SQLite

# 2015 February 16
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
}
source $testdir/tester.tcl
set ::testprefix ota11


#--------------------------------------------------------------------
# Test that the xAccess() method of an ota vfs handles queries other
# than SQLITE_ACCESS_EXISTS correctly. The test code below causes
# SQLite to call xAccess(SQLITE_ACCESS_READWRITE) on the directory
# path argument passed to "PRAGMA temp_store_directory".
#
do_test 1.1 {
  sqlite3ota_create_vfs -default ota ""
  reset_db
  catchsql { PRAGMA temp_store_directory = '/no/such/directory' }
} {1 {not a writable directory}}

do_test 1.2 {
  catchsql " PRAGMA temp_store_directory = '[pwd]' "
} {0 {}}

do_test 1.3 {
  catchsql " PRAGMA temp_store_directory = '' "
} {0 {}}

do_test 1.4 {
  db close
  sqlite3ota_destroy_vfs ota
} {}

#--------------------------------------------------------------------
# Try to trick ota into operating on a database opened in wal mode.
#
reset_db
do_execsql_test 2.1 {
  CREATE TABLE t1(a PRIMARY KEY, b, c);
  INSERT INTO t1 VALUES(1, 2, 3);
  PRAGMA journal_mode = 'wal';
  CREATE TABLE t2(d PRIMARY KEY, e, f);
} {wal}

do_test 2.2 {
  db_save 
  db close

  forcedelete ota.db
  sqlite3 dbo ota.db
  dbo eval {
    CREATE TABLE data_t1(a, b, c, ota_control);
    INSERT INTO data_t1 VALUES(4, 5, 6, 0);
    INSERT INTO data_t1 VALUES(7, 8, 9, 0);
  }
  dbo close

  db_restore 
  hexio_write test.db 18 0101
  file exists test.db-wal
} {1}

breakpoint
do_test 2.3 {
  sqlite3ota ota test.db ota.db
  ota step
} {SQLITE_ERROR}

do_test 2.4 {
  list [catch {ota close} msg] $msg
} {1 {SQLITE_ERROR - cannot update wal mode database}}

finish_test

  list [catch { run_ota test.db ota.db } msg] $msg
} {1 SQLITE_ERROR}

do_execsql_test 2.5 {
  PRAGMA integrity_check;
} {ok}


#-------------------------------------------------------------------------
# Test that sqlite3ota_create_vfs() returns an error if the requested 
# parent VFS is unknown.
#
# And that nothing disasterous happens if a VFS name passed to
# sqlite3ota_destroy_vfs() is unknown or not an OTA vfs.
#
do_test 3.1 {
  list [catch {sqlite3ota_create_vfs xyz nosuchparent} msg] $msg
} {1 SQLITE_NOTFOUND}

do_test 3.2 {
  sqlite3ota_destroy_vfs nosuchvfs
  sqlite3ota_destroy_vfs unix
  sqlite3ota_destroy_vfs win32
} {}

finish_test

  ota close
} {SQLITE_OK}

do_test 2.1 {
  sqlite3 db test.db
  db eval {PRAGMA journal_mode = wal}
  db close
  breakpoint
  sqlite3ota ota test.db ota.db
  ota step
} {SQLITE_ERROR}

do_test 2.2 {
  list [catch { ota close } msg] $msg
} {1 {SQLITE_ERROR - cannot update wal mode database}}

struct OtaState {
  int eStage;
  char *zTbl;
  char *zIdx;
  i64 iWalCksum;
  int nRow;
  i64 nProgress;
  u32 iCookie;
};

/*
** An iterator of this type is used to iterate through all objects in
** the target database that require updating. For each such table, the
** iterator visits, in order:
**

  const char *zWal;               /* Wal filename for this main db file */
  ota_file *pWalFd;               /* Wal file descriptor for this main db */
  ota_file *pMainNext;            /* Next MAIN_DB file */
};





/*
** Prepare the SQL statement in buffer zSql against database handle db.
** If successful, set *ppStmt to point to the new statement and return
** SQLITE_OK. 
**
** Otherwise, if an error does occur, set *ppStmt to NULL and return
** an SQLite error code. Additionally, set output variable *pzErrmsg to

        break;

      case OTA_STATE_CKPT:
        pRet->iWalCksum = sqlite3_column_int64(pStmt, 1);
        break;

      case OTA_STATE_COOKIE:





        pRet->iCookie = (u32)sqlite3_column_int64(pStmt, 1);




        break;

      default:
        rc = SQLITE_CORRUPT;
        break;
    }
  }

*/
static void otaDeleteOalFile(sqlite3ota *p){
  char *zOal = sqlite3_mprintf("%s-oal", p->zTarget);
  assert( p->rc==SQLITE_OK && p->zErrmsg==0 );
  unlink(zOal);
  sqlite3_free(zOal);
}

static void otaCreateVfs(sqlite3ota *p){
  int rnd;
  char zRnd[64];

  assert( p->rc==SQLITE_OK );
  sqlite3_randomness(sizeof(int), (void*)&rnd);
  sprintf(zRnd, "ota_vfs_%d", rnd);
  p->rc = sqlite3ota_create_vfs(zRnd, 0);
  if( p->rc==SQLITE_OK ){
    sqlite3_vfs *pVfs = sqlite3_vfs_find(zRnd);
    assert( pVfs );
    p->zVfsName = pVfs->zName;
  }
}

static void otaDeleteVfs(sqlite3ota *p){
  if( p->zVfsName ){
    sqlite3ota_destroy_vfs(p->zVfsName);
    p->zVfsName = 0;
  }
}

/*
** Open and return a new OTA handle. 
*/
sqlite3ota *sqlite3ota_open(const char *zTarget, const char *zOta){
  sqlite3ota *p;
  int nTarget = strlen(zTarget);
  int nOta = strlen(zOta);

  p = (sqlite3ota*)sqlite3_malloc(sizeof(sqlite3ota)+nTarget+1+nOta+1);
  if( p ){
    OtaState *pState = 0;

    /* Create the custom VFS. */
    memset(p, 0, sizeof(sqlite3ota));
    otaCreateVfs(p);

    /* Open the target database */
    if( p->rc==SQLITE_OK ){
      p->zTarget = (char*)&p[1];
      memcpy(p->zTarget, zTarget, nTarget+1);
      p->zOta = &p->zTarget[nTarget+1];
      memcpy(p->zOta, zOta, nOta+1);
      otaOpenDatabase(p);
    }

    /* If it has not already been created, create the ota_state table */
    if( p->rc==SQLITE_OK ){
      p->rc = sqlite3_exec(p->db, OTA_CREATE_STATE, 0, 0, &p->zErrmsg);
    }

    /* Check that this is not a wal mode database. If it is, it cannot be
    ** updated. There is also a check for a live *-wal file in otaVfsAccess()
    ** function, on the off chance that the target is a wal database for
    ** which the first page of the db file has been overwritten by garbage
    ** during an earlier failed checkpoint.  */
#if 0
    if( p->rc==SQLITE_OK && p->pTargetFd->iWriteVer>1 ){
      p->rc = SQLITE_ERROR;
      p->zErrmsg = sqlite3_mprintf("cannot update wal mode database");
    }
#endif

    if( p->rc==SQLITE_OK ){
      pState = otaLoadState(p);
      assert( pState || p->rc!=SQLITE_OK );
      if( p->rc==SQLITE_OK ){

        if( pState->eStage==0 ){ 
          otaDeleteOalFile(p);
          p->eStage = OTA_STAGE_OAL;
        }else{
          p->eStage = pState->eStage;
        }
        p->nProgress = pState->nProgress;
      }
    }
    assert( p->rc!=SQLITE_OK || p->eStage!=0 );

    if( p->rc==SQLITE_OK ){
      if( p->eStage==OTA_STAGE_OAL ){
        if( p->pTargetFd->pWalFd ){
          p->rc = SQLITE_ERROR;
          p->zErrmsg = sqlite3_mprintf("cannot update wal mode database");
        }

        /* At this point (pTargetFd->iCookie) contains the value of the
        ** change-counter cookie (the thing that gets incremented when a 
        ** transaction is committed in rollback mode) currently stored on 
        ** page 1 of the database file. */
        else if( pState->eStage==OTA_STAGE_OAL 
         && p->pTargetFd->iCookie!=pState->iCookie 
        ){
          p->rc = SQLITE_BUSY;
          p->zErrmsg = sqlite3_mprintf("database modified during ota update");
        }

        /* Open the transaction */
        if( p->rc==SQLITE_OK ){
          p->rc = sqlite3_exec(p->db, "BEGIN IMMEDIATE", 0, 0, &p->zErrmsg);
        }
  
        /* Point the object iterator at the first object */

  if( p->openFlags & SQLITE_OPEN_MAIN_DB ){
    ota_file **pp;
    sqlite3_mutex_enter(p->pOtaVfs->mutex);
    for(pp=&p->pOtaVfs->pMain; *pp!=p; pp=&((*pp)->pMainNext));
    *pp = p->pMainNext;
    sqlite3_mutex_leave(p->pOtaVfs->mutex);
    p->pReal->pMethods->xShmUnmap(p->pReal, 0);
  }

  /* Close the underlying file handle */
  rc = p->pReal->pMethods->xClose(p->pReal);
  return rc;
}

static int otaVfsGetLastError(sqlite3_vfs *pVfs, int a, char *b){
  return 0;
}

void sqlite3ota_destroy_vfs(const char *zName){
  sqlite3_vfs *pVfs = sqlite3_vfs_find(zName);
  if( pVfs && pVfs->xOpen==otaVfsOpen ){
    sqlite3_vfs_unregister(pVfs);
    sqlite3_free(pVfs);
  }
}

int sqlite3ota_create_vfs(const char *zName, const char *zParent){

    otaVfsSleep,                  /* xSleep */
    otaVfsCurrentTime,            /* xCurrentTime */
    otaVfsGetLastError,           /* xGetLastError */
    0,                            /* xCurrentTimeInt64 (version 2) */
    0, 0, 0                       /* Unimplemented version 3 methods */
  };


  ota_vfs *pNew = 0;              /* Newly allocated VFS */
  int nName;
  int rc = SQLITE_OK;

  int nByte;
  nName = strlen(zName);




  nByte = sizeof(ota_vfs) + nName + 1;
  pNew = (ota_vfs*)sqlite3_malloc(nByte);
  if( pNew==0 ){
    rc = SQLITE_NOMEM;
  }else{
    sqlite3_vfs *pParent;           /* Parent VFS */
    memset(pNew, 0, nByte);


    pParent = sqlite3_vfs_find(zParent);
    if( pParent==0 ){
      rc = SQLITE_NOTFOUND;
    }else{
      char *zSpace;
      memcpy(&pNew->base, &vfs_template, sizeof(sqlite3_vfs));
      pNew->base.mxPathname = pParent->mxPathname;
      pNew->base.szOsFile = sizeof(ota_file) + pParent->szOsFile;
      pNew->pRealVfs = pParent;

      pNew->base.zName = (const char*)(zSpace = (char*)&pNew[1]);
      memcpy(zSpace, zName, nName);

      /* Register the new VFS (not as the default) */
      rc = sqlite3_vfs_register(&pNew->base, 0);


    }
  }














  if( rc!=SQLITE_OK ){
    sqlite3_free(pNew);


  }

  return rc;





}


/**************************************************************************/

#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_OTA) */