vdbeapi.c

嵌入式数据系统软件！

/*
** 2004 May 26
**
** 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.
**
*************************************************************************
**
** This file contains code use to implement APIs that are part of the
** VDBE.
*/
#include "sqliteInt.h"
#include "vdbeInt.h"

/*
** Return TRUE (non-zero) of the statement supplied as an argument needs
** to be recompiled.  A statement needs to be recompiled whenever the
** execution environment changes in a way that would alter the program
** that sqlite3_prepare() generates.  For example, if new functions or
** collating sequences are registered or if an authorizer function is
** added or changed.
*/
int sqlite3_expired(sqlite3_stmt *pStmt){
  Vdbe *p = (Vdbe*)pStmt;
  return p==0 || p->expired;
}

/*
** The following routine destroys a virtual machine that is created by
** the sqlite3_compile() routine. The integer returned is an SQLITE_
** success/failure code that describes the result of executing the virtual
** machine.
**
** This routine sets the error code and string returned by
** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
*/
int sqlite3_finalize(sqlite3_stmt *pStmt){
  int rc;
  if( pStmt==0 ){
    rc = SQLITE_OK;
  }else{
    Vdbe *v = (Vdbe*)pStmt;
    sqlite3_mutex *mutex = v->db->mutex;
    sqlite3_mutex_enter(mutex);
    rc = sqlite3VdbeFinalize(v);
    sqlite3_mutex_leave(mutex);
  }
  return rc;
}

/*
** Terminate the current execution of an SQL statement and reset it
** back to its starting state so that it can be reused. A success code from
** the prior execution is returned.
**
** This routine sets the error code and string returned by
** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
*/
int sqlite3_reset(sqlite3_stmt *pStmt){
  int rc;
  if( pStmt==0 ){
    rc = SQLITE_OK;
  }else{
    Vdbe *v = (Vdbe*)pStmt;
    sqlite3_mutex_enter(v->db->mutex);
    rc = sqlite3VdbeReset(v);
    sqlite3VdbeMakeReady(v, -1, 0, 0, 0);
    assert( (rc & (v->db->errMask))==rc );
    sqlite3_mutex_leave(v->db->mutex);
  }
  return rc;
}

/*
** Set all the parameters in the compiled SQL statement to NULL.
*/
int sqlite3_clear_bindings(sqlite3_stmt *pStmt){
  int i;
  int rc = SQLITE_OK;
  Vdbe *v = (Vdbe*)pStmt;
  sqlite3_mutex_enter(v->db->mutex);
  for(i=1; rc==SQLITE_OK && i<=sqlite3_bind_parameter_count(pStmt); i++){
    rc = sqlite3_bind_null(pStmt, i);
  }
  sqlite3_mutex_leave(v->db->mutex);
  return rc;
}


/**************************** sqlite3_value_  *******************************
** The following routines extract information from a Mem or sqlite3_value
** structure.
*/
const void *sqlite3_value_blob(sqlite3_value *pVal){
  Mem *p = (Mem*)pVal;
  if( p->flags & (MEM_Blob|MEM_Str) ){
    sqlite3VdbeMemExpandBlob(p);
    p->flags &= ~MEM_Str;
    p->flags |= MEM_Blob;
    return p->z;
  }else{
    return sqlite3_value_text(pVal);
  }
}
int sqlite3_value_bytes(sqlite3_value *pVal){
  return sqlite3ValueBytes(pVal, SQLITE_UTF8);
}
int sqlite3_value_bytes16(sqlite3_value *pVal){
  return sqlite3ValueBytes(pVal, SQLITE_UTF16NATIVE);
}
double sqlite3_value_double(sqlite3_value *pVal){
  return sqlite3VdbeRealValue((Mem*)pVal);
}
int sqlite3_value_int(sqlite3_value *pVal){
  return sqlite3VdbeIntValue((Mem*)pVal);
}
sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
  return sqlite3VdbeIntValue((Mem*)pVal);
}
const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
  return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
}
#ifndef SQLITE_OMIT_UTF16
const void *sqlite3_value_text16(sqlite3_value* pVal){
  return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
}
const void *sqlite3_value_text16be(sqlite3_value *pVal){
  return sqlite3ValueText(pVal, SQLITE_UTF16BE);
}
const void *sqlite3_value_text16le(sqlite3_value *pVal){
  return sqlite3ValueText(pVal, SQLITE_UTF16LE);
}
#endif /* SQLITE_OMIT_UTF16 */
int sqlite3_value_type(sqlite3_value* pVal){
  return pVal->type;
}

/**************************** sqlite3_result_  *******************************
** The following routines are used by user-defined functions to specify
** the function result.
*/
void sqlite3_result_blob(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  assert( n>=0 );
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, 0, xDel);
}
void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetDouble(&pCtx->s, rVal);
}
void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  pCtx->isError = 1;
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
}
#ifndef SQLITE_OMIT_UTF16
void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  pCtx->isError = 1;
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
}
#endif
void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetInt64(&pCtx->s, (i64)iVal);
}
void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetInt64(&pCtx->s, iVal);
}
void sqlite3_result_null(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetNull(&pCtx->s);
}
void sqlite3_result_text(
  sqlite3_context *pCtx, 
  const char *z, 
  int n,
  void (*xDel)(void *)
){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, xDel);
}
#ifndef SQLITE_OMIT_UTF16
void sqlite3_result_text16(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, xDel);
}
void sqlite3_result_text16be(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16BE, xDel);
}
void sqlite3_result_text16le(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16LE, xDel);
}
#endif /* SQLITE_OMIT_UTF16 */
void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemCopy(&pCtx->s, pValue);
}
void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetZeroBlob(&pCtx->s, n);
}

/* Force an SQLITE_TOOBIG error. */
void sqlite3_result_error_toobig(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetZeroBlob(&pCtx->s, SQLITE_MAX_LENGTH+1);
}

/* An SQLITE_NOMEM error. */
void sqlite3_result_error_nomem(sqlite3_context *pCtx){
  assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
  sqlite3VdbeMemSetNull(&pCtx->s);
  pCtx->isError = 1;
  pCtx->s.db->mallocFailed = 1;
}

/*
** Execute the statement pStmt, either until a row of data is ready, the
** statement is completely executed or an error occurs.
**
** This routine implements the bulk of the logic behind the sqlite_step()
** API.  The only thing omitted is the automatic recompile if a 
** schema change has occurred.  That detail is handled by the
** outer sqlite3_step() wrapper procedure.
*/
static int sqlite3Step(Vdbe *p){
  sqlite3 *db;
  int rc;

  assert(p);
  if( p->magic!=VDBE_MAGIC_RUN ){
    return SQLITE_MISUSE;
  }

  /* Assert that malloc() has not failed */
  db = p->db;
  assert( !db->mallocFailed );

  if( p->aborted ){
    return SQLITE_ABORT;
  }
  if( p->pc<=0 && p->expired ){
    if( p->rc==SQLITE_OK ){
      p->rc = SQLITE_SCHEMA;
    }
    rc = SQLITE_ERROR;
    goto end_of_step;
  }
  if( sqlite3SafetyOn(db) ){
    p->rc = SQLITE_MISUSE;
    return SQLITE_MISUSE;
  }
  if( p->pc<0 ){
    /* If there are no other statements currently running, then
    ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
    ** from interrupting a statement that has not yet started.
    */
    if( db->activeVdbeCnt==0 ){
      db->u1.isInterrupted = 0;
    }

#ifndef SQLITE_OMIT_TRACE
    /* Invoke the trace callback if there is one
    */
    if( db->xTrace && !db->init.busy ){
      assert( p->nOp>0 );
      assert( p->aOp[p->nOp-1].opcode==OP_Noop );
      assert( p->aOp[p->nOp-1].p3!=0 );
      assert( p->aOp[p->nOp-1].p3type==P3_DYNAMIC );
      sqlite3SafetyOff(db);
      db->xTrace(db->pTraceArg, p->aOp[p->nOp-1].p3);
      if( sqlite3SafetyOn(db) ){
        p->rc = SQLITE_MISUSE;
        return SQLITE_MISUSE;
      }
    }
    if( db->xProfile && !db->init.busy ){
      double rNow;
      sqlite3OsCurrentTime(db->pVfs, &rNow);
      p->startTime = (rNow - (int)rNow)*3600.0*24.0*1000000000.0;
    }
#endif

    /* Print a copy of SQL as it is executed if the SQL_TRACE pragma is turned
    ** on in debugging mode.
    */
#ifdef SQLITE_DEBUG
    if( (db->flags & SQLITE_SqlTrace)!=0 ){
      sqlite3DebugPrintf("SQL-trace: %s\n", p->aOp[p->nOp-1].p3);
    }
#endif /* SQLITE_DEBUG */

    db->activeVdbeCnt++;
    p->pc = 0;
  }
#ifndef SQLITE_OMIT_EXPLAIN
  if( p->explain ){
    rc = sqlite3VdbeList(p);
  }else
#endif /* SQLITE_OMIT_EXPLAIN */
  {
    rc = sqlite3VdbeExec(p);
  }

  if( sqlite3SafetyOff(db) ){
    rc = SQLITE_MISUSE;
  }

#ifndef SQLITE_OMIT_TRACE
  /* Invoke the profile callback if there is one
  */
  if( rc!=SQLITE_ROW && db->xProfile && !db->init.busy ){
    double rNow;
    u64 elapseTime;

    sqlite3OsCurrentTime(db->pVfs, &rNow);
    elapseTime = (rNow - (int)rNow)*3600.0*24.0*1000000000.0 - p->startTime;
    assert( p->nOp>0 );
    assert( p->aOp[p->nOp-1].opcode==OP_Noop );
    assert( p->aOp[p->nOp-1].p3!=0 );
    assert( p->aOp[p->nOp-1].p3type==P3_DYNAMIC );
    db->xProfile(db->pProfileArg, p->aOp[p->nOp-1].p3, elapseTime);
  }
#endif

  sqlite3Error(p->db, rc, 0);
  p->rc = sqlite3ApiExit(p->db, p->rc);
end_of_step:
  assert( (rc&0xff)==rc );
  if( p->zSql && (rc&0xff)<SQLITE_ROW ){
    /* This behavior occurs if sqlite3_prepare_v2() was used to build
    ** the prepared statement.  Return error codes directly */
    sqlite3Error(p->db, p->rc, 0);
    return p->rc;
  }else{