tclsqlite.c

sqlite数据库管理系统开放源码

/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** A TCL Interface to SQLite
**
** $Id: tclsqlite.c,v 1.59.2.1 2004/06/19 11:57:40 drh Exp $
*/
#ifndef NO_TCL     /* Omit this whole file if TCL is unavailable */

#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>

/*
** If TCL uses UTF-8 and SQLite is configured to use iso8859, then we
** have to do a translation when going between the two.  Set the 
** UTF_TRANSLATION_NEEDED macro to indicate that we need to do
** this translation.  
*/
#if defined(TCL_UTF_MAX) && !defined(SQLITE_UTF8)
# define UTF_TRANSLATION_NEEDED 1
#endif

/*
** New SQL functions can be created as TCL scripts.  Each such function
** is described by an instance of the following structure.
*/
typedef struct SqlFunc SqlFunc;
struct SqlFunc {
  Tcl_Interp *interp;   /* The TCL interpret to execute the function */
  char *zScript;        /* The script to be run */
  SqlFunc *pNext;       /* Next function on the list of them all */
};

/*
** There is one instance of this structure for each SQLite database
** that has been opened by the SQLite TCL interface.
*/
typedef struct SqliteDb SqliteDb;
struct SqliteDb {
  sqlite *db;           /* The "real" database structure */
  Tcl_Interp *interp;   /* The interpreter used for this database */
  char *zBusy;          /* The busy callback routine */
  char *zCommit;        /* The commit hook callback routine */
  char *zTrace;         /* The trace callback routine */
  char *zProgress;      /* The progress callback routine */
  char *zAuth;          /* The authorization callback routine */
  SqlFunc *pFunc;       /* List of SQL functions */
  int rc;               /* Return code of most recent sqlite_exec() */
};

/*
** An instance of this structure passes information thru the sqlite
** logic from the original TCL command into the callback routine.
*/
typedef struct CallbackData CallbackData;
struct CallbackData {
  Tcl_Interp *interp;       /* The TCL interpreter */
  char *zArray;             /* The array into which data is written */
  Tcl_Obj *pCode;           /* The code to execute for each row */
  int once;                 /* Set for first callback only */
  int tcl_rc;               /* Return code from TCL script */
  int nColName;             /* Number of entries in the azColName[] array */
  char **azColName;         /* Column names translated to UTF-8 */
};

#ifdef UTF_TRANSLATION_NEEDED
/*
** Called for each row of the result.
**
** This version is used when TCL expects UTF-8 data but the database
** uses the ISO8859 format.  A translation must occur from ISO8859 into
** UTF-8.
*/
static int DbEvalCallback(
  void *clientData,      /* An instance of CallbackData */
  int nCol,              /* Number of columns in the result */
  char ** azCol,         /* Data for each column */
  char ** azN            /* Name for each column */
){
  CallbackData *cbData = (CallbackData*)clientData;
  int i, rc;
  Tcl_DString dCol;
  Tcl_DStringInit(&dCol);
  if( cbData->azColName==0 ){
    assert( cbData->once );
    cbData->once = 0;
    if( cbData->zArray[0] ){
      Tcl_SetVar2(cbData->interp, cbData->zArray, "*", "", 0);
    }
    cbData->azColName = malloc( nCol*sizeof(char*) );
    if( cbData->azColName==0 ){ return 1; }
    cbData->nColName = nCol;
    for(i=0; i<nCol; i++){
      Tcl_ExternalToUtfDString(NULL, azN[i], -1, &dCol);
      cbData->azColName[i] = malloc( Tcl_DStringLength(&dCol) + 1 );
      if( cbData->azColName[i] ){
        strcpy(cbData->azColName[i], Tcl_DStringValue(&dCol));
      }else{
        return 1;
      }
      if( cbData->zArray[0] ){
        Tcl_SetVar2(cbData->interp, cbData->zArray, "*",
             Tcl_DStringValue(&dCol), TCL_LIST_ELEMENT|TCL_APPEND_VALUE);
        if( azN[nCol]!=0 ){
          Tcl_DString dType;
          Tcl_DStringInit(&dType);
          Tcl_DStringAppend(&dType, "typeof:", -1);
          Tcl_DStringAppend(&dType, Tcl_DStringValue(&dCol), -1);
          Tcl_DStringFree(&dCol);
          Tcl_ExternalToUtfDString(NULL, azN[i+nCol], -1, &dCol);
          Tcl_SetVar2(cbData->interp, cbData->zArray, 
               Tcl_DStringValue(&dType), Tcl_DStringValue(&dCol),
               TCL_LIST_ELEMENT|TCL_APPEND_VALUE);
          Tcl_DStringFree(&dType);
        }
      }
      
      Tcl_DStringFree(&dCol);
    }
  }
  if( azCol!=0 ){
    if( cbData->zArray[0] ){
      for(i=0; i<nCol; i++){
        char *z = azCol[i];
        if( z==0 ) z = "";
        Tcl_DStringInit(&dCol);
        Tcl_ExternalToUtfDString(NULL, z, -1, &dCol);
        Tcl_SetVar2(cbData->interp, cbData->zArray, cbData->azColName[i], 
              Tcl_DStringValue(&dCol), 0);
        Tcl_DStringFree(&dCol);
      }
    }else{
      for(i=0; i<nCol; i++){
        char *z = azCol[i];
        if( z==0 ) z = "";
        Tcl_DStringInit(&dCol);
        Tcl_ExternalToUtfDString(NULL, z, -1, &dCol);
        Tcl_SetVar(cbData->interp, cbData->azColName[i],
                   Tcl_DStringValue(&dCol), 0);
        Tcl_DStringFree(&dCol);
      }
    }
  }
  rc = Tcl_EvalObj(cbData->interp, cbData->pCode);
  if( rc==TCL_CONTINUE ) rc = TCL_OK;
  cbData->tcl_rc = rc;
  return rc!=TCL_OK;
}
#endif /* UTF_TRANSLATION_NEEDED */

#ifndef UTF_TRANSLATION_NEEDED
/*
** Called for each row of the result.
**
** This version is used when either of the following is true:
**
**    (1) This version of TCL uses UTF-8 and the data in the
**        SQLite database is already in the UTF-8 format.
**
**    (2) This version of TCL uses ISO8859 and the data in the
**        SQLite database is already in the ISO8859 format.
*/
static int DbEvalCallback(
  void *clientData,      /* An instance of CallbackData */
  int nCol,              /* Number of columns in the result */
  char ** azCol,         /* Data for each column */
  char ** azN            /* Name for each column */
){
  CallbackData *cbData = (CallbackData*)clientData;
  int i, rc;
  if( azCol==0 || (cbData->once && cbData->zArray[0]) ){
    Tcl_SetVar2(cbData->interp, cbData->zArray, "*", "", 0);
    for(i=0; i<nCol; i++){
      Tcl_SetVar2(cbData->interp, cbData->zArray, "*", azN[i],
         TCL_LIST_ELEMENT|TCL_APPEND_VALUE);
      if( azN[nCol] ){
        char *z = sqlite_mprintf("typeof:%s", azN[i]);
        Tcl_SetVar2(cbData->interp, cbData->zArray, z, azN[i+nCol],
           TCL_LIST_ELEMENT|TCL_APPEND_VALUE);
        sqlite_freemem(z);
      }
    }
    cbData->once = 0;
  }
  if( azCol!=0 ){
    if( cbData->zArray[0] ){
      for(i=0; i<nCol; i++){
        char *z = azCol[i];
        if( z==0 ) z = "";
        Tcl_SetVar2(cbData->interp, cbData->zArray, azN[i], z, 0);
      }
    }else{
      for(i=0; i<nCol; i++){
        char *z = azCol[i];
        if( z==0 ) z = "";
        Tcl_SetVar(cbData->interp, azN[i], z, 0);
      }
    }
  }
  rc = Tcl_EvalObj(cbData->interp, cbData->pCode);
  if( rc==TCL_CONTINUE ) rc = TCL_OK;
  cbData->tcl_rc = rc;
  return rc!=TCL_OK;
}
#endif

/*
** This is an alternative callback for database queries.  Instead
** of invoking a TCL script to handle the result, this callback just
** appends each column of the result to a list.  After the query
** is complete, the list is returned.
*/
static int DbEvalCallback2(
  void *clientData,      /* An instance of CallbackData */
  int nCol,              /* Number of columns in the result */
  char ** azCol,         /* Data for each column */
  char ** azN            /* Name for each column */
){
  Tcl_Obj *pList = (Tcl_Obj*)clientData;
  int i;
  if( azCol==0 ) return 0;
  for(i=0; i<nCol; i++){
    Tcl_Obj *pElem;
    if( azCol[i] && *azCol[i] ){
#ifdef UTF_TRANSLATION_NEEDED
      Tcl_DString dCol;
      Tcl_DStringInit(&dCol);
      Tcl_ExternalToUtfDString(NULL, azCol[i], -1, &dCol);
      pElem = Tcl_NewStringObj(Tcl_DStringValue(&dCol), -1);
      Tcl_DStringFree(&dCol);
#else
      pElem = Tcl_NewStringObj(azCol[i], -1);
#endif
    }else{
      pElem = Tcl_NewObj();
    }
    Tcl_ListObjAppendElement(0, pList, pElem);
  }
  return 0;
}

/*
** This is a second alternative callback for database queries.  A the
** first column of the first row of the result is made the TCL result.
*/
static int DbEvalCallback3(
  void *clientData,      /* An instance of CallbackData */
  int nCol,              /* Number of columns in the result */
  char ** azCol,         /* Data for each column */
  char ** azN            /* Name for each column */
){
  Tcl_Interp *interp = (Tcl_Interp*)clientData;
  Tcl_Obj *pElem;
  if( azCol==0 ) return 1;
  if( nCol==0 ) return 1;
#ifdef UTF_TRANSLATION_NEEDED
  {
    Tcl_DString dCol;
    Tcl_DStringInit(&dCol);
    Tcl_ExternalToUtfDString(NULL, azCol[0], -1, &dCol);
    pElem = Tcl_NewStringObj(Tcl_DStringValue(&dCol), -1);
    Tcl_DStringFree(&dCol);
  }
#else
  pElem = Tcl_NewStringObj(azCol[0], -1);
#endif
  Tcl_SetObjResult(interp, pElem);
  return 1;
}

/*
** Called when the command is deleted.
*/
static void DbDeleteCmd(void *db){
  SqliteDb *pDb = (SqliteDb*)db;
  sqlite_close(pDb->db);
  while( pDb->pFunc ){
    SqlFunc *pFunc = pDb->pFunc;
    pDb->pFunc = pFunc->pNext;
    Tcl_Free((char*)pFunc);
  }
  if( pDb->zBusy ){
    Tcl_Free(pDb->zBusy);
  }
  if( pDb->zTrace ){
    Tcl_Free(pDb->zTrace);
  }
  if( pDb->zAuth ){
    Tcl_Free(pDb->zAuth);
  }
  Tcl_Free((char*)pDb);
}

/*
** This routine is called when a database file is locked while trying
** to execute SQL.
*/
static int DbBusyHandler(void *cd, const char *zTable, int nTries){
  SqliteDb *pDb = (SqliteDb*)cd;
  int rc;
  char zVal[30];
  char *zCmd;
  Tcl_DString cmd;

  Tcl_DStringInit(&cmd);
  Tcl_DStringAppend(&cmd, pDb->zBusy, -1);
  Tcl_DStringAppendElement(&cmd, zTable);
  sprintf(zVal, " %d", nTries);
  Tcl_DStringAppend(&cmd, zVal, -1);
  zCmd = Tcl_DStringValue(&cmd);
  rc = Tcl_Eval(pDb->interp, zCmd);
  Tcl_DStringFree(&cmd);
  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
    return 0;
  }
  return 1;
}

/*
** This routine is invoked as the 'progress callback' for the database.
*/
static int DbProgressHandler(void *cd){
  SqliteDb *pDb = (SqliteDb*)cd;
  int rc;

  assert( pDb->zProgress );
  rc = Tcl_Eval(pDb->interp, pDb->zProgress);
  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
    return 1;
  }
  return 0;
}

/*
** This routine is called by the SQLite trace handler whenever a new
** block of SQL is executed.  The TCL script in pDb->zTrace is executed.
*/
static void DbTraceHandler(void *cd, const char *zSql){
  SqliteDb *pDb = (SqliteDb*)cd;
  Tcl_DString str;

  Tcl_DStringInit(&str);
  Tcl_DStringAppend(&str, pDb->zTrace, -1);
  Tcl_DStringAppendElement(&str, zSql);
  Tcl_Eval(pDb->interp, Tcl_DStringValue(&str));
  Tcl_DStringFree(&str);
  Tcl_ResetResult(pDb->interp);
}

/*
** This routine is called when a transaction is committed.  The
** TCL script in pDb->zCommit is executed.  If it returns non-zero or
** if it throws an exception, the transaction is rolled back instead
** of being committed.
*/
static int DbCommitHandler(void *cd){
  SqliteDb *pDb = (SqliteDb*)cd;
  int rc;

  rc = Tcl_Eval(pDb->interp, pDb->zCommit);
  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
    return 1;
  }
  return 0;
}

/*
** This routine is called to evaluate an SQL function implemented
** using TCL script.
*/
static void tclSqlFunc(sqlite_func *context, int argc, const char **argv){
  SqlFunc *p = sqlite_user_data(context);
  Tcl_DString cmd;
  int i;
  int rc;

  Tcl_DStringInit(&cmd);
  Tcl_DStringAppend(&cmd, p->zScript, -1);
  for(i=0; i<argc; i++){
    Tcl_DStringAppendElement(&cmd, argv[i] ? argv[i] : "");
  }
  rc = Tcl_Eval(p->interp, Tcl_DStringValue(&cmd));
  if( rc ){
    sqlite_set_result_error(context, Tcl_GetStringResult(p->interp), -1); 
  }else{
    sqlite_set_result_string(context, Tcl_GetStringResult(p->interp), -1);
  }
}
#ifndef SQLITE_OMIT_AUTHORIZATION
/*
** This is the authentication function.  It appends the authentication
** type code and the two arguments to zCmd[] then invokes the result
** on the interpreter.  The reply is examined to determine if the
** authentication fails or succeeds.
*/
static int auth_callback(
  void *pArg,
  int code,
  const char *zArg1,
  const char *zArg2,
  const char *zArg3,
  const char *zArg4
){
  char *zCode;
  Tcl_DString str;
  int rc;
  const char *zReply;
  SqliteDb *pDb = (SqliteDb*)pArg;

  switch( code ){
    case SQLITE_COPY              : zCode="SQLITE_COPY"; break;
    case SQLITE_CREATE_INDEX      : zCode="SQLITE_CREATE_INDEX"; break;
    case SQLITE_CREATE_TABLE      : zCode="SQLITE_CREATE_TABLE"; break;
    case SQLITE_CREATE_TEMP_INDEX : zCode="SQLITE_CREATE_TEMP_INDEX"; break;
    case SQLITE_CREATE_TEMP_TABLE : zCode="SQLITE_CREATE_TEMP_TABLE"; break;
    case SQLITE_CREATE_TEMP_TRIGGER: zCode="SQLITE_CREATE_TEMP_TRIGGER"; break;
    case SQLITE_CREATE_TEMP_VIEW  : zCode="SQLITE_CREATE_TEMP_VIEW"; break;
    case SQLITE_CREATE_TRIGGER    : zCode="SQLITE_CREATE_TRIGGER"; break;
    case SQLITE_CREATE_VIEW       : zCode="SQLITE_CREATE_VIEW"; break;
    case SQLITE_DELETE            : zCode="SQLITE_DELETE"; break;
    case SQLITE_DROP_INDEX        : zCode="SQLITE_DROP_INDEX"; break;