[sql] Import reference version of SQLite 3.17..

third_party/sqlite/sqlite-src-3170000/src/test_fs.c

+/*
+** 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.
+**
+*************************************************************************
+** Virtual table module "fsdir"
+**
+** This module is designed to be used as a read-only eponymous virtual table.
+** Its schema is as follows:
+**
+**   CREATE TABLE fsdir(dir TEXT, name TEXT);
+**
+** When queried, a WHERE term of the form "dir = $dir" must be provided. The
+** virtual table then appears to have one row for each entry in file-system
+** directory $dir. Column dir contains a copy of $dir, and column "name"
+** contains the name of the directory entry.
+**
+** If the specified $dir cannot be opened or is not a directory, it is not
+** an error. The virtual table appears to be empty in this case.
+**
+*************************************************************************
+** Virtual table module "fstree"
+**
+** This module is also a read-only eponymous virtual table with the 
+** following schema:
+**
+**   CREATE TABLE fstree(path TEXT, size INT, data BLOB);
+**
+** Running a "SELECT * FROM fstree" query on this table returns the entire
+** contents of the file-system, starting at "/". To restrict the search
+** space, the virtual table supports LIKE and GLOB constraints on the
+** 'path' column. For example:
+**
+**   SELECT * FROM fstree WHERE path LIKE '/home/dan/sqlite/%'
+*/
+#include "sqliteInt.h"
+#if defined(INCLUDE_SQLITE_TCL_H)
+#  include "sqlite_tcl.h"
+#else
+#  include "tcl.h"
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#if SQLITE_OS_UNIX || defined(__MINGW_H)
+# include <unistd.h>
+# include <dirent.h>
+# ifndef DIRENT
+#  define DIRENT dirent
+# endif
+#endif
+#if SQLITE_OS_WIN
+# include <io.h>
+# if !defined(__MINGW_H)
+#  include "test_windirent.h"
+# endif
+# ifndef S_ISREG
+#  define S_ISREG(mode) (((mode) & S_IFMT) == S_IFREG)
+# endif
+#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;
+};
+
+/*************************************************************************
+** Start of fsdir implementation.
+*/
+typedef struct FsdirVtab FsdirVtab;
+typedef struct FsdirCsr FsdirCsr;
+struct FsdirVtab {
+  sqlite3_vtab base;
+};
+
+struct FsdirCsr {
+  sqlite3_vtab_cursor base;
+  char *zDir;                     /* Buffer containing directory scanned */
+  DIR *pDir;                      /* Open directory */
+  sqlite3_int64 iRowid;
+  struct DIRENT entry;            /* Current entry */
+};
+
+/*
+** This function is the implementation of both the xConnect and xCreate
+** methods of the fsdir 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 fsdirConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  FsdirVtab *pTab;
+
+  if( argc!=3 ){
+    *pzErr = sqlite3_mprintf("wrong number of arguments");
+    return SQLITE_ERROR;
+  }
+
+  pTab = (FsdirVtab *)sqlite3_malloc(sizeof(FsdirVtab));
+  if( !pTab ) return SQLITE_NOMEM;
+  memset(pTab, 0, sizeof(FsdirVtab));
+
+  *ppVtab = &pTab->base;
+  sqlite3_declare_vtab(db, "CREATE TABLE xyz(dir, name);");
+
+  return SQLITE_OK;
+}
+
+/*
+** xDestroy/xDisconnect implementation.
+*/
+static int fsdirDisconnect(sqlite3_vtab *pVtab){
+  sqlite3_free(pVtab);
+  return SQLITE_OK;
+}
+
+/*
+** xBestIndex implementation. The only constraint supported is:
+**
+**   (dir = ?)
+*/
+static int fsdirBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  int ii;
+
+  pIdxInfo->estimatedCost = 1000000000.0;
+
+  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
+    struct sqlite3_index_constraint const *p = &pIdxInfo->aConstraint[ii];
+    if( p->iColumn==0 && p->usable && p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
+      struct sqlite3_index_constraint_usage *pUsage;
+      pUsage = &pIdxInfo->aConstraintUsage[ii];
+      pUsage->omit = 1;
+      pUsage->argvIndex = 1;
+      pIdxInfo->idxNum = 1;
+      pIdxInfo->estimatedCost = 1.0;
+      break;
+    }
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** xOpen implementation.
+**
+** Open a new fsdir cursor.
+*/
+static int fsdirOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  FsdirCsr *pCur;
+  /* Allocate an extra 256 bytes because it is undefined how big dirent.d_name
+  ** is and we need enough space.  Linux provides plenty already, but
+  ** Solaris only provides one byte. */
+  pCur = (FsdirCsr*)sqlite3_malloc(sizeof(FsdirCsr)+256);
+  if( pCur==0 ) return SQLITE_NOMEM;
+  memset(pCur, 0, sizeof(FsdirCsr));
+  *ppCursor = &pCur->base;
+  return SQLITE_OK;
+}
+
+/*
+** Close a fsdir cursor.
+*/
+static int fsdirClose(sqlite3_vtab_cursor *cur){
+  FsdirCsr *pCur = (FsdirCsr*)cur;
+  if( pCur->pDir ) closedir(pCur->pDir);
+  sqlite3_free(pCur->zDir);
+  sqlite3_free(pCur);
+  return SQLITE_OK;
+}
+
+/*
+** Skip the cursor to the next entry.
+*/
+static int fsdirNext(sqlite3_vtab_cursor *cur){
+  FsdirCsr *pCsr = (FsdirCsr*)cur;
+
+  if( pCsr->pDir ){
+    struct DIRENT *pRes = 0;
+#if defined(__MINGW_H)
+    pRes = readdir(pCsr->pDir);
+    if( pRes!=0 ){
+      memcpy(&pCsr->entry, pRes, sizeof(struct DIRENT));
+    }
+#else
+    readdir_r(pCsr->pDir, &pCsr->entry, &pRes);
+#endif
+    if( pRes==0 ){
+      closedir(pCsr->pDir);
+      pCsr->pDir = 0;
+    }
+    pCsr->iRowid++;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** xFilter method implementation.
+*/
+static int fsdirFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  FsdirCsr *pCsr = (FsdirCsr*)pVtabCursor;
+  const char *zDir;
+  int nDir;
+
+
+  if( idxNum!=1 || argc!=1 ){
+    return SQLITE_ERROR;
+  }
+
+  pCsr->iRowid = 0;
+  sqlite3_free(pCsr->zDir);
+  if( pCsr->pDir ){
+    closedir(pCsr->pDir);
+    pCsr->pDir = 0;
+  }
+
+  zDir = (const char*)sqlite3_value_text(argv[0]);
+  nDir = sqlite3_value_bytes(argv[0]);
+  pCsr->zDir = sqlite3_malloc(nDir+1);
+  if( pCsr->zDir==0 ) return SQLITE_NOMEM;
+  memcpy(pCsr->zDir, zDir, nDir+1);
+
+  pCsr->pDir = opendir(pCsr->zDir);
+  return fsdirNext(pVtabCursor); 
+}
+
+/*
+** xEof method implementation.
+*/
+static int fsdirEof(sqlite3_vtab_cursor *cur){
+  FsdirCsr *pCsr = (FsdirCsr*)cur;
+  return pCsr->pDir==0;
+}
+
+/*
+** xColumn method implementation.
+*/
+static int fsdirColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  FsdirCsr *pCsr = (FsdirCsr*)cur;
+  switch( i ){
+    case 0: /* dir */
+      sqlite3_result_text(ctx, pCsr->zDir, -1, SQLITE_STATIC);
+      break;
+
+    case 1: /* name */
+      sqlite3_result_text(ctx, pCsr->entry.d_name, -1, SQLITE_TRANSIENT);
+      break;
+
+    default:
+      assert( 0 );
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** xRowid method implementation.
+*/
+static int fsdirRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  FsdirCsr *pCsr = (FsdirCsr*)cur;
+  *pRowid = pCsr->iRowid;
+  return SQLITE_OK;
+}
+/*
+** End of fsdir implementation.
+*************************************************************************/
+
+/*************************************************************************
+** Start of fstree implementation.
+*/
+typedef struct FstreeVtab FstreeVtab;
+typedef struct FstreeCsr FstreeCsr;
+struct FstreeVtab {
+  sqlite3_vtab base;
+  sqlite3 *db;
+};
+
+struct FstreeCsr {
+  sqlite3_vtab_cursor base;
+  sqlite3_stmt *pStmt;            /* Statement to list paths */
+  int fd;                         /* File descriptor open on current path */
+};
+
+/*
+** This function is the implementation of both the xConnect and xCreate
+** methods of the fstree 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 fstreeConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  FstreeVtab *pTab;
+
+  if( argc!=3 ){
+    *pzErr = sqlite3_mprintf("wrong number of arguments");
+    return SQLITE_ERROR;
+  }
+
+  pTab = (FstreeVtab *)sqlite3_malloc(sizeof(FstreeVtab));
+  if( !pTab ) return SQLITE_NOMEM;
+  memset(pTab, 0, sizeof(FstreeVtab));
+  pTab->db = db;
+
+  *ppVtab = &pTab->base;
+  sqlite3_declare_vtab(db, "CREATE TABLE xyz(path, size, data);");
+
+  return SQLITE_OK;
+}
+
+/*
+** xDestroy/xDisconnect implementation.
+*/
+static int fstreeDisconnect(sqlite3_vtab *pVtab){
+  sqlite3_free(pVtab);
+  return SQLITE_OK;
+}
+
+/*
+** xBestIndex implementation. The only constraint supported is:
+**
+**   (dir = ?)
+*/
+static int fstreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  int ii;
+
+  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
+    struct sqlite3_index_constraint const *p = &pIdxInfo->aConstraint[ii];
+    if( p->iColumn==0 && p->usable && (
+          p->op==SQLITE_INDEX_CONSTRAINT_GLOB
+       || p->op==SQLITE_INDEX_CONSTRAINT_LIKE
+       || p->op==SQLITE_INDEX_CONSTRAINT_EQ
+    )){
+      struct sqlite3_index_constraint_usage *pUsage;
+      pUsage = &pIdxInfo->aConstraintUsage[ii];
+      pIdxInfo->idxNum = p->op;
+      pUsage->argvIndex = 1;
+      pIdxInfo->estimatedCost = 100000.0;
+      return SQLITE_OK;
+    }
+  }
+
+  pIdxInfo->estimatedCost = 1000000000.0;
+  return SQLITE_OK;
+}
+
+/*
+** xOpen implementation.
+**
+** Open a new fstree cursor.
+*/
+static int fstreeOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  FstreeCsr *pCur;
+  pCur = (FstreeCsr*)sqlite3_malloc(sizeof(FstreeCsr));
+  if( pCur==0 ) return SQLITE_NOMEM;
+  memset(pCur, 0, sizeof(FstreeCsr));
+  pCur->fd = -1;
+  *ppCursor = &pCur->base;
+  return SQLITE_OK;
+}
+
+static void fstreeCloseFd(FstreeCsr *pCsr){
+  if( pCsr->fd>=0 ){
+    close(pCsr->fd);
+    pCsr->fd = -1;
+  }
+}
+
+/*
+** Close a fstree cursor.
+*/
+static int fstreeClose(sqlite3_vtab_cursor *cur){
+  FstreeCsr *pCsr = (FstreeCsr*)cur;
+  sqlite3_finalize(pCsr->pStmt);
+  fstreeCloseFd(pCsr);
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+/*
+** Skip the cursor to the next entry.
+*/
+static int fstreeNext(sqlite3_vtab_cursor *cur){
+  FstreeCsr *pCsr = (FstreeCsr*)cur;
+  int rc;
+
+  fstreeCloseFd(pCsr);
+  rc = sqlite3_step(pCsr->pStmt);
+  if( rc!=SQLITE_ROW ){
+    rc = sqlite3_finalize(pCsr->pStmt);
+    pCsr->pStmt = 0;
+  }else{
+    rc = SQLITE_OK;
+    pCsr->fd = open((const char*)sqlite3_column_text(pCsr->pStmt, 0), O_RDONLY);
+  }
+
+  return rc;
+}
+
+/*
+** xFilter method implementation.
+*/
+static int fstreeFilter(
+  sqlite3_vtab_cursor *pVtabCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  FstreeCsr *pCsr = (FstreeCsr*)pVtabCursor;
+  FstreeVtab *pTab = (FstreeVtab*)(pCsr->base.pVtab);
+  int rc;
+  const char *zSql = 
+"WITH r(d) AS ("
+"  SELECT CASE WHEN dir=?2 THEN ?3 ELSE dir END || '/' || name "
+"    FROM fsdir WHERE dir=?1 AND name NOT LIKE '.%'"
+"  UNION ALL"
+"  SELECT dir || '/' || name FROM r, fsdir WHERE dir=d AND name NOT LIKE '.%'"
+") SELECT d FROM r;";
+
+  char *zRoot;
+  int nRoot;
+  char *zPrefix;
+  int nPrefix;
+  const char *zDir;
+  int nDir;
+  char aWild[2] = { '\0', '\0' };
+
+#if SQLITE_OS_WIN
+  const char *zDrive = windirent_getenv("fstreeDrive");
+  if( zDrive==0 ){
+    zDrive = windirent_getenv("SystemDrive");
+  }
+  zRoot = sqlite3_mprintf("%s%c", zDrive, '/');
+  nRoot = sqlite3Strlen30(zRoot);
+  zPrefix = sqlite3_mprintf("%s", zDrive);
+  nPrefix = sqlite3Strlen30(zPrefix);
+#else
+  zRoot = "/";
+  nRoot = 1;
+  zPrefix = "";
+  nPrefix = 0;
+#endif
+
+  zDir = zRoot;
+  nDir = nRoot;
+
+  fstreeCloseFd(pCsr);
+  sqlite3_finalize(pCsr->pStmt);
+  pCsr->pStmt = 0;
+  rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
+  if( rc!=SQLITE_OK ) return rc;
+
+  if( idxNum ){
+    const char *zQuery = (const char*)sqlite3_value_text(argv[0]);
+    switch( idxNum ){
+      case SQLITE_INDEX_CONSTRAINT_GLOB:
+        aWild[0] = '*';
+        aWild[1] = '?';
+        break;
+      case SQLITE_INDEX_CONSTRAINT_LIKE:
+        aWild[0] = '_';
+        aWild[1] = '%';
+        break;
+    }
+
+    if( sqlite3_strnicmp(zQuery, zPrefix, nPrefix)==0 ){
+      int i;
+      for(i=nPrefix; zQuery[i]; i++){
+        if( zQuery[i]==aWild[0] || zQuery[i]==aWild[1] ) break;
+        if( zQuery[i]=='/' ) nDir = i;
+      }
+      zDir = zQuery;
+    }
+  }
+
+  sqlite3_bind_text(pCsr->pStmt, 1, zDir, nDir, SQLITE_TRANSIENT);
+  sqlite3_bind_text(pCsr->pStmt, 2, zRoot, nRoot, SQLITE_TRANSIENT);
+  sqlite3_bind_text(pCsr->pStmt, 3, zPrefix, nPrefix, SQLITE_TRANSIENT);
+
+#if SQLITE_OS_WIN
+  sqlite3_free(zPrefix);
+  sqlite3_free(zRoot);
+#endif
+
+  return fstreeNext(pVtabCursor); 
+}
+
+/*
+** xEof method implementation.
+*/
+static int fstreeEof(sqlite3_vtab_cursor *cur){
+  FstreeCsr *pCsr = (FstreeCsr*)cur;
+  return pCsr->pStmt==0;
+}
+
+/*
+** xColumn method implementation.
+*/
+static int fstreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  FstreeCsr *pCsr = (FstreeCsr*)cur;
+  if( i==0 ){      /* path */
+    sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pStmt, 0));
+  }else{
+    struct stat sBuf;
+    fstat(pCsr->fd, &sBuf);
+
+    if( S_ISREG(sBuf.st_mode) ){
+      if( i==1 ){
+        sqlite3_result_int64(ctx, sBuf.st_size);
+      }else{
+        int nRead;
+        char *aBuf = sqlite3_malloc(sBuf.st_mode+1);
+        if( !aBuf ) return SQLITE_NOMEM;
+        nRead = read(pCsr->fd, aBuf, sBuf.st_mode);
+        if( nRead!=sBuf.st_mode ){
+          return SQLITE_IOERR;
+        }
+        sqlite3_result_blob(ctx, aBuf, nRead, SQLITE_TRANSIENT);
+        sqlite3_free(aBuf);
+      }
+    }
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** xRowid method implementation.
+*/
+static int fstreeRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
+  *pRowid = 0;
+  return SQLITE_OK;
+}
+/*
+** End of fstree implementation.
+*************************************************************************/
+
+
+
+
+/*
+** 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 x(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 || i==2 );
+  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;
+
+    int n;
+    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;
+    }
+
+    n = (int)read(fd, pCur->zBuf, sbuf.st_size);
+    close(fd);
+    if( n!=sbuf.st_size ) return SQLITE_ERROR;
+    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 */
+};
+
+static sqlite3_module fsdirModule = {
+  0,                              /* iVersion */
+  fsdirConnect,                   /* xCreate */
+  fsdirConnect,                   /* xConnect */
+  fsdirBestIndex,                 /* xBestIndex */
+  fsdirDisconnect,                /* xDisconnect */
+  fsdirDisconnect,                /* xDestroy */
+  fsdirOpen,                      /* xOpen - open a cursor */
+  fsdirClose,                     /* xClose - close a cursor */
+  fsdirFilter,                    /* xFilter - configure scan constraints */
+  fsdirNext,                      /* xNext - advance a cursor */
+  fsdirEof,                       /* xEof - check for end of scan */
+  fsdirColumn,                    /* xColumn - read data */
+  fsdirRowid,                     /* xRowid - read data */
+  0,                              /* xUpdate */
+  0,                              /* xBegin */
+  0,                              /* xSync */
+  0,                              /* xCommit */
+  0,                              /* xRollback */
+  0,                              /* xFindMethod */
+  0,                              /* xRename */
+};
+
+static sqlite3_module fstreeModule = {
+  0,                              /* iVersion */
+  fstreeConnect,                  /* xCreate */
+  fstreeConnect,                  /* xConnect */
+  fstreeBestIndex,                /* xBestIndex */
+  fstreeDisconnect,               /* xDisconnect */
+  fstreeDisconnect,               /* xDestroy */
+  fstreeOpen,                     /* xOpen - open a cursor */
+  fstreeClose,                    /* xClose - close a cursor */
+  fstreeFilter,                   /* xFilter - configure scan constraints */
+  fstreeNext,                     /* xNext - advance a cursor */
+  fstreeEof,                      /* xEof - check for end of scan */
+  fstreeColumn,                   /* xColumn - read data */
+  fstreeRowid,                    /* 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 SQLITE_TCLAPI 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);
+  sqlite3_create_module(db, "fsdir", &fsdirModule, 0);
+  sqlite3_create_module(db, "fstree", &fstreeModule, 0);
+#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;
+}