SQLite源码剖析(6)
/*** 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
/* no-op宏经常在接口前标记那些实验性的和不推荐的接口。新应用程序最好
**不使用不推荐的接口，它们支持向后兼容。程序员必须意识到实验性接口
**会在某个版本中改变
** These no-op macros are used in front of interfaces to mark those
** interfaces as either deprecated or experimental. New applications
** should not use deprecated interfaces - they are support for backwards
** compatibility only. Application writers should be aware that
** experimental interfaces are subject to change in point releases.
**这些宏在他们需要时，能实现编译器魔法compiler magic警告信息，
**编译器魔法最终产生BUG报告，编译器会试着使用noop宏。
** These macros used to resolve to various kinds of compiler magic that
** would generate warning messages when they were used. But that
** compiler magic ended up generating such a flurry of bug reports
** that we have taken it all out and gone back to using simple
** noop macros.
*/
#define SQLITE_DEPRECATED
#define SQLITE_EXPERIMENTAL
/*
** Ensure these symbols were not defined by some previous header file.
*/
//如果SQLITE_VERSION、SQLITE_VERSION_NUMBER标志已经定义，则取消
#ifdef SQLITE_VERSION
# undef SQLITE_VERSION
#endif
#ifdef SQLITE_VERSION_NUMBER
# undef SQLITE_VERSION_NUMBER
#endif
/*
** CAPI3REF: Compile-Time Library Version Numbers
** SQLITE_VERSION 宏为版本号，[X.Y.Z的SQLITE版本号中,X是主版本号，Y
**是次版本号，Z是发行号
** ^(The C preprocessor macro in the sqlite3.h header
** evaluates to a string literal that is the SQLite version in the
** format "X.Y.Z" where X is the major version number (always 3 for
** SQLite3) and Y is the minor version number and Z is the release number.)^
** ^(The C preprocessor macro resolves
** to an integer with the value (X*1000000 + Y*1000 + Z) where X, Y,
**and Z are the same numbers used in .)^
** SQLITE_VERSION_NUMBER根据SQLITE_VERSION中版本号计算一个
**整数（X*1000000 + Y*1000 + Z）
** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
** be larger than the release from which it is derived. Either Y will
** be held constant and Z will be incremented or else Y will be incremented
** and Z will be reset to zero.
**
** Since version 3.6.18, SQLite source code has been stored in the
** <a href="http://www.fossil-scm.org/">Fossil configuration management
** system</a>. ^The SQLITE_SOURCE_ID macro evalutes to
** a string which identifies a particular check-in of SQLite
** within its configuration management system. ^The SQLITE_SOURCE_ID
** string contains the date and time of the check-in (UTC) and an SHA1
** hash of the entire source tree.
** SQLITE_SOURCE_ID 为一个字符串，为SQLITE配置管理系统中的check-in
**详情包含check-in的日期和时间以及整个源码树的SHA1哈希
** See also: ,
** , ,
** and .
*/
//定义版本号，并计算SQLITE_VERSION_NUMBER
#define SQLITE_VERSION "3.6.23.1"
#define SQLITE_VERSION_NUMBER 3006023
#define SQLITE_SOURCE_ID "2010-03-26 22:28:06 b078b588d617e07886ad156e9f54ade6d823568e"
/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version, sqlite3_sourceid
** 这些接口通过库而不是头文件提供了
*SQLITE_VERSION、SQLITE_VERSION_NUMBER以**及SQLITE_SOURCE_ID宏
**的相同信息
** These interfaces provide the same information as the ,
** , and C preprocessor macros
** but are associated with the library instead of the header file. ^(Cautious
** programmers might include assert() statements in their application to
** verify that values returned by these interfaces match the macros in
** the header, and thus insure that the application is
** compiled with matching library and header files.
**可小心地通过包含以下的assert()声明，在应用程序核实匹配头文件中宏的
**这些接口，以确保应用程序使用相匹配的库和头文件编译
** <blockquote><pre>
** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
** </pre></blockquote>)^
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
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