diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/sqlite.h.in | 8 | ||||
| -rw-r--r-- | src/test_sqllog.c | 59 |
2 files changed, 52 insertions, 15 deletions
diff --git a/src/sqlite.h.in b/src/sqlite.h.in index 3c6291eeb..3265b3196 100644 --- a/src/sqlite.h.in +++ b/src/sqlite.h.in @@ -1633,12 +1633,12 @@ struct sqlite3_mem_methods { ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE ** <dd> These options are obsolete and should not be used by new code. ** They are retained for backwards compatibility but are now no-ops. -** </dl> +** </dd> ** ** [[SQLITE_CONFIG_SQLLOG]] ** <dt>SQLITE_CONFIG_SQLLOG ** <dd>This option is only available if sqlite is compiled with the -** SQLITE_ENABLE_SQLLOG pre-processor macro defined. The first argument should +** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). ** The second should be of type (void*). The callback is invoked by the library ** in three separate circumstances, identified by the value passed as the @@ -1648,7 +1648,9 @@ struct sqlite3_mem_methods { ** fourth parameter is 1, then the SQL statement that the third parameter ** points to has just been executed. Or, if the fourth parameter is 2, then ** the connection being passed as the second parameter is being closed. The -** third parameter is passed NULL In this case. +** third parameter is passed NULL In this case. An example of using this +** configuration option can be seen in the "test_sqllog.c" source file in +** the canonical SQLite source tree.</dd> ** ** [[SQLITE_CONFIG_MMAP_SIZE]] ** <dt>SQLITE_CONFIG_MMAP_SIZE diff --git a/src/test_sqllog.c b/src/test_sqllog.c index 24c675b5e..4aa68b7c4 100644 --- a/src/test_sqllog.c +++ b/src/test_sqllog.c @@ -13,22 +13,32 @@ ** OVERVIEW ** ** This file contains experimental code used to record data from live -** SQLite applications that may be useful for offline analysis. Specifically: +** SQLite applications that may be useful for offline analysis. +** Specifically, this module can be used to capture the following +** information: ** ** 1) The initial contents of all database files opened by the ** application, and ** ** 2) All SQL statements executed by the application. ** +** The captured information can then be used to run (for example) +** performance analysis looking for slow queries or to look for +** optimization opportunities in either the application or in SQLite +** itself. +** ** USAGE ** ** To use this module, SQLite must be compiled with the SQLITE_ENABLE_SQLLOG -** pre-processor symbol defined and this file linked into the application -** somehow. +** pre-processor symbol defined and this file linked into the application. +** One way to link this file into the application is to append the content +** of this file onto the end of the "sqlite3.c" amalgamation and then +** recompile the application as normal except with the addition of the +** -DSQLITE_ENABLE_SQLLOG option. ** ** At runtime, logging is enabled by setting environment variable ** SQLITE_SQLLOG_DIR to the name of a directory in which to store logged -** data. The directory must already exist. +** data. The logging directory must already exist. ** ** Usually, if the application opens the same database file more than once ** (either by attaching it or by using more than one database handle), only @@ -57,14 +67,16 @@ ** logging proceeds as expected. Errors are logged by calling sqlite3_log(). */ +#ifndef _SQLITE3_H_ #include "sqlite3.h" -#include "stdio.h" -#include "stdlib.h" -#include "string.h" -#include "assert.h" +#endif +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> -#include "sys/types.h" -#include "unistd.h" +#include <sys/types.h> +#include <unistd.h> static int getProcessId(void){ #if SQLITE_OS_WIN return (int)_getpid(); @@ -73,7 +85,7 @@ static int getProcessId(void){ #endif } - +/* Names of environment variables to be used */ #define ENVIRONMENT_VARIABLE1_NAME "SQLITE_SQLLOG_DIR" #define ENVIRONMENT_VARIABLE2_NAME "SQLITE_SQLLOG_REUSE_FILES" @@ -86,6 +98,9 @@ static int getProcessId(void){ */ #define MAX_CONNECTIONS 256 +/* There is one instance of this object for each SQLite database connection +** that is being logged. +*/ struct SLConn { int isErr; /* True if an error has occurred */ sqlite3 *db; /* Connection handle */ @@ -93,7 +108,9 @@ struct SLConn { FILE *fd; /* File descriptor for log file */ }; -struct SLGlobal { +/* This object is a singleton that keeps track of all data loggers. +*/ +static struct SLGlobal { /* Protected by MUTEX_STATIC_MASTER */ sqlite3_mutex *mutex; /* Recursive mutex */ int nConn; /* Size of aConn[] array */ @@ -388,6 +405,24 @@ static void testSqllogStmt(struct SLConn *p, const char *zSql){ /* ** The SQLITE_CONFIG_SQLLOG callback registered by sqlite3_init_sqllog(). +** +** The eType parameter has the following values: +** +** 0: Opening a new database connection. zSql is the name of the +** file being opened. db is a pointer to the newly created database +** connection. +** +** 1: An SQL statement has run to completion. zSql is the text of the +** SQL statement with all parameters expanded to their actual values. +** +** 2: Closing a database connection. zSql is NULL. The db pointer to +** the database connection being closed has already been shut down +** and cannot be used for any further SQL. +** +** The pCtx parameter is a copy of the pointer that was originally passed +** into the sqlite3_config(SQLITE_CONFIG_SQLLOG) statement. In this +** particular implementation, pCtx is always a pointer to the +** sqllogglobal global variable define above. */ static void testSqllog(void *pCtx, sqlite3 *db, const char *zSql, int eType){ struct SLConn *p = 0; |