SQLite

#include "sqlite3.h"
#include <string.h>
#include <assert.h>
#include "sqliteInt.h"

/************************ Shim Definitions ******************************/

#define SQLITE_MULTIPLEX_CHUNK_SIZE 0x40000000
#define SQLITE_MULTIPLEX_MAX_CHUNKS 32

/************************ Object Definitions ******************************/

/* Forward declaration of all object types */
typedef struct multiplexGroup multiplexGroup;
typedef struct multiplexConn multiplexConn;

  multiplexGroup *pGroups;

  /* Chunk params.
  */
  int nChunkSize;
  int nMaxChunks;

  /* Storage for temp file names.  Allocated during 
  ** initialization to the max pathname of the underlying VFS.
  */
  char *zName;

} gMultiplex;

/************************* Utility Routines *********************************/
/*
** Acquire and release the mutex used to serialize access to the
** list of multiplexGroups.
*/

        return pSubOpen;
      }
      return NULL;
    }
    *rc = SQLITE_OK;
    return pSubOpen;
  }
  *rc = SQLITE_FULL;
  return NULL;
}

/************************* VFS Method Wrappers *****************************/

/*
** This is the xOpen method used for the "multiplex" VFS.
**
** Most of the work is done by the underlying original VFS.  This method
** simply links the new file into the appropriate multiplex group if it is a
** file that needs to be tracked.
*/

  sqlite3_file *pSubOpen;                        /* Real file descriptor */
  sqlite3_vfs *pOrigVfs = gMultiplex.pOrigVfs;   /* Real VFS */
  int nName = sqlite3Strlen30(zName);
  int i;

  UNUSED_PARAMETER(pVfs);








  /* We need to create a group structure and manage
  ** access to this group of files.
  */
  multiplexEnter();
  pMultiplexOpen = (multiplexConn*)pConn;
  /* allocate space for group, file handles, 
  ** and file name (+ extra for "-0000\0") 

    }else{
      sqlite3_free(pGroup);
    }
  }
  multiplexLeave();
  return rc;
}

/*
** This is the xDelete method used for the "multiplex" VFS.
** It attempts to delete the filename specified, as well
** as addiitional files with the "-####" extension.
*/
static int multiplexDelete(
  sqlite3_vfs *pVfs,         /* The multiplex VFS */
  const char *zName,         /* Name of file to delete */
  int syncDir
){
  sqlite3_vfs *pOrigVfs = gMultiplex.pOrigVfs;   /* Real VFS */
  int rc = SQLITE_OK;
  int nName = sqlite3Strlen30(zName);
  int i;

  UNUSED_PARAMETER(pVfs);

  multiplexEnter();
  memcpy(gMultiplex.zName, zName, nName+1);
  for(i=0; i<gMultiplex.nMaxChunks; i++){
    int rc2;
    int exists = 0;
    if( i ) sqlite3_snprintf(nName+6, gMultiplex.zName+nName, "-%04d", i);
    rc2 = pOrigVfs->xAccess(pOrigVfs, gMultiplex.zName, SQLITE_ACCESS_EXISTS, &exists);
    if( rc2==SQLITE_OK && exists){
      /* if it exists, delete it */
      rc2 = pOrigVfs->xDelete(pOrigVfs, gMultiplex.zName, syncDir);
      if( rc2!=SQLITE_OK ) rc = rc2;
    }else{
      /* stop at first "gap" */
      break;
    }
  }
  multiplexLeave();
  return rc;
}

/************************ I/O Method Wrappers *******************************/

/* xClose requests get passed through to the original VFS.
** We loop over all open chunk handles and close them.
** The group structure for this file is unlinked from 
** our list of groups and freed.
*/
static int multiplexClose(sqlite3_file *pConn){
  multiplexConn *p = (multiplexConn*)pConn;
  multiplexGroup *pGroup = p->pGroup;
  int rc = SQLITE_OK;
  int i;
  multiplexEnter();
  /* close any open handles */
  for(i=0; i<gMultiplex.nMaxChunks; i++){
    if( pGroup->bOpen[i] ){
      sqlite3_file *pSubOpen = pGroup->pReal[i];
      int rc2 = pSubOpen->pMethods->xClose(pSubOpen);
      if( rc2!=SQLITE_OK ) rc = rc2;
      pGroup->bOpen[i] = 0;
    }
  }
  /* remove from linked list */
  if( pGroup->pNext ) pGroup->pNext->pPrev = pGroup->pPrev;
  if( pGroup->pPrev ){
    pGroup->pPrev->pNext = pGroup->pNext;
  }else{
    gMultiplex.pGroups = pGroup->pNext;
  }
  sqlite3_free(pGroup);

  if( gMultiplex.isInitialized ) return SQLITE_MISUSE;
  pOrigVfs = sqlite3_vfs_find(zOrigVfsName);
  if( pOrigVfs==0 ) return SQLITE_ERROR;
  assert( pOrigVfs!=&gMultiplex.sThisVfs );
  gMultiplex.pMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
  if( !gMultiplex.pMutex ){
    return SQLITE_NOMEM;
  }
  gMultiplex.zName = sqlite3_malloc(pOrigVfs->mxPathname);
  if( !gMultiplex.zName ){
    sqlite3_mutex_free(gMultiplex.pMutex);
    return SQLITE_NOMEM;
  }
  gMultiplex.nChunkSize = SQLITE_MULTIPLEX_CHUNK_SIZE;
  gMultiplex.nMaxChunks = SQLITE_MULTIPLEX_MAX_CHUNKS;
  gMultiplex.pGroups = NULL;
  gMultiplex.isInitialized = 1;
  gMultiplex.pOrigVfs = pOrigVfs;
  gMultiplex.sThisVfs = *pOrigVfs;
  gMultiplex.sThisVfs.szOsFile += sizeof(multiplexConn);
  gMultiplex.sThisVfs.zName = "multiplex";
  gMultiplex.sThisVfs.xOpen = multiplexOpen;
  gMultiplex.sThisVfs.xDelete = multiplexDelete;
  gMultiplex.sIoMethodsV1.iVersion = 1;
  gMultiplex.sIoMethodsV1.xClose = multiplexClose;
  gMultiplex.sIoMethodsV1.xRead = multiplexRead;
  gMultiplex.sIoMethodsV1.xWrite = multiplexWrite;
  gMultiplex.sIoMethodsV1.xTruncate = multiplexTruncate;
  gMultiplex.sIoMethodsV1.xSync = multiplexSync;
  gMultiplex.sIoMethodsV1.xFileSize = multiplexFileSize;

** THIS ROUTINE IS NOT THREADSAFE.  Call this routine exactly once while
** shutting down in order to free all remaining multiplex groups.
*/
int sqlite3_multiplex_shutdown(void){
  if( gMultiplex.isInitialized==0 ) return SQLITE_MISUSE;
  if( gMultiplex.pGroups ) return SQLITE_MISUSE;
  gMultiplex.isInitialized = 0;
  sqlite3_free(gMultiplex.zName);
  sqlite3_mutex_free(gMultiplex.pMutex);
  sqlite3_vfs_unregister(&gMultiplex.sThisVfs);
  memset(&gMultiplex, 0, sizeof(gMultiplex));
  return SQLITE_OK;
}

/*

#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/malloc_common.tcl

set g_chunk_size 2147483648
set g_max_chunks 32

proc multiplex_set {chunk_size max_chunks} {
  global g_chunk_size
  global g_max_chunks
  set g_chunk_size $chunk_size
  set g_max_chunks $max_chunks
  sqlite3_multiplex_set $chunk_size $max_chunks
}

proc multiplex_delete {name} {
  global g_max_chunks
  forcedelete $name
  forcedelete $name-journal
  forcedelete $name-wal
  for {set i 1} {$i<$g_max_chunks} {incr i} {
    set num [format "%04d" $i]
    forcedelete $name-$num
    forcedelete $name-journal-$num
    forcedelete $name-wal-$num
  }
}

db close

#-------------------------------------------------------------------------
#   multiplex-1.1.*: Test initialize and shutdown.

do_test multiplex-1.1 { sqlite3_multiplex_initialize nosuchvfs 1 } {SQLITE_ERROR}
do_test multiplex-1.2 { sqlite3_multiplex_initialize "" 1 }        {SQLITE_OK}
do_test multiplex-1.3 { sqlite3_multiplex_initialize "" 1 }        {SQLITE_MISUSE}
do_test multiplex-1.4 { sqlite3_multiplex_shutdown }               {SQLITE_OK}

do_test multiplex-1.5 { sqlite3_multiplex_initialize "" 0 }        {SQLITE_OK}
do_test multiplex-1.6 { sqlite3_multiplex_shutdown }               {SQLITE_OK}
do_test multiplex-1.7 { sqlite3_multiplex_initialize "" 1 }        {SQLITE_OK}
do_test multiplex-1.8 { sqlite3_multiplex_shutdown }               {SQLITE_OK}

do_test multiplex-1.9  { sqlite3_multiplex_initialize "" 1 }       {SQLITE_OK}
do_test multiplex-1.10.1 { multiplex_set 32768 16 }                {SQLITE_OK}
do_test multiplex-1.10.2 { multiplex_set 32768 -1 }                {SQLITE_MISUSE}
do_test multiplex-1.10.3 { multiplex_set -1 16 }                   {SQLITE_MISUSE}
do_test multiplex-1.10.4 { multiplex_set 31 16 }                   {SQLITE_MISUSE}
do_test multiplex-1.10.5 { multiplex_set 32768 33 }                {SQLITE_MISUSE}
do_test multiplex-1.11 { sqlite3_multiplex_shutdown }              {SQLITE_OK}


#-------------------------------------------------------------------------
# Some simple warm-body tests with a single database file in rollback 
# mode:
#
#   multiplex-2.1.*: Test simple writing to a multiplex file.
#
#   multiplex-2.2.*: More writing.
#
#   multiplex-2.3.*: Open and close a second db.
#
#   multiplex-2.4.*: Try to shutdown the multiplex system before closing the db
#                file. Check that this fails and the multiplex system still works
#                afterwards. Then close the database and successfully shut
#                down the multiplex system.
#
#   multiplex-2.5.*: More reading/writing.
#
#   multiplex-2.6.*: More reading/writing with varying small chunk sizes.

sqlite3_multiplex_initialize "" 1
multiplex_set 32768 16

do_test multiplex-2.1.2 {
  sqlite3 db test.db
  execsql {
    PRAGMA page_size=1024;
    PRAGMA auto_vacuum=OFF;
    PRAGMA journal_mode=DELETE;

  sqlite3_multiplex_shutdown
} {SQLITE_OK}


do_test multiplex-2.5.1 {
  multiplex_delete test.db
  sqlite3_multiplex_initialize "" 1
  multiplex_set 4096 16
} {SQLITE_OK}

do_test multiplex-2.5.2 {
  sqlite3 db test.db
  execsql {
    PRAGMA page_size = 1024;
    PRAGMA journal_mode = delete;

  db eval {SELECT a,length(b) FROM t1 WHERE a=2}
} {2 4000}

do_test multiplex-2.5.8 {
  db eval {SELECT a,length(b) FROM t1 WHERE a=4}
} {4 4000}

do_test multiplex-2.5.9 { file size test.db } [list $g_chunk_size]
do_test multiplex-2.5.10 { file size test.db-0001 } [list $g_chunk_size]

do_test multiplex-2.5.99 {
  db close
  sqlite3_multiplex_shutdown
} {SQLITE_OK}


for {set sz 151} {$sz<8000} {set sz [expr $sz+419]} {

  do_test multiplex-2.6.1.$sz {
    multiplex_delete test.db
    sqlite3_multiplex_initialize "" 1
    multiplex_set $sz 32
  } {SQLITE_OK}

  do_test multiplex-2.6.2.$sz {
    sqlite3 db test.db
    execsql {
      PRAGMA page_size = 1024;
      PRAGMA journal_mode = delete;
      PRAGMA auto_vacuum = off;
      CREATE TABLE t1(a PRIMARY KEY, b);
    }
  } {delete}

  do_test multiplex-2.6.3.$sz { 
    execsql { 
      INSERT INTO t1 VALUES(1, 'one');
      INSERT INTO t1 VALUES(2, randomblob($g_chunk_size));
    }
  } {}

  do_test multiplex-2.6.4.$sz {
    db eval {SELECT b FROM t1 WHERE a=1}
  } {one}

  do_test multiplex-2.6.5.$sz {
    db eval {SELECT length(b) FROM t1 WHERE a=2}
  } [list $g_chunk_size]

  do_test multiplex-2.6.6.$sz { file size test.db } [list $g_chunk_size]

  do_test multiplex-2.6.99.$sz {
    db close
    sqlite3_multiplex_shutdown
  } {SQLITE_OK}

}

#-------------------------------------------------------------------------
# Try some tests with more than one connection to a database file. Still
# in rollback mode.
#
#   multiplex-3.1.*: Two connections to a single database file.
#
#   multiplex-3.2.*: Two connections to each of several database files (that
#                are in the same multiplex group).
#
do_test multiplex-3.1.1 {
  multiplex_delete test.db
  sqlite3_multiplex_initialize "" 1
  multiplex_set 32768 16
} {SQLITE_OK}
do_test multiplex-3.1.2 {
  sqlite3 db test.db
  execsql {
    PRAGMA page_size = 1024;
    PRAGMA journal_mode = delete;
    PRAGMA auto_vacuum = off;

  foreach db {db1a db2a db2b db1b} { catch { $db close } }
} {}

#-------------------------------------------------------------------------
#

sqlite3_multiplex_initialize "" 1
multiplex_set 32768 16

# Return a list of all currently defined multiplexs.
proc multiplex_list {} {
  set allq {}
  foreach q [sqlite3_multiplex_dump] {
    lappend allq [lindex $q 0]
  }

#-------------------------------------------------------------------------
# The following tests test that the multiplex VFS handles malloc and IO 
# errors.
#

sqlite3_multiplex_initialize "" 1
multiplex_set 32768 16

do_faultsim_test multiplex-5.1 -prep {
  catch {db close}
} -body {
  sqlite3 db test2.db
}
do_faultsim_test multiplex-5.2 -prep {
  catch {db close}
} -body {
  sqlite3 db test.db
}

catch { db close }
multiplex_delete test.db
multiplex_delete test2.db

do_test multiplex-5.3.prep {
  sqlite3 db test.db
  execsql {
    PRAGMA auto_vacuum = 1;
    PRAGMA page_size = 1024;
    CREATE TABLE t1(a, b);

do_test multiplex-5.4.1 {
  catch { db close }
  multiplex_delete test.db
  file mkdir test.db
  list [catch { sqlite3 db test.db } msg] $msg
} {1 {unable to open database file}}
catch { file delete test.db }

do_faultsim_test multiplex-5.5 -prep {
  catch { sqlite3_multiplex_shutdown }
} -body {
  sqlite3_multiplex_initialize "" 1
  multiplex_set 32768 16
}

catch { sqlite3_multiplex_shutdown }
finish_test