SQLite

Check-in [63a7dd75e6]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Add QNX-specific performance tweaks to the unix VFS. (Cherry-pick merge of [b02849e7bde458].)
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 63a7dd75e61afb3d05a1434f66ad6a5f08352aad
User & Date: drh 2012-10-26 13:46:24.545
Context
2012-10-26
18:40
Make sure the automatic index optimization is checked even if the covering index scan optimization was previously selected. (check-in: ac1d5d8a55 user: drh tags: trunk)
13:46
Add QNX-specific performance tweaks to the unix VFS. (Cherry-pick merge of [b02849e7bde458].) (check-in: 63a7dd75e6 user: drh tags: trunk)
00:55
Make sure all virtual table cursors have been closed on a prepared statement prior to unlinking the perpared statement from its database connection. The test case for this is in TH3, in the main39.test module. (check-in: 6d42d806ad user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/os_unix.c.
214
215
216
217
218
219
220




221
222
223
224
225
226
227
  unsigned short int ctrlFlags;       /* Behavioral bits.  UNIXFILE_* flags */
  int lastErrno;                      /* The unix errno from last I/O error */
  void *lockingContext;               /* Locking style specific state */
  UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
  const char *zPath;                  /* Name of the file */
  unixShm *pShm;                      /* Shared memory segment information */
  int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */




#if SQLITE_ENABLE_LOCKING_STYLE
  int openFlags;                      /* The flags specified at open() */
#endif
#if SQLITE_ENABLE_LOCKING_STYLE || defined(__APPLE__)
  unsigned fsFlags;                   /* cached details from statfs() */
#endif
#if OS_VXWORKS







>
>
>
>







214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
  unsigned short int ctrlFlags;       /* Behavioral bits.  UNIXFILE_* flags */
  int lastErrno;                      /* The unix errno from last I/O error */
  void *lockingContext;               /* Locking style specific state */
  UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
  const char *zPath;                  /* Name of the file */
  unixShm *pShm;                      /* Shared memory segment information */
  int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
#ifdef __QNXNTO__
  int sectorSize;                     /* Device sector size */
  int deviceCharacteristics;          /* Precomputed device characteristics */
#endif
#if SQLITE_ENABLE_LOCKING_STYLE
  int openFlags;                      /* The flags specified at open() */
#endif
#if SQLITE_ENABLE_LOCKING_STYLE || defined(__APPLE__)
  unsigned fsFlags;                   /* cached details from statfs() */
#endif
#if OS_VXWORKS
3634
3635
3636
3637
3638
3639
3640

3641
3642
3643
3644

















































































3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660





3661
3662
3663
3664
3665

3666
3667
3668
3669
3670
3671
3672
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and its journal file) that the sector size will be the
** same for both.
*/

static int unixSectorSize(sqlite3_file *pFile){
  (void)pFile;
  return SQLITE_DEFAULT_SECTOR_SIZE;
}


















































































/*
** Return the device characteristics for the file.
**
** This VFS is set up to return SQLITE_IOCAP_POWERSAFE_OVERWRITE by default.
** However, that choice is contraversial since technically the underlying
** file system does not always provide powersafe overwrites.  (In other
** words, after a power-loss event, parts of the file that were never
** written might end up being altered.)  However, non-PSOW behavior is very,
** very rare.  And asserting PSOW makes a large reduction in the amount
** of required I/O for journaling, since a lot of padding is eliminated.
**  Hence, while POWERSAFE_OVERWRITE is on by default, there is a file-control
** available to turn it off and URI query parameter available to turn it off.
*/
static int unixDeviceCharacteristics(sqlite3_file *id){
  unixFile *p = (unixFile*)id;





  if( p->ctrlFlags & UNIXFILE_PSOW ){
    return SQLITE_IOCAP_POWERSAFE_OVERWRITE;
  }else{
    return 0;
  }

}

#ifndef SQLITE_OMIT_WAL


/*
** Object used to represent an shared memory buffer.  







>
|
|


>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
















>
>
>
>
>

|
<
<

>







3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753


3754
3755
3756
3757
3758
3759
3760
3761
3762
** larger for some devices.
**
** SQLite code assumes this function cannot fail. It also assumes that
** if two files are created in the same file-system directory (i.e.
** a database and its journal file) that the sector size will be the
** same for both.
*/
#ifndef __QNXNTO__ 
static int unixSectorSize(sqlite3_file *NotUsed){
  UNUSED_PARAMETER(NotUsed);
  return SQLITE_DEFAULT_SECTOR_SIZE;
}
#endif

/*
** The following version of unixSectorSize() is optimized for QNX.
*/
#ifdef __QNXNTO__
#include <sys/dcmd_blk.h>
#include <sys/statvfs.h>
static int unixSectorSize(sqlite3_file *id){
  unixFile *pFile = (unixFile*)id;
  if( pFile->sectorSize == 0 ){
    struct statvfs fsInfo;
       
    /* Set defaults for non-supported filesystems */
    pFile->sectorSize = SQLITE_DEFAULT_SECTOR_SIZE;
    pFile->deviceCharacteristics = 0;
    if( fstatvfs(pFile->h, &fsInfo) == -1 ) {
      return pFile->sectorSize;
    }

    if( !strcmp(fsInfo.f_basetype, "tmp") ) {
      pFile->sectorSize = fsInfo.f_bsize;
      pFile->deviceCharacteristics =
        SQLITE_IOCAP_ATOMIC4K |       /* All ram filesystem writes are atomic */
        SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until
                                      ** the write succeeds */
        SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind
                                      ** so it is ordered */
        0;
    }else if( strstr(fsInfo.f_basetype, "etfs") ){
      pFile->sectorSize = fsInfo.f_bsize;
      pFile->deviceCharacteristics =
        /* etfs cluster size writes are atomic */
        (pFile->sectorSize / 512 * SQLITE_IOCAP_ATOMIC512) |
        SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until
                                      ** the write succeeds */
        SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind
                                      ** so it is ordered */
        0;
    }else if( !strcmp(fsInfo.f_basetype, "qnx6") ){
      pFile->sectorSize = fsInfo.f_bsize;
      pFile->deviceCharacteristics =
        SQLITE_IOCAP_ATOMIC |         /* All filesystem writes are atomic */
        SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until
                                      ** the write succeeds */
        SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind
                                      ** so it is ordered */
        0;
    }else if( !strcmp(fsInfo.f_basetype, "qnx4") ){
      pFile->sectorSize = fsInfo.f_bsize;
      pFile->deviceCharacteristics =
        /* full bitset of atomics from max sector size and smaller */
        ((pFile->sectorSize / 512 * SQLITE_IOCAP_ATOMIC512) << 1) - 2 |
        SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind
                                      ** so it is ordered */
        0;
    }else if( strstr(fsInfo.f_basetype, "dos") ){
      pFile->sectorSize = fsInfo.f_bsize;
      pFile->deviceCharacteristics =
        /* full bitset of atomics from max sector size and smaller */
        ((pFile->sectorSize / 512 * SQLITE_IOCAP_ATOMIC512) << 1) - 2 |
        SQLITE_IOCAP_SEQUENTIAL |     /* The ram filesystem has no write behind
                                      ** so it is ordered */
        0;
    }else{
      pFile->deviceCharacteristics =
        SQLITE_IOCAP_ATOMIC512 |      /* blocks are atomic */
        SQLITE_IOCAP_SAFE_APPEND |    /* growing the file does not occur until
                                      ** the write succeeds */
        0;
    }
  }
  /* Last chance verification.  If the sector size isn't a multiple of 512
  ** then it isn't valid.*/
  if( pFile->sectorSize % 512 != 0 ){
    pFile->deviceCharacteristics = 0;
    pFile->sectorSize = SQLITE_DEFAULT_SECTOR_SIZE;
  }
  return pFile->sectorSize;
}
#endif /* __QNXNTO__ */

/*
** Return the device characteristics for the file.
**
** This VFS is set up to return SQLITE_IOCAP_POWERSAFE_OVERWRITE by default.
** However, that choice is contraversial since technically the underlying
** file system does not always provide powersafe overwrites.  (In other
** words, after a power-loss event, parts of the file that were never
** written might end up being altered.)  However, non-PSOW behavior is very,
** very rare.  And asserting PSOW makes a large reduction in the amount
** of required I/O for journaling, since a lot of padding is eliminated.
**  Hence, while POWERSAFE_OVERWRITE is on by default, there is a file-control
** available to turn it off and URI query parameter available to turn it off.
*/
static int unixDeviceCharacteristics(sqlite3_file *id){
  unixFile *p = (unixFile*)id;
  int rc = 0;
#ifdef __QNXNTO__
  if( p->sectorSize==0 ) unixSectorSize(id);
  rc = p->deviceCharacteristics;
#endif
  if( p->ctrlFlags & UNIXFILE_PSOW ){
    rc |= SQLITE_IOCAP_POWERSAFE_OVERWRITE;


  }
  return rc;
}

#ifndef SQLITE_OMIT_WAL


/*
** Object used to represent an shared memory buffer.