SQLite

/*
** 2004 April 6
**
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.373 2007/05/04 13:15:56 drh Exp $
** $Id: btree.c,v 1.374 2007/05/04 18:36:45 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

  CellInfo info;            /* A parse of the cell we are pointing at */
  u8 wrFlag;                /* True if writable */
  u8 eState;                /* One of the CURSOR_XXX constants (see below) */
  void *pKey;      /* Saved key that was cursor's last known position */
  i64 nKey;        /* Size of pKey, or last integer key */
  int skip;        /* (skip<0) -> Prev() is a no-op. (skip>0) -> Next() is */
#ifndef SQLITE_OMIT_INCRBLOB
  u8 cacheOverflow;         /* True to use aOverflow */
  u8 isIncrblobHandle;      /* True if this cursor is an incr. io handle */
  Pgno *aOverflow;          /* Cache of overflow page locations */
#endif
};

/*
** Potential values for BtCursor.eState.
**

** If the second argument argument - doSeek - is false, then instead of 
** returning the cursor to it's saved position, any saved position is deleted
** and the cursor state set to CURSOR_INVALID.
*/
static int restoreOrClearCursorPositionX(BtCursor *pCur){
  int rc;
  assert( pCur->eState==CURSOR_REQUIRESEEK );
  if( pCur->isIncrblobHandle ){
    return SQLITE_ABORT;
  }
  pCur->eState = CURSOR_INVALID;
  rc = sqlite3BtreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &pCur->skip);
  if( rc==SQLITE_OK ){
    sqliteFree(pCur->pKey);
    pCur->pKey = 0;
    assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );
  }

** Data is read to or from the buffer pBuf.
**
** This routine does not make a distinction between key and data.
** It just reads or writes bytes from the payload area.  Data might 
** appear on the main page or be scattered out on multiple overflow 
** pages.
**
** If the BtCursor.cacheOverflow flag is set, and the current
** If the BtCursor.isIncrblobHandle flag is set, and the current
** cursor entry uses one or more overflow pages, this function
** allocates space for and lazily popluates the overflow page-list 
** cache array (BtCursor.aOverflow). Subsequent calls use this
** cache to make seeking to the supplied offset more efficient.
**
** Once an overflow page-list cache has been allocated, it may be
** invalidated if some other cursor writes to the same table, or if

  if( rc==SQLITE_OK && amt>0 ){
    const int ovflSize = pBt->usableSize - 4;  /* Bytes content per ovfl page */
    Pgno nextPage;

    nextPage = get4byte(&aPayload[pCur->info.nLocal]);

#ifndef SQLITE_OMIT_INCRBLOB
    /* If the cacheOverflow flag is set and the BtCursor.aOverflow[]
    /* If the isIncrblobHandle flag is set and the BtCursor.aOverflow[]
    ** has not been allocated, allocate it now. The array is sized at
    ** one entry for each overflow page in the overflow chain. The
    ** page number of the first overflow page is stored in aOverflow[0],
    ** etc. A value of 0 in the aOverflow[] array means "not yet known"
    ** (the cache is lazily populated).
    */
    if( pCur->cacheOverflow && !pCur->aOverflow ){
    if( pCur->isIncrblobHandle && !pCur->aOverflow ){
      int nOvfl = (pCur->info.nPayload-pCur->info.nLocal+ovflSize-1)/ovflSize;
      pCur->aOverflow = (Pgno *)sqliteMalloc(sizeof(Pgno)*nOvfl);
      if( nOvfl && !pCur->aOverflow ){
        rc = SQLITE_NOMEM;
      }
    }

/*
** Argument pCsr must be a cursor opened for writing on an 
** INTKEY table currently pointing at a valid table entry. 
** This function modifies the data stored as part of that entry.
** Only the data content may only be modified, it is not possible
** to change the length of the data stored.
*/
int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, const void *z){
int sqlite3BtreePutData(BtCursor *pCsr, u32 offset, u32 amt, void *z){
  BtShared *pBt = pCsr->pBtree->pBt;

  assert(pCsr->isIncrblobHandle);
  if( pCsr->eState==CURSOR_REQUIRESEEK ){
    return SQLITE_ABORT;
  }

  /* Check some preconditions: 
  **   (a) a write-transaction is open, 
  **   (b) the cursor is open for writing,
  **   (c) there is no read-lock on the table being modified and
  **   (d) the cursor points at a valid row of an intKey table.
  **   (a) the cursor is open for writing,
  **   (b) there is no read-lock on the table being modified and
  **   (c) the cursor points at a valid row of an intKey table.
  */
  if( pBt->inTransaction!=TRANS_WRITE ){
    /* Must start a transaction before writing to a blob */
    return pBt->readOnly ? SQLITE_READONLY : SQLITE_ERROR;
  }
  assert( !pBt->readOnly );
  if( !pCsr->wrFlag ){
    return SQLITE_PERM;   /* Cursor not open for writing */
    return SQLITE_READONLY;
  }
  assert( !pBt->readOnly && pBt->inTransaction==TRANS_WRITE );
  if( checkReadLocks(pCsr->pBtree, pCsr->pgnoRoot, pCsr) ){
    return SQLITE_LOCKED; /* The table pCur points to has a read lock */
  }
  if( pCsr->eState==CURSOR_INVALID || !pCsr->pPage->intKey ){
    return SQLITE_ERROR;
  }

**
** This function sets a flag only. The actual page location cache
** (stored in BtCursor.aOverflow[]) is allocated and used by function
** accessPayload() (the worker function for sqlite3BtreeData() and
** sqlite3BtreePutData()).
*/
void sqlite3BtreeCacheOverflow(BtCursor *pCur){
  assert(!pCur->cacheOverflow);
  assert(!pCur->isIncrblobHandle);
  assert(!pCur->aOverflow);
  pCur->cacheOverflow = 1;
  pCur->isIncrblobHandle = 1;
}
#endif

/*
** The following debugging interface has to be in this file (rather
** than in, for example, test1.c) so that it can get access to
** the definition of BtShared.

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.78 2007/05/02 16:48:37 danielk1977 Exp $
** @(#) $Id: btree.h,v 1.79 2007/05/04 18:36:45 danielk1977 Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/

const void *sqlite3BtreeDataFetch(BtCursor*, int *pAmt);
int sqlite3BtreeDataSize(BtCursor*, u32 *pSize);
int sqlite3BtreeData(BtCursor*, u32 offset, u32 amt, void*);

char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
struct Pager *sqlite3BtreePager(Btree*);

int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, const void*);
int sqlite3BtreePutData(BtCursor*, u32 offset, u32 amt, void*);
void sqlite3BtreeCacheOverflow(BtCursor *);

#ifdef SQLITE_TEST
int sqlite3BtreeCursorInfo(BtCursor*, int*, int);
void sqlite3BtreeCursorList(Btree*);
#endif

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** A TCL Interface to SQLite.  Append this file to sqlite3.c and
** compile the whole thing to build a TCL-enabled version of SQLite.
**
** $Id: tclsqlite.c,v 1.184 2007/05/04 13:15:56 drh Exp $
** $Id: tclsqlite.c,v 1.185 2007/05/04 18:36:45 danielk1977 Exp $
*/
#include "tcl.h"
#include <errno.h>

/*
** Some additional include files are needed if this file is not
** appended to the amalgamation.

  SqlPreparedStmt *stmtLast; /* Last statement in the list */
  int maxStmt;               /* The next maximum number of stmtList */
  int nStmt;                 /* Number of statements in stmtList */
  IncrblobChannel *pIncrblob;/* Linked list of open incrblob channels */
};

struct IncrblobChannel {
  SqliteDb *pDb;            /* Associated database connection */
  sqlite3_blob *pBlob;      /* sqlite3 blob handle */
  SqliteDb *pDb;            /* Associated database connection */
  int iSeek;                /* Current seek offset */

  Tcl_Channel channel;      /* Channel identifier */
  IncrblobChannel *pNext;   /* Linked list of all open incrblob channels */
  IncrblobChannel *pPrev;   /* Linked list of all open incrblob channels */
};

/*
** Close all incrblob channels opened using database connection pDb.

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing all sorts of SQLite interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.242 2007/05/02 16:51:59 drh Exp $
** $Id: test1.c,v 1.243 2007/05/04 18:36:45 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

  Tcl_ListObjAppendElement(0, pRet, Tcl_NewIntObj(autoincrement));
  Tcl_SetObjResult(interp, pRet);

  return TCL_OK;
}
#endif

#ifndef SQLITE_OMIT_INCRBLOB

/*
** sqlite3_blob_read  CHANNEL OFFSET N
*/
static int test_blob_read(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  Tcl_Channel channel;
  ClientData instanceData;
  sqlite3_blob *pBlob;
  int notUsed;
  int nByte;
  int iOffset;
  unsigned char *zBuf;
  int rc;
  
  if( objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "CHANNEL OFFSET N");
    return TCL_ERROR;
  }

  channel = Tcl_GetChannel(interp, Tcl_GetString(objv[1]), &notUsed);
  if( !channel
   || TCL_OK!=Tcl_GetIntFromObj(interp, objv[2], &iOffset)
   || TCL_OK!=Tcl_GetIntFromObj(interp, objv[3], &nByte)
   || nByte<0 || iOffset<0
  ){ 
    return TCL_ERROR;
  }

  instanceData = Tcl_GetChannelInstanceData(channel);
  pBlob = *((sqlite3_blob **)instanceData);

  zBuf = (unsigned char *)Tcl_Alloc(nByte);
  rc = sqlite3_blob_read(pBlob, zBuf, nByte, iOffset);
  if( rc==SQLITE_OK ){
    Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(zBuf, nByte));
  }else{
    Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
  }
  Tcl_Free((char *)zBuf);

  return (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
}

/*
** sqlite3_blob_write CHANNEL OFFSET DATA
*/
static int test_blob_write(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  Tcl_Channel channel;
  ClientData instanceData;
  sqlite3_blob *pBlob;
  int notUsed;
  int iOffset;
  int rc;

  unsigned char *zBuf;
  int nBuf;
  
  if( objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "CHANNEL OFFSET DATA");
    return TCL_ERROR;
  }

  channel = Tcl_GetChannel(interp, Tcl_GetString(objv[1]), &notUsed);
  if( !channel
   || TCL_OK!=Tcl_GetIntFromObj(interp, objv[2], &iOffset)
   || iOffset<0
  ){ 
    return TCL_ERROR;
  }

  instanceData = Tcl_GetChannelInstanceData(channel);
  pBlob = *((sqlite3_blob **)instanceData);

  zBuf = Tcl_GetByteArrayFromObj(objv[3], &nBuf);
  rc = sqlite3_blob_write(pBlob, zBuf, nBuf, iOffset);
  if( rc!=SQLITE_OK ){
    Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), TCL_VOLATILE);
  }

  return (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
}
#endif

/*
** Usage: sqlite3_load_extension DB-HANDLE FILE ?PROC?
*/
static int test_load_extension(
  ClientData clientData, /* Not used */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */

#ifndef SQLITE_OMIT_SHARED_CACHE
     { "sqlite3_enable_shared_cache", test_enable_shared, 0  },
#endif
     { "sqlite3_libversion_number", test_libversion_number, 0  },
#ifdef SQLITE_ENABLE_COLUMN_METADATA
     { "sqlite3_table_column_metadata", test_table_column_metadata, 0  },
#endif
#ifndef SQLITE_OMIT_INCRBLOB
     { "sqlite3_blob_read",  test_blob_read, 0  },
     { "sqlite3_blob_write", test_blob_write, 0  },
#endif
  };
  static int bitmask_size = sizeof(Bitmask)*8;
  int i;
  extern int sqlite3_os_trace;
  extern int sqlite3_where_trace;
  extern int sqlite3_sync_count, sqlite3_fullsync_count;
  extern int sqlite3_opentemp_count;

/*
** 2007 May 1
**
** 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.
**
*************************************************************************
**
** $Id: vdbeblob.c,v 1.7 2007/05/04 13:15:57 drh Exp $
** $Id: vdbeblob.c,v 1.8 2007/05/04 18:36:45 danielk1977 Exp $
*/

#include "sqliteInt.h"
#include "vdbeInt.h"

#ifndef SQLITE_OMIT_INCRBLOB

int sqlite3_blob_close(sqlite3_blob *pBlob){
  Incrblob *p = (Incrblob *)pBlob;
  sqlite3_stmt *pStmt = p->pStmt;
  sqliteFree(p);
  return sqlite3_finalize(pStmt);
}

/*
** Read data from a blob handle.
*/
int sqlite3_blob_read(sqlite3_blob *pBlob, void *z, int n, int iOffset){
  int rc = SQLITE_ERROR;

int blobReadWrite(
  sqlite3_blob *pBlob, 
  void *z, 
  int n, 
  int iOffset, 
  int (*xCall)(BtCursor*, u32, u32, void*)
){
  int rc;
  Incrblob *p = (Incrblob *)pBlob;
  Vdbe *v = (Vdbe *)(p->pStmt);
  sqlite3 *db;  

  /* If there is no statement handle, then the blob-handle has
  ** already been invalidated. Return SQLITE_ABORT in this case.
  */
  if( !v ) return SQLITE_ABORT;

  /* Request is out of range. Return a transient error. */
  if( (iOffset+n)<=p->nByte ){
  if( (iOffset+n)>p->nByte ){
    rc = sqlite3BtreeData(p->pCsr, iOffset+p->iOffset, n, z);
    return SQLITE_ERROR;
  }

  /* Call either BtreeData() or BtreePutData(). If SQLITE_ABORT is
  ** returned, clean-up the statement handle.
  */
  db = v->db;
  rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
  if( rc==SQLITE_ABORT ){
    sqlite3VdbeFinalize(v);
    p->pStmt = 0;
  }else{
  v->rc = rc;
  return sqlite3ApiExit(v->db, v->rc);
    v->rc = rc;
  }

  return sqlite3ApiExit(db, rc);
}

/*
** Read data from a blob handle.
*/
int sqlite3_blob_read(sqlite3_blob *pBlob, void *z, int n, int iOffset){
  return blobReadWrite(pBlob, z, n, iOffset, sqlite3BtreeData);
}

/*
** Write data to a blob handle.
*/
int sqlite3_blob_write(sqlite3_blob *pBlob, const void *z, int n, int iOffset){
  int rc = SQLITE_ERROR;
  Incrblob *p = (Incrblob *)pBlob;
  Vdbe *v = (Vdbe *)(p->pStmt);
  if( (iOffset+n)<=p->nByte ){
    rc = sqlite3BtreePutData(p->pCsr, iOffset+p->iOffset, n, z);
  return blobReadWrite(pBlob, (void *)z, n, iOffset, sqlite3BtreePutData);
  }
  v->rc = rc;
  return sqlite3ApiExit(v->db, v->rc);
}

/*
** Query a blob handle for the size of the data.
*/
int sqlite3_blob_bytes(sqlite3_blob *pBlob){
  Incrblob *p = (Incrblob *)pBlob;
  return p->nByte;
}

#endif /* #ifndef SQLITE_OMIT_INCRBLOB */

# 2007 May 1
#
# 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.
#
#***********************************************************************
#
# $Id: incrblob.test,v 1.7 2007/05/04 14:36:22 drh Exp $
# $Id: incrblob.test,v 1.8 2007/05/04 18:36:46 danielk1977 Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test incrblob-1.1 {
  execsql {

}

#------------------------------------------------------------------------
# incrblob-3.*: 
#
# Test the outcome of trying to write to a read-only blob handle.
#
# TODO: The following test only tests the tcl interface, not the
# underlying sqlite3 interface. Need to find some other method
# to call sqlite3_blob_write() on a readonly handle...
#
do_test incrblob-3.1 {
  set ::blob [db incrblob -readonly blobs v 1]
  seek $::blob -40 end
  read $::blob 20
} "1234567890abcdefghij"
do_test incrblob-3.2 {
  seek $::blob 0
  set rc [catch {
    puts -nonewline $::blob "helloworld"
  } msg]
  close $::blob
  list $rc $msg
} "1 {channel \"$::blob\" wasn't opened for writing}"

do_test incrblob-3.3 {
  set ::blob [db incrblob -readonly blobs v 1]
  seek $::blob -40 end
  read $::blob 20
} "1234567890abcdefghij"
do_test incrblob-3.4 {
  set rc [catch {
    sqlite3_blob_write $::blob 20 "qwertyuioplkjhgfds" 
  } msg]
  list $rc $msg
} {1 SQLITE_READONLY}
catch {close $::blob}

#------------------------------------------------------------------------
# incrblob-4.*: 
#
# Try a couple of error conditions:
#
#     4.1 - Attempt to open a row that does not exist.

do_test incrblob-6.7 {
  set ::blob [db2 incrblob blobs i 4]
  gets $::blob
} {connection}
do_test incrblob-6.8 {
  tell $::blob
} {10}
breakpoint
do_test incrblob-6.9 {
  seek $::blob 0
  puts -nonewline $::blob "invocation"
  flush $::blob
} {}

# At this point rollback or commit should be illegal (because 

do_test incrblob-6.14 {
  execsql {
    SELECT * FROM blobs WHERE rowid = 4;
  }
} {a different invocation}
db2 close

#-----------------------------------------------------------------------
# The following tests verify the behaviour of the incremental IO
# APIs in the following cases:
#
#     7.1 A row that containing an open blob is modified.
#
#     7.2 A CREATE TABLE requires that an overflow page that is part
#         of an open blob is moved.
#
#     7.3 An INCREMENTAL VACUUM moves an overflow page that is part
#         of an open blob.
#
# In the first case above, correct behaviour is for all subsequent
# read/write operations on the blob-handle to return SQLITE_ABORT.
# More accurately, blob-handles are invalidated whenever the table
# they belong to is written to.
#
# The second two cases have no external effect. They are testing
# that the internal cache of overflow page numbers is correctly
# invalidated.
#
do_test incrblob-7.1.0 {
  execsql {
    BEGIN;
    DROP TABLE blobs;
    CREATE TABLE t1 (a, b, c, d BLOB);
    INSERT INTO t1(a, b, c, d) VALUES(1, 2, 3, 4);
    COMMIT;
  }
} {}

foreach {tn arg} {1 "" 2 -readonly} {

  execsql {
    UPDATE t1 SET d = zeroblob(10000);
  }

  do_test incrblob-7.1.$tn.1 {
    set ::b [eval db incrblob $arg t1 d 1]
    binary scan [sqlite3_blob_read $::b 5000 5] c* c
    set c
  } {0 0 0 0 0}
  do_test incrblob-7.1.$tn.2 {
    execsql {
      UPDATE t1 SET d = 15;
    }
  } {}
  do_test incrblob-7.1.$tn.3 {
    set rc [catch { sqlite3_blob_read $::b 5000 5 } msg]
    list $rc $msg
  } {1 SQLITE_ABORT}
  do_test incrblob-7.1.$tn.4 {
    execsql {
      SELECT d FROM t1;
    }
  } {15}
  do_test incrblob-7.1.$tn.5 {
    set rc [catch { close $::b } msg]
    list $rc $msg
  } {0 {}}
  do_test incrblob-7.1.$tn.6 {
    execsql {
      SELECT d FROM t1;
    }
  } {15}

}

set fd [open [info script]]
set ::data [read $fd]
close $fd

db close
file delete -force test.db test.db-journal
sqlite3 db test.db

do_test incrblob-7.2.1 {
  execsql {
    PRAGMA auto_vacuum = "incremental";
    CREATE TABLE t1(a INTEGER PRIMARY KEY, b);        -- root@page3
    INSERT INTO t1 VALUES(123, $::data);
  }
  set ::b [db incrblob -readonly t1 b 123]
  read $::b
} $::data
do_test incrblob-7.2.2 {
  execsql {
    CREATE TABLE t2(a INTEGER PRIMARY KEY, b);        -- root@page4
  }
  seek $::b 0
  read $::b
} $::data
do_test incrblob-7.2.3 {
  close $::b
  execsql {
    SELECT rootpage FROM sqlite_master;
  }
} {3 4}

set ::otherdata "[string range $::data 0 1000][string range $::data 1001 end]"
do_test incrblob-7.3.1 {
  execsql {
    INSERT INTO t2 VALUES(456, $::otherdata);
  }
  set ::b [db incrblob -readonly t2 b 456]
  read $::b
} $::otherdata
do_test incrblob-7.3.2 {
  expr [file size test.db]/1024
} 30
do_test incrblob-7.3.3 {
  execsql {
    DELETE FROM t1 WHERE a = 123;
    INCREMENTAL VACUUM;
  }
  seek $::b 0
  read $::b
} $::otherdata

finish_test