SQLite

/*
** 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 1.5 2007/05/03 18:14:10 danielk1977 Exp $
*/

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

#ifndef SQLITE_OMIT_INCRBLOB

      return rc;
    }

    pTab = sqlite3LocateTable(&sParse, zTable, zDb);
    if( !pTab ){
      if( sParse.zErrMsg ){
        sqlite3_snprintf(sizeof(zErr), zErr, "%s", sParse.zErrMsg);

      }
      sqliteFree(sParse.zErrMsg);
      rc = SQLITE_ERROR;
      sqlite3SafetyOff(db);
      goto blob_open_out;
    }

    /* Now search pTab for the exact column. */
    for(iCol=0; iCol < pTab->nCol; iCol++) {
      if( sqlite3StrICmp(pTab->aCol[iCol].zName, zColumn)==0 ){
        break;
      }
    }
    if( iCol==pTab->nCol ){
      sqlite3_snprintf(sizeof(zErr), zErr, "no such column: \"%s\"", zColumn);
      rc = SQLITE_ERROR;
      sqlite3SafetyOff(db);
      goto blob_open_out;
    }

    /* If the value is being opened for writing, check that the
    ** column is not indexed. It is against the rules to open an
    ** indexed column for writing.
    */
    if( flags ){
      Index *pIdx;
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        int j;
        for(j=0; j<pIdx->nColumn; j++){
          if( pIdx->aiColumn[j]==iCol ){
            strcpy(zErr, "cannot open indexed column for writing");
            rc = SQLITE_ERROR;
            sqlite3SafetyOff(db);
            goto blob_open_out;
          }
        }
      }
    }

    v = sqlite3VdbeCreate(db);
    if( v ){
      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      sqlite3VdbeAddOpList(v, sizeof(openBlob)/sizeof(VdbeOpList), openBlob);

      /* Configure the OP_Transaction */
      sqlite3VdbeChangeP1(v, 0, iDb);
      sqlite3VdbeChangeP2(v, 0, (flags ? 1 : 0));

      /* Configure the OP_VerifyCookie */
      sqlite3VdbeChangeP1(v, 1, iDb);
      sqlite3VdbeChangeP2(v, 1, pTab->pSchema->schema_cookie);

      /* Configure the db number pushed onto the stack */
      sqlite3VdbeChangeP1(v, 2, iDb);

      /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
      ** parameter of the other to pTab->tnum. 
      */
      sqlite3VdbeChangeToNoop(v, (flags ? 3 : 4), 1);
      sqlite3VdbeChangeP2(v, (flags ? 4 : 3), pTab->tnum);

      /* Configure the OP_SetNumColumns. Configure the cursor to
      ** think that the table has one more column than it really
      ** does. An OP_Column to retrieve this imaginary column will

    }

    sqlite3_bind_int64((sqlite3_stmt *)v, 1, iRow);
    rc = sqlite3_step((sqlite3_stmt *)v);
    if( rc!=SQLITE_ROW ){
      nAttempt++;
      rc = sqlite3_finalize((sqlite3_stmt *)v);
      sqlite3_snprintf(sizeof(zErr), zErr, sqlite3_errmsg(db));
      v = 0;
    }
  } while( nAttempt<5 && rc==SQLITE_SCHEMA );

  if( rc==SQLITE_ROW ){
    /* The row-record has been opened successfully. Check that the
    ** column in question contains text or a blob. If it contains
    ** text, it is up to the caller to get the encoding right.
    */
    Incrblob *pBlob;
    u32 type = v->apCsr[0]->aType[iCol];

    if( type<12 ){
      sqlite3_snprintf(sizeof(zErr), zErr, "cannot open value of type %s",
          type==0?"null": type==7?"real": "integer"
      );
      rc = SQLITE_ERROR;
      goto blob_open_out;
    }
    pBlob = (Incrblob *)sqliteMalloc(sizeof(Incrblob));
    if( sqlite3MallocFailed() ){
      sqliteFree(pBlob);
      goto blob_open_out;
    }
    pBlob->flags = flags;
    pBlob->pCsr =  v->apCsr[0]->pCursor;
    sqlite3BtreeCacheOverflow(pBlob->pCsr);
    pBlob->pStmt = (sqlite3_stmt *)v;
    pBlob->iOffset = v->apCsr[0]->aOffset[iCol];
    pBlob->nByte = sqlite3VdbeSerialTypeLen(type);
    *ppBlob = (sqlite3_blob *)pBlob;
    rc = SQLITE_OK;
  }else if( rc==SQLITE_OK ){
    sqlite3_snprintf(sizeof(zErr), zErr, "no such rowid: %lld", iRow);
    rc = SQLITE_ERROR;
  }

blob_open_out:
  if( rc!=SQLITE_OK || sqlite3MallocFailed() ){
    sqlite3_finalize((sqlite3_stmt *)v);
  }
  zErr[sizeof(zErr)-1] = '\0';
  sqlite3Error(db, rc, zErr);
  return sqlite3ApiExit(db, rc);
}

/*
** Close a blob handle.
*/

# 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 1.6 2007/05/03 18:14:10 danielk1977 Exp $
#

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

do_test incrblob-1.1 {
  execsql {

  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}"

#------------------------------------------------------------------------
# incrblob-4.*: 
#
# Try a couple of error conditions:
#
#     4.1 - Attempt to open a row that does not exist.
#     4.2 - Attempt to open a column that does not exist.
#     4.3 - Attempt to open a table that does not exist.
#     4.4 - Attempt to open a database that does not exist.
#
#     4.5 - Attempt to open an integer
#     4.6 - Attempt to open a real value
#     4.7 - Attempt to open an SQL null
#
#     4.8 - Attempt to open an indexed column for writing
#     4.9 - Attempt to open an indexed column for reading (this works)
#
do_test incrblob-4.1 {
  set rc [catch {
    set ::blob [db incrblob blobs v 2]
  } msg ] 
  list $rc $msg
} {1 {no such rowid: 2}}

do_test incrblob-4.2 {
  set rc [catch {
    set ::blob [db incrblob blobs blue 1]
  } msg ] 
  list $rc $msg
} {1 {no such column: "blue"}}

do_test incrblob-4.3 {
  set rc [catch {
    set ::blob [db incrblob nosuchtable blue 1]
  } msg ]
  list $rc $msg
} {1 {no such table: main.nosuchtable}}

do_test incrblob-4.4 {
  set rc [catch {
    set ::blob [db incrblob nosuchdb blobs v 1]
  } msg ] 
  list $rc $msg
} {1 {no such table: nosuchdb.blobs}}

do_test incrblob-4.5 {
  set rc [catch {
    set ::blob [db incrblob blobs i 1]
  } msg ] 
  list $rc $msg
} {1 {cannot open value of type integer}}
do_test incrblob-4.6 {
  execsql {
    INSERT INTO blobs(k, v, i) VALUES(123, 567.765, NULL);
  }
  set rc [catch {
    set ::blob [db incrblob blobs v 2]
  } msg ] 
  list $rc $msg
} {1 {cannot open value of type real}}
do_test incrblob-4.7 {
  set rc [catch {
    set ::blob [db incrblob blobs i 2]
  } msg ] 
  list $rc $msg
} {1 {cannot open value of type null}}

do_test incrblob-4.8 {
  execsql {
    INSERT INTO blobs(k, v, i) VALUES(X'010203040506070809', 'hello', 'world');
  }
  set rc [catch {
    set ::blob [db incrblob blobs k 3]
  } msg ] 
  list $rc $msg
} {1 {cannot open indexed column for writing}}

do_test incrblob-4.9.1 {
  set rc [catch {
    set ::blob [db incrblob -readonly blobs k 3]
  } msg]
} {0}
do_test incrblob-4.9.2 {
  binary scan [read $::blob] c* c
  close $::blob
  set c
} {1 2 3 4 5 6 7 8 9}

#------------------------------------------------------------------------
# incrblob-5.*: 
#
#     Test that opening a blob in an attached database works.
#
do_test incrblob-5.1 {
  file delete -force test2.db test2.db-journal
  set ::size [expr [file size [info script]]]
  execsql {
    ATTACH 'test2.db' AS aux;
    CREATE TABLE aux.files(name, text);
    INSERT INTO aux.files VALUES('this one', zeroblob($::size));
  }
  set fd  [db incrblob aux files text 1]
  set fd2 [open [info script]]
  puts -nonewline $fd [read $fd2]
  close $fd
  close $fd2
  set ::text [db one {select text from aux.files}]
  string length $::text
} [file size [info script]]
do_test incrblob-5.2 {
  set fd2 [open [info script]]
  set ::data [read $fd2]
  close $fd2
  set ::data
} $::text

# free memory
unset ::data
unset ::text

#------------------------------------------------------------------------
# incrblob-6.*: 
#
#     Test that opening a blob for write-access is impossible if
#     another connection has the database RESERVED lock.
#
#     Then test that blob writes that take place inside of a
#     transaction are not visible to external connections until
#     after the transaction is commited and the blob channel 
#     closed.
#
do_test incrblob-6.1 {
  sqlite3 db2 test.db
  execsql {
    BEGIN;
    INSERT INTO blobs(k, v, i) VALUES('a', 'different', 'connection');
  } db2
} {}
do_test incrblob-6.2 {
  execsql {
    SELECT rowid FROM blobs
  }
} {1 2 3}
do_test incrblob-6.3 {
  set rc [catch {
    db incrblob blobs v 1
  } msg]
  list $rc $msg
} {1 {database is locked}}
do_test incrblob-6.4 {
  set rc [catch {
    db incrblob blobs v 3
  } msg]
  list $rc $msg
} {1 {database is locked}}
do_test incrblob-6.5 {
  set ::blob [db incrblob -readonly blobs v 3]
  read $::blob
} {hello}
do_test incrblob-6.6 {
  close $::blob
} {}

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 
# there is an open blob channel).
do_test incrblob-6.10 {
  catchsql {
    ROLLBACK;
  } db2
} {1 {cannot rollback transaction - SQL statements in progress}}
do_test incrblob-6.11 {
  catchsql {
    COMMIT;
  } db2
} {1 {cannot commit transaction - SQL statements in progress}}

do_test incrblob-6.12 {
  execsql {
    SELECT * FROM blobs WHERE rowid = 4;
  }
} {}
do_test incrblob-6.13 {
  close $::blob
  execsql {
    COMMIT;
  } db2
} {}
do_test incrblob-6.14 {
  execsql {
    SELECT * FROM blobs WHERE rowid = 4;
  }
} {a different invocation}
db2 close

finish_test