SQLite

**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.248 2004/08/18 15:58:23 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs

  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  sqlite3CodeVerifySchema(pParse, iDb);
  pParse->writeMask |= 1<<iDb;
  if( setStatement ){
    sqlite3VdbeAddOp(v, OP_Statement, iDb, 0);
  }
  if( iDb!=1 && pParse->db->aDb[1].pBt!=0 ){
    sqlite3BeginWriteOperation(pParse, setStatement, 1);
  }
}

/*
** Generate code that concludes an operation that may have changed
** the database.  If a statement transaction was started, then emit

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.156 2004/08/18 15:58:23 drh Exp $
*/
#include "os.h"         /* Must be first to enable large file support */
#include "sqliteInt.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

/*
** Macros for troubleshooting.  Normally turned off
*/
#if 0

#define TRACE1(X)       sqlite3DebugPrintf(X)

#define TRACE2(X,Y)     sqlite3DebugPrintf(X,Y)
#define TRACE3(X,Y,Z)   sqlite3DebugPrintf(X,Y,Z)
#define TRACE4(X,Y,Z,W) sqlite3DebugPrintf(X,Y,Z,W)
#else


#define TRACE1(X)
#define TRACE2(X,Y)
#define TRACE3(X,Y,Z)
#define TRACE4(X,Y,Z,W)
#endif


/*
** The page cache as a whole is always in one of the following
** states:
**

  ** not the database file. The page is left marked dirty in this case.
  **
  ** If in EXCLUSIVE state, then we update the pager cache if it exists
  ** and the main file. The page is then marked not dirty.
  */
  pPg = pager_lookup(pPager, pgno);
  assert( pPager->state>=PAGER_EXCLUSIVE || pPg );
  TRACE3("PLAYBACK %d page %d\n", pPager->fd.h, pgno);
  if( pPager->state>=PAGER_EXCLUSIVE ){
    sqlite3OsSeek(&pPager->fd, (pgno-1)*(off_t)pPager->pageSize);
    rc = sqlite3OsWrite(&pPager->fd, aData, pPager->pageSize);
  }
  if( pPg ){
    /* No page should ever be rolled back that is in use, except for page
    ** 1 which is held in use in order to keep the lock on the database

  int rc = SQLITE_OK;
  for(pPg=pPager->pAll; pPg; pPg=pPg->pNextAll){
    char zBuf[SQLITE_MAX_PAGE_SIZE];
    if( !pPg->dirty ) continue;
    if( (int)pPg->pgno <= pPager->origDbSize ){
      sqlite3OsSeek(&pPager->fd, pPager->pageSize*(off_t)(pPg->pgno-1));
      rc = sqlite3OsRead(&pPager->fd, zBuf, pPager->pageSize);
      TRACE3("REFETCH %d page %d\n", pPager->fd.h, pPg->pgno);
      if( rc ) break;
      CODEC(pPager, zBuf, pPg->pgno, 2);
    }else{
      memset(zBuf, 0, pPager->pageSize);
    }
    if( pPg->nRef==0 || memcmp(zBuf, PGHDR_TO_DATA(pPg), pPager->pageSize) ){
      memcpy(PGHDR_TO_DATA(pPg), zBuf, pPager->pageSize);

  nameLen = strlen(zFullPathname);
  pPager = sqliteMalloc( sizeof(*pPager) + nameLen*3 + 30 );
  if( pPager==0 ){
    sqlite3OsClose(&fd);
    sqliteFree(zFullPathname);
    return SQLITE_NOMEM;
  }
  TRACE3("OPEN %d %s\n", fd.h, zFullPathname);
  pPager->zFilename = (char*)&pPager[1];
  pPager->zDirectory = &pPager->zFilename[nameLen+1];
  pPager->zJournal = &pPager->zDirectory[nameLen+1];
  strcpy(pPager->zFilename, zFullPathname);
  strcpy(pPager->zDirectory, zFullPathname);
  for(i=nameLen; i>0 && pPager->zDirectory[i-1]!='/'; i--){}
  if( i>0 ) pPager->zDirectory[i-1] = 0;

      assert( !pHist->pOrig );
      assert( !pHist->pStmt );
    }
#endif
    pNext = pPg->pNextAll;
    sqliteFree(pPg);
  }
  TRACE2("CLOSE %d\n", pPager->fd.h);
  sqlite3OsClose(&pPager->fd);
  assert( pPager->journalOpen==0 );
  /* Temp files are automatically deleted by the OS
  ** if( pPager->tempFile ){
  **   sqlite3OsDelete(pPager->zFilename);
  ** }
  */

  if( pPager->zFilename!=(char*)&pPager[1] ){
    assert( 0 );  /* Cannot happen */
    sqliteFree(pPager->zFilename);
    sqliteFree(pPager->zJournal);
    sqliteFree(pPager->zDirectory);
  }
  sqliteFree(pPager);

  }
  pPager->state = PAGER_EXCLUSIVE;

  while( pList ){
    assert( pList->dirty );
    sqlite3OsSeek(&pPager->fd, (pList->pgno-1)*(off_t)pPager->pageSize);
    CODEC(pPager, PGHDR_TO_DATA(pList), pList->pgno, 6);
    TRACE3("STORE %d page %d\n", pPager->fd.h, pList->pgno);
    rc = sqlite3OsWrite(&pPager->fd, PGHDR_TO_DATA(pList), pPager->pageSize);
    CODEC(pPager, PGHDR_TO_DATA(pList), pList->pgno, 0);
    if( rc ) return rc;
    pList->dirty = 0;
    pList = pList->pDirty;
  }
  return SQLITE_OK;

    if( pPager->dbSize<(int)pgno ){
      memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
    }else{
      int rc;
      assert( pPager->memDb==0 );
      sqlite3OsSeek(&pPager->fd, (pgno-1)*(off_t)pPager->pageSize);
      rc = sqlite3OsRead(&pPager->fd, PGHDR_TO_DATA(pPg), pPager->pageSize);
      TRACE3("FETCH %d page %d\n", pPager->fd.h, pPg->pgno);
      CODEC(pPager, PGHDR_TO_DATA(pPg), pPg->pgno, 3);
      if( rc!=SQLITE_OK ){
        off_t fileSize;
        if( sqlite3OsFileSize(&pPager->fd,&fileSize)!=SQLITE_OK
               || fileSize>=pgno*pPager->pageSize ){
          sqlite3pager_unref(PGHDR_TO_DATA(pPg));
          return rc;

  */
  if( !pPg->inJournal && (pPager->useJournal || pPager->memDb) ){
    if( (int)pPg->pgno <= pPager->origDbSize ){
      int szPg;
      u32 saved;
      if( pPager->memDb ){
        PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
        TRACE3("JOURNAL %d page %d\n", pPager->fd.h, pPg->pgno);
        assert( pHist->pOrig==0 );
        pHist->pOrig = sqliteMallocRaw( pPager->pageSize );
        if( pHist->pOrig ){
          memcpy(pHist->pOrig, PGHDR_TO_DATA(pPg), pPager->pageSize);
        }
        pPg->inJournal = 1;
      }else{
        u32 cksum;
        CODEC(pPager, pData, pPg->pgno, 7);
        cksum = pager_cksum(pPager, pPg->pgno, pData);
        saved = *(u32*)PGHDR_TO_EXTRA(pPg, pPager);
        store32bits(cksum, pPg, pPager->pageSize);
        szPg = pPager->pageSize+8;
        store32bits(pPg->pgno, pPg, -4);
        rc = sqlite3OsWrite(&pPager->jfd, &((char*)pData)[-4], szPg);
        pPager->journalOff += szPg;
        TRACE4("JOURNAL %d page %d needSync=%d\n",
                pPager->fd.h, pPg->pgno, pPg->needSync);
        CODEC(pPager, pData, pPg->pgno, 0);
        *(u32*)PGHDR_TO_EXTRA(pPg, pPager) = saved;
        if( rc!=SQLITE_OK ){
          sqlite3pager_rollback(pPager);
          pPager->errMask |= PAGER_ERR_FULL;
          return rc;
        }
        pPager->nRec++;
        assert( pPager->aInJournal!=0 );
        pPager->aInJournal[pPg->pgno/8] |= 1<<(pPg->pgno&7);
        pPg->needSync = !pPager->noSync;
        pPg->inJournal = 1;
        if( pPager->stmtInUse ){
          pPager->aInStmt[pPg->pgno/8] |= 1<<(pPg->pgno&7);
          page_add_to_stmt_list(pPg);
        }
      }
    }else{
      pPg->needSync = !pPager->journalStarted && !pPager->noSync;
      TRACE4("APPEND %d page %d needSync=%d\n",
              pPager->fd.h, pPg->pgno, pPg->needSync);
    }
    if( pPg->needSync ){
      pPager->needSync = 1;
    }
  }

  /* If the statement journal is open and the page is not in it,
  ** then write the current page to the statement journal.  Note that
  ** the statement journal format differs from the standard journal format
  ** in that it omits the checksums and the header.
  */
  if( pPager->stmtInUse && !pPg->inStmt && (int)pPg->pgno<=pPager->stmtSize ){
    assert( pPg->inJournal || (int)pPg->pgno>pPager->origDbSize );
    if( pPager->memDb ){
      PgHistory *pHist = PGHDR_TO_HIST(pPg, pPager);
      assert( pHist->pStmt==0 );
      pHist->pStmt = sqliteMallocRaw( pPager->pageSize );
      if( pHist->pStmt ){
        memcpy(pHist->pStmt, PGHDR_TO_DATA(pPg), pPager->pageSize);
      }
      TRACE3("STMT-JOURNAL %d page %d\n", pPager->fd.h, pPg->pgno);
    }else{
      store32bits(pPg->pgno, pPg, -4);
      CODEC(pPager, pData, pPg->pgno, 7);
      rc = sqlite3OsWrite(&pPager->stfd, ((char*)pData)-4, pPager->pageSize+4);
      TRACE3("STMT-JOURNAL %d page %d\n", pPager->fd.h, pPg->pgno);
      CODEC(pPager, pData, pPg->pgno, 0);
      if( rc!=SQLITE_OK ){
        sqlite3pager_rollback(pPager);
        pPager->errMask |= PAGER_ERR_FULL;
        return rc;
      }
      pPager->stmtNRec++;

        assert( !((PgHistory *)PGHDR_TO_HIST(p, pPager))->pStmt );
        continue;
      }

      pHist = PGHDR_TO_HIST(p, pPager);
      if( pHist->pOrig ){
        memcpy(PGHDR_TO_DATA(p), pHist->pOrig, pPager->pageSize);
        TRACE3("ROLLBACK-PAGE %d of %d\n", p->pgno, pPager->fd.h);
      }else{
        TRACE3("PAGE %d is clean on %d\n", p->pgno, pPager->fd.h);
      }
      clearHistory(pHist);
      p->dirty = 0;
      p->inJournal = 0;
      p->inStmt = 0;
      p->pPrevStmt = p->pNextStmt = 0;

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the ATTACH and DETACH commands
# and related functionality.
#
# $Id: attach.test,v 1.26 2004/08/18 15:58:24 drh Exp $
#

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

for {set i 2} {$i<=15} {incr i} {
  file delete -force test$i.db

  foreach {idx name file} [execsql {PRAGMA database_list} $db] {
    lappend list $idx $name
  }
  return $list
}
do_test attach-1.11b {
  db_list db
} {0 main 2 db2 3 db3 4 db4 5 db5 6 db6 7 db7 8 db8 9 db9}
do_test attach-1.12 {
  catchsql {
    ATTACH 'test.db' as db2;
  }
} {1 {database db2 is already in use}}
do_test attach-1.13 {
  catchsql {

  }
} {1 {too many attached databases - max 10}}
do_test attach-1.20.1 {
  execsql {
    DETACH db5;
  }
  db_list db
} {0 main 2 db2 3 db3 4 db4 5 db6 6 db7 7 db8 8 db9 9 db10 10 db11}
integrity_check attach-1.20.2
do_test attach-1.21 {
  catchsql {
    ATTACH 'test.db' as db12;
  }
} {0 {}}
do_test attach-1.22 {

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is testing the ATTACH and DETACH commands
# and related functionality.
#
# $Id: attach2.test,v 1.24 2004/08/18 15:58:24 drh Exp $
#

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


# Ticket #354

  # to commit a write to test.db from db2
  catchsql {
    INSERT INTO t1 VALUES(1, 2)
  } db2 
} {1 {database is locked}}

lock_status 4.4.1 db {main shared temp closed file2 unlocked}
lock_status 4.4.2 db2 {main unlocked temp closed file2 unlocked}

do_test attach2-4.5 {
  # Handle 'db2' reserves file2.
  execsql {BEGIN} db2
  execsql {INSERT INTO file2.t1 VALUES(1, 2)} db2
  # Lock status:
  #    db  - shared(main)
  #    db2 - reserved(file2)
} {}

lock_status 4.5.1 db {main shared temp closed file2 unlocked}
lock_status 4.5.2 db2 {main unlocked temp closed file2 reserved}

do_test attach2-4.6.1 {
  # Reads are allowed against a reserved database.
  catchsql {
    SELECT * FROM file2.t1;
  }
  # Lock status:
  #    db  - shared(main), shared(file2)
  #    db2 - reserved(file2)
} {0 {}}

lock_status 4.6.1.1 db {main shared temp closed file2 shared}
lock_status 4.6.1.2 db2 {main unlocked temp closed file2 reserved}

do_test attach2-4.6.2 {
  # Writes against a reserved database are not allowed.
  catchsql {
    UPDATE file2.t1 SET a=0;
  }
} {1 {database is locked}}

lock_status 4.6.2.1 db {main shared temp closed file2 shared}
lock_status 4.6.2.2 db2 {main unlocked temp closed file2 reserved}

do_test attach2-4.7 {
  # Ensure handle 'db' retains the lock on the main file after
  # failing to obtain a write-lock on file2.
  catchsql {
    INSERT INTO t1 VALUES(1, 2)
  } db2 
} {0 {}}

lock_status 4.7.1 db {main shared temp closed file2 shared}
lock_status 4.7.2 db2 {main reserved temp closed file2 reserved}

do_test attach2-4.8 {
  # We should still be able to read test.db from db2
  execsql {SELECT * FROM t1} db2
} {1 2}

lock_status 4.8.1 db {main shared temp closed file2 shared}
lock_status 4.8.2 db2 {main reserved temp closed file2 reserved}

do_test attach2-4.9 {
  # Try to upgrade the handle 'db' lock.
  catchsql {
    INSERT INTO t1 VALUES(1, 2)
  }
} {1 {database is locked}}

lock_status 4.9.1 db {main shared temp closed file2 shared}
lock_status 4.9.2 db2 {main reserved temp closed file2 reserved}

btree_breakpoint
do_test attach2-4.10 {
  # We cannot commit db2 while db is holding a read-lock
  catchsql {COMMIT} db2
} {1 {database is locked}}

lock_status 4.10.1 db {main shared temp closed file2 shared}
lock_status 4.10.2 db2 {main pending temp closed file2 reserved}

set sqlite_os_trace 0
btree_breakpoint
do_test attach2-4.11 {
  # db is able to commit.
  catchsql {COMMIT}
} {0 {}}

lock_status 4.11.1 db {main unlocked temp closed file2 unlocked}
lock_status 4.11.2 db2 {main pending temp closed file2 reserved}

do_test attach2-4.12 {
  # Now we can commit db2
  catchsql {COMMIT} db2
} {0 {}}

lock_status 4.12.1 db {main unlocked temp closed file2 unlocked}
lock_status 4.12.2 db2 {main unlocked temp closed file2 unlocked}

do_test attach2-4.13 {
  execsql {SELECT * FROM file2.t1}
} {1 2}
do_test attach2-4.14 {
  execsql {INSERT INTO t1 VALUES(1, 2)}
} {}