SQLite

/*
** 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 1.127 2005/06/26 17:55:34 drh Exp $
*/
#ifndef NO_TCL     /* Omit this whole file if TCL is unavailable */

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

#define NUM_PREPARED_STMTS 10
#define MAX_PREPARED_STMTS 100

/*
** 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 

/*
** 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 */
  Tcl_Obj *pScript;     /* The Tcl_Obj representation of the script */
  int useEvalObjv;      /* True if it is safe to use Tcl_EvalObjv */
  char *zName;          /* Name of this function */
  SqlFunc *pNext;       /* Next function on the list of them all */
};

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

/*
** Prepared statements are cached for faster execution.  Each prepared
** statement is described by an instance of the following structure.
*/
typedef struct SqlPreparedStmt SqlPreparedStmt;

/*
** 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 {
  sqlite3 *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 */
  char *zNull;               /* Text to substitute for an SQL NULL value */
  SqlFunc *pFunc;            /* List of SQL functions */
  SqlCollate *pCollate;      /* List of SQL collation functions */
  int rc;                    /* Return code of most recent sqlite3_exec() */
  Tcl_Obj *pCollateNeeded;   /* Collation needed script */
  SqlPreparedStmt *stmtList; /* List of prepared statements*/
  SqlPreparedStmt *stmtLast; /* Last statement in the list */
  int maxStmt;               /* The next maximum number of stmtList */
  int nStmt;                 /* Number of statements in stmtList */
};

/*
** Look at the script prefix in pCmd.  We will be executing this script
** after first appending one or more arguments.  This routine analyzes
** the script to see if it is safe to use Tcl_EvalObjv() on the script
** rather than the more general Tcl_EvalEx().  Tcl_EvalObjv() is much
** faster.
**
** Scripts that are safe to use with Tcl_EvalObjv() consists of a
** command name followed by zero or more arguments with no [...] or $
** or {...} or ; to be seen anywhere.  Most callback scripts consist
** of just a single procedure name and they meet this requirement.
*/
static int safeToUseEvalObjv(Tcl_Interp *interp, Tcl_Obj *pCmd){
  /* We could try to do something with Tcl_Parse().  But we will instead
  ** just do a search for forbidden characters.  If any of the forbidden
  ** characters appear in pCmd, we will report the string as unsafe.
  */
  const char *z;
  int n;
  z = Tcl_GetStringFromObj(pCmd, &n);
  while( n-- > 0 ){
    int c = *(z++);
    if( c=='$' || c=='[' || c==';' ) return 0;
  }
  return 1;
}

/*
** Find an SqlFunc structure with the given name.  Or create a new
** one if an existing one cannot be found.  Return a pointer to the
** structure.
*/
static SqlFunc *findSqlFunc(SqliteDb *pDb, const char *zName){
  SqlFunc *p, *pNew;
  int i;
  pNew = (SqlFunc*)Tcl_Alloc( sizeof(*pNew) + strlen(zName) + 1 );
  pNew->zName = (char*)&pNew[1];
  for(i=0; zName[i]; i++){ pNew->zName[i] = tolower(zName[i]); }
  pNew->zName[i] = 0;
  for(p=pDb->pFunc; p; p=p->pNext){ 
    if( strcmp(p->zName, pNew->zName)==0 ){
      Tcl_Free((char*)pNew);
      return p;
    }
  }
  pNew->interp = pDb->interp;
  pNew->pScript = 0;
  pNew->pNext = pDb->pFunc;
  pDb->pFunc = pNew;
  return pNew;
}

/*
** Finalize and free a list of prepared statements
*/
static void flushStmtCache( SqliteDb *pDb ){
  SqlPreparedStmt *pPreStmt;

static void DbDeleteCmd(void *db){
  SqliteDb *pDb = (SqliteDb*)db;
  flushStmtCache(pDb);
  sqlite3_close(pDb->db);
  while( pDb->pFunc ){
    SqlFunc *pFunc = pDb->pFunc;
    pDb->pFunc = pFunc->pNext;
    Tcl_DecrRefCount(pFunc->pScript);
    Tcl_Free((char*)pFunc);
  }
  while( pDb->pCollate ){
    SqlCollate *pCollate = pDb->pCollate;
    pDb->pCollate = pCollate->pNext;
    Tcl_Free((char*)pCollate);
  }

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





  sprintf(zVal, "%d", nTries);


  rc = Tcl_VarEval(pDb->interp, pDb->zBusy, " ", zVal, (char*)0);

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

/*

  SqlCollate *p = (SqlCollate *)pCtx;
  Tcl_Obj *pCmd;

  pCmd = Tcl_NewStringObj(p->zScript, -1);
  Tcl_IncrRefCount(pCmd);
  Tcl_ListObjAppendElement(p->interp, pCmd, Tcl_NewStringObj(zA, nA));
  Tcl_ListObjAppendElement(p->interp, pCmd, Tcl_NewStringObj(zB, nB));
  Tcl_EvalObjEx(p->interp, pCmd, TCL_EVAL_DIRECT);
  Tcl_DecrRefCount(pCmd);
  return (atoi(Tcl_GetStringResult(p->interp)));
}

/*
** This routine is called to evaluate an SQL function implemented
** using TCL script.
*/
static void tclSqlFunc(sqlite3_context *context, int argc, sqlite3_value**argv){
  SqlFunc *p = sqlite3_user_data(context);
  Tcl_Obj *pCmd;
  int i;
  int rc;

  if( argc==0 ){
    /* If there are no arguments to the function, call Tcl_EvalObjEx on the
    ** script object directly.  This allows the TCL compiler to generate
    ** bytecode for the command on the first invocation and thus make
    ** subsequent invocations much faster. */
    pCmd = p->pScript;
    Tcl_IncrRefCount(pCmd);
    rc = Tcl_EvalObjEx(p->interp, pCmd, 0);
    Tcl_DecrRefCount(pCmd);
  }else{
    /* If there are arguments to the function, make a shallow copy of the
    ** script object, lappend the arguments, then evaluate the copy.
    **
    ** By "shallow" copy, we mean a only the outer list Tcl_Obj is duplicated.
    ** The new Tcl_Obj contains pointers to the original list elements. 
    ** That way, when Tcl_EvalObjv() is run and shimmers the first element
    ** of the list to tclCmdNameType, that alternate representation will
    ** be preserved and reused on the next invocation.
    */
    Tcl_Obj **aArg;
    int nArg;
    if( Tcl_ListObjGetElements(p->interp, p->pScript, &nArg, &aArg) ){
      sqlite3_result_error(context, Tcl_GetStringResult(p->interp), -1); 
      return;
    }     
    pCmd = Tcl_NewListObj(nArg, aArg);
    Tcl_IncrRefCount(pCmd);
    for(i=0; i<argc; i++){
      sqlite3_value *pIn = argv[i];
      Tcl_Obj *pVal;
            
      /* Set pVal to contain the i'th column of this row. */
      switch( sqlite3_value_type(pIn) ){
        case SQLITE_BLOB: {
          int bytes = sqlite3_value_bytes(pIn);
          pVal = Tcl_NewByteArrayObj(sqlite3_value_blob(pIn), bytes);
          break;
        }
        case SQLITE_INTEGER: {
          sqlite_int64 v = sqlite3_value_int64(pIn);
          if( v>=-2147483647 && v<=2147483647 ){
            pVal = Tcl_NewIntObj(v);
          }else{
            pVal = Tcl_NewWideIntObj(v);
          }
          break;
        }
        case SQLITE_FLOAT: {
          double r = sqlite3_value_double(pIn);
          pVal = Tcl_NewDoubleObj(r);
          break;
        }
        case SQLITE_NULL: {
          pVal = Tcl_NewStringObj("", 0);
          break;
        }
        default: {
          int bytes = sqlite3_value_bytes(pIn);
          pVal = Tcl_NewStringObj(sqlite3_value_text(pIn), bytes);
          break;
        }
      }
      rc = Tcl_ListObjAppendElement(p->interp, pCmd, pVal);
      if( rc ){
        Tcl_DecrRefCount(pCmd);
        sqlite3_result_error(context, Tcl_GetStringResult(p->interp), -1); 
        return;
      }
    }
    if( !p->useEvalObjv ){
      /* Tcl_EvalObjEx() will automatically call Tcl_EvalObjv() if pCmd
      ** is a list without a string representation.  To prevent this from
      ** happening, make sure pCmd has a valid string representation */
      Tcl_GetString(pCmd);
    }
    rc = Tcl_EvalObjEx(p->interp, pCmd, TCL_EVAL_DIRECT);
    Tcl_DecrRefCount(pCmd);
  }

  if( rc && rc!=TCL_RETURN ){
    sqlite3_result_error(context, Tcl_GetStringResult(p->interp), -1); 
  }else{
    Tcl_Obj *pVar = Tcl_GetObjResult(p->interp);
    int n;
    u8 *data;
    char *zType = pVar->typePtr ? pVar->typePtr->name : "";
    char c = zType[0];
    if( c=='b' && strcmp(zType,"bytearray")==0 && pVar->bytes==0 ){
      /* Only return a BLOB type if the Tcl variable is a bytearray and
      ** has no string representation. */
      data = Tcl_GetByteArrayFromObj(pVar, &n);
      sqlite3_result_blob(context, data, n, SQLITE_TRANSIENT);
    }else if( (c=='b' && strcmp(zType,"boolean")==0) ||
          (c=='i' && strcmp(zType,"int")==0) ){
      Tcl_GetIntFromObj(0, pVar, &n);
      sqlite3_result_int(context, n);

  **     $db function NAME SCRIPT
  **
  ** Create a new SQL function called NAME.  Whenever that function is
  ** called, invoke SCRIPT to evaluate the function.
  */
  case DB_FUNCTION: {
    SqlFunc *pFunc;
    Tcl_Obj *pScript;
    char *zName;


    if( objc!=4 ){
      Tcl_WrongNumArgs(interp, 2, objv, "NAME SCRIPT");
      return TCL_ERROR;
    }
    zName = Tcl_GetStringFromObj(objv[2], 0);
    pScript = objv[3];
    pFunc = findSqlFunc(pDb, zName);
    if( pFunc==0 ) return TCL_ERROR;
    if( pFunc->pScript ){
      Tcl_DecrRefCount(pFunc->pScript);
    }
    pFunc->pScript = pScript;

    Tcl_IncrRefCount(pScript);
    pFunc->useEvalObjv = safeToUseEvalObjv(interp, pScript);
    rc = sqlite3_create_function(pDb->db, zName, -1, SQLITE_UTF8,
        pFunc, tclSqlFunc, 0, 0);
    if( rc!=SQLITE_OK ){
      rc = TCL_ERROR;
      Tcl_SetResult(interp, (char *)sqlite3_errmsg(pDb->db), TCL_VOLATILE);
    }else{
      /* Must flush any cached statements */

}
sqlite_int64 sqlite3_column_int64(sqlite3_stmt *pStmt, int i){
  return sqlite3_value_int64( columnMem(pStmt,i) );
}
const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int i){
  return sqlite3_value_text( columnMem(pStmt,i) );
}
#if 0
sqlite3_value *sqlite3_column_value(sqlite3_stmt *pStmt, int i){
  return columnMem(pStmt, i);
}
#endif
#ifndef SQLITE_OMIT_UTF16
const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
  return sqlite3_value_text16( columnMem(pStmt,i) );
}
#endif /* SQLITE_OMIT_UTF16 */
int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
  return sqlite3_value_type( columnMem(pStmt,i) );

# This file implements regression tests for TCL interface to the
# SQLite library. 
#
# Actually, all tests are based on the TCL interface, so the main
# interface is pretty well tested.  This file contains some addition
# tests for fringe issues that the main test suite does not cover.
#
# $Id: tclsqlite.test,v 1.41 2005/06/26 17:55:34 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Check the error messages generated by tclsqlite
#
if {[sqlite3 -has-codec]} {

  db function ret_dbl {return [expr {[clock seconds]*0.5}]}
  execsql {SELECT typeof(ret_dbl())}
} {real}
do_test tcl-9.3 {
  db function ret_int {clock seconds}
  execsql {SELECT typeof(ret_int())}
} {integer}

# Recursive calls to the same user-defined function
#
do_test tcl-9.10 {
  proc userfunc_r1 {n} {
    if {$n<=0} {return 0}
    set nm1 [expr {$n-1}]
    return [expr {[db eval {SELECT r1($nm1)}]+$n}]
  }
  db function r1 userfunc_r1
  execsql {SELECT r1(10)}
} {55}
do_test tcl-9.11 {
  execsql {SELECT r1(100)}
} {5050}


finish_test