factors[i] = mix(k, &u)
+	}
+}
+
+// Seek sets Pos to |pos| % Cycle.
+func (r *FC32) Seek(pos int64) { //vet:ignore
+	if pos < 0 {
+		pos = -pos
+	}
+	pos %= r.cycle
+	r.pos = pos
+	for i, p := range r.set {
+		r.mods[i] = int(pos % p)
+	}
+}
+
+func (r *FC32) step(dir int) int {
+	for { // avg loops per step: 3/2 (HQ: 2)
+		y := int64(0)
+		pos := r.pos
+		pos += int64(dir)
+		switch {
+		case pos < 0:
+			pos = r.cycle - 1
+		case pos >= r.cycle:
+			pos = 0
+		}
+		r.pos = pos
+		for i, mod := range r.mods {
+			mod += dir
+			p := int(r.set[i])
+			switch {
+			case mod < 0:
+				mod = p - 1
+			case mod >= p:
+				mod = 0
+			}
+			r.mods[i] = mod
+			y += r.factors[i][mod]
+		}
+		if y <= r.delta {
+			return int(y) + r.lo
+		}
+	}
+}
+
+func delete(set []int64, i int) (y []int64) {
+	for j, v := range set {
+		if j != i {
+			y = append(y, v)
+		}
+	}
+	return
+}
+
+func mix(set []int64, seed *uint64) (y []int64) {
+	for len(set) != 0 {
+		*seed = rol(*seed)
+		i := int(*seed % uint64(len(set)))
+		y = append(y, set[i])
+		set = delete(set, i)
+	}
+	return
+}
+
+func rol(u uint64) (y uint64) {
+	y = u << 1
+	if int64(u) < 0 {
+		y |= 1
+	}
+	return
+}
+
+// FCBig is a full cycle PRNG covering ranges outside of the int32 limits.
+// For more info see the FC32 docs.
+// Next/Prev PRN on a 1e15 cycle can be produced in about 2 µsec.
+type FCBig struct {
+	cycle   *big.Int     // On average: 3 * delta / 2, (HQ: 2 * delta)
+	delta   *big.Int     // hi - lo
+	factors [][]*big.Int // This trades some space for hopefully a bit of speed (multiple adding vs multiplying).
+	lo      *big.Int
+	mods    []int    // pos % set
+	pos     *big.Int // Within cycle.
+	primes  []int64  // Ordered. ∏ primes == cycle.
+	set     []int64  // Reordered primes (magnitude order bases) according to seed.
+}
+
+// NewFCBig returns a newly created FCBig adjusted for the closed interval [lo, hi] or an Error if any.
+// If hq == true then trade some generation time for improved (pseudo)randomness.
+func NewFCBig(lo, hi *big.Int, hq bool) (r *FCBig, err error) {
+	if lo.Cmp(hi) > 0 {
+		return nil, fmt.Errorf("invalid range %d > %d", lo, hi)
+	}
+
+	delta := big.NewInt(0)
+	delta.Add(delta, hi).Sub(delta, lo)
+
+	// Find the primorial covering whole delta
+	n, set, pp, p := big.NewInt(1), []int64{}, big.NewInt(0), uint32(2)
+	if hq {
+		p++
+	}
+	for {
+		set = append(set, int64(p))
+		pp.SetInt64(int64(p))
+		n.Mul(n, pp)
+		if n.Cmp(delta) > 0 {
+			break
+		}
+		p, _ = NextPrime(p)
+	}
+
+	// Adjust the set so n ∊ [delta, 2 * delta] (HQ: [delta, 3 * delta])
+	// while keeping the cardinality of the set (correlates with the statistic "randomness quality")
+	// at max, i.e. discard atmost one member.
+	dd1 := big.NewInt(1)
+	dd1.Add(dd1, delta)
+	dd2 := big.NewInt(0)
+	dd2.Lsh(dd1, 1)
+	i := -1 // no candidate prime
+	if n.Cmp(dd2) > 0 {
+		q := big.NewInt(0)
+		for j, p := range set {
+			pp.SetInt64(p)
+			q.Set(n)
+			q.Div(q, pp)
+			if q.Cmp(dd1) < 0 {
+				break
+			}
+
+			i = j // mark the highest candidate prime set index
+		}
+	}
+	if i >= 0 { // shrink the inner cycle
+		pp.SetInt64(set[i])
+		n.Div(n, pp)
+		set = delete(set, i)
+	}
+	r = &FCBig{
+		cycle:   n,
+		delta:   delta,
+		factors: make([][]*big.Int, len(set)),
+		lo:      lo,
+		mods:    make([]int, len(set)),
+		pos:     big.NewInt(0),
+		primes:  set,
+	}
+	r.Seed(1) // the default seed should be always non zero
+	return
+}
+
+// Cycle reports the length of the inner FCPRNG cycle.
+// Cycle is atmost the double (HQ: triple) of the generator period (hi - lo + 1).
+func (r *FCBig) Cycle() *big.Int {
+	return r.cycle
+}
+
+// Next returns the first PRN after Pos.
+func (r *FCBig) Next() *big.Int {
+	return r.step(1)
+}
+
+// Pos reports the current position within the inner cycle.
+func (r *FCBig) Pos() *big.Int {
+	return r.pos
+}
+
+// Prev return the first PRN before Pos.
+func (r *FCBig) Prev() *big.Int {
+	return r.step(-1)
+}
+
+// Seed uses the provided seed value to initialize the generator to a deterministic state.
+// A zero seed produces a "canonical" generator with worse randomness than for most non zero seeds.
+// Still, the FC property holds for any seed value.
+func (r *FCBig) Seed(seed int64) {
+	u := uint64(seed)
+	r.set = mix(r.primes, &u)
+	n := big.NewInt(1)
+	v := big.NewInt(0)
+	pp := big.NewInt(0)
+	for i, p := range r.set {
+		k := make([]*big.Int, p)
+		v.SetInt64(0)
+		for j := range k {
+			k[j] = big.NewInt(0)
+			k[j].Set(v)
+			v.Add(v, n)
+		}
+		pp.SetInt64(p)
+		n.Mul(n, pp)
+		r.factors[i] = mixBig(k, &u)
+	}
+}
+
+// Seek sets Pos to |pos| % Cycle.
+func (r *FCBig) Seek(pos *big.Int) {
+	r.pos.Set(pos)
+	r.pos.Abs(r.pos)
+	r.pos.Mod(r.pos, r.cycle)
+	mod := big.NewInt(0)
+	pp := big.NewInt(0)
+	for i, p := range r.set {
+		pp.SetInt64(p)
+		r.mods[i] = int(mod.Mod(r.pos, pp).Int64())
+	}
+}
+
+func (r *FCBig) step(dir int) (y *big.Int) {
+	y = big.NewInt(0)
+	d := big.NewInt(int64(dir))
+	for { // avg loops per step: 3/2 (HQ: 2)
+		r.pos.Add(r.pos, d)
+		switch {
+		case r.pos.Sign() < 0:
+			r.pos.Add(r.pos, r.cycle)
+		case r.pos.Cmp(r.cycle) >= 0:
+			r.pos.SetInt64(0)
+		}
+		for i, mod := range r.mods {
+			mod += dir
+			p := int(r.set[i])
+			switch {
+			case mod < 0:
+				mod = p - 1
+			case mod >= p:
+				mod = 0
+			}
+			r.mods[i] = mod
+			y.Add(y, r.factors[i][mod])
+		}
+		if y.Cmp(r.delta) <= 0 {
+			y.Add(y, r.lo)
+			return
+		}
+		y.SetInt64(0)
+	}
+}
+
+func deleteBig(set []*big.Int, i int) (y []*big.Int) {
+	for j, v := range set {
+		if j != i {
+			y = append(y, v)
+		}
+	}
+	return
+}
+
+func mixBig(set []*big.Int, seed *uint64) (y []*big.Int) {
+	for len(set) != 0 {
+		*seed = rol(*seed)
+		i := int(*seed % uint64(len(set)))
+		y = append(y, set[i])
+		set = deleteBig(set, i)
+	}
+	return
+}

vendor/github.com/cznic/mathutil/test_deps.go

+// Copyright (c) 2014 The mathutil Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mathutil
+
+// Pull test dependencies too.
+// Enables easy 'go test X' after 'go get X'
+import (
+// nothing yet
+)

vendor/github.com/pkg/errors/LICENSE

+Copyright (c) 2015, Dave Cheney <dave@cheney.net>
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/pkg/errors/README.md

+# errors [![Travis-CI](https://travis-ci.org/pkg/errors.svg)](https://travis-ci.org/pkg/errors) [![AppVeyor](https://ci.appveyor.com/api/projects/status/b98mptawhudj53ep/branch/master?svg=true)](https://ci.appveyor.com/project/davecheney/errors/branch/master) [![GoDoc](https://godoc.org/github.com/pkg/errors?status.svg)](http://godoc.org/github.com/pkg/errors) [![Report card](https://goreportcard.com/badge/github.com/pkg/errors)](https://goreportcard.com/report/github.com/pkg/errors) [![Sourcegraph](https://sourcegraph.com/github.com/pkg/errors/-/badge.svg)](https://sourcegraph.com/github.com/pkg/errors?badge)
+
+Package errors provides simple error handling primitives.
+
+`go get github.com/pkg/errors`
+
+The traditional error handling idiom in Go is roughly akin to
+```go
+if err != nil {
+        return err
+}
+```
+which applied recursively up the call stack results in error reports without context or debugging information. The errors package allows programmers to add context to the failure path in their code in a way that does not destroy the original value of the error.
+
+## Adding context to an error
+
+The errors.Wrap function returns a new error that adds context to the original error. For example
+```go
+_, err := ioutil.ReadAll(r)
+if err != nil {
+        return errors.Wrap(err, "read failed")
+}
+```
+## Retrieving the cause of an error
+
+Using `errors.Wrap` constructs a stack of errors, adding context to the preceding error. Depending on the nature of the error it may be necessary to reverse the operation of errors.Wrap to retrieve the original error for inspection. Any error value which implements this interface can be inspected by `errors.Cause`.
+```go
+type causer interface {
+        Cause() error
+}
+```
+`errors.Cause` will recursively retrieve the topmost error which does not implement `causer`, which is assumed to be the original cause. For example:
+```go
+switch err := errors.Cause(err).(type) {
+case *MyError:
+        // handle specifically
+default:
+        // unknown error
+}
+```
+
+[Read the package documentation for more information](https://godoc.org/github.com/pkg/errors).
+
+## Contributing
+
+We welcome pull requests, bug fixes and issue reports. With that said, the bar for adding new symbols to this package is intentionally set high.
+
+Before proposing a change, please discuss your change by raising an issue.
+
+## License
+
+BSD-2-Clause

vendor/github.com/pkg/errors/appveyor.yml

+version: build-{build}.{branch}
+
+clone_folder: C:\gopath\src\github.com\pkg\errors
+shallow_clone: true # for startup speed
+
+environment:
+  GOPATH: C:\gopath
+
+platform:
+  - x64
+
+# http://www.appveyor.com/docs/installed-software
+install:
+  # some helpful output for debugging builds
+  - go version
+  - go env
+  # pre-installed MinGW at C:\MinGW is 32bit only
+  # but MSYS2 at C:\msys64 has mingw64
+  - set PATH=C:\msys64\mingw64\bin;%PATH%
+  - gcc --version
+  - g++ --version
+
+build_script:
+  - go install -v ./...
+
+test_script:
+  - set PATH=C:\gopath\bin;%PATH%
+  - go test -v ./...
+
+#artifacts:
+#  - path: '%GOPATH%\bin\*.exe'
+deploy: off

vendor/github.com/pkg/errors/errors.go

+// Package errors provides simple error handling primitives.
+//
+// The traditional error handling idiom in Go is roughly akin to
+//
+//     if err != nil {
+//             return err
+//     }
+//
+// which applied recursively up the call stack results in error reports
+// without context or debugging information. The errors package allows
+// programmers to add context to the failure path in their code in a way
+// that does not destroy the original value of the error.
+//
+// Adding context to an error
+//
+// The errors.Wrap function returns a new error that adds context to the
+// original error by recording a stack trace at the point Wrap is called,
+// and the supplied message. For example
+//
+//     _, err := ioutil.ReadAll(r)
+//     if err != nil {
+//             return errors.Wrap(err, "read failed")
+//     }
+//
+// If additional control is required the errors.WithStack and errors.WithMessage
+// functions destructure errors.Wrap into its component operations of annotating
+// an error with a stack trace and an a message, respectively.
+//
+// Retrieving the cause of an error
+//
+// Using errors.Wrap constructs a stack of errors, adding context to the
+// preceding error. Depending on the nature of the error it may be necessary
+// to reverse the operation of errors.Wrap to retrieve the original error
+// for inspection. Any error value which implements this interface
+//
+//     type causer interface {
+//             Cause() error
+//     }
+//
+// can be inspected by errors.Cause. errors.Cause will recursively retrieve
+// the topmost error which does not implement causer, which is assumed to be
+// the original cause. For example:
+//
+//     switch err := errors.Cause(err).(type) {
+//     case *MyError:
+//             // handle specifically
+//     default:
+//             // unknown error
+//     }
+//
+// causer interface is not exported by this package, but is considered a part
+// of stable public API.
+//
+// Formatted printing of errors
+//
+// All error values returned from this package implement fmt.Formatter and can
+// be formatted by the fmt package. The following verbs are supported
+//
+//     %s    print the error. If the error has a Cause it will be
+//           printed recursively
+//     %v    see %s
+//     %+v   extended format. Each Frame of the error's StackTrace will
+//           be printed in detail.
+//
+// Retrieving the stack trace of an error or wrapper
+//
+// New, Errorf, Wrap, and Wrapf record a stack trace at the point they are
+// invoked. This information can be retrieved with the following interface.
+//
+//     type stackTracer interface {
+//             StackTrace() errors.StackTrace
+//     }
+//
+// Where errors.StackTrace is defined as
+//
+//     type StackTrace []Frame
+//
+// The Frame type represents a call site in the stack trace. Frame supports
+// the fmt.Formatter interface that can be used for printing information about
+// the stack trace of this error. For example:
+//
+//     if err, ok := err.(stackTracer); ok {
+//             for _, f := range err.StackTrace() {
+//                     fmt.Printf("%+s:%d", f)
+//             }
+//     }
+//
+// stackTracer interface is not exported by this package, but is considered a part
+// of stable public API.
+//
+// See the documentation for Frame.Format for more details.
+package errors
+
+import (
+	"fmt"
+	"io"
+)
+
+// New returns an error with the supplied message.
+// New also records the stack trace at the point it was called.
+func New(message string) error {
+	return &fundamental{
+		msg:   message,
+		stack: callers(),
+	}
+}
+
+// Errorf formats according to a format specifier and returns the string
+// as a value that satisfies error.
+// Errorf also records the stack trace at the point it was called.
+func Errorf(format string, args ...interface{}) error {
+	return &fundamental{
+		msg:   fmt.Sprintf(format, args...),
+		stack: callers(),
+	}
+}
+
+// fundamental is an error that has a message and a stack, but no caller.
+type fundamental struct {
+	msg string
+	*stack
+}
+
+func (f *fundamental) Error() string { return f.msg }
+
+func (f *fundamental) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			io.WriteString(s, f.msg)
+			f.stack.Format(s, verb)
+			return
+		}
+		fallthrough
+	case 's':
+		io.WriteString(s, f.msg)
+	case 'q':
+		fmt.Fprintf(s, "%q", f.msg)
+	}
+}
+
+// WithStack annotates err with a stack trace at the point WithStack was called.
+// If err is nil, WithStack returns nil.
+func WithStack(err error) error {
+	if err == nil {
+		return nil
+	}
+	return &withStack{
+		err,
+		callers(),
+	}
+}
+
+type withStack struct {
+	error
+	*stack
+}
+
+func (w *withStack) Cause() error { return w.error }
+
+func (w *withStack) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			fmt.Fprintf(s, "%+v", w.Cause())
+			w.stack.Format(s, verb)
+			return
+		}
+		fallthrough
+	case 's':
+		io.WriteString(s, w.Error())
+	case 'q':
+		fmt.Fprintf(s, "%q", w.Error())
+	}
+}
+
+// Wrap returns an error annotating err with a stack trace
+// at the point Wrap is called, and the supplied message.
+// If err is nil, Wrap returns nil.
+func Wrap(err error, message string) error {
+	if err == nil {
+		return nil
+	}
+	err = &withMessage{
+		cause: err,
+		msg:   message,
+	}
+	return &withStack{
+		err,
+		callers(),
+	}
+}
+
+// Wrapf returns an error annotating err with a stack trace
+// at the point Wrapf is call, and the format specifier.
+// If err is nil, Wrapf returns nil.
+func Wrapf(err error, format string, args ...interface{}) error {
+	if err == nil {
+		return nil
+	}
+	err = &withMessage{
+		cause: err,
+		msg:   fmt.Sprintf(format, args...),
+	}
+	return &withStack{
+		err,
+		callers(),
+	}
+}
+
+// WithMessage annotates err with a new message.
+// If err is nil, WithMessage returns nil.
+func WithMessage(err error, message string) error {
+	if err == nil {
+		return nil
+	}
+	return &withMessage{
+		cause: err,
+		msg:   message,
+	}
+}
+
+type withMessage struct {
+	cause error
+	msg   string
+}
+
+func (w *withMessage) Error() string { return w.msg + ": " + w.cause.Error() }
+func (w *withMessage) Cause() error  { return w.cause }
+
+func (w *withMessage) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			fmt.Fprintf(s, "%+v\n", w.Cause())
+			io.WriteString(s, w.msg)
+			return
+		}
+		fallthrough
+	case 's', 'q':
+		io.WriteString(s, w.Error())
+	}
+}
+
+// Cause returns the underlying cause of the error, if possible.
+// An error value has a cause if it implements the following
+// interface:
+//
+//     type causer interface {
+//            Cause() error
+//     }
+//
+// If the error does not implement Cause, the original error will
+// be returned. If the error is nil, nil will be returned without further
+// investigation.
+func Cause(err error) error {
+	type causer interface {
+		Cause() error
+	}
+
+	for err != nil {
+		cause, ok := err.(causer)
+		if !ok {
+			break
+		}
+		err = cause.Cause()
+	}
+	return err
+}

vendor/github.com/pkg/errors/stack.go

+package errors
+
+import (
+	"fmt"
+	"io"
+	"path"
+	"runtime"
+	"strings"
+)
+
+// Frame represents a program counter inside a stack frame.
+type Frame uintptr
+
+// pc returns the program counter for this frame;
+// multiple frames may have the same PC value.
+func (f Frame) pc() uintptr { return uintptr(f) - 1 }
+
+// file returns the full path to the file that contains the
+// function for this Frame's pc.
+func (f Frame) file() string {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return "unknown"
+	}
+	file, _ := fn.FileLine(f.pc())
+	return file
+}
+
+// line returns the line number of source code of the
+// function for this Frame's pc.
+func (f Frame) line() int {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return 0
+	}
+	_, line := fn.FileLine(f.pc())
+	return line
+}
+
+// Format formats the frame according to the fmt.Formatter interface.
+//
+//    %s    source file
+//    %d    source line
+//    %n    function name
+//    %v    equivalent to %s:%d
+//
+// Format accepts flags that alter the printing of some verbs, as follows:
+//
+//    %+s   function name and path of source file relative to the compile time
+//          GOPATH separated by \n\t (<funcname>\n\t<path>)
+//    %+v   equivalent to %+s:%d
+func (f Frame) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 's':
+		switch {
+		case s.Flag('+'):
+			pc := f.pc()
+			fn := runtime.FuncForPC(pc)
+			if fn == nil {
+				io.WriteString(s, "unknown")
+			} else {
+				file, _ := fn.FileLine(pc)
+				fmt.Fprintf(s, "%s\n\t%s", fn.Name(), file)
+			}
+		default:
+			io.WriteString(s, path.Base(f.file()))
+		}
+	case 'd':
+		fmt.Fprintf(s, "%d", f.line())
+	case 'n':
+		name := runtime.FuncForPC(f.pc()).Name()
+		io.WriteString(s, funcname(name))
+	case 'v':
+		f.Format(s, 's')
+		io.WriteString(s, ":")
+		f.Format(s, 'd')
+	}
+}
+
+// StackTrace is stack of Frames from innermost (newest) to outermost (oldest).
+type StackTrace []Frame
+
+// Format formats the stack of Frames according to the fmt.Formatter interface.
+//
+//    %s	lists source files for each Frame in the stack
+//    %v	lists the source file and line number for each Frame in the stack
+//
+// Format accepts flags that alter the printing of some verbs, as follows:
+//
+//    %+v   Prints filename, function, and line number for each Frame in the stack.
+func (st StackTrace) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		switch {
+		case s.Flag('+'):
+			for _, f := range st {
+				fmt.Fprintf(s, "\n%+v", f)
+			}
+		case s.Flag('#'):
+			fmt.Fprintf(s, "%#v", []Frame(st))
+		default:
+			fmt.Fprintf(s, "%v", []Frame(st))
+		}
+	case 's':
+		fmt.Fprintf(s, "%s", []Frame(st))
+	}
+}
+
+// stack represents a stack of program counters.
+type stack []uintptr
+
+func (s *stack) Format(st fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		switch {
+		case st.Flag('+'):
+			for _, pc := range *s {
+				f := Frame(pc)
+				fmt.Fprintf(st, "\n%+v", f)
+			}
+		}
+	}
+}
+
+func (s *stack) StackTrace() StackTrace {
+	f := make([]Frame, len(*s))
+	for i := 0; i < len(f); i++ {
+		f[i] = Frame((*s)[i])
+	}
+	return f
+}
+
+func callers() *stack {
+	const depth = 32
+	var pcs [depth]uintptr
+	n := runtime.Callers(3, pcs[:])
+	var st stack = pcs[0:n]
+	return &st
+}
+
+// funcname removes the path prefix component of a function's name reported by func.Name().
+func funcname(name string) string {
+	i := strings.LastIndex(name, "/")
+	name = name[i+1:]
+	i = strings.Index(name, ".")
+	return name[i+1:]
+}

vendor/github.com/sirupsen/logrus/LICENSE

+The MIT License (MIT)
+
+Copyright (c) 2014 Simon Eskildsen
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

vendor/github.com/sirupsen/logrus/alt_exit.go

+package logrus
+
+// The following code was sourced and modified from the
+// https://github.com/tebeka/atexit package governed by the following license:
+//
+// Copyright (c) 2012 Miki Tebeka <miki.tebeka@gmail.com>.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+import (
+	"fmt"
+	"os"
+)
+
+var handlers = []func(){}
+
+func runHandler(handler func()) {
+	defer func() {
+		if err := recover(); err != nil {
+			fmt.Fprintln(os.Stderr, "Error: Logrus exit handler error:", err)
+		}
+	}()
+
+	handler()
+}
+
+func runHandlers() {
+	for _, handler := range handlers {
+		runHandler(handler)
+	}
+}
+
+// Exit runs all the Logrus atexit handlers and then terminates the program using os.Exit(code)
+func Exit(code int) {
+	runHandlers()
+	os.Exit(code)
+}
+
+// RegisterExitHandler adds a Logrus Exit handler, call logrus.Exit to invoke
+// all handlers. The handlers will also be invoked when any Fatal log entry is
+// made.
+//
+// This method is useful when a caller wishes to use logrus to log a fatal
+// message but also needs to gracefully shutdown. An example usecase could be
+// closing database connections, or sending a alert that the application is
+// closing.
+func RegisterExitHandler(handler func()) {
+	handlers = append(handlers, handler)
+}

vendor/github.com/sirupsen/logrus/doc.go

+/*
+Package logrus is a structured logger for Go, completely API compatible with the standard library logger.
+
+
+The simplest way to use Logrus is simply the package-level exported logger:
+
+  package main
+
+  import (
+    log "github.com/Sirupsen/logrus"
+  )
+
+  func main() {
+    log.WithFields(log.Fields{
+      "animal": "walrus",
+      "number": 1,
+      "size":   10,
+    }).Info("A walrus appears")
+  }
+
+Output:
+  time="2015-09-07T08:48:33Z" level=info msg="A walrus appears" animal=walrus number=1 size=10
+
+For a full guide visit https://github.com/Sirupsen/logrus
+*/
+package logrus

vendor/github.com/sirupsen/logrus/entry.go

+package logrus
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"sync"
+	"time"
+)
+
+var bufferPool *sync.Pool
+
+func init() {
+	bufferPool = &sync.Pool{
+		New: func() interface{} {
+			return new(bytes.Buffer)
+		},
+	}
+}
+
+// Defines the key when adding errors using WithError.
+var ErrorKey = "error"
+
+// An entry is the final or intermediate Logrus logging entry. It contains all
+// the fields passed with WithField{,s}. It's finally logged when Debug, Info,
+// Warn, Error, Fatal or Panic is called on it. These objects can be reused and
+// passed around as much as you wish to avoid field duplication.
+type Entry struct {
+	Logger *Logger
+
+	// Contains all the fields set by the user.
+	Data Fields
+
+	// Time at which the log entry was created
+	Time time.Time
+
+	// Level the log entry was logged at: Debug, Info, Warn, Error, Fatal or Panic
+	Level Level
+
+	// Message passed to Debug, Info, Warn, Error, Fatal or Panic
+	Message string
+
+	// When formatter is called in entry.log(), an Buffer may be set to entry
+	Buffer *bytes.Buffer
+}
+
+func NewEntry(logger *Logger) *Entry {
+	return &Entry{
+		Logger: logger,
+		// Default is three fields, give a little extra room
+		Data: make(Fields, 5),
+	}
+}
+
+// Returns the string representation from the reader and ultimately the
+// formatter.
+func (entry *Entry) String() (string, error) {
+	serialized, err := entry.Logger.Formatter.Format(entry)
+	if err != nil {
+		return "", err
+	}
+	str := string(serialized)
+	return str, nil
+}
+
+// Add an error as single field (using the key defined in ErrorKey) to the Entry.
+func (entry *Entry) WithError(err error) *Entry {
+	return entry.WithField(ErrorKey, err)
+}
+
+// Add a single field to the Entry.
+func (entry *Entry) WithField(key string, value interface{}) *Entry {
+	return entry.WithFields(Fields{key: value})
+}
+
+// Add a map of fields to the Entry.
+func (entry *Entry) WithFields(fields Fields) *Entry {
+	data := make(Fields, len(entry.Data)+len(fields))
+	for k, v := range entry.Data {
+		data[k] = v
+	}
+	for k, v := range fields {
+		data[k] = v
+	}
+	return &Entry{Logger: entry.Logger, Data: data}
+}
+
+// This function is not declared with a pointer value because otherwise
+// race conditions will occur when using multiple goroutines
+func (entry Entry) log(level Level, msg string) {
+	var buffer *bytes.Buffer
+	entry.Time = time.Now()
+	entry.Level = level
+	entry.Message = msg
+
+	if err := entry.Logger.Hooks.Fire(level, &entry); err != nil {
+		entry.Logger.mu.Lock()
+		fmt.Fprintf(os.Stderr, "Failed to fire hook: %v\n", err)
+		entry.Logger.mu.Unlock()
+	}
+	buffer = bufferPool.Get().(*bytes.Buffer)
+	buffer.Reset()
+	defer bufferPool.Put(buffer)
+	entry.Buffer = buffer
+	serialized, err := entry.Logger.Formatter.Format(&entry)
+	entry.Buffer = nil
+	if err != nil {
+		entry.Logger.mu.Lock()
+		fmt.Fprintf(os.Stderr, "Failed to obtain reader, %v\n", err)
+		entry.Logger.mu.Unlock()
+	} else {
+		entry.Logger.mu.Lock()
+		_, err = entry.Logger.Out.Write(serialized)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to write to log, %v\n", err)
+		}
+		entry.Logger.mu.Unlock()
+	}
+
+	// To avoid Entry#log() returning a value that only would make sense for
+	// panic() to use in Entry#Panic(), we avoid the allocation by checking
+	// directly here.
+	if level <= PanicLevel {
+		panic(&entry)
+	}
+}
+
+func (entry *Entry) Debug(args ...interface{}) {
+	if entry.Logger.level() >= DebugLevel {
+		entry.log(DebugLevel, fmt.Sprint(args...))
+	}
+}
+
+func (entry *Entry) Print(args ...interface{}) {
+	entry.Info(args...)
+}
+
+func (entry *Entry) Info(args ...interface{}) {
+	if entry.Logger.level() >= InfoLevel {
+		entry.log(InfoLevel, fmt.Sprint(args...))
+	}
+}
+
+func (entry *Entry) Warn(args ...interface{}) {
+	if entry.Logger.level() >= WarnLevel {
+		entry.log(WarnLevel, fmt.Sprint(args...))
+	}
+}
+
+func (entry *Entry) Warning(args ...interface{}) {
+	entry.Warn(args...)
+}
+
+func (entry *Entry) Error(args ...interface{}) {
+	if entry.Logger.level() >= ErrorLevel {
+		entry.log(ErrorLevel, fmt.Sprint(args...))
+	}
+}
+
+func (entry *Entry) Fatal(args ...interface{}) {
+	if entry.Logger.level() >= FatalLevel {
+		entry.log(FatalLevel, fmt.Sprint(args...))
+	}
+	Exit(1)
+}
+
+func (entry *Entry) Panic(args ...interface{}) {
+	if entry.Logger.level() >= PanicLevel {
+		entry.log(PanicLevel, fmt.Sprint(args...))
+	}
+	panic(fmt.Sprint(args...))
+}
+
+// Entry Printf family functions
+
+func (entry *Entry) Debugf(format string, args ...interface{}) {
+	if entry.Logger.level() >= DebugLevel {
+		entry.Debug(fmt.Sprintf(format, args...))
+	}
+}
+
+func (entry *Entry) Infof(format string, args ...interface{}) {
+	if entry.Logger.level() >= InfoLevel {
+		entry.Info(fmt.Sprintf(format, args...))
+	}
+}
+
+func (entry *Entry) Printf(format string, args ...interface{}) {
+	entry.Infof(format, args...)
+}
+
+func (entry *Entry) Warnf(format string, args ...interface{}) {
+	if entry.Logger.level() >= WarnLevel {
+		entry.Warn(fmt.Sprintf(format, args...))
+	}
+}
+
+func (entry *Entry) Warningf(format string, args ...interface{}) {
+	entry.Warnf(format, args...)
+}
+
+func (entry *Entry) Errorf(format string, args ...interface{}) {
+	if entry.Logger.level() >= ErrorLevel {
+		entry.Error(fmt.Sprintf(format, args...))
+	}
+}
+
+func (entry *Entry) Fatalf(format string, args ...interface{}) {
+	if entry.Logger.level() >= FatalLevel {
+		entry.Fatal(fmt.Sprintf(format, args...))
+	}
+	Exit(1)
+}
+
+func (entry *Entry) Panicf(format string, args ...interface{}) {
+	if entry.Logger.level() >= PanicLevel {
+		entry.Panic(fmt.Sprintf(format, args...))
+	}
+}
+
+// Entry Println family functions
+
+func (entry *Entry) Debugln(args ...interface{}) {
+	if entry.Logger.level() >= DebugLevel {
+		entry.Debug(entry.sprintlnn(args...))
+	}
+}
+
+func (entry *Entry) Infoln(args ...interface{}) {
+	if entry.Logger.level() >= InfoLevel {
+		entry.Info(entry.sprintlnn(args...))
+	}
+}
+
+func (entry *Entry) Println(args ...interface{}) {
+	entry.Infoln(args...)
+}
+
+func (entry *Entry) Warnln(args ...interface{}) {
+	if entry.Logger.level() >= WarnLevel {
+		entry.Warn(entry.sprintlnn(args...))
+	}
+}
+
+func (entry *Entry) Warningln(args ...interface{}) {
+	entry.Warnln(args...)
+}
+
+func (entry *Entry) Errorln(args ...interface{}) {
+	if entry.Logger.level() >= ErrorLevel {
+		entry.Error(entry.sprintlnn(args...))
+	}
+}
+
+func (entry *Entry) Fatalln(args ...interface{}) {
+	if entry.Logger.level() >= FatalLevel {
+		entry.Fatal(entry.sprintlnn(args...))
+	}
+	Exit(1)
+}
+
+func (entry *Entry) Panicln(args ...interface{}) {
+	if entry.Logger.level() >= PanicLevel {
+		entry.Panic(entry.sprintlnn(args...))
+	}
+}
+
+// Sprintlnn => Sprint no newline. This is to get the behavior of how
+// fmt.Sprintln where spaces are always added between operands, regardless of
+// their type. Instead of vendoring the Sprintln implementation to spare a
+// string allocation, we do the simplest thing.
+func (entry *Entry) sprintlnn(args ...interface{}) string {
+	msg := fmt.Sprintln(args...)
+	return msg[:len(msg)-1]
+}

vendor/github.com/sirupsen/logrus/exported.go

+package logrus
+
+import (
+	"io"
+)
+
+var (
+	// std is the name of the standard logger in stdlib `log`
+	std = New()
+)
+
+func StandardLogger() *Logger {
+	return std
+}
+
+// SetOutput sets the standard logger output.
+func SetOutput(out io.Writer) {
+	std.mu.Lock()
+	defer std.mu.Unlock()
+	std.Out = out
+}
+
+// SetFormatter sets the standard logger formatter.
+func SetFormatter(formatter Formatter) {
+	std.mu.Lock()
+	defer std.mu.Unlock()
+	std.Formatter = formatter
+}
+
+// SetLevel sets the standard logger level.
+func SetLevel(level Level) {
+	std.mu.Lock()
+	defer std.mu.Unlock()
+	std.setLevel(level)
+}
+
+// GetLevel returns the standard logger level.
+func GetLevel() Level {
+	std.mu.Lock()
+	defer std.mu.Unlock()
+	return std.level()
+}
+
+// AddHook adds a hook to the standard logger hooks.
+func AddHook(hook Hook) {
+	std.mu.Lock()
+	defer std.mu.Unlock()
+	std.Hooks.Add(hook)
+}
+
+// WithError creates an entry from the standard logger and adds an error to it, using the value defined in ErrorKey as key.
+func WithError(err error) *Entry {
+	return std.WithField(ErrorKey, err)
+}
+
+// WithField creates an entry from the standard logger and adds a field to
+// it. If you want multiple fields, use `WithFields`.
+//
+// Note that it doesn't log until you call Debug, Print, Info, Warn, Fatal
+// or Panic on the Entry it returns.
+func WithField(key string, value interface{}) *Entry {
+	return std.WithField(key, value)
+}
+
+// WithFields creates an entry from the standard logger and adds multiple
+// fields to it. This is simply a helper for `WithField`, invoking it
+// once for each field.
+//
+// Note that it doesn't log until you call Debug, Print, Info, Warn, Fatal
+// or Panic on the Entry it returns.
+func WithFields(fields Fields) *Entry {
+	return std.WithFields(fields)
+}
+
+// Debug logs a message at level Debug on the standard logger.
+func Debug(args ...interface{}) {
+	std.Debug(args...)
+}
+
+// Print logs a message at level Info on the standard logger.
+func Print(args ...interface{}) {
+	std.Print(args...)
+}
+
+// Info logs a message at level Info on the standard logger.
+func Info(args ...interface{}) {
+	std.Info(args...)
+}
+
+// Warn logs a message at level Warn on the standard logger.
+func Warn(args ...interface{}) {
+	std.Warn(args...)
+}
+
+// Warning logs a message at level Warn on the standard logger.
+func Warning(args ...interface{}) {
+	std.Warning(args...)
+}
+
+// Error logs a message at level Error on the standard logger.
+func Error(args ...interface{}) {
+	std.Error(args...)
+}
+
+// Panic logs a message at level Panic on the standard logger.
+func Panic(args ...interface{}) {
+	std.Panic(args...)
+}
+
+// Fatal logs a message at level Fatal on the standard logger.
+func Fatal(args ...interface{}) {
+	std.Fatal(args...)
+}
+
+// Debugf logs a message at level Debug on the standard logger.
+func Debugf(format string, args ...interface{}) {
+	std.Debugf(format, args...)
+}
+
+// Printf logs a message at level Info on the standard logger.
+func Printf(format string, args ...interface{}) {
+	std.Printf(format, args...)
+}
+
+// Infof logs a message at level Info on the standard logger.
+func Infof(format string, args ...interface{}) {
+	std.Infof(format, args...)
+}
+
+// Warnf logs a message at level Warn on the standard logger.
+func Warnf(format string, args ...interface{}) {
+	std.Warnf(format, args...)
+}
+
+// Warningf logs a message at level Warn on the standard logger.
+func Warningf(format string, args ...interface{}) {
+	std.Warningf(format, args...)
+}
+
+// Errorf logs a message at level Error on the standard logger.
+func Errorf(format string, args ...interface{}) {
+	std.Errorf(format, args...)
+}
+
+// Panicf logs a message at level Panic on the standard logger.
+func Panicf(format string, args ...interface{}) {
+	std.Panicf(format, args...)
+}
+
+// Fatalf logs a message at level Fatal on the standard logger.
+func Fatalf(format string, args ...interface{}) {
+	std.Fatalf(format, args...)
+}
+
+// Debugln logs a message at level Debug on the standard logger.
+func Debugln(args ...interface{}) {
+	std.Debugln(args...)
+}
+
+// Println logs a message at level Info on the standard logger.
+func Println(args ...interface{}) {
+	std.Println(args...)
+}
+
+// Infoln logs a message at level Info on the standard logger.
+func Infoln(args ...interface{}) {
+	std.Infoln(args...)
+}
+
+// Warnln logs a message at level Warn on the standard logger.
+func Warnln(args ...interface{}) {
+	std.Warnln(args...)
+}
+
+// Warningln logs a message at level Warn on the standard logger.
+func Warningln(args ...interface{}) {
+	std.Warningln(args...)
+}
+
+// Errorln logs a message at level Error on the standard logger.
+func Errorln(args ...interface{}) {
+	std.Errorln(args...)
+}
+
+// Panicln logs a message at level Panic on the standard logger.
+func Panicln(args ...interface{}) {
+	std.Panicln(args...)
+}
+
+// Fatalln logs a message at level Fatal on the standard logger.
+func Fatalln(args ...interface{}) {
+	std.Fatalln(args...)
+}

vendor/github.com/sirupsen/logrus/formatter.go

+package logrus
+
+import "time"
+
+const DefaultTimestampFormat = time.RFC3339
+
+// The Formatter interface is used to implement a custom Formatter. It takes an
+// `Entry`. It exposes all the fields, including the default ones:
+//
+// * `entry.Data["msg"]`. The message passed from Info, Warn, Error ..
+// * `entry.Data["time"]`. The timestamp.
+// * `entry.Data["level"]. The level the entry was logged at.
+//
+// Any additional fields added with `WithField` or `WithFields` are also in
+// `entry.Data`. Format is expected to return an array of bytes which are then
+// logged to `logger.Out`.
+type Formatter interface {
+	Format(*Entry) ([]byte, error)
+}
+
+// This is to not silently overwrite `time`, `msg` and `level` fields when
+// dumping it. If this code wasn't there doing:
+//
+//  logrus.WithField("level", 1).Info("hello")
+//
+// Would just silently drop the user provided level. Instead with this code
+// it'll logged as:
+//
+//  {"level": "info", "fields.level": 1, "msg": "hello", "time": "..."}
+//
+// It's not exported because it's still using Data in an opinionated way. It's to
+// avoid code duplication between the two default formatters.
+func prefixFieldClashes(data Fields) {
+	if t, ok := data["time"]; ok {
+		data["fields.time"] = t
+	}
+
+	if m, ok := data["msg"]; ok {
+		data["fields.msg"] = m
+	}
+
+	if l, ok := data["level"]; ok {
+		data["fields.level"] = l
+	}
+}

vendor/github.com/sirupsen/logrus/hooks.go

+package logrus
+
+// A hook to be fired when logging on the logging levels returned from
+// `Levels()` on your implementation of the interface. Note that this is not
+// fired in a goroutine or a channel with workers, you should handle such
+// functionality yourself if your call is non-blocking and you don't wish for
+// the logging calls for levels returned from `Levels()` to block.
+type Hook interface {
+	Levels() []Level
+	Fire(*Entry) error
+}
+
+// Internal type for storing the hooks on a logger instance.
+type LevelHooks map[Level][]Hook
+
+// Add a hook to an instance of logger. This is called with
+// `log.Hooks.Add(new(MyHook))` where `MyHook` implements the `Hook` interface.
+func (hooks LevelHooks) Add(hook Hook) {
+	for _, level := range hook.Levels() {
+		hooks[level] = append(hooks[level], hook)
+	}
+}
+
+// Fire all the hooks for the passed level. Used by `entry.log` to fire
+// appropriate hooks for a log entry.
+func (hooks LevelHooks) Fire(level Level, entry *Entry) error {
+	for _, hook := range hooks[level] {
+		if err := hook.Fire(entry); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

vendor/github.com/sirupsen/logrus/json_formatter.go

+package logrus
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+type fieldKey string
+type FieldMap map[fieldKey]string
+
+const (
+	FieldKeyMsg   = "msg"
+	FieldKeyLevel = "level"
+	FieldKeyTime  = "time"
+)
+
+func (f FieldMap) resolve(key fieldKey) string {
+	if k, ok := f[key]; ok {
+		return k
+	}
+
+	return string(key)
+}
+
+type JSONFormatter struct {
+	// TimestampFormat sets the format used for marshaling timestamps.
+	TimestampFormat string
+
+	// DisableTimestamp allows disabling automatic timestamps in output
+	DisableTimestamp bool
+
+	// FieldMap allows users to customize the names of keys for various fields.
+	// As an example:
+	// formatter := &JSONFormatter{
+	//   	FieldMap: FieldMap{
+	// 		 FieldKeyTime: "@timestamp",
+	// 		 FieldKeyLevel: "@level",
+	// 		 FieldKeyLevel: "@message",
+	//    },
+	// }
+	FieldMap FieldMap
+}
+
+func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
+	data := make(Fields, len(entry.Data)+3)
+	for k, v := range entry.Data {
+		switch v := v.(type) {
+		case error:
+			// Otherwise errors are ignored by `encoding/json`
+			// https://github.com/Sirupsen/logrus/issues/137
+			data[k] = v.Error()
+		default:
+			data[k] = v
+		}
+	}
+	prefixFieldClashes(data)
+
+	timestampFormat := f.TimestampFormat
+	if timestampFormat == "" {
+		timestampFormat = DefaultTimestampFormat
+	}
+
+	if !f.DisableTimestamp {
+		data[f.FieldMap.resolve(FieldKeyTime)] = entry.Time.Format(timestampFormat)
+	}
+	data[f.FieldMap.resolve(FieldKeyMsg)] = entry.Message
+	data[f.FieldMap.resolve(FieldKeyLevel)] = entry.Level.String()
+
+	serialized, err := json.Marshal(data)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to marshal fields to JSON, %v", err)
+	}
+	return append(serialized, '\n'), nil
+}

vendor/github.com/sirupsen/logrus/logger.go

+package logrus
+
+import (
+	"io"
+	"os"
+	"sync"
+	"sync/atomic"
+)
+
+type Logger struct {
+	// The logs are `io.Copy`'d to this in a mutex. It's common to set this to a
+	// file, or leave it default which is `os.Stderr`. You can also set this to
+	// something more adventorous, such as logging to Kafka.
+	Out io.Writer
+	// Hooks for the logger instance. These allow firing events based on logging
+	// levels and log entries. For example, to send errors to an error tracking
+	// service, log to StatsD or dump the core on fatal errors.
+	Hooks LevelHooks
+	// All log entries pass through the formatter before logged to Out. The
+	// included formatters are `TextFormatter` and `JSONFormatter` for which
+	// TextFormatter is the default. In development (when a TTY is attached) it
+	// logs with colors, but to a file it wouldn't. You can easily implement your
+	// own that implements the `Formatter` interface, see the `README` or included
+	// formatters for examples.
+	Formatter Formatter
+	// The logging level the logger should log at. This is typically (and defaults
+	// to) `logrus.Info`, which allows Info(), Warn(), Error() and Fatal() to be
+	// logged. `logrus.Debug` is useful in
+	Level Level
+	// Used to sync writing to the log. Locking is enabled by Default
+	mu MutexWrap
+	// Reusable empty entry
+	entryPool sync.Pool
+}
+
+type MutexWrap struct {
+	lock     sync.Mutex
+	disabled bool
+}
+
+func (mw *MutexWrap) Lock() {
+	if !mw.disabled {
+		mw.lock.Lock()
+	}
+}
+
+func (mw *MutexWrap) Unlock() {
+	if !mw.disabled {
+		mw.lock.Unlock()
+	}
+}
+
+func (mw *MutexWrap) Disable() {
+	mw.disabled = true
+}
+
+// Creates a new logger. Configuration should be set by changing `Formatter`,
+// `Out` and `Hooks` directly on the default logger instance. You can also just
+// instantiate your own:
+//
+//    var log = &Logger{
+//      Out: os.Stderr,
+//      Formatter: new(JSONFormatter),
+//      Hooks: make(LevelHooks),
+//      Level: logrus.DebugLevel,
+//    }
+//
+// It's recommended to make this a global instance called `log`.
+func New() *Logger {
+	return &Logger{
+		Out:       os.Stderr,
+		Formatter: new(TextFormatter),
+		Hooks:     make(LevelHooks),
+		Level:     InfoLevel,
+	}
+}
+
+func (logger *Logger) newEntry() *Entry {
+	entry, ok := logger.entryPool.Get().(*Entry)
+	if ok {
+		return entry
+	}
+	return NewEntry(logger)
+}
+
+func (logger *Logger) releaseEntry(entry *Entry) {
+	logger.entryPool.Put(entry)
+}
+
+// Adds a field to the log entry, note that it doesn't log until you call
+// Debug, Print, Info, Warn, Fatal or Panic. It only creates a log entry.
+// If you want multiple fields, use `WithFields`.
+func (logger *Logger) WithField(key string, value interface{}) *Entry {
+	entry := logger.newEntry()
+	defer logger.releaseEntry(entry)
+	return entry.WithField(key, value)
+}
+
+// Adds a struct of fields to the log entry. All it does is call `WithField` for
+// each `Field`.
+func (logger *Logger) WithFields(fields Fields) *Entry {
+	entry := logger.newEntry()
+	defer logger.releaseEntry(entry)
+	return entry.WithFields(fields)
+}
+
+// Add an error as single field to the log entry.  All it does is call
+// `WithError` for the given `error`.
+func (logger *Logger) WithError(err error) *Entry {
+	entry := logger.newEntry()
+	defer logger.releaseEntry(entry)
+	return entry.WithError(err)
+}
+
+func (logger *Logger) Debugf(format string, args ...interface{}) {
+	if logger.level() >= DebugLevel {
+		entry := logger.newEntry()
+		entry.Debugf(format, args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Infof(format string, args ...interface{}) {
+	if logger.level() >= InfoLevel {
+		entry := logger.newEntry()
+		entry.Infof(format, args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Printf(format string, args ...interface{}) {
+	entry := logger.newEntry()
+	entry.Printf(format, args...)
+	logger.releaseEntry(entry)
+}
+
+func (logger *Logger) Warnf(format string, args ...interface{}) {
+	if logger.level() >= WarnLevel {
+		entry := logger.newEntry()
+		entry.Warnf(format, args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Warningf(format string, args ...interface{}) {
+	if logger.level() >= WarnLevel {
+		entry := logger.newEntry()
+		entry.Warnf(format, args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Errorf(format string, args ...interface{}) {
+	if logger.level() >= ErrorLevel {
+		entry := logger.newEntry()
+		entry.Errorf(format, args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Fatalf(format string, args ...interface{}) {
+	if logger.level() >= FatalLevel {
+		entry := logger.newEntry()
+		entry.Fatalf(format, args...)
+		logger.releaseEntry(entry)
+	}
+	Exit(1)
+}
+
+func (logger *Logger) Panicf(format string, args ...interface{}) {
+	if logger.level() >= PanicLevel {
+		entry := logger.newEntry()
+		entry.Panicf(format, args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Debug(args ...interface{}) {
+	if logger.level() >= DebugLevel {
+		entry := logger.newEntry()
+		entry.Debug(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Info(args ...interface{}) {
+	if logger.level() >= InfoLevel {
+		entry := logger.newEntry()
+		entry.Info(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Print(args ...interface{}) {
+	entry := logger.newEntry()
+	entry.Info(args...)
+	logger.releaseEntry(entry)
+}
+
+func (logger *Logger) Warn(args ...interface{}) {
+	if logger.level() >= WarnLevel {
+		entry := logger.newEntry()
+		entry.Warn(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Warning(args ...interface{}) {
+	if logger.level() >= WarnLevel {
+		entry := logger.newEntry()
+		entry.Warn(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Error(args ...interface{}) {
+	if logger.level() >= ErrorLevel {
+		entry := logger.newEntry()
+		entry.Error(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Fatal(args ...interface{}) {
+	if logger.level() >= FatalLevel {
+		entry := logger.newEntry()
+		entry.Fatal(args...)
+		logger.releaseEntry(entry)
+	}
+	Exit(1)
+}
+
+func (logger *Logger) Panic(args ...interface{}) {
+	if logger.level() >= PanicLevel {
+		entry := logger.newEntry()
+		entry.Panic(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Debugln(args ...interface{}) {
+	if logger.level() >= DebugLevel {
+		entry := logger.newEntry()
+		entry.Debugln(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Infoln(args ...interface{}) {
+	if logger.level() >= InfoLevel {
+		entry := logger.newEntry()
+		entry.Infoln(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Println(args ...interface{}) {
+	entry := logger.newEntry()
+	entry.Println(args...)
+	logger.releaseEntry(entry)
+}
+
+func (logger *Logger) Warnln(args ...interface{}) {
+	if logger.level() >= WarnLevel {
+		entry := logger.newEntry()
+		entry.Warnln(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Warningln(args ...interface{}) {
+	if logger.level() >= WarnLevel {
+		entry := logger.newEntry()
+		entry.Warnln(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Errorln(args ...interface{}) {
+	if logger.level() >= ErrorLevel {
+		entry := logger.newEntry()
+		entry.Errorln(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+func (logger *Logger) Fatalln(args ...interface{}) {
+	if logger.level() >= FatalLevel {
+		entry := logger.newEntry()
+		entry.Fatalln(args...)
+		logger.releaseEntry(entry)
+	}
+	Exit(1)
+}
+
+func (logger *Logger) Panicln(args ...interface{}) {
+	if logger.level() >= PanicLevel {
+		entry := logger.newEntry()
+		entry.Panicln(args...)
+		logger.releaseEntry(entry)
+	}
+}
+
+//When file is opened with appending mode, it's safe to
+//write concurrently to a file (within 4k message on Linux).
+//In these cases user can choose to disable the lock.
+func (logger *Logger) SetNoLock() {
+	logger.mu.Disable()
+}
+
+func (logger *Logger) level() Level {
+	return Level(atomic.LoadUint32((*uint32)(&logger.Level)))
+}
+
+func (logger *Logger) setLevel(level Level) {
+	atomic.StoreUint32((*uint32)(&logger.Level), uint32(level))
+}

vendor/github.com/sirupsen/logrus/logrus.go

+package logrus
+
+import (
+	"fmt"
+	"log"
+	"strings"
+)
+
+// Fields type, used to pass to `WithFields`.
+type Fields map[string]interface{}
+
+// Level type
+type Level uint32
+
+// Convert the Level to a string. E.g. PanicLevel becomes "panic".
+func (level Level) String() string {
+	switch level {
+	case DebugLevel:
+		return "debug"
+	case InfoLevel:
+		return "info"
+	case WarnLevel:
+		return "warning"
+	case ErrorLevel:
+		return "error"
+	case FatalLevel:
+		return "fatal"
+	case PanicLevel:
+		return "panic"
+	}
+
+	return "unknown"
+}
+
+// ParseLevel takes a string level and returns the Logrus log level constant.
+func ParseLevel(lvl string) (Level, error) {
+	switch strings.ToLower(lvl) {
+	case "panic":
+		return PanicLevel, nil
+	case "fatal":
+		return FatalLevel, nil
+	case "error":
+		return ErrorLevel, nil
+	case "warn", "warning":
+		return WarnLevel, nil
+	case "info":
+		return InfoLevel, nil
+	case "debug":
+		return DebugLevel, nil
+	}
+
+	var l Level
+	return l, fmt.Errorf("not a valid logrus Level: %q", lvl)
+}
+
+// A constant exposing all logging levels
+var AllLevels = []Level{
+	PanicLevel,
+	FatalLevel,
+	ErrorLevel,
+	WarnLevel,
+	InfoLevel,
+	DebugLevel,
+}
+
+// These are the different logging levels. You can set the logging level to log
+// on your instance of logger, obtained with `logrus.New()`.
+const (
+	// PanicLevel level, highest level of severity. Logs and then calls panic with the
+	// message passed to Debug, Info, ...
+	PanicLevel Level = iota
+	// FatalLevel level. Logs and then calls `os.Exit(1)`. It will exit even if the
+	// logging level is set to Panic.
+	FatalLevel
+	// ErrorLevel level. Logs. Used for errors that should definitely be noted.
+	// Commonly used for hooks to send errors to an error tracking service.
+	ErrorLevel
+	// WarnLevel level. Non-critical entries that deserve eyes.
+	WarnLevel
+	// InfoLevel level. General operational entries about what's going on inside the
+	// application.
+	InfoLevel
+	// DebugLevel level. Usually only enabled when debugging. Very verbose logging.
+	DebugLevel
+)
+
+// Won't compile if StdLogger can't be realized by a log.Logger
+var (
+	_ StdLogger = &log.Logger{}
+	_ StdLogger = &Entry{}
+	_ StdLogger = &Logger{}
+)
+
+// StdLogger is what your logrus-enabled library should take, that way
+// it'll accept a stdlib logger and a logrus logger. There's no standard
+// interface, this is the closest we get, unfortunately.
+type StdLogger interface {
+	Print(...interface{})
+	Printf(string, ...interface{})
+	Println(...interface{})
+
+	Fatal(...interface{})
+	Fatalf(string, ...interface{})
+	Fatalln(...interface{})
+
+	Panic(...interface{})
+	Panicf(string, ...interface{})
+	Panicln(...interface{})
+}
+
+// The FieldLogger interface generalizes the Entry and Logger types
+type FieldLogger interface {
+	WithField(key string, value interface{}) *Entry
+	WithFields(fields Fields) *Entry
+	WithError(err error) *Entry
+
+	Debugf(format string, args ...interface{})
+	Infof(format string, args ...interface{})
+	Printf(format string, args ...interface{})
+	Warnf(format string, args ...interface{})
+	Warningf(format string, args ...interface{})
+	Errorf(format string, args ...interface{})
+	Fatalf(format string, args ...interface{})
+	Panicf(format string, args ...interface{})
+
+	Debug(args ...interface{})
+	Info(args ...interface{})
+	Print(args ...interface{})
+	Warn(args ...interface{})
+	Warning(args ...interface{})
+	Error(args ...interface{})
+	Fatal(args ...interface{})
+	Panic(args ...interface{})
+
+	Debugln(args ...interface{})
+	Infoln(args ...interface{})
+	Println(args ...interface{})
+	Warnln(args ...interface{})
+	Warningln(args ...interface{})
+	Errorln(args ...interface{})
+	Fatalln(args ...interface{})
+	Panicln(args ...interface{})
+}

vendor/github.com/sirupsen/logrus/terminal_appengine.go

+// +build appengine
+
+package logrus
+
+import "io"
+
+// IsTerminal returns true if stderr's file descriptor is a terminal.
+func IsTerminal(f io.Writer) bool {
+	return true
+}

vendor/github.com/sirupsen/logrus/terminal_bsd.go

+// +build darwin freebsd openbsd netbsd dragonfly
+// +build !appengine
+
+package logrus
+
+import "syscall"
+
+const ioctlReadTermios = syscall.TIOCGETA
+
+type Termios syscall.Termios

vendor/github.com/sirupsen/logrus/terminal_linux.go

+// Based on ssh/terminal:
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+
+package logrus
+
+import "syscall"
+
+const ioctlReadTermios = syscall.TCGETS
+
+type Termios syscall.Termios

vendor/github.com/sirupsen/logrus/terminal_notwindows.go

+// Based on ssh/terminal:
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build linux darwin freebsd openbsd netbsd dragonfly
+// +build !appengine
+
+package logrus
+
+import (
+	"io"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+// IsTerminal returns true if stderr's file descriptor is a terminal.
+func IsTerminal(f io.Writer) bool {
+	var termios Termios
+	switch v := f.(type) {
+	case *os.File:
+		_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(v.Fd()), ioctlReadTermios, uintptr(unsafe.Pointer(&termios)), 0, 0, 0)
+		return err == 0
+	default:
+		return false
+	}
+}

vendor/github.com/sirupsen/logrus/terminal_solaris.go

+// +build solaris,!appengine
+
+package logrus
+
+import (
+	"io"
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+// IsTerminal returns true if the given file descriptor is a terminal.
+func IsTerminal(f io.Writer) bool {
+	switch v := f.(type) {
+	case *os.File:
+		_, err := unix.IoctlGetTermios(int(v.Fd()), unix.TCGETA)
+		return err == nil
+	default:
+		return false
+	}
+}

vendor/github.com/sirupsen/logrus/terminal_windows.go

+// Based on ssh/terminal:
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build windows,!appengine
+
+package logrus
+
+import (
+	"io"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+var kernel32 = syscall.NewLazyDLL("kernel32.dll")
+
+var (
+	procGetConsoleMode = kernel32.NewProc("GetConsoleMode")
+)
+
+// IsTerminal returns true if stderr's file descriptor is a terminal.
+func IsTerminal(f io.Writer) bool {
+	switch v := f.(type) {
+	case *os.File:
+		var st uint32
+		r, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, uintptr(v.Fd()), uintptr(unsafe.Pointer(&st)), 0)
+		return r != 0 && e == 0
+	default:
+		return false
+	}
+}

vendor/github.com/sirupsen/logrus/text_formatter.go

+package logrus
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+)
+
+const (
+	nocolor = 0
+	red     = 31
+	green   = 32
+	yellow  = 33
+	blue    = 34
+	gray    = 37
+)
+
+var (
+	baseTimestamp time.Time
+)
+
+func init() {
+	baseTimestamp = time.Now()
+}
+
+type TextFormatter struct {
+	// Set to true to bypass checking for a TTY before outputting colors.
+	ForceColors bool
+
+	// Force disabling colors.
+	DisableColors bool
+
+	// Disable timestamp logging. useful when output is redirected to logging
+	// system that already adds timestamps.
+	DisableTimestamp bool
+
+	// Enable logging the full timestamp when a TTY is attached instead of just
+	// the time passed since beginning of execution.
+	FullTimestamp bool
+
+	// TimestampFormat to use for display when a full timestamp is printed
+	TimestampFormat string
+
+	// The fields are sorted by default for a consistent output. For applications
+	// that log extremely frequently and don't use the JSON formatter this may not
+	// be desired.
+	DisableSorting bool
+
+	// QuoteEmptyFields will wrap empty fields in quotes if true
+	QuoteEmptyFields bool
+
+	// QuoteCharacter can be set to the override the default quoting character "
+	// with something else. For example: ', or `.
+	QuoteCharacter string
+
+	// Whether the logger's out is to a terminal
+	isTerminal bool
+
+	sync.Once
+}
+
+func (f *TextFormatter) init(entry *Entry) {
+	if len(f.QuoteCharacter) == 0 {
+		f.QuoteCharacter = "\""
+	}
+	if entry.Logger != nil {
+		f.isTerminal = IsTerminal(entry.Logger.Out)
+	}
+}
+
+func (f *TextFormatter) Format(entry *Entry) ([]byte, error) {
+	var b *bytes.Buffer
+	keys := make([]string, 0, len(entry.Data))
+	for k := range entry.Data {
+		keys = append(keys, k)
+	}
+
+	if !f.DisableSorting {
+		sort.Strings(keys)
+	}
+	if entry.Buffer != nil {
+		b = entry.Buffer
+	} else {
+		b = &bytes.Buffer{}
+	}
+
+	prefixFieldClashes(entry.Data)
+
+	f.Do(func() { f.init(entry) })
+
+	isColored := (f.ForceColors || f.isTerminal) && !f.DisableColors
+
+	timestampFormat := f.TimestampFormat
+	if timestampFormat == "" {
+		timestampFormat = DefaultTimestampFormat
+	}
+	if isColored {
+		f.printColored(b, entry, keys, timestampFormat)
+	} else {
+		if !f.DisableTimestamp {
+			f.appendKeyValue(b, "time", entry.Time.Format(timestampFormat))
+		}
+		f.appendKeyValue(b, "level", entry.Level.String())
+		if entry.Message != "" {
+			f.appendKeyValue(b, "msg", entry.Message)
+		}
+		for _, key := range keys {
+			f.appendKeyValue(b, key, entry.Data[key])
+		}
+	}
+
+	b.WriteByte('\n')
+	return b.Bytes(), nil
+}
+
+func (f *TextFormatter) printColored(b *bytes.Buffer, entry *Entry, keys []string, timestampFormat string) {
+	var levelColor int
+	switch entry.Level {
+	case DebugLevel:
+		levelColor = gray
+	case WarnLevel:
+		levelColor = yellow
+	case ErrorLevel, FatalLevel, PanicLevel:
+		levelColor = red
+	default:
+		levelColor = blue
+	}
+
+	levelText := strings.ToUpper(entry.Level.String())[0:4]
+
+	if f.DisableTimestamp {
+		fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m %-44s ", levelColor, levelText, entry.Message)
+	} else if !f.FullTimestamp {
+		fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m[%04d] %-44s ", levelColor, levelText, int(entry.Time.Sub(baseTimestamp)/time.Second), entry.Message)
+	} else {
+		fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m[%s] %-44s ", levelColor, levelText, entry.Time.Format(timestampFormat), entry.Message)
+	}
+	for _, k := range keys {
+		v := entry.Data[k]
+		fmt.Fprintf(b, " \x1b[%dm%s\x1b[0m=", levelColor, k)
+		f.appendValue(b, v)
+	}
+}
+
+func (f *TextFormatter) needsQuoting(text string) bool {
+	if f.QuoteEmptyFields && len(text) == 0 {
+		return true
+	}
+	for _, ch := range text {
+		if !((ch >= 'a' && ch <= 'z') ||
+			(ch >= 'A' && ch <= 'Z') ||
+			(ch >= '0' && ch <= '9') ||
+			ch == '-' || ch == '.') {
+			return true
+		}
+	}
+	return false
+}
+
+func (f *TextFormatter) appendKeyValue(b *bytes.Buffer, key string, value interface{}) {
+
+	b.WriteString(key)
+	b.WriteByte('=')
+	f.appendValue(b, value)
+	b.WriteByte(' ')
+}
+
+func (f *TextFormatter) appendValue(b *bytes.Buffer, value interface{}) {
+	switch value := value.(type) {
+	case string:
+		if !f.needsQuoting(value) {
+			b.WriteString(value)
+		} else {
+			fmt.Fprintf(b, "%s%v%s", f.QuoteCharacter, value, f.QuoteCharacter)
+		}
+	case error:
+		errmsg := value.Error()
+		if !f.needsQuoting(errmsg) {
+			b.WriteString(errmsg)
+		} else {
+			fmt.Fprintf(b, "%s%v%s", f.QuoteCharacter, errmsg, f.QuoteCharacter)
+		}
+	default:
+		fmt.Fprint(b, value)
+	}
+}

vendor/github.com/sirupsen/logrus/writer.go

+package logrus
+
+import (
+	"bufio"
+	"io"
+	"runtime"
+)
+
+func (logger *Logger) Writer() *io.PipeWriter {
+	return logger.WriterLevel(InfoLevel)
+}
+
+func (logger *Logger) WriterLevel(level Level) *io.PipeWriter {
+	return NewEntry(logger).WriterLevel(level)
+}
+
+func (entry *Entry) Writer() *io.PipeWriter {
+	return entry.WriterLevel(InfoLevel)
+}
+
+func (entry *Entry) WriterLevel(level Level) *io.PipeWriter {
+	reader, writer := io.Pipe()
+
+	var printFunc func(args ...interface{})
+
+	switch level {
+	case DebugLevel:
+		printFunc = entry.Debug
+	case InfoLevel:
+		printFunc = entry.Info
+	case WarnLevel:
+		printFunc = entry.Warn
+	case ErrorLevel:
+		printFunc = entry.Error
+	case FatalLevel:
+		printFunc = entry.Fatal
+	case PanicLevel:
+		printFunc = entry.Panic
+	default:
+		printFunc = entry.Print
+	}
+
+	go entry.writerScanner(reader, printFunc)
+	runtime.SetFinalizer(writer, writerFinalizer)
+
+	return writer
+}
+
+func (entry *Entry) writerScanner(reader *io.PipeReader, printFunc func(args ...interface{})) {
+	scanner := bufio.NewScanner(reader)
+	for scanner.Scan() {
+		printFunc(scanner.Text())
+	}
+	if err := scanner.Err(); err != nil {
+		entry.Errorf("Error while reading from Writer: %s", err)
+	}
+	reader.Close()
+}
+
+func writerFinalizer(writer *io.PipeWriter) {
+	writer.Close()
+}

vendor/golang.org/x/crypto/LICENSE

+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/golang.org/x/crypto/PATENTS

+Additional IP Rights Grant (Patents)
+
+"This implementation" means the copyrightable works distributed by
+Google as part of the Go project.
+
+Google hereby grants to You a perpetual, worldwide, non-exclusive,
+no-charge, royalty-free, irrevocable (except as stated in this section)
+patent license to make, have made, use, offer to sell, sell, import,
+transfer and otherwise run, modify and propagate the contents of this
+implementation of Go, where such license applies only to those patent
+claims, both currently owned or controlled by Google and acquired in
+the future, licensable by Google that are necessarily infringed by this
+implementation of Go.  This grant does not include claims that would be
+infringed only as a consequence of further modification of this
+implementation.  If you or your agent or exclusive licensee institute or
+order or agree to the institution of patent litigation against any
+entity (including a cross-claim or counterclaim in a lawsuit) alleging
+that this implementation of Go or any code incorporated within this
+implementation of Go constitutes direct or contributory patent
+infringement, or inducement of patent infringement, then any patent
+rights granted to you under this License for this implementation of Go
+shall terminate as of the date such litigation is filed.

vendor/golang.org/x/crypto/ssh/terminal/util_bsd.go

+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd netbsd openbsd
+
+package terminal
+
+import "golang.org/x/sys/unix"
+
+const ioctlReadTermios = unix.TIOCGETA
+const ioctlWriteTermios = unix.TIOCSETA