SQLite

#ifdef SQLITE_DEBUG
# define FTS5_CORRUPT sqlite3Fts5Corrupt()
int sqlite3Fts5Corrupt(void);
#else
# define FTS5_CORRUPT SQLITE_CORRUPT_VTAB
#endif

/*
** The assert_nc() macro is similar to the assert() macro, except that it
** is used for assert() conditions that are true only if it can be 
** guranteed that the database is not corrupt.
*/
#ifdef SQLITE_TEST
extern int sqlite3_fts5_may_be_corrupt;
# define assert_nc(x) assert(sqlite3_fts5_may_be_corrupt || (x))
#else
# define assert_nc(x) assert(x)
#endif

/**************************************************************************
** Interface to code in fts5.c. 
*/
typedef struct Fts5Global Fts5Global;

int sqlite3Fts5GetTokenizer(
  Fts5Global*, 

  if( p->pReader ){
    sqlite3_blob *pReader = p->pReader;
    p->pReader = 0;
    sqlite3_blob_close(pReader);
  }
}

/*
** Check if row iRowid exists in the %_data table, and that it contains
** a blob value. If so, return SQLITE_ERROR (yes - SQLITE_ERROR, not 
** SQLITE_OK). If not, return SQLITE_CORRUPT_VTAB.
**
** If an error occurs (e.g. OOM or IOERR), return the relevant error code.
**
** This function does not need to be efficient. It is part of vary rarely
** invoked error handling code only.
*/
#if 0
static int fts5CheckMissingRowid(Fts5Index *p, i64 iRowid){
  const char *zFmt = "SELECT typeof(block)=='blob' FROM '%q'.%Q WHERE id=%lld";
  int bOk = 0;
  int rc;
  char *zSql;

  zSql = sqlite3_mprintf(zFmt, p->pConfig->zDb, p->zDataTbl, iRowid);
  if( zSql==0 ){
    rc = SQLITE_NOMEM;
  }else{
    sqlite3_stmt *pStmt;
    rc = sqlite3_prepare_v2(p->pConfig->db, zSql, -1, &pStmt, 0);
    if( rc==SQLITE_OK ){
      if( SQLITE_ROW==sqlite3_step(pStmt) ){
        bOk = sqlite3_column_int(pStmt, 0);
      }
      rc = sqlite3_finalize(pStmt);
    }
    sqlite3_free(zSql);
  }

  if( rc==SQLITE_OK ){
    rc = bOk ? SQLITE_ERROR : FTS5_CORRUPT;
  }

  return rc;
}
#endif

static Fts5Data *fts5DataReadOrBuffer(
  Fts5Index *p, 
  Fts5Buffer *pBuf, 
  i64 iRowid
){
  Fts5Data *pRet = 0;
  if( p->rc==SQLITE_OK ){
    int rc = SQLITE_OK;








    if( p->pReader ){
      /* This call may return SQLITE_ABORT if there has been a savepoint
      ** rollback since it was last used. In this case a new blob handle
      ** is required.  */
      rc = sqlite3_blob_reopen(p->pReader, iRowid);
      if( rc==SQLITE_ABORT ){
        fts5CloseReader(p);
        rc = SQLITE_OK;
      }
    }

    /* If the blob handle is not yet open, open and seek it. Otherwise, use
    ** the blob_reopen() API to reseek the existing blob handle.  */
    if( p->pReader==0 ){
      Fts5Config *pConfig = p->pConfig;
      rc = sqlite3_blob_open(pConfig->db, 
          pConfig->zDb, p->zDataTbl, "block", iRowid, 0, &p->pReader
      );
    }

    /* If either of the sqlite3_blob_open() or sqlite3_blob_reopen() calls
    ** above returned SQLITE_ERROR, return SQLITE_CORRUPT_VTAB instead.
    ** All the reasons those functions might return SQLITE_ERROR - missing
    ** table, missing row, non-blob/text in block column - indicate 
    ** backing store corruption.  */
    if( rc==SQLITE_ERROR ) rc = FTS5_CORRUPT;

    if( rc==SQLITE_OK ){
      u8 *aOut;                   /* Read blob data into this buffer */
      int nByte = sqlite3_blob_bytes(p->pReader);
      if( pBuf ){
        fts5BufferZero(pBuf);
        fts5BufferGrow(&rc, pBuf, nByte);

** Leave Fts5SegIter.iLeafOffset pointing to the first byte of the 
** position list content (if any).
*/
static void fts5SegIterLoadNPos(Fts5Index *p, Fts5SegIter *pIter){
  if( p->rc==SQLITE_OK ){
    const u8 *a = &pIter->pLeaf->p[pIter->iLeafOffset];
    int iOff = pIter->iLeafOffset;  /* Offset to read at */
    pIter->iLeafOffset += fts5GetPoslistSize(a, &pIter->nPos, &pIter->bDel);
  }
}

/*
** Fts5SegIter.iLeafOffset currently points to the first byte of the 
** "nSuffix" field of a term. Function parameter nKeep contains the value
** of the "nPrefix" field (if there was one - it is passed 0 if this is
** the first term in the segment).
**
** This function populates:
**
**   Fts5SegIter.term
**   Fts5SegIter.rowid


**
** accordingly and leaves (Fts5SegIter.iLeafOffset) set to the content of
** the first position list. The position list belonging to document 
** (Fts5SegIter.iRowid).
*/
static void fts5SegIterLoadTerm(Fts5Index *p, Fts5SegIter *pIter, int nKeep){
  u8 *a = pIter->pLeaf->p;        /* Buffer to read data from */

      }
    }
  }

  pIter->nEmpty = pIter->aLvl[0].s.nEmpty;
  pIter->bDlidx = pIter->aLvl[0].s.bDlidx;
  pIter->iLeaf = pIter->aLvl[0].s.iChild;

}

static void fts5BtreeIterFree(Fts5BtreeIter *pIter){
  int i;
  for(i=0; i<pIter->nLvl; i++){
    Fts5BtreeIterLevel *pLvl = &pIter->aLvl[i];
    fts5NodeIterFree(&pLvl->s);

  int iIdx,                       /* Index that pSeg is a part of */
  Fts5StructureSegment *pSeg      /* Segment to check internal consistency */
){
  Fts5BtreeIter iter;             /* Used to iterate through b-tree hierarchy */

  /* Iterate through the b-tree hierarchy.  */
  for(fts5BtreeIterInit(p, iIdx, pSeg, &iter);
      p->rc==SQLITE_OK && iter.bEof==0;
      fts5BtreeIterNext(&iter)
  ){
    i64 iRow;                     /* Rowid for this leaf */
    Fts5Data *pLeaf;              /* Data for this leaf */
    int iOff;                     /* Offset of first term on leaf */
    int i;                        /* Used to iterate through empty leaves */

#ifdef SQLITE_ENABLE_FTS5

#include "fts5.h"
#include <string.h>
#include <assert.h>

/*
** This variable is set to true when running corruption tests. Otherwise
** false. If it is false, extra assert() conditions in the fts5 code are
** activated - conditions that are only true if it is guaranteed that the
** fts5 database is not corrupt.
*/
int sqlite3_fts5_may_be_corrupt = 0;

/*************************************************************************
** This is a copy of the first part of the SqliteDb structure in 
** tclsqlite.c.  We need it here so that the get_sqlite_pointer routine
** can extract the sqlite3* pointer from an existing Tcl SQLite
** connection.
*/
struct SqliteDb {

  return TCL_OK;
}

static void xF5tFree(ClientData clientData){
  ckfree(clientData);
}

/*
**      sqlite3_fts5_may_be_corrupt BOOLEAN
**
** Set or clear the global "may-be-corrupt" flag. Return the old value.
*/
static int f5tMayBeCorrupt(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  int bOld = sqlite3_fts5_may_be_corrupt;

  if( objc!=2 && objc!=1 ){
    Tcl_WrongNumArgs(interp, 1, objv, "?BOOLEAN?");
    return TCL_ERROR;
  }
  if( objc==2 ){
    int bNew;
    if( Tcl_GetBooleanFromObj(interp, objv[1], &bNew) ) return TCL_ERROR;
    sqlite3_fts5_may_be_corrupt = bNew;
  }

  Tcl_SetObjResult(interp, Tcl_NewIntObj(bOld));
  return TCL_OK;
}

/*
** Entry point.
*/
int Fts5tcl_Init(Tcl_Interp *interp){
  static struct Cmd {
    char *zName;
    Tcl_ObjCmdProc *xProc;
    int bTokenizeCtx;
  } aCmd[] = {
    { "sqlite3_fts5_create_tokenizer", f5tCreateTokenizer, 1 },
    { "sqlite3_fts5_token",            f5tTokenizerReturn, 1 },
    { "sqlite3_fts5_tokenize",         f5tTokenize, 0 },
    { "sqlite3_fts5_create_function",  f5tCreateFunction, 0 },
    { "sqlite3_fts5_may_be_corrupt",   f5tMayBeCorrupt, 0 }
  };
  int i;
  F5tTokenizerContext *pContext;

  pContext = ckalloc(sizeof(F5tTokenizerContext));
  memset(pContext, 0, sizeof(*pContext));

# 2014 Dec 20
#
# 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.
#
#***********************************************************************
#
# This file tests that the FTS5 'integrity-check' command detects 
# inconsistencies (corruption) in the on-disk backing tables.
#

source [file join [file dirname [info script]] fts5_common.tcl]
set testprefix fts5corrupt

do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x);

set segid [lindex [fts5_level_segids t1] 0]

do_test 1.3 {
  execsql {
    DELETE FROM t1_data WHERE rowid = fts5_rowid('segment', 0, $segid, 0, 4);
  }
  catchsql { INSERT INTO t1(t1) VALUES('integrity-check') }
} {1 {database disk image is malformed}}

do_test 1.4 {
  db_restore_and_reopen
  execsql {
    UPDATE t1_data set block = X'00000000' || substr(block, 5) WHERE
    rowid = fts5_rowid('segment', 0, $segid, 0, 4);
  }

# 2015 Apr 24
#
# 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.
#
#***********************************************************************
#
# This file tests that FTS5 handles corrupt databases (i.e. internal
# inconsistencies in the backing tables) correctly. In this case 
# "correctly" means without crashing.
#

source [file join [file dirname [info script]] fts5_common.tcl]
set testprefix fts5corrupt2

# Create a simple FTS5 table containing 100 documents. Each document 
# contains 10 terms, each of which start with the character "x".
#
expr srand(0)
db func rnddoc fts5_rnddoc
do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE t1 USING fts5(x);
  INSERT INTO t1(t1, rank) VALUES('pgsz', 32);
  WITH ii(i) AS (SELECT 1 UNION SELECT i+1 FROM ii WHERE i<100)
  INSERT INTO t1 SELECT rnddoc(10) FROM ii;
}

set mask [expr 31 << 31]

# Test 1:
#
#   For each page in the t1_data table, open a transaction and DELETE
#   the t1_data entry. Then run:
#
#     * an integrity-check, and
#     * unless the deleted block was a b-tree node, a query for "t1 MATCH 'x*'"
#
#   and check that the corruption is detected in both cases. The 
#   rollback the transaction.
#
# Test 2:
#
#   Same thing, except instead of deleting a row from t1_data, replace its
#   blob content with integer value 14.
#
foreach {tno stmt} {
  1 { DELETE FROM t1_data WHERE rowid=$rowid }
  2 { UPDATE t1_data SET block=14 WHERE rowid=$rowid }
} {
  break
  set tn 0
  foreach rowid [db eval {SELECT rowid FROM t1_data WHERE rowid>10}] {
    incr tn
    #if {$tn!=224} continue
  
    do_test 1.$tno.$tn.1.$rowid {
      execsql { BEGIN }
      execsql $stmt
      catchsql { INSERT INTO t1(t1) VALUES('integrity-check') }
    } {1 {database disk image is malformed}}
  
    if {($rowid & $mask)==0} {
      # Node is a leaf node, not a b-tree node.
      do_catchsql_test 1.$tno.$tn.2.$rowid {
        SELECT rowid FROM t1 WHERE t1 MATCH 'x*'
      } {1 {database disk image is malformed}}
    }
  
    do_execsql_test 1.$tno.$tn.3.$rowid {
      ROLLBACK;
      INSERT INTO t1(t1) VALUES('integrity-check');
    } {}
  }
}

# Run N-1 tests, where N is the number of bytes in the rightmost leaf page
# of the fts index. For test $i, truncate the rightmost leafpage to $i
# bytes. Then test both the integrity-check detects the corruption.
#
# Also tested is that "MATCH 'x*'" does not crash and sometimes reports
# corruption. It may not report the db as corrupt because truncating the
# final leaf to some sizes may create a valid leaf page.
#
set lrowid [db one {SELECT max(rowid) FROM t1_data WHERE (rowid & $mask)=0}] 
set nbyte [db one {SELECT length(block) FROM t1_data WHERE rowid=$lrowid}]
set all [db eval {SELECT rowid FROM t1}]
for {set i [expr $nbyte-2]} {$i>=0} {incr i -1} {
  do_execsql_test 2.$i.1 {
    BEGIN;
      UPDATE t1_data SET block = substr(block, 1, $i) WHERE rowid=$lrowid;
  }

  do_catchsql_test 2.$i.2 {
    INSERT INTO t1(t1) VALUES('integrity-check');
  } {1 {database disk image is malformed}}

  do_test 2.$i.3 {
    set res [catchsql {SELECT rowid FROM t1 WHERE t1 MATCH 'x*'}]
    expr {
        $res=="1 {database disk image is malformed}" 
     || $res=="0 {$all}" 
    }
  } 1

  do_execsql_test 2.$i.4 {
    ROLLBACK;
    INSERT INTO t1(t1) VALUES('integrity-check');
  } {}
}

finish_test

do_execsql_test 1.5 {
  DELETE FROM f1_data;
} {}

do_catchsql_test 1.6 {
  INSERT INTO f1(f1) VALUES('integrity-check');
} {1 {database disk image is malformed}}

do_execsql_test 1.7 {
  INSERT INTO f1(f1) VALUES('rebuild');
  INSERT INTO f1(f1) VALUES('integrity-check');
} {}

finish_test