vdbeaux.c

sqlite-source-2_8_16.zip 轻量级嵌入式数据库源码

*/
int sqliteVdbeList(
  Vdbe *p                   /* The VDBE */
){
  sqlite *db = p->db;
  int i;
  int rc = SQLITE_OK;
  static char *azColumnNames[] = {
     "addr", "opcode", "p1",  "p2",  "p3", 
     "int",  "text",   "int", "int", "text",
     0
  };

  assert( p->popStack==0 );
  assert( p->explain );
  p->azColName = azColumnNames;
  p->azResColumn = p->zArgv;
  for(i=0; i<5; i++) p->zArgv[i] = p->aStack[i].zShort;
  i = p->pc;
  if( i>=p->nOp ){
    p->rc = SQLITE_OK;
    rc = SQLITE_DONE;
  }else if( db->flags & SQLITE_Interrupt ){
    db->flags &= ~SQLITE_Interrupt;
    if( db->magic!=SQLITE_MAGIC_BUSY ){
      p->rc = SQLITE_MISUSE;
    }else{
      p->rc = SQLITE_INTERRUPT;
    }
    rc = SQLITE_ERROR;
    sqliteSetString(&p->zErrMsg, sqlite_error_string(p->rc), (char*)0);
  }else{
    sprintf(p->zArgv[0],"%d",i);
    sprintf(p->zArgv[2],"%d", p->aOp[i].p1);
    sprintf(p->zArgv[3],"%d", p->aOp[i].p2);
    if( p->aOp[i].p3type==P3_POINTER ){
      sprintf(p->aStack[4].zShort, "ptr(%#lx)", (long)p->aOp[i].p3);
      p->zArgv[4] = p->aStack[4].zShort;
    }else{
      p->zArgv[4] = p->aOp[i].p3;
    }
    p->zArgv[1] = sqliteOpcodeNames[p->aOp[i].opcode];
    p->pc = i+1;
    p->azResColumn = p->zArgv;
    p->nResColumn = 5;
    p->rc = SQLITE_OK;
    rc = SQLITE_ROW;
  }
  return rc;
}

/*
** Prepare a virtual machine for execution.  This involves things such
** as allocating stack space and initializing the program counter.
** After the VDBE has be prepped, it can be executed by one or more
** calls to sqliteVdbeExec().  
*/
void sqliteVdbeMakeReady(
  Vdbe *p,                       /* The VDBE */
  int nVar,                      /* Number of '?' see in the SQL statement */
  int isExplain                  /* True if the EXPLAIN keywords is present */
){
  int n;

  assert( p!=0 );
  assert( p->magic==VDBE_MAGIC_INIT );

  /* Add a HALT instruction to the very end of the program.
  */
  if( p->nOp==0 || (p->aOp && p->aOp[p->nOp-1].opcode!=OP_Halt) ){
    sqliteVdbeAddOp(p, OP_Halt, 0, 0);
  }

  /* No instruction ever pushes more than a single element onto the
  ** stack.  And the stack never grows on successive executions of the
  ** same loop.  So the total number of instructions is an upper bound
  ** on the maximum stack depth required.
  **
  ** Allocation all the stack space we will ever need.
  */
  if( p->aStack==0 ){
    p->nVar = nVar;
    assert( nVar>=0 );
    n = isExplain ? 10 : p->nOp;
    p->aStack = sqliteMalloc(
      n*(sizeof(p->aStack[0]) + 2*sizeof(char*))     /* aStack and zArgv */
        + p->nVar*(sizeof(char*)+sizeof(int)+1)    /* azVar, anVar, abVar */
    );
    p->zArgv = (char**)&p->aStack[n];
    p->azColName = (char**)&p->zArgv[n];
    p->azVar = (char**)&p->azColName[n];
    p->anVar = (int*)&p->azVar[p->nVar];
    p->abVar = (u8*)&p->anVar[p->nVar];
  }

  sqliteHashInit(&p->agg.hash, SQLITE_HASH_BINARY, 0);
  p->agg.pSearch = 0;
#ifdef MEMORY_DEBUG
  if( sqliteOsFileExists("vdbe_trace") ){
    p->trace = stdout;
  }
#endif
  p->pTos = &p->aStack[-1];
  p->pc = 0;
  p->rc = SQLITE_OK;
  p->uniqueCnt = 0;
  p->returnDepth = 0;
  p->errorAction = OE_Abort;
  p->undoTransOnError = 0;
  p->popStack =  0;
  p->explain |= isExplain;
  p->magic = VDBE_MAGIC_RUN;
#ifdef VDBE_PROFILE
  {
    int i;
    for(i=0; i<p->nOp; i++){
      p->aOp[i].cnt = 0;
      p->aOp[i].cycles = 0;
    }
  }
#endif
}


/*
** Remove any elements that remain on the sorter for the VDBE given.
*/
void sqliteVdbeSorterReset(Vdbe *p){
  while( p->pSort ){
    Sorter *pSorter = p->pSort;
    p->pSort = pSorter->pNext;
    sqliteFree(pSorter->zKey);
    sqliteFree(pSorter->pData);
    sqliteFree(pSorter);
  }
}

/*
** Reset an Agg structure.  Delete all its contents. 
**
** For installable aggregate functions, if the step function has been
** called, make sure the finalizer function has also been called.  The
** finalizer might need to free memory that was allocated as part of its
** private context.  If the finalizer has not been called yet, call it
** now.
*/
void sqliteVdbeAggReset(Agg *pAgg){
  int i;
  HashElem *p;
  for(p = sqliteHashFirst(&pAgg->hash); p; p = sqliteHashNext(p)){
    AggElem *pElem = sqliteHashData(p);
    assert( pAgg->apFunc!=0 );
    for(i=0; i<pAgg->nMem; i++){
      Mem *pMem = &pElem->aMem[i];
      if( pAgg->apFunc[i] && (pMem->flags & MEM_AggCtx)!=0 ){
        sqlite_func ctx;
        ctx.pFunc = pAgg->apFunc[i];
        ctx.s.flags = MEM_Null;
        ctx.pAgg = pMem->z;
        ctx.cnt = pMem->i;
        ctx.isStep = 0;
        ctx.isError = 0;
        (*pAgg->apFunc[i]->xFinalize)(&ctx);
        if( pMem->z!=0 && pMem->z!=pMem->zShort ){
          sqliteFree(pMem->z);
        }
        if( ctx.s.flags & MEM_Dyn ){
          sqliteFree(ctx.s.z);
        }
      }else if( pMem->flags & MEM_Dyn ){
        sqliteFree(pMem->z);
      }
    }
    sqliteFree(pElem);
  }
  sqliteHashClear(&pAgg->hash);
  sqliteFree(pAgg->apFunc);
  pAgg->apFunc = 0;
  pAgg->pCurrent = 0;
  pAgg->pSearch = 0;
  pAgg->nMem = 0;
}

/*
** Delete a keylist
*/
void sqliteVdbeKeylistFree(Keylist *p){
  while( p ){
    Keylist *pNext = p->pNext;
    sqliteFree(p);
    p = pNext;
  }
}

/*
** Close a cursor and release all the resources that cursor happens
** to hold.
*/
void sqliteVdbeCleanupCursor(Cursor *pCx){
  if( pCx->pCursor ){
    sqliteBtreeCloseCursor(pCx->pCursor);
  }
  if( pCx->pBt ){
    sqliteBtreeClose(pCx->pBt);
  }
  sqliteFree(pCx->pData);
  memset(pCx, 0, sizeof(Cursor));
}

/*
** Close all cursors
*/
static void closeAllCursors(Vdbe *p){
  int i;
  for(i=0; i<p->nCursor; i++){
    sqliteVdbeCleanupCursor(&p->aCsr[i]);
  }
  sqliteFree(p->aCsr);
  p->aCsr = 0;
  p->nCursor = 0;
}

/*
** Clean up the VM after execution.
**
** This routine will automatically close any cursors, lists, and/or
** sorters that were left open.  It also deletes the values of
** variables in the azVariable[] array.
*/
static void Cleanup(Vdbe *p){
  int i;
  if( p->aStack ){
    Mem *pTos = p->pTos;
    while( pTos>=p->aStack ){
      if( pTos->flags & MEM_Dyn ){
        sqliteFree(pTos->z);
      }
      pTos--;
    }
    p->pTos = pTos;
  }
  closeAllCursors(p);
  if( p->aMem ){
    for(i=0; i<p->nMem; i++){
      if( p->aMem[i].flags & MEM_Dyn ){
        sqliteFree(p->aMem[i].z);
      }
    }
  }
  sqliteFree(p->aMem);
  p->aMem = 0;
  p->nMem = 0;
  if( p->pList ){
    sqliteVdbeKeylistFree(p->pList);
    p->pList = 0;
  }
  sqliteVdbeSorterReset(p);
  if( p->pFile ){
    if( p->pFile!=stdin ) fclose(p->pFile);
    p->pFile = 0;
  }
  if( p->azField ){
    sqliteFree(p->azField);
    p->azField = 0;
  }
  p->nField = 0;
  if( p->zLine ){
    sqliteFree(p->zLine);
    p->zLine = 0;
  }
  p->nLineAlloc = 0;
  sqliteVdbeAggReset(&p->agg);
  if( p->aSet ){
    for(i=0; i<p->nSet; i++){
      sqliteHashClear(&p->aSet[i].hash);
    }
  }
  sqliteFree(p->aSet);
  p->aSet = 0;
  p->nSet = 0;
  if( p->keylistStack ){
    int ii;
    for(ii = 0; ii < p->keylistStackDepth; ii++){
      sqliteVdbeKeylistFree(p->keylistStack[ii]);
    }
    sqliteFree(p->keylistStack);
    p->keylistStackDepth = 0;
    p->keylistStack = 0;
  }
  sqliteFree(p->contextStack);
  p->contextStack = 0;
  sqliteFree(p->zErrMsg);
  p->zErrMsg = 0;
}

/*
** Clean up a VDBE after execution but do not delete the VDBE just yet.
** Write any error messages into *pzErrMsg.  Return the result code.
**
** After this routine is run, the VDBE should be ready to be executed
** again.
*/
int sqliteVdbeReset(Vdbe *p, char **pzErrMsg){
  sqlite *db = p->db;
  int i;

  if( p->magic!=VDBE_MAGIC_RUN && p->magic!=VDBE_MAGIC_HALT ){
    sqliteSetString(pzErrMsg, sqlite_error_string(SQLITE_MISUSE), (char*)0);
    return SQLITE_MISUSE;
  }
  if( p->zErrMsg ){
    if( pzErrMsg && *pzErrMsg==0 ){
      *pzErrMsg = p->zErrMsg;
    }else{
      sqliteFree(p->zErrMsg);
    }
    p->zErrMsg = 0;
  }else if( p->rc ){
    sqliteSetString(pzErrMsg, sqlite_error_string(p->rc), (char*)0);
  }
  Cleanup(p);
  if( p->rc!=SQLITE_OK ){
    switch( p->errorAction ){
      case OE_Abort: {
        if( !p->undoTransOnError ){
          for(i=0; i<db->nDb; i++){
            if( db->aDb[i].pBt ){
              sqliteBtreeRollbackCkpt(db->aDb[i].pBt);
            }
          }
          break;
        }
        /* Fall through to ROLLBACK */
      }
      case OE_Rollback: {
        sqliteRollbackAll(db);
        db->flags &= ~SQLITE_InTrans;
        db->onError = OE_Default;
        break;
      }
      default: {
        if( p->undoTransOnError ){
          sqliteRollbackAll(db);
          db->flags &= ~SQLITE_InTrans;
          db->onError = OE_Default;
        }
        break;
      }
    }
    sqliteRollbackInternalChanges(db);
  }
  for(i=0; i<db->nDb; i++){
    if( db->aDb[i].pBt && db->aDb[i].inTrans==2 ){
      sqliteBtreeCommitCkpt(db->aDb[i].pBt);
      db->aDb[i].inTrans = 1;
    }
  }
  assert( p->pTos<&p->aStack[p->pc] || sqlite_malloc_failed==1 );
#ifdef VDBE_PROFILE
  {
    FILE *out = fopen("vdbe_profile.out", "a");
    if( out ){
      int i;
      fprintf(out, "---- ");
      for(i=0; i<p->nOp; i++){
        fprintf(out, "%02x", p->aOp[i].opcode);
      }
      fprintf(out, "\n");
      for(i=0; i<p->nOp; i++){
        fprintf(out, "%6d %10lld %8lld ",
           p->aOp[i].cnt,
           p->aOp[i].cycles,
           p->aOp[i].cnt>0 ? p->aOp[i].cycles/p->aOp[i].cnt : 0
        );
        sqliteVdbePrintOp(out, i, &p->aOp[i]);
      }
      fclose(out);
    }
  }
#endif
  p->magic = VDBE_MAGIC_INIT;
  return p->rc;
}

/*
** Clean up and delete a VDBE after execution.  Return an integer which is
** the result code.  Write any error message text into *pzErrMsg.
*/
int sqliteVdbeFinalize(Vdbe *p, char **pzErrMsg){
  int rc;
  sqlite *db;

  if( p->magic!=VDBE_MAGIC_RUN && p->magic!=VDBE_MAGIC_HALT ){
    sqliteSetString(pzErrMsg, sqlite_error_string(SQLITE_MISUSE), (char*)0);
    return SQLITE_MISUSE;
  }
  db = p->db;
  rc = sqliteVdbeReset(p, pzErrMsg);
  sqliteVdbeDelete(p);
  if( db->want_to_close && db->pVdbe==0 ){
    sqlite_close(db);
  }
  if( rc==SQLITE_SCHEMA ){
    sqliteResetInternalSchema(db, 0);
  }
  return rc;
}

/*
** Set the values of all variables.  Variable $1 in the original SQL will
** be the string azValue[0].  $2 will have the value azValue[1].  And
** so forth.  If a value is out of range (for example $3 when nValue==2)
** then its value will be NULL.
**
** This routine overrides any prior call.
*/
int sqlite_bind(sqlite_vm *pVm, int i, const char *zVal, int len, int copy){
  Vdbe *p = (Vdbe*)pVm;
  if( p->magic!=VDBE_MAGIC_RUN || p->pc!=0 ){
    return SQLITE_MISUSE;
  }
  if( i<1 || i>p->nVar ){
    return SQLITE_RANGE;
  }
  i--;
  if( p->abVar[i] ){
    sqliteFree(p->azVar[i]);
  }
  if( zVal==0 ){
    copy = 0;
    len = 0;
  }
  if( len<0 ){
    len = strlen(zVal)+1;
  }
  if( copy ){
    p->azVar[i] = sqliteMalloc( len );
    if( p->azVar[i] ) memcpy(p->azVar[i], zVal, len);
  }else{
    p->azVar[i] = (char*)zVal;
  }
  p->abVar[i] = copy;
  p->anVar[i] = len;
  return SQLITE_OK;
}


/*
** Delete an entire VDBE.
*/
void sqliteVdbeDelete(Vdbe *p){
  int i;
  if( p==0 ) return;
  Cleanup(p);
  if( p->pPrev ){
    p->pPrev->pNext = p->pNext;
  }else{
    assert( p->db->pVdbe==p );
    p->db->pVdbe = p->pNext;
  }
  if( p->pNext ){
    p->pNext->pPrev = p->pPrev;
  }
  p->pPrev = p->pNext = 0;
  if( p->nOpAlloc==0 ){
    p->aOp = 0;
    p->nOp = 0;
  }
  for(i=0; i<p->nOp; i++){
    if( p->aOp[i].p3type==P3_DYNAMIC ){
      sqliteFree(p->aOp[i].p3);
    }
  }
  for(i=0; i<p->nVar; i++){
    if( p->abVar[i] ) sqliteFree(p->azVar[i]);
  }
  sqliteFree(p->aOp);
  sqliteFree(p->aLabel);
  sqliteFree(p->aStack);
  p->magic = VDBE_MAGIC_DEAD;
  sqliteFree(p);
}

/*
** Convert an integer in between the native integer format and
** the bigEndian format used as the record number for tables.
**
** The bigEndian format (most significant byte first) is used for
** record numbers so that records will sort into the correct order
** even though memcmp() is used to compare the keys.  On machines
** whose native integer format is little endian (ex: i486) the
** order of bytes is reversed.  On native big-endian machines
** (ex: Alpha, Sparc, Motorola) the byte order is the same.
**
** This function is its own inverse.  In other words
**
**         X == byteSwap(byteSwap(X))
*/
int sqliteVdbeByteSwap(int x){
  union {
     char zBuf[sizeof(int)];
     int i;
  } ux;
  ux.zBuf[3] = x&0xff;
  ux.zBuf[2] = (x>>8)&0xff;
  ux.zBuf[1] = (x>>16)&0xff;
  ux.zBuf[0] = (x>>24)&0xff;
  return ux.i;
}

/*
** If a MoveTo operation is pending on the given cursor, then do that
** MoveTo now.  Return an error code.  If no MoveTo is pending, this
** routine does nothing and returns SQLITE_OK.
*/
int sqliteVdbeCursorMoveto(Cursor *p){
  if( p->deferredMoveto ){
    int res;
    extern int sqlite_search_count;
    sqliteBtreeMoveto(p->pCursor, (char*)&p->movetoTarget, sizeof(int), &res);
    p->lastRecno = keyToInt(p->movetoTarget);
    p->recnoIsValid = res==0;
    if( res<0 ){
      sqliteBtreeNext(p->pCursor, &res);
    }
    sqlite_search_count++;
    p->deferredMoveto = 0;
  }
  return SQLITE_OK;
}