root/third_party/sqlite/src/src/test_tclvar.c

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DEFINITIONS

This source file includes following definitions.
  1. tclvarConnect
  2. tclvarDisconnect
  3. tclvarOpen
  4. tclvarClose
  5. next2
  6. tclvarNext
  7. tclvarFilter
  8. tclvarColumn
  9. tclvarRowid
  10. tclvarEof
  11. tclvarBestIndex
  12. register_tclvar_module
  13. Sqlitetesttclvar_Init

/*
** 2006 June 13
**
** 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.
**
*************************************************************************
** Code for testing the virtual table interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** The emphasis of this file is a virtual table that provides
** access to TCL variables.
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

typedef struct tclvar_vtab tclvar_vtab;
typedef struct tclvar_cursor tclvar_cursor;

/* 
** A tclvar virtual-table object 
*/
struct tclvar_vtab {
  sqlite3_vtab base;
  Tcl_Interp *interp;
};

/* A tclvar cursor object */
struct tclvar_cursor {
  sqlite3_vtab_cursor base;

  Tcl_Obj *pList1;     /* Result of [info vars ?pattern?] */
  Tcl_Obj *pList2;     /* Result of [array names [lindex $pList1 $i1]] */
  int i1;              /* Current item in pList1 */
  int i2;              /* Current item (if any) in pList2 */
};

/* Methods for the tclvar module */
static int tclvarConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  tclvar_vtab *pVtab;
  static const char zSchema[] = 
     "CREATE TABLE whatever(name TEXT, arrayname TEXT, value TEXT)";
  pVtab = sqlite3MallocZero( sizeof(*pVtab) );
  if( pVtab==0 ) return SQLITE_NOMEM;
  *ppVtab = &pVtab->base;
  pVtab->interp = (Tcl_Interp *)pAux;
  sqlite3_declare_vtab(db, zSchema);
  return SQLITE_OK;
}
/* Note that for this virtual table, the xCreate and xConnect
** methods are identical. */

static int tclvarDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}
/* The xDisconnect and xDestroy methods are also the same */

/*
** Open a new tclvar cursor.
*/
static int tclvarOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  tclvar_cursor *pCur;
  pCur = sqlite3MallocZero(sizeof(tclvar_cursor));
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

/*
** Close a tclvar cursor.
*/
static int tclvarClose(sqlite3_vtab_cursor *cur){
  tclvar_cursor *pCur = (tclvar_cursor *)cur;
  if( pCur->pList1 ){
    Tcl_DecrRefCount(pCur->pList1);
  }
  if( pCur->pList2 ){
    Tcl_DecrRefCount(pCur->pList2);
  }
  sqlite3_free(pCur);
  return SQLITE_OK;
}

/*
** Returns 1 if data is ready, or 0 if not.
*/
static int next2(Tcl_Interp *interp, tclvar_cursor *pCur, Tcl_Obj *pObj){
  Tcl_Obj *p;

  if( pObj ){
    if( !pCur->pList2 ){
      p = Tcl_NewStringObj("array names", -1);
      Tcl_IncrRefCount(p);
      Tcl_ListObjAppendElement(0, p, pObj);
      Tcl_EvalObjEx(interp, p, TCL_EVAL_GLOBAL);
      Tcl_DecrRefCount(p);
      pCur->pList2 = Tcl_GetObjResult(interp);
      Tcl_IncrRefCount(pCur->pList2);
      assert( pCur->i2==0 );
    }else{
      int n = 0;
      pCur->i2++;
      Tcl_ListObjLength(0, pCur->pList2, &n);
      if( pCur->i2>=n ){
        Tcl_DecrRefCount(pCur->pList2);
        pCur->pList2 = 0;
        pCur->i2 = 0;
        return 0;
      }
    }
  }

  return 1;
}

static int tclvarNext(sqlite3_vtab_cursor *cur){
  Tcl_Obj *pObj;
  int n = 0;
  int ok = 0;

  tclvar_cursor *pCur = (tclvar_cursor *)cur;
  Tcl_Interp *interp = ((tclvar_vtab *)(cur->pVtab))->interp;

  Tcl_ListObjLength(0, pCur->pList1, &n);
  while( !ok && pCur->i1<n ){
    Tcl_ListObjIndex(0, pCur->pList1, pCur->i1, &pObj);
    ok = next2(interp, pCur, pObj);
    if( !ok ){
      pCur->i1++;
    }
  }

  return 0;
}

static int tclvarFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  tclvar_cursor *pCur = (tclvar_cursor *)pVtabCursor;
  Tcl_Interp *interp = ((tclvar_vtab *)(pVtabCursor->pVtab))->interp;

  Tcl_Obj *p = Tcl_NewStringObj("info vars", -1);
  Tcl_IncrRefCount(p);

  assert( argc==0 || argc==1 );
  if( argc==1 ){
    Tcl_Obj *pArg = Tcl_NewStringObj((char*)sqlite3_value_text(argv[0]), -1);
    Tcl_ListObjAppendElement(0, p, pArg);
  }
  Tcl_EvalObjEx(interp, p, TCL_EVAL_GLOBAL);
  if( pCur->pList1 ){
    Tcl_DecrRefCount(pCur->pList1);
  }
  if( pCur->pList2 ){
    Tcl_DecrRefCount(pCur->pList2);
    pCur->pList2 = 0;
  }
  pCur->i1 = 0;
  pCur->i2 = 0;
  pCur->pList1 = Tcl_GetObjResult(interp);
  Tcl_IncrRefCount(pCur->pList1);
  assert( pCur->i1==0 && pCur->i2==0 && pCur->pList2==0 );

  Tcl_DecrRefCount(p);
  return tclvarNext(pVtabCursor);
}

static int tclvarColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  Tcl_Obj *p1;
  Tcl_Obj *p2;
  const char *z1; 
  const char *z2 = "";
  tclvar_cursor *pCur = (tclvar_cursor*)cur;
  Tcl_Interp *interp = ((tclvar_vtab *)cur->pVtab)->interp;

  Tcl_ListObjIndex(interp, pCur->pList1, pCur->i1, &p1);
  Tcl_ListObjIndex(interp, pCur->pList2, pCur->i2, &p2);
  z1 = Tcl_GetString(p1);
  if( p2 ){
    z2 = Tcl_GetString(p2);
  }
  switch (i) {
    case 0: {
      sqlite3_result_text(ctx, z1, -1, SQLITE_TRANSIENT);
      break;
    }
    case 1: {
      sqlite3_result_text(ctx, z2, -1, SQLITE_TRANSIENT);
      break;
    }
    case 2: {
      Tcl_Obj *pVal = Tcl_GetVar2Ex(interp, z1, *z2?z2:0, TCL_GLOBAL_ONLY);
      sqlite3_result_text(ctx, Tcl_GetString(pVal), -1, SQLITE_TRANSIENT);
      break;
    }
  }
  return SQLITE_OK;
}

static int tclvarRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  *pRowid = 0;
  return SQLITE_OK;
}

static int tclvarEof(sqlite3_vtab_cursor *cur){
  tclvar_cursor *pCur = (tclvar_cursor*)cur;
  return (pCur->pList2?0:1);
}

static int tclvarBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int ii;

  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
    struct sqlite3_index_constraint const *pCons = &pIdxInfo->aConstraint[ii];
    if( pCons->iColumn==0 && pCons->usable
           && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      struct sqlite3_index_constraint_usage *pUsage;
      pUsage = &pIdxInfo->aConstraintUsage[ii];
      pUsage->omit = 0;
      pUsage->argvIndex = 1;
      return SQLITE_OK;
    }
  }

  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
    struct sqlite3_index_constraint const *pCons = &pIdxInfo->aConstraint[ii];
    if( pCons->iColumn==0 && pCons->usable
           && pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
      struct sqlite3_index_constraint_usage *pUsage;
      pUsage = &pIdxInfo->aConstraintUsage[ii];
      pUsage->omit = 1;
      pUsage->argvIndex = 1;
      return SQLITE_OK;
    }
  }

  return SQLITE_OK;
}

/*
** A virtual table module that provides read-only access to a
** Tcl global variable namespace.
*/
static sqlite3_module tclvarModule = {
  0,                         /* iVersion */
  tclvarConnect,
  tclvarConnect,
  tclvarBestIndex,
  tclvarDisconnect, 
  tclvarDisconnect,
  tclvarOpen,                  /* xOpen - open a cursor */
  tclvarClose,                 /* xClose - close a cursor */
  tclvarFilter,                /* xFilter - configure scan constraints */
  tclvarNext,                  /* xNext - advance a cursor */
  tclvarEof,                   /* xEof - check for end of scan */
  tclvarColumn,                /* xColumn - read data */
  tclvarRowid,                 /* xRowid - read data */
  0,                           /* xUpdate */
  0,                           /* xBegin */
  0,                           /* xSync */
  0,                           /* xCommit */
  0,                           /* xRollback */
  0,                           /* xFindMethod */
  0,                           /* xRename */
};

/*
** Decode a pointer to an sqlite3 object.
*/
extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);

/*
** Register the echo virtual table module.
*/
static int register_tclvar_module(
  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3 *db;
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3_create_module(db, "tclvar", &tclvarModule, (void *)interp);
#endif
  return TCL_OK;
}

#endif


/*
** Register commands with the TCL interpreter.
*/
int Sqlitetesttclvar_Init(Tcl_Interp *interp){
#ifndef SQLITE_OMIT_VIRTUALTABLE
  static struct {
     char *zName;
     Tcl_ObjCmdProc *xProc;
     void *clientData;
  } aObjCmd[] = {
     { "register_tclvar_module",   register_tclvar_module, 0 },
  };
  int i;
  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 
        aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
  }
#endif
  return TCL_OK;
}

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