1 /* 2 ** 2013 Jan 11 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 ** The FS virtual table is created as follows: 17 ** 18 ** CREATE VIRTUAL TABLE tbl USING fs(idx); 19 ** 20 ** where idx is the name of a table in the db with 2 columns. The virtual 21 ** table also has two columns - file path and file contents. 22 ** 23 ** The first column of table idx must be an IPK, and the second contains file 24 ** paths. For example: 25 ** 26 ** CREATE TABLE idx(id INTEGER PRIMARY KEY, path TEXT); 27 ** INSERT INTO idx VALUES(4, '/etc/passwd'); 28 ** 29 ** Adding the row to the idx table automatically creates a row in the 30 ** virtual table with rowid=4, path=/etc/passwd and a text field that 31 ** contains data read from file /etc/passwd on disk. 32 */ 33 #include "sqliteInt.h" 34 #include "tcl.h" 35 36 #include <stdlib.h> 37 #include <string.h> 38 #include <sys/types.h> 39 #include <sys/stat.h> 40 #include <fcntl.h> 41 42 #if SQLITE_OS_UNIX 43 # include <unistd.h> 44 #endif 45 #if SQLITE_OS_WIN 46 # include <io.h> 47 #endif 48 49 #ifndef SQLITE_OMIT_VIRTUALTABLE 50 51 typedef struct fs_vtab fs_vtab; 52 typedef struct fs_cursor fs_cursor; 53 54 /* 55 ** A fs virtual-table object 56 */ 57 struct fs_vtab { 58 sqlite3_vtab base; 59 sqlite3 *db; 60 char *zDb; /* Name of db containing zTbl */ 61 char *zTbl; /* Name of docid->file map table */ 62 }; 63 64 /* A fs cursor object */ 65 struct fs_cursor { 66 sqlite3_vtab_cursor base; 67 sqlite3_stmt *pStmt; 68 char *zBuf; 69 int nBuf; 70 int nAlloc; 71 }; 72 73 /* 74 ** This function is the implementation of both the xConnect and xCreate 75 ** methods of the fs virtual table. 76 ** 77 ** The argv[] array contains the following: 78 ** 79 ** argv[0] -> module name ("fs") 80 ** argv[1] -> database name 81 ** argv[2] -> table name 82 ** argv[...] -> other module argument fields. 83 */ 84 static int fsConnect( 85 sqlite3 *db, 86 void *pAux, 87 int argc, const char *const*argv, 88 sqlite3_vtab **ppVtab, 89 char **pzErr 90 ){ 91 fs_vtab *pVtab; 92 int nByte; 93 const char *zTbl; 94 const char *zDb = argv[1]; 95 96 if( argc!=4 ){ 97 *pzErr = sqlite3_mprintf("wrong number of arguments"); 98 return SQLITE_ERROR; 99 } 100 zTbl = argv[3]; 101 102 nByte = sizeof(fs_vtab) + strlen(zTbl) + 1 + strlen(zDb) + 1; 103 pVtab = (fs_vtab *)sqlite3MallocZero( nByte ); 104 if( !pVtab ) return SQLITE_NOMEM; 105 106 pVtab->zTbl = (char *)&pVtab[1]; 107 pVtab->zDb = &pVtab->zTbl[strlen(zTbl)+1]; 108 pVtab->db = db; 109 memcpy(pVtab->zTbl, zTbl, strlen(zTbl)); 110 memcpy(pVtab->zDb, zDb, strlen(zDb)); 111 *ppVtab = &pVtab->base; 112 sqlite3_declare_vtab(db, "CREATE TABLE xyz(path TEXT, data TEXT)"); 113 114 return SQLITE_OK; 115 } 116 /* Note that for this virtual table, the xCreate and xConnect 117 ** methods are identical. */ 118 119 static int fsDisconnect(sqlite3_vtab *pVtab){ 120 sqlite3_free(pVtab); 121 return SQLITE_OK; 122 } 123 /* The xDisconnect and xDestroy methods are also the same */ 124 125 /* 126 ** Open a new fs cursor. 127 */ 128 static int fsOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){ 129 fs_cursor *pCur; 130 pCur = sqlite3MallocZero(sizeof(fs_cursor)); 131 *ppCursor = &pCur->base; 132 return SQLITE_OK; 133 } 134 135 /* 136 ** Close a fs cursor. 137 */ 138 static int fsClose(sqlite3_vtab_cursor *cur){ 139 fs_cursor *pCur = (fs_cursor *)cur; 140 sqlite3_finalize(pCur->pStmt); 141 sqlite3_free(pCur->zBuf); 142 sqlite3_free(pCur); 143 return SQLITE_OK; 144 } 145 146 static int fsNext(sqlite3_vtab_cursor *cur){ 147 fs_cursor *pCur = (fs_cursor *)cur; 148 int rc; 149 150 rc = sqlite3_step(pCur->pStmt); 151 if( rc==SQLITE_ROW || rc==SQLITE_DONE ) rc = SQLITE_OK; 152 153 return rc; 154 } 155 156 static int fsFilter( 157 sqlite3_vtab_cursor *pVtabCursor, 158 int idxNum, const char *idxStr, 159 int argc, sqlite3_value **argv 160 ){ 161 int rc; 162 fs_cursor *pCur = (fs_cursor *)pVtabCursor; 163 fs_vtab *p = (fs_vtab *)(pVtabCursor->pVtab); 164 165 assert( (idxNum==0 && argc==0) || (idxNum==1 && argc==1) ); 166 if( idxNum==1 ){ 167 char *zStmt = sqlite3_mprintf( 168 "SELECT * FROM %Q.%Q WHERE rowid=?", p->zDb, p->zTbl); 169 if( !zStmt ) return SQLITE_NOMEM; 170 rc = sqlite3_prepare_v2(p->db, zStmt, -1, &pCur->pStmt, 0); 171 sqlite3_free(zStmt); 172 if( rc==SQLITE_OK ){ 173 sqlite3_bind_value(pCur->pStmt, 1, argv[0]); 174 } 175 }else{ 176 char *zStmt = sqlite3_mprintf("SELECT * FROM %Q.%Q", p->zDb, p->zTbl); 177 if( !zStmt ) return SQLITE_NOMEM; 178 rc = sqlite3_prepare_v2(p->db, zStmt, -1, &pCur->pStmt, 0); 179 sqlite3_free(zStmt); 180 } 181 182 if( rc==SQLITE_OK ){ 183 rc = fsNext(pVtabCursor); 184 } 185 return rc; 186 } 187 188 static int fsColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){ 189 fs_cursor *pCur = (fs_cursor*)cur; 190 191 assert( i==0 || i==1 ); 192 if( i==0 ){ 193 sqlite3_result_value(ctx, sqlite3_column_value(pCur->pStmt, 0)); 194 }else{ 195 const char *zFile = (const char *)sqlite3_column_text(pCur->pStmt, 1); 196 struct stat sbuf; 197 int fd; 198 199 fd = open(zFile, O_RDONLY); 200 if( fd<0 ) return SQLITE_IOERR; 201 fstat(fd, &sbuf); 202 203 if( sbuf.st_size>=pCur->nAlloc ){ 204 int nNew = sbuf.st_size*2; 205 char *zNew; 206 if( nNew<1024 ) nNew = 1024; 207 208 zNew = sqlite3Realloc(pCur->zBuf, nNew); 209 if( zNew==0 ){ 210 close(fd); 211 return SQLITE_NOMEM; 212 } 213 pCur->zBuf = zNew; 214 pCur->nAlloc = nNew; 215 } 216 217 read(fd, pCur->zBuf, sbuf.st_size); 218 close(fd); 219 pCur->nBuf = sbuf.st_size; 220 pCur->zBuf[pCur->nBuf] = '\0'; 221 222 sqlite3_result_text(ctx, pCur->zBuf, -1, SQLITE_TRANSIENT); 223 } 224 return SQLITE_OK; 225 } 226 227 static int fsRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ 228 fs_cursor *pCur = (fs_cursor*)cur; 229 *pRowid = sqlite3_column_int64(pCur->pStmt, 0); 230 return SQLITE_OK; 231 } 232 233 static int fsEof(sqlite3_vtab_cursor *cur){ 234 fs_cursor *pCur = (fs_cursor*)cur; 235 return (sqlite3_data_count(pCur->pStmt)==0); 236 } 237 238 static int fsBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ 239 int ii; 240 241 for(ii=0; ii<pIdxInfo->nConstraint; ii++){ 242 struct sqlite3_index_constraint const *pCons = &pIdxInfo->aConstraint[ii]; 243 if( pCons->iColumn<0 && pCons->usable 244 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){ 245 struct sqlite3_index_constraint_usage *pUsage; 246 pUsage = &pIdxInfo->aConstraintUsage[ii]; 247 pUsage->omit = 0; 248 pUsage->argvIndex = 1; 249 pIdxInfo->idxNum = 1; 250 pIdxInfo->estimatedCost = 1.0; 251 break; 252 } 253 } 254 255 return SQLITE_OK; 256 } 257 258 /* 259 ** A virtual table module that provides read-only access to a 260 ** Tcl global variable namespace. 261 */ 262 static sqlite3_module fsModule = { 263 0, /* iVersion */ 264 fsConnect, 265 fsConnect, 266 fsBestIndex, 267 fsDisconnect, 268 fsDisconnect, 269 fsOpen, /* xOpen - open a cursor */ 270 fsClose, /* xClose - close a cursor */ 271 fsFilter, /* xFilter - configure scan constraints */ 272 fsNext, /* xNext - advance a cursor */ 273 fsEof, /* xEof - check for end of scan */ 274 fsColumn, /* xColumn - read data */ 275 fsRowid, /* xRowid - read data */ 276 0, /* xUpdate */ 277 0, /* xBegin */ 278 0, /* xSync */ 279 0, /* xCommit */ 280 0, /* xRollback */ 281 0, /* xFindMethod */ 282 0, /* xRename */ 283 }; 284 285 /* 286 ** Decode a pointer to an sqlite3 object. 287 */ 288 extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb); 289 290 /* 291 ** Register the echo virtual table module. 292 */ 293 static int register_fs_module( 294 ClientData clientData, /* Pointer to sqlite3_enable_XXX function */ 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 if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR; 305 #ifndef SQLITE_OMIT_VIRTUALTABLE 306 sqlite3_create_module(db, "fs", &fsModule, (void *)interp); 307 #endif 308 return TCL_OK; 309 } 310 311 #endif 312 313 314 /* 315 ** Register commands with the TCL interpreter. 316 */ 317 int Sqlitetestfs_Init(Tcl_Interp *interp){ 318 #ifndef SQLITE_OMIT_VIRTUALTABLE 319 static struct { 320 char *zName; 321 Tcl_ObjCmdProc *xProc; 322 void *clientData; 323 } aObjCmd[] = { 324 { "register_fs_module", register_fs_module, 0 }, 325 }; 326 int i; 327 for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){ 328 Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 329 aObjCmd[i].xProc, aObjCmd[i].clientData, 0); 330 } 331 #endif 332 return TCL_OK; 333 } 334