base.js

/* jshint esversion: 6 */

var base = base || {};

if (typeof window !== 'undefined' && typeof window.Long != 'undefined') {
    window.long = { Long: window.Long };
}

if (!DataView.prototype.getFloat16) {
    DataView.prototype.getFloat16 = function(byteOffset, littleEndian) {
        const value = this.getUint16(byteOffset, littleEndian);
        const e = (value & 0x7C00) >> 10;
        let f = value & 0x03FF;
        if (e == 0) {
            f = 0.00006103515625 * (f / 1024);
        }
        else if (e == 0x1F) {
            f = f ? NaN : Infinity;
        }
        else {
            f = DataView.__float16_pow[e] * (1 + (f / 1024));
        }
        return value & 0x8000 ? -f : f;
    };
    DataView.__float16_pow = {
        1: 1/16384, 2: 1/8192, 3: 1/4096, 4: 1/2048, 5: 1/1024, 6: 1/512, 7: 1/256, 8: 1/128,
        9: 1/64, 10: 1/32, 11: 1/16, 12: 1/8, 13: 1/4, 14: 1/2, 15: 1, 16: 2,
        17: 4, 18: 8, 19: 16, 20: 32, 21: 64, 22: 128, 23: 256, 24: 512,
        25: 1024, 26: 2048, 27: 4096, 28: 8192, 29: 16384, 30: 32768, 31: 65536
    };
}

if (!DataView.prototype.setFloat16) {
    DataView.prototype.setFloat16 = function(byteOffset, value, littleEndian) {
        DataView.__float16_float[0] = value;
        value = DataView.__float16_int[0];
        const s = (value >>> 16) & 0x8000;
        const e = (value >>> 23) & 0xff;
        const f = value & 0x7fffff;
        const v = s | DataView.__float16_base[e] | (f >> DataView.__float16_shift[e]);
        this.setUint16(byteOffset, v, littleEndian);
    };
    DataView.__float16_float = new Float32Array(1);
    DataView.__float16_int = new Uint32Array(DataView.__float16_float.buffer, 0, DataView.__float16_float.length);
    DataView.__float16_base = new Uint32Array(256);
    DataView.__float16_shift = new Uint32Array(256);
    for (let i = 0; i < 256; ++i) {
        let e = i - 127;
        if (e < -27) {
            DataView.__float16_base[i] = 0x0000;
            DataView.__float16_shift[i] = 24;
        }
        else if (e < -14) {
            DataView.__float16_base[i] = 0x0400 >> -e - 14;
            DataView.__float16_shift[i] = -e - 1;
        }
        else if (e <= 15) {
            DataView.__float16_base[i] = e + 15 << 10;
            DataView.__float16_shift[i] = 13;
        }
        else if (e < 128) {
            DataView.__float16_base[i] = 0x7c00;
            DataView.__float16_shift[i] = 24;
        }
        else {
            DataView.__float16_base[i] = 0x7c00;
            DataView.__float16_shift[i] = 13;
        }
    }
}

if (!DataView.prototype.getBits) {
    DataView.prototype.getBits = function(offset, bits /*, signed */) {
        offset = offset * bits;
        const available = (this.byteLength << 3) - offset;
        if (bits > available) {
            throw new RangeError();
        }
        let value = 0;
        let index = 0;
        while (index < bits) {
            const remainder = offset & 7;
            const size = Math.min(bits - index, 8 - remainder);
            value <<= size;
            value |= (this.getUint8(offset >> 3) >> (8 - size - remainder)) & ~(0xff << size);
            offset += size;
            index += size;
        }
        return value;
    };
}