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) + (int)strlen(zTbl) + 1 + (int)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 int n; 199 200 fd = open(zFile, O_RDONLY); 201 if( fd<0 ) return SQLITE_IOERR; 202 fstat(fd, &sbuf); 203 204 if( sbuf.st_size>=pCur->nAlloc ){ 205 int nNew = sbuf.st_size*2; 206 char *zNew; 207 if( nNew<1024 ) nNew = 1024; 208 209 zNew = sqlite3Realloc(pCur->zBuf, nNew); 210 if( zNew==0 ){ 211 close(fd); 212 return SQLITE_NOMEM; 213 } 214 pCur->zBuf = zNew; 215 pCur->nAlloc = nNew; 216 } 217 218 n = (int)read(fd, pCur->zBuf, sbuf.st_size); 219 close(fd); 220 if( n!=sbuf.st_size ) return SQLITE_ERROR; 221 pCur->nBuf = sbuf.st_size; 222 pCur->zBuf[pCur->nBuf] = '\0'; 223 224 sqlite3_result_text(ctx, pCur->zBuf, -1, SQLITE_TRANSIENT); 225 } 226 return SQLITE_OK; 227 } 228 229 static int fsRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ 230 fs_cursor *pCur = (fs_cursor*)cur; 231 *pRowid = sqlite3_column_int64(pCur->pStmt, 0); 232 return SQLITE_OK; 233 } 234 235 static int fsEof(sqlite3_vtab_cursor *cur){ 236 fs_cursor *pCur = (fs_cursor*)cur; 237 return (sqlite3_data_count(pCur->pStmt)==0); 238 } 239 240 static int fsBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ 241 int ii; 242 243 for(ii=0; ii<pIdxInfo->nConstraint; ii++){ 244 struct sqlite3_index_constraint const *pCons = &pIdxInfo->aConstraint[ii]; 245 if( pCons->iColumn<0 && pCons->usable 246 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ ){ 247 struct sqlite3_index_constraint_usage *pUsage; 248 pUsage = &pIdxInfo->aConstraintUsage[ii]; 249 pUsage->omit = 0; 250 pUsage->argvIndex = 1; 251 pIdxInfo->idxNum = 1; 252 pIdxInfo->estimatedCost = 1.0; 253 break; 254 } 255 } 256 257 return SQLITE_OK; 258 } 259 260 /* 261 ** A virtual table module that provides read-only access to a 262 ** Tcl global variable namespace. 263 */ 264 static sqlite3_module fsModule = { 265 0, /* iVersion */ 266 fsConnect, 267 fsConnect, 268 fsBestIndex, 269 fsDisconnect, 270 fsDisconnect, 271 fsOpen, /* xOpen - open a cursor */ 272 fsClose, /* xClose - close a cursor */ 273 fsFilter, /* xFilter - configure scan constraints */ 274 fsNext, /* xNext - advance a cursor */ 275 fsEof, /* xEof - check for end of scan */ 276 fsColumn, /* xColumn - read data */ 277 fsRowid, /* xRowid - read data */ 278 0, /* xUpdate */ 279 0, /* xBegin */ 280 0, /* xSync */ 281 0, /* xCommit */ 282 0, /* xRollback */ 283 0, /* xFindMethod */ 284 0, /* xRename */ 285 }; 286 287 /* 288 ** Decode a pointer to an sqlite3 object. 289 */ 290 extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb); 291 292 /* 293 ** Register the echo virtual table module. 294 */ 295 static int register_fs_module( 296 ClientData clientData, /* Pointer to sqlite3_enable_XXX function */ 297 Tcl_Interp *interp, /* The TCL interpreter that invoked this command */ 298 int objc, /* Number of arguments */ 299 Tcl_Obj *CONST objv[] /* Command arguments */ 300 ){ 301 sqlite3 *db; 302 if( objc!=2 ){ 303 Tcl_WrongNumArgs(interp, 1, objv, "DB"); 304 return TCL_ERROR; 305 } 306 if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR; 307 #ifndef SQLITE_OMIT_VIRTUALTABLE 308 sqlite3_create_module(db, "fs", &fsModule, (void *)interp); 309 #endif 310 return TCL_OK; 311 } 312 313 #endif 314 315 316 /* 317 ** Register commands with the TCL interpreter. 318 */ 319 int Sqlitetestfs_Init(Tcl_Interp *interp){ 320 #ifndef SQLITE_OMIT_VIRTUALTABLE 321 static struct { 322 char *zName; 323 Tcl_ObjCmdProc *xProc; 324 void *clientData; 325 } aObjCmd[] = { 326 { "register_fs_module", register_fs_module, 0 }, 327 }; 328 int i; 329 for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){ 330 Tcl_CreateObjCommand(interp, aObjCmd[i].zName, 331 aObjCmd[i].xProc, aObjCmd[i].clientData, 0); 332 } 333 #endif 334 return TCL_OK; 335 } 336