AutoBuffer.h

/***************************************************************************
 * 
 * Copyright (c) 2008 Baidu.com, Inc. All Rights Reserved
 * $Id: bsl_auto_buffer.h,v 1.9 2009/10/14 08:24:58 chenxm Exp $ 
 * 
 **************************************************************************/
 
 
 
/**
 * @file AutoBuffer.h
 * @author chenxm(chenxiaoming@baidu.com)
 * @date 2008/09/02 12:15:49
 * @version $Revision: 1.9 $ 
 * @brief 
 *  
 **/
#ifndef  __BSL_AUTO_BUFFER_H_
#define  __BSL_AUTO_BUFFER_H_
#include <cstring>
#include <cstdarg>
#include <cstdlib>
#include <cstdio>
#include <algorithm>
#include "bsl/utils/bsl_memcpy.h"
#include "bsl/pool/bsl_pool.h"


namespace bsl{
    /**
    * @brief 类似于auto_ptr但更加安全的字符串缓冲区类
    *  
    *  该类的一大特点是不会抛出异常。在内存不足的时候，该类会截断字符串并置"被截断位"。
    *  AutoBuffer对象自行管理一片用于表示字符串的缓冲区，并提供方法追加各种类型对象。
    *  若内存不足时，内存容量将番倍，若申请新内存失败，将填满旧内存，而且使truncated()方法返回true。
    */
    class AutoBuffer{
    public:
        /**
         * @brief 构造函数
         *
         * 可传入__capacity参数指定预分配的内存空间。如__capacity==0没有动态内存分配。
         * 初始化内存池，默认不使用内存池，即直接malloc和free
         *
         * 注：如内存分配失败不会抛出异常。其结果相当于以0为参数构造。
         *
         * @param [in] __capacity   : size_t
         * @see 
         * @author chenxm
         * @date 2009/02/04 17:39:57
        **/
        explicit AutoBuffer( size_t __capacity = DEFAULT_CAPACITY )
            :_size(0), _capacity(__capacity), _truncated(false), _str(NULL), 
             _mempool(NULL) {
            if ( __capacity != 0 ){
                _str = static_cast<char *>(_mempool == NULL ? 
                        malloc(_capacity + 1) : _mempool->malloc(_capacity + 1));
                if ( _str ){
                    _str[0] = '\0';
                }else{
                    _capacity = 0;
                }
            }
        }

        /**
         * @brief 使用allocator的构造函数
         *
         * 可传入__capacity参数指定预分配的内存空间。如__capacity==0没有动态内存分配。
         * 可传入pool参数指定使用的内存池
         *
         * 注：如内存分配失败不会抛出异常。其结果相当于以0为参数构造。
         * 
         * @param [in] pool         : mempool&
         * @param [in] __capacity   : size_t
         * @see
         * @author liaoshangbin
         * @date 2010/7/29 12:06:16
        **/
        explicit AutoBuffer( mempool& pool, size_t __capacity = DEFAULT_CAPACITY )
            :_size(0), _capacity(__capacity), _truncated(false), _str(NULL), _mempool(&pool) {
            if ( __capacity != 0 ) {
                _str = static_cast<char *>(_mempool == NULL ?
                        malloc(_capacity + 1) : _mempool->malloc(_capacity + 1));
                if ( _str ){
                    _str[0] = '\0';
                }else{
                    _capacity = 0;
                }                
            }
        }

        /**
         * @brief 把另一AutoBuffer的内存转移到本AutoBuffer（另一AutoBuffer会被清空），O(1)复杂度
         *        因为不同AutoBuffer使用的内存池会有不同
         *        先释放自身_str的内存，然后_str指向other._str浅复制字符串，
         *        自身的_mempool指向other._mempool，这样_mempool还是处理_str这块内存
         *        后清空other._str，other成为空的AutoBuffer还可以继续使用
         *
         * @param [in] other   : AutoBuffer&
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 17:45:30
        **/
        AutoBuffer& transfer_from ( AutoBuffer& other ){
            if ( &other != this ){
                if ( _str ){
                    _mempool == NULL ? free( _str) : _mempool->free( _str, _capacity+1 );
                }
                _size       = other._size;      
                _capacity   = other._capacity;
                _truncated  = other._truncated;
                _str        = other._str;
                _mempool    = other._mempool;
                other._size     = 0;
                other._capacity = 0;
                other._truncated= false;
                other._str      = NULL;
            }
            return *this;
        }

        /**
         * @brief 交换两AutoBuffer内容，O(1)复杂度
         *
         * @param [in] other   : AutoBuffer&
         * @return  void 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:14:15
        **/
        void swap( AutoBuffer& other ){
            std::swap( _str,        other._str );
            std::swap( _size,       other._size );
            std::swap( _capacity,   other._capacity );
            std::swap( _truncated,  other._truncated );
            std::swap( _mempool,    other._mempool );
        }

        /**
         * @brief 析构函数
         *
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:14:47
        **/
        ~AutoBuffer( ){
            if ( _str ){
                _mempool == NULL ? free( _str ) : _mempool->free( _str, _capacity + 1 );
            }
        }

        /**
         * @brief AutoBuffer长度。不包括最后的'\0'
         *
         * @return  size_t 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:14:56
        **/
        size_t size() const{
            return _size;
        }
        
        /**
         * @brief AutoBuffer当前容量。保证容量>=长度。当容量不足时，容量会自动增长。
         *
         * @return  size_t 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:15:23
        **/
        size_t capacity() const {
            return _capacity;
        }

        /**
         * @brief 返回AutoBuffer是否为空
         *
         * @return  bool 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:16:26
        **/
        bool empty() const {
            return _size == 0;
        }

        /**
         * @brief 返回AutoBuffer是否为满
         *
         * @return  bool 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:16:39
        **/
        bool full() const {
            return _size == _capacity;
        }

        /**
         * @brief 返回AutoBuffer是否发生了截断
         *
         * @return  bool 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:16:58
        **/
        bool truncated() const {
            return _truncated;
        }

        /**
         * @brief 返回AutoBuffer内容的C风格字符串表示。O(1)复杂度
         *
         * @return  const char* 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:17:26
        **/
        const char * c_str() const {
            if ( _str ){
                return _str;
            }else{
                return "";
            }
        }

        /**
         * @brief 清空内容
         *
         * @return  void 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:18:12
        **/
        void clear() {
            if ( _str && _capacity ){
                _str[0] = '\0';
            }
            _size = 0;
        }

        /**
         * @brief 手动扩大内存容量
         *
         * @param [in] __capacity   : size_t
         * @return  bool 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:18:34
        **/
        bool reserve( size_t __capacity ) {
            if ( __capacity > _capacity  ){
                if ( __capacity < _capacity * 2 ){ 
                    __capacity = _capacity * 2;
                }

                char * _new = static_cast<char*>(_mempool == NULL ?
                        malloc(__capacity + 1) : _mempool->malloc(__capacity + 1));
                if ( !_new ){
                    return false;
                }

                if ( _str ){
                    xmemcpy( _new, _str, _size + 1 );
                    _mempool == NULL ? free( _str) : _mempool->free( _str, _capacity + 1);
                }

                _str        = _new;
                _capacity   = __capacity;
            }
            return true;
        }

        /**
         * @brief 追加另一个AutoBuffer
         *
         * @param [in] other   : const AutoBuffer&
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/09/27 16:49:30
        **/
        AutoBuffer& operator << (const AutoBuffer& other){
            return push( other._str, other._size );
        }

        /**
         * @brief 追加一个std::string,不包含c_str()中结尾的'\0'
         *
         * @param [in] str   : const std::string &
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenyanling
         * @date 2011/09/20 13:18:30
        **/
        AutoBuffer& operator << (const std::string& str){
            return push( str.c_str(),str.length() );
        }


        /**
         * @brief 追加布尔值
         *
         * @param [in] b   : bool
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:27:49
        **/
        AutoBuffer& operator << (bool b){
            if ( b ){
                return push( TRUE_LITERAL, TRUE_LITERAL_LEN );
            }else{
                return push( FALSE_LITERAL, FALSE_LITERAL_LEN );
            }
        }

        /**
         * @brief 追加字符，忽略'\0'
         *
         * @param [in] c   : char
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:28:03
        **/
        AutoBuffer& operator << (char c){
            if ( c == '\0' ){
                return *this;
            }
            if ( _size == _capacity ){    //full
                reserve( _size + 1 );     //may fail, make best effort.
            }
            if ( _size < _capacity ){
                _str[_size]    = c;
                _str[++_size]  = '\0';
                _truncated = false;
            }else{
                _truncated = true;
            }
            return *this;
       }

        /**
         * @brief 追加有符号8位整数
         *
         * @param [in] uc   : signed char
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/09/27 16:47:27
        **/
        AutoBuffer& operator << (signed char sc){
            return pushf( "%hhd", sc );
        }

        /**
         * @brief 追加无符号8位整数
         *
         * @param [in] uc   : unsigned char
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:28:22
        **/
        AutoBuffer& operator << (unsigned char uc){
            return pushf( "%hhu", uc );
        }

        /**
         * @brief 追加宽字符
         *
         * @param [in] wc   : wchar_t
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:28:38
        **/
        AutoBuffer& operator << (wchar_t wc){
            if ( wc == 0 ){
                return *this;
            }
#if __GNUC__ <= 2
            wchar_t ws[] = { wc, 0 };
            return pushf( "%ls", ws );
#else
            return pushf( "%lc", wc );
#endif
        }

        /**
         * @brief 追加宽字符串
         *
         * @param [in] ws   : const wchar_t*
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:28:56
        **/
        AutoBuffer& operator << (const wchar_t *ws){
            if ( ws != NULL ){
                pushf( "%ls", ws );
            }else{
                _truncated = false;
            }
            return *this;
        }

        /**
         * @brief 追加short型整数
         *          
         * @param  [in] i   : short
         * @return AutoBuffer& operator
         * @retval
         * @see
         * @author liaoshangbin
         * @data 2010/08/17 18:35:32
         **/
        AutoBuffer& operator << (short i) {
            return pushf( "%hd", i );
        }

        /**
         * @brief 追加unsigned short型整数
         *          
         * @param  [in] i   : unsigned short
         * @return AutoBuffer& operator
         * @retval
         * @see
         * @author liaoshangbin
         * @data 2010/08/17 18:42:27
         **/
        AutoBuffer& operator << (unsigned short i) {
            return pushf( "%hu", i );
        }

        /**
         * @brief 追加int型整数
         *
         * @param [in] i   : int
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:29:10
        **/
        AutoBuffer& operator << (int i){
            return pushf( "%d", i );
        }

        /**
         * @brief 追加unsigned int型整数
         *
         * @param [in] i   : unsigned int
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:29:24
        **/
        AutoBuffer& operator << (unsigned int i){
            return pushf( "%u", i );
        }

        /**
         * @brief 追加long int型整数
         *
         * @param [in] i   : long int
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:29:44
        **/
        AutoBuffer& operator << (long int i){
            return pushf( "%ld", i );
        }

        /**
         * @brief 追加unsigned long int型整数
         *
         * @param [in] i   : unsigned long int
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:29:58
        **/
        AutoBuffer& operator << (unsigned long int i){
            return pushf( "%lu", i );
        }

        /**
         * @brief 追加字符串
         *
         * @param [in] cstr   : const char*
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:30:26
        **/
        AutoBuffer& operator << (const char* cstr ){
            if ( cstr != NULL ){
                push( cstr, strlen(cstr) );
            }else{
                _truncated = false;
            }
            return *this;
        }

        /**
         * @brief 追加long long型整数
         *
         * @param [in] ll   : long long
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:30:34
        **/
        AutoBuffer& operator << (long long ll){
            return pushf( "%lld", ll );
        }

        /**
         * @brief 追加unsigned long long型整数
         *
         * @param [in] ll   : unsigned long long
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:30:44
        **/
        AutoBuffer& operator << (unsigned long long ll){
            return pushf( "%llu", ll );
        }

        /**
         * @brief 追加double型浮点数
         *
         * @param [in] n   : double
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:30:59
        **/
        AutoBuffer& operator << (double n){
            return pushf( "%lg", n );
        }

        /**
         * @brief 追加long double型浮点数
         *
         * @param [in] n   : long double
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:31:19
        **/
        AutoBuffer& operator << (long double n){
            return pushf( "%Lg", n );
        }

        /**
         * @brief 追加指针字面值
         *
         * @param [in] p   : void*
         * @return  AutoBuffer&  operator 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/09/27 16:53:41
        **/
        AutoBuffer& operator << (void *p){
            return pushf( "%p", p );
        }

        /**
         * @brief 追加另一个AutoBuffer
         *
         * @param [in] other   : const AutoBuffer&
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/09/27 16:54:00
        **/
        AutoBuffer& push(const AutoBuffer& other){
            return push( other._str, other._size );
        }

        /**
         * @brief 追加布尔值
         *
         * @param [in] b   : bool
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:31:46
        **/
        AutoBuffer& push(bool b){
            if ( b ){
                return push( TRUE_LITERAL, TRUE_LITERAL_LEN );
            }else{
                return push( FALSE_LITERAL, FALSE_LITERAL_LEN );
            }
        }

        /**
         * @brief 追加字符，忽略'\0'
         *
         * @param [in] c   : char
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:31:58
        **/
        AutoBuffer& push(char c){
            if ( c == '\0' ){
                return *this;
            }
            if ( _size == _capacity ){    //full
                reserve( _size + 1 );     //may fail
            }
            if ( _size < _capacity ){
                _str[_size]    = c;
                _str[++_size]  = '\0';
                _truncated = false;
            }else{
                _truncated = true;
            }
            return *this;
        }

        /**
         * @brief 追加有符号8位整数
         *
         * @param [in] uc   : signed char
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/09/27 16:52:42
        **/
        AutoBuffer& push(signed char sc){
            return pushf("%hhd", sc);
        }

        /**
         * @brief 追加无符号8位整数
         *
         * @param [in] uc   : unsigned char
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:39:33
        **/
        AutoBuffer& push(unsigned char uc){
            return pushf("%hhu", uc);
        }

        /**
         * @brief 追加多个字符，忽略'\0'
         *
         * @param [in] count   : int
         * @param [in] c   : char
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm / zhujianwei 
         * @date 2009/02/04 18:40:04 / mod. by zhjw at 2010/09/21
        **/
        AutoBuffer& push(size_t count, char c){
            if ( c != '\0' ){
                if ( count > _capacity - _size ){    //full
                    count = (count <= size_t(-1) - _size) ? count : (size_t(-1) - _size);  //limit the size
                    if( !reserve( _size + count ) ){
                        //reserve fail
                        count = _capacity - _size;
                        _truncated = true;
                    }else{
                        _truncated = false;
                    }
                }
                if ( count ){
                    //str != NULL
                    memset( _str + _size, c, count );
                    _str[ _size+=count ] = '\0';
                }
            }
            return *this;
        }

        /**
         * @brief 追加宽字符，忽略'\0'
         *
         * @param [in] wc   : wchar_t
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:40:37
        **/
        AutoBuffer& push(wchar_t wc){
            if ( wc == 0 ){
                return *this;
            }
#if __GNUC__ <= 2
            wchar_t ws[] = { wc, 0 };
            return pushf( "%ls", ws );
#else
            return pushf( "%lc", wc );
#endif
        }

        /**
         * @brief 追加宽字符串，忽略'\0'
         *
         * @param [in] ws   : const wchar_t*
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:40:58
        **/
        AutoBuffer& push(const wchar_t * ws){
            if ( ws != NULL ){
                pushf( "%ls", ws );
            }else{
                _truncated = false;
            }
            return *this;
        }
        
        /**
         * @brief 追加short型整数
         *          
         * @param  [in] i   : short
         * @return AutoBuffer&
         * @retval
         * @see
         * @author liaoshangbin
         * @data 2010/08/17 18:43:58
         **/
        AutoBuffer& push(short i) {
            return pushf( "%hd", i );
        }

        /**
         * @brief 追加unsigned short型整数
         *          
         * @param  [in] i   : unsigned short
         * @return  AutoBuffer&
         * @retval
         * @see
         * @author liaoshangbin
         * @data 2010/08/17 18:44:41
         **/
        AutoBuffer& push(unsigned short i) {
            return pushf( "%hu", i );
        }

        /**
         * @brief 追加int型整数
         *
         * @param [in] i   : int
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:41:22
        **/
        AutoBuffer& push(int i){
            return pushf( "%d", i );
        }

        /**
         * @brief 追加unsigned int型整数
         *
         * @param [in] i   : unsigned int
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:41:36
        **/
        AutoBuffer& push(unsigned int i){
            return pushf( "%u", i );
        }

        /**
         * @brief 追加long int型整数
         *
         * @param [in] i   : long int
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:41:50
        **/
        AutoBuffer& push(long int i){
            return pushf( "%ld", i );
        }

        /**
         * @brief 追加unsigned long int型整数
         *
         * @param [in] i   : unsigned long int
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:42:00
        **/
        AutoBuffer& push(unsigned long int i){
            return pushf( "%lu", i );
        }

        /**
         * @brief 追加字符串
         *
         * @param [in] cstr   : const char*
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:42:15
        **/
        AutoBuffer& push(const char* cstr ){
            if ( cstr != NULL ){
                push( cstr, strlen(cstr) );
            }else{
                _truncated = false;
            }
            return *this;
        }

        /**
         * @brief 追加字符串子串
         *
         * 调用者必须保证strlen(cstr) >= sub_str_len，否则行为未定义
         *
         * @param [in] cstr   : const char*
         * @param [in] sub_str_len   : size_t
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:42:28
        **/
        AutoBuffer& push(const char* cstr, size_t sub_str_len );
        
        /**
         * @brief 追加long long型整数
         *
         * @param [in] ll   : long long
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:42:47
        **/
        AutoBuffer& push(long long ll ){
            return pushf( "%lld", ll );
        }

        /**
         * @brief 追加unsigned long long型整数
         *
         * @param [in] ll   : unsigned long long
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:43:23
        **/
        AutoBuffer& push(unsigned long long ll ){
            return pushf( "%llu", ll );
        }

        /**
         * @brief 追加double型浮点数
         *
         * @param [in] n   : double
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:43:39
        **/
        AutoBuffer& push( double n ){
            return pushf( "%lg", n );
        }

        /**
         * @brief 追加long double型浮点数
         *
         * @param [in] n   : long double
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:43:52
        **/
        AutoBuffer& push( long double n ){
            return pushf( "%Lg", n );
        }

        /**
         * @brief 追加void *字符串
         *
         * @param [in] p   : void*
         * @return  AutoBuffer&
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/04/12 01:33:41
        **/
        AutoBuffer& push( void *p ){
            return pushf( "%p", p );
        }

        //attrbute can only be put at function declarations until g++ 3
        /**
         * @brief 以类似printf()语法追加字符串
         *
         * @param [in] format   : const char*
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:44:19
        **/
        AutoBuffer& pushf( const char *format, ... ) __attribute__ ((format (printf, 2, 3) ));

        /**
         * @brief 以类似vprintf()语法追加字符串
         *
         * @param [in] format   : const char*
         * @param [in] ap   : va_list
         * @return  AutoBuffer& 
         * @retval   
         * @see 
         * @author chenxm
         * @date 2009/02/04 18:44:53
        **/
        AutoBuffer& vpushf( const char *format, va_list ap );


    public:
        /**
         * @brief 默认AutoBuffer的字符串容量
         *          
        **/
        static const int DEFAULT_CAPACITY = 64;
        /**
         * @brief 布尔型true的字面值
         *          
        **/
        static const char * const TRUE_LITERAL; 
        /**
         * @brief 布尔型false的字面值
         *
        **/
        static const char * const FALSE_LITERAL; 

    private:
        /**
         * @brief 复制构造函数
         *  
         **/
        AutoBuffer( const AutoBuffer& other );
        /**
         * @brief 复制赋值运算符
         *
        **/
        AutoBuffer& operator = ( const AutoBuffer& );
        /**
         * @brief AutoBuffer的长度
         *
        **/
        size_t  _size;
        /**
         * @brief AutoBuffer的容量
         *
        **/
        size_t  _capacity;
        /**
         * @brief 最近一次操作是否发生截断
         *
        **/
        bool    _truncated;
        /**
         * @brief AutoBuffer的内部字符串缓冲区
         *
        **/
        char *  _str;
        /**
         * @brief 布尔型true的字面值长度
         *
        **/
        static const size_t TRUE_LITERAL_LEN; 
        /**
         * @brief 布尔型false的字面值长度
         *
        **/
        static const size_t FALSE_LITERAL_LEN; 
        
        /**
         * @brief 当前使用的内存池的指针
         *
        **/
        mempool* _mempool;

    };

}   //namespace bsl;


#endif  //__BSL_AUTO_BUFFER_H_

/* vim: set ts=4 sw=4 sts=4 tw=100 */