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 ** $Id: test_schema.c,v 1.1 2006/06/15 15:59:20 danielk1977 Exp $ 17 */ 18 19 /* The code in this file defines a sqlite3 module that provides 20 ** a read-only view of the current database schema. There is one 21 ** row in the schema table for each column in the database. 22 */ 23 #define SCHEMA \ 24 "CREATE TABLE x(" \ 25 "database," /* Name of database (i.e. main, temp etc.) */ \ 26 "tablename," /* Name of table */ \ 27 "cid," /* Column number (from left-to-right, 0 upward) */ \ 28 "name," /* Column name */ \ 29 "type," /* Specified type (i.e. VARCHAR(32)) */ \ 30 "not_null," /* Boolean. True if NOT NULL was specified */ \ 31 "dflt_value," /* Default value for this column */ \ 32 "pk" /* True if this column is part of the primary key */ \ 33 ")" 34 35 /* If SQLITE_TEST is defined this code is preprocessed for use as part 36 ** of the sqlite test binary "testfixture". Otherwise it is preprocessed 37 ** to be compiled into an sqlite dynamic extension. 38 */ 39 #ifdef SQLITE_TEST 40 #include "sqliteInt.h" 41 #include "tcl.h" 42 #define MALLOC(x) sqliteRawMalloc(x) 43 #define FREE(x) sqliteFree(x) 44 #else 45 #include "sqlite3ext.h" 46 SQLITE_EXTENSION_INIT1 47 #define MALLOC(x) malloc(x) 48 #define FREE(x) free(x) 49 #endif 50 51 #include <stdlib.h> 52 #include <string.h> 53 #include <assert.h> 54 55 typedef struct schema_vtab schema_vtab; 56 typedef struct schema_cursor schema_cursor; 57 58 /* A schema table object */ 59 struct schema_vtab { 60 sqlite3_vtab base; 61 sqlite3 *db; 62 }; 63 64 /* A schema table cursor object */ 65 struct schema_cursor { 66 sqlite3_vtab_cursor base; 67 sqlite3_stmt *pDbList; 68 sqlite3_stmt *pTableList; 69 sqlite3_stmt *pColumnList; 70 int rowid; 71 }; 72 73 /* 74 ** Table destructor for the schema module. 75 */ 76 static int schemaDestroy(sqlite3_vtab *pVtab){ 77 FREE(pVtab); 78 return 0; 79 } 80 81 /* 82 ** Table constructor for the schema module. 83 */ 84 static int schemaCreate( 85 sqlite3 *db, 86 void *pAux, 87 int argc, char **argv, 88 sqlite3_vtab **ppVtab 89 ){ 90 int rc = SQLITE_NOMEM; 91 schema_vtab *pVtab = MALLOC(sizeof(schema_vtab)); 92 if( pVtab ){ 93 memset(pVtab, 0, sizeof(schema_vtab)); 94 pVtab->db = db; 95 rc = sqlite3_declare_vtab(db, SCHEMA); 96 } 97 *ppVtab = (sqlite3_vtab *)pVtab; 98 return rc; 99 } 100 101 /* 102 ** Open a new cursor on the schema table. 103 */ 104 static int schemaOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){ 105 int rc = SQLITE_NOMEM; 106 schema_cursor *pCur; 107 pCur = MALLOC(sizeof(schema_cursor)); 108 if( pCur ){ 109 memset(pCur, 0, sizeof(schema_cursor)); 110 *ppCursor = (sqlite3_vtab_cursor *)pCur; 111 rc = SQLITE_OK; 112 } 113 return rc; 114 } 115 116 /* 117 ** Close a schema table cursor. 118 */ 119 static int schemaClose(sqlite3_vtab_cursor *cur){ 120 schema_cursor *pCur = (schema_cursor *)cur; 121 sqlite3_finalize(pCur->pDbList); 122 sqlite3_finalize(pCur->pTableList); 123 sqlite3_finalize(pCur->pColumnList); 124 FREE(pCur); 125 return SQLITE_OK; 126 } 127 128 /* 129 ** Retrieve a column of data. 130 */ 131 static int schemaColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){ 132 schema_cursor *pCur = (schema_cursor *)cur; 133 switch( i ){ 134 case 0: 135 sqlite3_result_value(ctx, sqlite3_column_value(pCur->pDbList, 1)); 136 break; 137 case 1: 138 sqlite3_result_value(ctx, sqlite3_column_value(pCur->pTableList, 0)); 139 break; 140 default: 141 sqlite3_result_value(ctx, sqlite3_column_value(pCur->pColumnList, i-2)); 142 break; 143 } 144 return SQLITE_OK; 145 } 146 147 /* 148 ** Retrieve the current rowid. 149 */ 150 static int schemaRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ 151 schema_cursor *pCur = (schema_cursor *)cur; 152 *pRowid = pCur->rowid; 153 return SQLITE_OK; 154 } 155 156 static int finalize(sqlite3_stmt **ppStmt){ 157 int rc = sqlite3_finalize(*ppStmt); 158 *ppStmt = 0; 159 return rc; 160 } 161 162 /* 163 ** Advance the cursor to the next row. 164 */ 165 static int schemaNext(sqlite3_vtab_cursor *cur){ 166 int rc; 167 schema_cursor *pCur = (schema_cursor *)cur; 168 schema_vtab *pVtab = (schema_vtab *)(cur->pVtab); 169 char *zSql = 0; 170 171 while( !pCur->pColumnList || SQLITE_ROW!=sqlite3_step(pCur->pColumnList) ){ 172 if( SQLITE_OK!=(rc = finalize(&pCur->pColumnList)) ) goto fail; 173 174 while( !pCur->pTableList || SQLITE_ROW!=sqlite3_step(pCur->pTableList) ){ 175 if( SQLITE_OK!=(rc = finalize(&pCur->pTableList)) ) goto fail; 176 177 assert(pCur->pDbList); 178 while( SQLITE_ROW!=sqlite3_step(pCur->pDbList) ){ 179 if( SQLITE_OK!=(rc = finalize(&pCur->pDbList)) ) goto fail; 180 return 0; 181 } 182 183 /* Set zSql to the SQL to pull the list of tables from the 184 ** sqlite_master (or sqlite_temp_master) table of the database 185 ** identfied by the row pointed to by the SQL statement pCur->pDbList 186 ** (iterating through a "PRAGMA database_list;" statement). 187 */ 188 if( sqlite3_column_int(pCur->pDbList, 0)==1 ){ 189 zSql = sqlite3_mprintf( 190 "SELECT name FROM sqlite_temp_master WHERE type='table'" 191 ); 192 }else{ 193 sqlite3_stmt *pDbList = pCur->pDbList; 194 zSql = sqlite3_mprintf( 195 "SELECT name FROM %Q.sqlite_master WHERE type='table'", 196 sqlite3_column_text(pDbList, 1) 197 ); 198 } 199 if( !zSql ){ 200 rc = SQLITE_NOMEM; 201 goto fail; 202 } 203 204 rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pTableList, 0); 205 sqlite3_free(zSql); 206 if( rc!=SQLITE_OK ) goto fail; 207 } 208 209 /* Set zSql to the SQL to the table_info pragma for the table currently 210 ** identified by the rows pointed to by statements pCur->pDbList and 211 ** pCur->pTableList. 212 */ 213 zSql = sqlite3_mprintf("PRAGMA %Q.table_info(%Q)", 214 sqlite3_column_text(pCur->pDbList, 1), 215 sqlite3_column_text(pCur->pTableList, 0) 216 ); 217 218 if( !zSql ){ 219 rc = SQLITE_NOMEM; 220 goto fail; 221 } 222 rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pColumnList, 0); 223 sqlite3_free(zSql); 224 if( rc!=SQLITE_OK ) goto fail; 225 } 226 pCur->rowid++; 227 228 fail: 229 /* TODO: Handle rc */ 230 return 1; 231 } 232 233 /* 234 ** Reset a schema table cursor. 235 */ 236 static int schemaFilter( 237 sqlite3_vtab_cursor *pVtabCursor, 238 int idxNum, const char *idxStr, 239 int argc, sqlite3_value **argv 240 ){ 241 int rc; 242 schema_vtab *pVtab = (schema_vtab *)(pVtabCursor->pVtab); 243 schema_cursor *pCur = (schema_cursor *)pVtabCursor; 244 pCur->rowid = 0; 245 finalize(&pCur->pTableList); 246 finalize(&pCur->pColumnList); 247 finalize(&pCur->pDbList); 248 rc = sqlite3_prepare(pVtab->db,"PRAGMA database_list", -1, &pCur->pDbList, 0); 249 return (rc==SQLITE_OK ? schemaNext(pVtabCursor) : rc); 250 } 251 252 /* 253 ** Analyse the WHERE condition. 254 */ 255 static int schemaBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ 256 return SQLITE_OK; 257 } 258 259 /* 260 ** A virtual table module that merely echos method calls into TCL 261 ** variables. 262 */ 263 static sqlite3_module schemaModule = { 264 0, /* iVersion */ 265 "schema", /* zName */ 266 schemaCreate, 267 schemaCreate, 268 schemaBestIndex, 269 schemaDestroy, 270 schemaDestroy, 271 schemaOpen, /* xOpen - open a cursor */ 272 schemaClose, /* xClose - close a cursor */ 273 schemaFilter, /* xFilter - configure scan constraints */ 274 schemaNext, /* xNext - advance a cursor */ 275 schemaColumn, /* xColumn - read data */ 276 schemaRowid, /* xRowid - read data */ 277 }; 278 279 280 #ifdef SQLITE_TEST 281 282 /* 283 ** Decode a pointer to an sqlite3 object. 284 */ 285 static int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb){ 286 *ppDb = (sqlite3*)sqlite3TextToPtr(zA); 287 return TCL_OK; 288 } 289 290 /* 291 ** Register the schema virtual table module. 292 */ 293 static int register_schema_module( 294 ClientData clientData, /* Not used */ 295 Tcl_Interp *interp, /* The TCL interpreter that invoked this command */ 296 int objc, /* Number of arguments */ 297 Tcl_Obj *CONST objv[] /* Command arguments */ 298 ){ 299 sqlite3 *db; 300 if( objc!=2 ){ 301 Tcl_WrongNumArgs(interp, 1, objv, "DB"); 302 return TCL_ERROR; 303 } 304 #ifndef SQLITE_OMIT_VIRTUALTABLE 305 sqlite3_create_module(db, "schema", &schemaModule, 0); 306 #endif 307 return TCL_OK; 308 } 309 310 /* 311 ** Register commands with the TCL interpreter. 312 */ 313 int Sqlitetestschema_Init(Tcl_Interp *interp){ 314 static struct { 315 char *zName; 316 Tcl_ObjCmdProc *xProc; 317 void *clientData; 318 } aObjCmd[] = { 319 { "register_schema_module", register_schema_module, 0 }, 320 }; 321 int i; 322 for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){ 323 Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 324 aObjCmd[i].xProc, aObjCmd[i].clientData, 0); 325 } 326 return TCL_OK; 327 } 328 329 #else 330 331 /* 332 ** Extension load function. 333 */ 334 int schema_init( 335 sqlite3 *db, 336 char **pzErrMsg, 337 const sqlite3_api_routines *pApi 338 ){ 339 SQLITE_EXTENSION_INIT2(pApi); 340 sqlite3_create_module(db, "schema", &schemaModule, 0); 341 return 0; 342 } 343 344 #endif 345