/*
** 2013 Jan 11
**
** 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 FS virtual table is created as follows:
**
** CREATE VIRTUAL TABLE tbl USING fs(idx);
**
** where idx is the name of a table in the db with 2 columns. The virtual
** table also has two columns - file path and file contents.
**
** The first column of table idx must be an IPK, and the second contains file
** paths. For example:
**
** CREATE TABLE idx(id INTEGER PRIMARY KEY, path TEXT);
** INSERT INTO idx VALUES(4, '/etc/passwd');
**
** Adding the row to the idx table automatically creates a row in the
** virtual table with rowid=4, path=/etc/passwd and a text field that
** contains data read from file /etc/passwd on disk.
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#if SQLITE_OS_UNIX
# include <unistd.h>
#endif
#if SQLITE_OS_WIN
# include <io.h>
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
typedef struct fs_vtab fs_vtab;
typedef struct fs_cursor fs_cursor;
/*
** A fs virtual-table object
*/
struct fs_vtab {
sqlite3_vtab base;
sqlite3 *db;
char *zDb; /* Name of db containing zTbl */
char *zTbl; /* Name of docid->file map table */
};
/* A fs cursor object */
struct fs_cursor {
sqlite3_vtab_cursor base;
sqlite3_stmt *pStmt;
char *zBuf;
int nBuf;
int nAlloc;
};
/*
** This function is the implementation of both the xConnect and xCreate
** methods of the fs virtual table.
**
** The argv[] array contains the following:
**
** argv[0] -> module name ("fs")
** argv[1] -> database name
** argv[2] -> table name
** argv[...] -> other module argument fields.
*/
static int fsConnect(
sqlite3 *db,
void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVtab,
char **pzErr
){
fs_vtab *pVtab;
int nByte;
const char *zTbl;
const char *zDb = argv[1];
if( argc!=4 ){
*pzErr = sqlite3_mprintf("wrong number of arguments");
return SQLITE_ERROR;
}
zTbl = argv[3];
nByte = sizeof(fs_vtab) + (int)strlen(zTbl) + 1 + (int)strlen(zDb) + 1;
pVtab = (fs_vtab *)sqlite3MallocZero( nByte );
if( !pVtab ) return SQLITE_NOMEM;
pVtab->zTbl = (char *)&pVtab[1];
pVtab->zDb = &pVtab->zTbl[strlen(zTbl)+1];
pVtab->db = db;
memcpy(pVtab->zTbl, zTbl, strlen(zTbl));
memcpy(pVtab->zDb, zDb, strlen(zDb));
*ppVtab = &pVtab->base;
sqlite3_declare_vtab(db, "CREATE TABLE xyz(path TEXT, data TEXT)");
return SQLITE_OK;
}
/* Note that for this virtual table, the xCreate and xConnect
** methods are identical. */
static int fsDisconnect(sqlite3_vtab *pVtab){
sqlite3_free(pVtab);
return SQLITE_OK;
}
/* The xDisconnect and xDestroy methods are also the same */
/*
** Open a new fs cursor.
*/
static int fsOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
fs_cursor *pCur;
pCur = sqlite3MallocZero(sizeof(fs_cursor));
*ppCursor = &pCur->base;
return SQLITE_OK;
}
/*
** Close a fs cursor.
*/
static int fsClose(sqlite3_vtab_cursor *cur){
fs_cursor *pCur = (fs_cursor *)cur;
sqlite3_finalize(pCur->pStmt);
sqlite3_free(pCur->zBuf);
sqlite3_free(pCur);
return SQLITE_OK;
}
static int fsNext(sqlite3_vtab_cursor *cur){
fs_cursor *pCur = (fs_cursor *)cur;
int rc;
rc = sqlite3_step(pCur->pStmt);
if( rc==SQLITE_ROW || rc==SQLITE_DONE ) rc = SQLITE_OK;
return rc;
}
static int fsFilter(
sqlite3_vtab_cursor *pVtabCursor,
int idxNum, const char *idxStr,
int argc, sqlite3_value **argv
){
int rc;
fs_cursor *pCur = (fs_cursor *)pVtabCursor;
fs_vtab *p = (fs_vtab *)(pVtabCursor->pVtab);
assert( (idxNum==0 && argc==0) || (idxNum==1 && argc==1) );
if( idxNum==1 ){
char *zStmt = sqlite3_mprintf(
"SELECT * FROM %Q.%Q WHERE rowid=?", p->zDb, p->zTbl);
if( !zStmt ) return SQLITE_NOMEM;
rc = sqlite3_prepare_v2(p->db, zStmt, -1, &pCur->pStmt, 0);
sqlite3_free(zStmt);
if( rc==SQLITE_OK ){
sqlite3_bind_value(pCur->pStmt, 1, argv[0]);
}
}else{
char *zStmt = sqlite3_mprintf("SELECT * FROM %Q.%Q", p->zDb, p->zTbl);
if( !zStmt ) return SQLITE_NOMEM;
rc = sqlite3_prepare_v2(p->db, zStmt, -1, &pCur->pStmt, 0);
sqlite3_free(zStmt);
}
if( rc==SQLITE_OK ){
rc = fsNext(pVtabCursor);
}
return rc;
}
static int fsColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
fs_cursor *pCur = (fs_cursor*)cur;
assert( i==0 || i==1 );
if( i==0 ){
sqlite3_result_value(ctx, sqlite3_column_value(pCur->pStmt, 0));
}else{
const char *zFile = (const char *)sqlite3_column_text(pCur->pStmt, 1);
struct stat sbuf;
int fd;
fd = open(zFile, O_RDONLY);
if( fd<0 ) return SQLITE_IOERR;
fstat(fd, &sbuf);
if( sbuf.st_size>=pCur->nAlloc ){
int nNew = sbuf.st_size*2;
char *zNew;
if( nNew<1024 ) nNew = 1024;
zNew = sqlite3Realloc(pCur->zBuf, nNew);
if( zNew==0 ){
close(fd);
return SQLITE_NOMEM;
}
pCur->zBuf = zNew;
pCur->nAlloc = nNew;
}
read(fd, pCur->zBuf, sbuf.st_size);
close(fd);
pCur->nBuf = sbuf.st_size;
pCur->zBuf[pCur->nBuf] = '\0';
sqlite3_result_text(ctx, pCur->zBuf, -1, SQLITE_TRANSIENT);
}
return SQLITE_OK;
}
static int fsRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
fs_cursor *pCur = (fs_cursor*)cur;
*pRowid = sqlite3_column_int64(pCur->pStmt, 0);
return SQLITE_OK;
}
static int fsEof(sqlite3_vtab_cursor *cur){
fs_cursor *pCur = (fs_cursor*)cur;
return (sqlite3_data_count(pCur->pStmt)==0);
}
static int fsBestIndex(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;
pIdxInfo->idxNum = 1;
pIdxInfo->estimatedCost = 1.0;
break;
}
}
return SQLITE_OK;
}
/*
** A virtual table module that provides read-only access to a
** Tcl global variable namespace.
*/
static sqlite3_module fsModule = {
0, /* iVersion */
fsConnect,
fsConnect,
fsBestIndex,
fsDisconnect,
fsDisconnect,
fsOpen, /* xOpen - open a cursor */
fsClose, /* xClose - close a cursor */
fsFilter, /* xFilter - configure scan constraints */
fsNext, /* xNext - advance a cursor */
fsEof, /* xEof - check for end of scan */
fsColumn, /* xColumn - read data */
fsRowid, /* 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_fs_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, "fs", &fsModule, (void *)interp);
#endif
return TCL_OK;
}
#endif
/*
** Register commands with the TCL interpreter.
*/
int Sqlitetestfs_Init(Tcl_Interp *interp){
#ifndef SQLITE_OMIT_VIRTUALTABLE
static struct {
char *zName;
Tcl_ObjCmdProc *xProc;
void *clientData;
} aObjCmd[] = {
{ "register_fs_module", register_fs_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;
}