src/test_schema.c

   1 /*
   2 ** 2006 June 10
   3 **
   4 ** The author disclaims copyright to this source code.  In place of
   5 ** a legal notice, here is a blessing:
   6 **
   7 **    May you do good and not evil.
   8 **    May you find forgiveness for yourself and forgive others.
   9 **    May you share freely, never taking more than you give.
  10 **
  11 *************************************************************************
  12 ** Code for testing the virtual table interfaces.  This code
  13 ** is not included in the SQLite library.  It is used for automated
  14 ** testing of the SQLite library.
  15 */
  16
  17 /* The code in this file defines a sqlite3 virtual-table module that
  18 ** provides a read-only view of the current database schema. There is one
  19 ** row in the schema table for each column in the database schema.
  20 */
  21 #define SCHEMA \
  22 "CREATE TABLE x("                                                            \
  23   "database,"          /* Name of database (i.e. main, temp etc.) */         \
  24   "tablename,"         /* Name of table */                                   \
  25   "cid,"               /* Column number (from left-to-right, 0 upward) */    \
  26   "name,"              /* Column name */                                     \
  27   "type,"              /* Specified type (i.e. VARCHAR(32)) */               \
  28   "not_null,"          /* Boolean. True if NOT NULL was specified */         \
  29   "dflt_value,"        /* Default value for this column */                   \
  30   "pk"                 /* True if this column is part of the primary key */  \
  31 ")"
  32
  33 /* If SQLITE_TEST is defined this code is preprocessed for use as part
  34 ** of the sqlite test binary "testfixture". Otherwise it is preprocessed
  35 ** to be compiled into an sqlite dynamic extension.
  36 */
  37 #ifdef SQLITE_TEST
  38   #include "sqliteInt.h"
  39   #include "tcl.h"
  40 #else
  41   #include "sqlite3ext.h"
  42   SQLITE_EXTENSION_INIT1
  43 #endif
  44
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <assert.h>
  48
  49 typedef struct schema_vtab schema_vtab;
  50 typedef struct schema_cursor schema_cursor;
  51
  52 /* A schema table object */
  53 struct schema_vtab {
  54   sqlite3_vtab base;
  55   sqlite3 *db;
  56 };
  57
  58 /* A schema table cursor object */
  59 struct schema_cursor {
  60   sqlite3_vtab_cursor base;
  61   sqlite3_stmt *pDbList;
  62   sqlite3_stmt *pTableList;
  63   sqlite3_stmt *pColumnList;
  64   int rowid;
  65 };
  66
  67 /*
  68 ** None of this works unless we have virtual tables.
  69 */
  70 #ifndef SQLITE_OMIT_VIRTUALTABLE
  71
  72 /*
  73 ** Table destructor for the schema module.
  74 */
  75 static int schemaDestroy(sqlite3_vtab *pVtab){
  76   sqlite3_free(pVtab);
  77   return 0;
  78 }
  79
  80 /*
  81 ** Table constructor for the schema module.
  82 */
  83 static int schemaCreate(
  84   sqlite3 *db,
  85   void *pAux,
  86   int argc, const char *const*argv,
  87   sqlite3_vtab **ppVtab,
  88   char **pzErr
  89 ){
  90   int rc = SQLITE_NOMEM;
  91   schema_vtab *pVtab = sqlite3_malloc(sizeof(schema_vtab));
  92   if( pVtab ){
  93     memset(pVtab, 0, sizeof(schema_vtab));
  94     pVtab->db = db;
  95 #ifndef SQLITE_OMIT_VIRTUALTABLE
  96     rc = sqlite3_declare_vtab(db, SCHEMA);
  97 #endif
  98   }
  99   *ppVtab = (sqlite3_vtab *)pVtab;
 100   return rc;
 101 }
 102
 103 /*
 104 ** Open a new cursor on the schema table.
 105 */
 106 static int schemaOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
 107   int rc = SQLITE_NOMEM;
 108   schema_cursor *pCur;
 109   pCur = sqlite3_malloc(sizeof(schema_cursor));
 110   if( pCur ){
 111     memset(pCur, 0, sizeof(schema_cursor));
 112     *ppCursor = (sqlite3_vtab_cursor *)pCur;
 113     rc = SQLITE_OK;
 114   }
 115   return rc;
 116 }
 117
 118 /*
 119 ** Close a schema table cursor.
 120 */
 121 static int schemaClose(sqlite3_vtab_cursor *cur){
 122   schema_cursor *pCur = (schema_cursor *)cur;
 123   sqlite3_finalize(pCur->pDbList);
 124   sqlite3_finalize(pCur->pTableList);
 125   sqlite3_finalize(pCur->pColumnList);
 126   sqlite3_free(pCur);
 127   return SQLITE_OK;
 128 }
 129
 130 /*
 131 ** Retrieve a column of data.
 132 */
 133 static int schemaColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
 134   schema_cursor *pCur = (schema_cursor *)cur;
 135   switch( i ){
 136     case 0:
 137       sqlite3_result_value(ctx, sqlite3_column_value(pCur->pDbList, 1));
 138       break;
 139     case 1:
 140       sqlite3_result_value(ctx, sqlite3_column_value(pCur->pTableList, 0));
 141       break;
 142     default:
 143       sqlite3_result_value(ctx, sqlite3_column_value(pCur->pColumnList, i-2));
 144       break;
 145   }
 146   return SQLITE_OK;
 147 }
 148
 149 /*
 150 ** Retrieve the current rowid.
 151 */
 152 static int schemaRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
 153   schema_cursor *pCur = (schema_cursor *)cur;
 154   *pRowid = pCur->rowid;
 155   return SQLITE_OK;
 156 }
 157
 158 static int finalize(sqlite3_stmt **ppStmt){
 159   int rc = sqlite3_finalize(*ppStmt);
 160   *ppStmt = 0;
 161   return rc;
 162 }
 163
 164 static int schemaEof(sqlite3_vtab_cursor *cur){
 165   schema_cursor *pCur = (schema_cursor *)cur;
 166   return (pCur->pDbList ? 0 : 1);
 167 }
 168
 169 /*
 170 ** Advance the cursor to the next row.
 171 */
 172 static int schemaNext(sqlite3_vtab_cursor *cur){
 173   int rc = SQLITE_OK;
 174   schema_cursor *pCur = (schema_cursor *)cur;
 175   schema_vtab *pVtab = (schema_vtab *)(cur->pVtab);
 176   char *zSql = 0;
 177
 178   while( !pCur->pColumnList || SQLITE_ROW!=sqlite3_step(pCur->pColumnList) ){
 179     if( SQLITE_OK!=(rc = finalize(&pCur->pColumnList)) ) goto next_exit;
 180
 181     while( !pCur->pTableList || SQLITE_ROW!=sqlite3_step(pCur->pTableList) ){
 182       if( SQLITE_OK!=(rc = finalize(&pCur->pTableList)) ) goto next_exit;
 183
 184       assert(pCur->pDbList);
 185       while( SQLITE_ROW!=sqlite3_step(pCur->pDbList) ){
 186         rc = finalize(&pCur->pDbList);
 187         goto next_exit;
 188       }
 189
 190       /* Set zSql to the SQL to pull the list of tables from the
 191       ** sqlite_master (or sqlite_temp_master) table of the database
 192       ** identfied by the row pointed to by the SQL statement pCur->pDbList
 193       ** (iterating through a "PRAGMA database_list;" statement).
 194       */
 195       if( sqlite3_column_int(pCur->pDbList, 0)==1 ){
 196         zSql = sqlite3_mprintf(
 197             "SELECT name FROM sqlite_temp_master WHERE type='table'"
 198         );
 199       }else{
 200         sqlite3_stmt *pDbList = pCur->pDbList;
 201         zSql = sqlite3_mprintf(
 202             "SELECT name FROM %Q.sqlite_master WHERE type='table'",
 203              sqlite3_column_text(pDbList, 1)
 204         );
 205       }
 206       if( !zSql ){
 207         rc = SQLITE_NOMEM;
 208         goto next_exit;
 209       }
 210
 211       rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pTableList, 0);
 212       sqlite3_free(zSql);
 213       if( rc!=SQLITE_OK ) goto next_exit;
 214     }
 215
 216     /* Set zSql to the SQL to the table_info pragma for the table currently
 217     ** identified by the rows pointed to by statements pCur->pDbList and
 218     ** pCur->pTableList.
 219     */
 220     zSql = sqlite3_mprintf("PRAGMA %Q.table_info(%Q)",
 221         sqlite3_column_text(pCur->pDbList, 1),
 222         sqlite3_column_text(pCur->pTableList, 0)
 223     );
 224
 225     if( !zSql ){
 226       rc = SQLITE_NOMEM;
 227       goto next_exit;
 228     }
 229     rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pColumnList, 0);
 230     sqlite3_free(zSql);
 231     if( rc!=SQLITE_OK ) goto next_exit;
 232   }
 233   pCur->rowid++;
 234
 235 next_exit:
 236   /* TODO: Handle rc */
 237   return rc;
 238 }
 239
 240 /*
 241 ** Reset a schema table cursor.
 242 */
 243 static int schemaFilter(
 244   sqlite3_vtab_cursor *pVtabCursor,
 245   int idxNum, const char *idxStr,
 246   int argc, sqlite3_value **argv
 247 ){
 248   int rc;
 249   schema_vtab *pVtab = (schema_vtab *)(pVtabCursor->pVtab);
 250   schema_cursor *pCur = (schema_cursor *)pVtabCursor;
 251   pCur->rowid = 0;
 252   finalize(&pCur->pTableList);
 253   finalize(&pCur->pColumnList);
 254   finalize(&pCur->pDbList);
 255   rc = sqlite3_prepare(pVtab->db,"PRAGMA database_list", -1, &pCur->pDbList, 0);
 256   return (rc==SQLITE_OK ? schemaNext(pVtabCursor) : rc);
 257 }
 258
 259 /*
 260 ** Analyse the WHERE condition.
 261 */
 262 static int schemaBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
 263   return SQLITE_OK;
 264 }
 265
 266 /*
 267 ** A virtual table module that merely echos method calls into TCL
 268 ** variables.
 269 */
 270 static sqlite3_module schemaModule = {
 271   0,                           /* iVersion */
 272   schemaCreate,
 273   schemaCreate,
 274   schemaBestIndex,
 275   schemaDestroy,
 276   schemaDestroy,
 277   schemaOpen,                  /* xOpen - open a cursor */
 278   schemaClose,                 /* xClose - close a cursor */
 279   schemaFilter,                /* xFilter - configure scan constraints */
 280   schemaNext,                  /* xNext - advance a cursor */
 281   schemaEof,                   /* xEof */
 282   schemaColumn,                /* xColumn - read data */
 283   schemaRowid,                 /* xRowid - read data */
 284   0,                           /* xUpdate */
 285   0,                           /* xBegin */
 286   0,                           /* xSync */
 287   0,                           /* xCommit */
 288   0,                           /* xRollback */
 289   0,                           /* xFindMethod */
 290   0,                           /* xRename */
 291 };
 292
 293 #endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */
 294
 295 #ifdef SQLITE_TEST
 296
 297 /*
 298 ** Decode a pointer to an sqlite3 object.
 299 */
 300 extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
 301
 302 /*
 303 ** Register the schema virtual table module.
 304 */
 305 static int register_schema_module(
 306   ClientData clientData, /* Not used */
 307   Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
 308   int objc,              /* Number of arguments */
 309   Tcl_Obj *CONST objv[]  /* Command arguments */
 310 ){
 311   sqlite3 *db;
 312   if( objc!=2 ){
 313     Tcl_WrongNumArgs(interp, 1, objv, "DB");
 314     return TCL_ERROR;
 315   }
 316   if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
 317 #ifndef SQLITE_OMIT_VIRTUALTABLE
 318   sqlite3_create_module(db, "schema", &schemaModule, 0);
 319 #endif
 320   return TCL_OK;
 321 }
 322
 323 /*
 324 ** Register commands with the TCL interpreter.
 325 */
 326 int Sqlitetestschema_Init(Tcl_Interp *interp){
 327   static struct {
 328      char *zName;
 329      Tcl_ObjCmdProc *xProc;
 330      void *clientData;
 331   } aObjCmd[] = {
 332      { "register_schema_module", register_schema_module, 0 },
 333   };
 334   int i;
 335   for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
 336     Tcl_CreateObjCommand(interp, aObjCmd[i].zName,
 337         aObjCmd[i].xProc, aObjCmd[i].clientData, 0);
 338   }
 339   return TCL_OK;
 340 }
 341
 342 #else
 343
 344 /*
 345 ** Extension load function.
 346 */
 347 int sqlite3_extension_init(
 348   sqlite3 *db,
 349   char **pzErrMsg,
 350   const sqlite3_api_routines *pApi
 351 ){
 352   SQLITE_EXTENSION_INIT2(pApi);
 353 #ifndef SQLITE_OMIT_VIRTUALTABLE
 354   sqlite3_create_module(db, "schema", &schemaModule, 0);
 355 #endif
 356   return 0;
 357 }
 358
 359 #endif