SQLITE源码剖析(5)

lx86

　　声明：本SQLite源码剖析系列为刘兴(http://deepfuture.iyunv.com/)原创，未经笔者授权，任何人和机构不能转载
　　
/************** Include sqlite3.h in the middle of sqliteInt.h ***************/
/************** Begin file sqlite3.h *****************************************/
//在sqliteInt.h中包含sqlite3.h
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************sqlite库的客户端接口，如果在这个文件中没有出现过某个C函数、
**结构、数据类型、或常量定义，那么它是不公开的SQLITE的API，
**不会声明随时有可能改变，也不能做为使用SQLITE开发的参考。
** This header file defines the interface that the SQLite library
** presents to client programs.  If a C-function, structure, datatype,
** or constant definition does not appear in this file, then it is
** not a published API of SQLite, is subject to change without
** notice, and should not be referenced by programs that use SQLite.
**有些定义被标明experimental(实验性的)，这些接口不久会被加入SQLITE。
**虽然不希望改变实验性接口，会保留较小改变的权力，使用in the wild
**标明的地方要谨慎改变
** Some of the definitions that are in this file are marked as
** "experimental".  Experimental interfaces are normally new
** features recently added to SQLite.  We do not anticipate changes
** to experimental interfaces but reserve the right to make minor changes
** if experience from use "in the wild" suggest such changes are prudent.
**SQLITE的官方C语言API文档从注解生成，这个文件在SQLITE接口
**操作方面具有权威
** The official C-language API documentation for SQLite is derived
** from comments in this file.  This file is the authoritative source
** on how SQLite interfaces are suppose to operate.
** 构造管理文件是sqlite.h.in，makefile对这个文件
**（比如嵌入式版本中）做较小改动，build过程中其名改为sqlite3.h
** The name of this file under configuration management is "sqlite.h.in".
** The makefile makes some minor changes to this file (such as inserting
** the version number) and changes its name to "sqlite3.h" as
** part of the build process.
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     
/*SQLITE接口需要va_list定义 Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
*/
// extern声明的函数和变量可以在本模块或其他模块中使用。
// extern "C"包含双重含义，其一：被它修饰的目标是“extern”的；
//其二：被它修饰的目标是“C”的。extern "C"仅被使用在C++调用C程
//序情况，C不能使用。#if 0把它屏蔽了，如果使用C++编译器，可以
//可以打开该选项
//比如test.cpp(C++源码文件)需要调用myc.h这个C头文件中
//用extern声明的函数，可以如下书写:
//extern "C"
//{
//#include "myc.h"
//}
#if 0
extern "C" {
#endif


/*
** Add the ability to override 'extern'
*/
//定义extern的宏，可使用SQLITE_EXTERN来完成extern功能
#ifndef SQLITE_EXTERN
# define SQLITE_EXTERN extern
#endif
//定义SQLITE_API宏
#ifndef SQLITE_API
# define SQLITE_API
#endif