**
** This file contains the implementation of an SQLite vfs wrapper for
** unix that generates per-database log files of all disk activity.
*/

/*
** This module contains code for a wrapper VFS that causes a log of
** most VFS calls to be written into a file on disk. The log 
** is stored as comma-separated variables.
**

** All calls on sqlite3_file objects are logged.
** Additionally, calls to the xAccess(), xOpen(), and xDelete()
** methods are logged. The other sqlite3_vfs object methods (xDlXXX,
** xRandomness, xSleep, xCurrentTime, xGetLastError and xCurrentTimeInt64) 
** are not logged.























*/

#include "sqlite3.h"
#include <string.h>
#include <assert.h>
#include <stdio.h>
#if SQLITE_OS_UNIX

**
** This file contains the implementation of an SQLite vfs wrapper for
** unix that generates per-database log files of all disk activity.
*/

/*
** This module contains code for a wrapper VFS that causes a log of
** most VFS calls to be written into a file on disk.

**
** Each database connection creates a separate log file in the same
** directory as the original database and named after the original
** database.  A unique suffix is added to avoid name collisions.  
** Separate log files are used so that concurrent processes do not
** try to write log operations to the same file at the same instant, 
** resulting in overwritten or comingled log text.
**
** Each individual log file records operations by a single database
** connection on both the original database and its associated rollback
** journal.
**
** The log files are in the comma-separated-value (CSV) format.  The
** log files can be imported into an SQLite database using the ".import"
** command of the SQLite command-line shell for analysis.
**
** One technique for using this module is to append the text of this
** module to the end of a standard "sqlite3.c" amalgamation file then
** add the following compile-time options:
**
**     -DSQLITE_EXTRA_INIT=sqlite3_register_vfslog
**     -DSQLITE_USE_FCNTL_TRACE
**
** The first compile-time option causes the sqlite3_register_vfslog()
** function, defined below, to be invoked when SQLite is initialized.
** That causes this custom VFS to become the default VFS for all
** subsequent connections.  The SQLITE_USE_FCNTL_TRACE option causes
** the SQLite core to issue extra sqlite3_file_control() operations
** with SQLITE_FCNTL_TRACE to give some indication of what is going
** on in the core.
*/

#include "sqlite3.h"
#include <string.h>
#include <assert.h>
#include <stdio.h>
#if SQLITE_OS_UNIX