Move bundled copy of sqlite one level deeper to better separate it...

third_party/sqlite/src/test_journal.c

Index: third_party/sqlite/src/test_journal.c
===================================================================
--- third_party/sqlite/src/test_journal.c	(revision 56608)
+++ third_party/sqlite/src/test_journal.c	(working copy)
@@ -1,837 +0,0 @@
-/*
-** 2008 Jan 22
-**
-** 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 contains code for a VFS layer that acts as a wrapper around
-** an existing VFS. The code in this file attempts to verify that SQLite
-** correctly populates and syncs a journal file before writing to a
-** corresponding database file.
-**
-** $Id: test_journal.c,v 1.17 2009/06/26 10:39:36 danielk1977 Exp $
-*/
-#if SQLITE_TEST          /* This file is used for testing only */
-
-#include "sqlite3.h"
-#include "sqliteInt.h"
-
-/*
-** INTERFACE
-**
-**   The public interface to this wrapper VFS is two functions:
-**
-**     jt_register()
-**     jt_unregister()
-**
-**   See header comments associated with those two functions below for 
-**   details.
-**
-** LIMITATIONS
-**
-**   This wrapper will not work if "PRAGMA synchronous = off" is used.
-**
-** OPERATION
-**
-**  Starting a Transaction:
-**
-**   When a write-transaction is started, the contents of the database is
-**   inspected and the following data stored as part of the database file 
-**   handle (type struct jt_file):
-**
-**     a) The page-size of the database file.
-**     b) The number of pages that are in the database file.
-**     c) The set of page numbers corresponding to free-list leaf pages.
-**     d) A check-sum for every page in the database file.
-**
-**   The start of a write-transaction is deemed to have occurred when a 
-**   28-byte journal header is written to byte offset 0 of the journal 
-**   file.
-**
-**  Syncing the Journal File:
-**
-**   Whenever the xSync method is invoked to sync a journal-file, the
-**   contents of the journal file are read. For each page written to
-**   the journal file, a check-sum is calculated and compared to the  
-**   check-sum calculated for the corresponding database page when the
-**   write-transaction was initialized. The success of the comparison
-**   is assert()ed. So if SQLite has written something other than the
-**   original content to the database file, an assert() will fail.
-**
-**   Additionally, the set of page numbers for which records exist in
-**   the journal file is added to (unioned with) the set of page numbers
-**   corresponding to free-list leaf pages collected when the 
-**   write-transaction was initialized. This set comprises the page-numbers 
-**   corresponding to those pages that SQLite may now safely modify.
-**
-**  Writing to the Database File:
-**
-**   When a block of data is written to a database file, the following
-**   invariants are asserted:
-**
-**     a) That the block of data is an aligned block of page-size bytes.
-**
-**     b) That if the page being written did not exist when the 
-**        transaction was started (i.e. the database file is growing), then
-**        the journal-file must have been synced at least once since
-**        the start of the transaction.
-**
-**     c) That if the page being written did exist when the transaction 
-**        was started, then the page must have either been a free-list
-**        leaf page at the start of the transaction, or else must have
-**        been stored in the journal file prior to the most recent sync.
-**
-**  Closing a Transaction:
-**
-**   When a transaction is closed, all data collected at the start of
-**   the transaction, or following an xSync of a journal-file, is 
-**   discarded. The end of a transaction is recognized when any one 
-**   of the following occur:
-**
-**     a) A block of zeroes (or anything else that is not a valid 
-**        journal-header) is written to the start of the journal file.
-**
-**     b) A journal file is truncated to zero bytes in size using xTruncate.
-**
-**     c) The journal file is deleted using xDelete.
-*/
-
-/*
-** Maximum pathname length supported by the jt backend.
-*/
-#define JT_MAX_PATHNAME 512
-
-/*
-** Name used to identify this VFS.
-*/
-#define JT_VFS_NAME "jt"
-
-typedef struct jt_file jt_file;
-struct jt_file {
-  sqlite3_file base;
-  const char *zName;       /* Name of open file */
-  int flags;               /* Flags the file was opened with */
-
-  /* The following are only used by database file file handles */
-  int eLock;               /* Current lock held on the file */
-  u32 nPage;               /* Size of file in pages when transaction started */
-  u32 nPagesize;           /* Page size when transaction started */
-  Bitvec *pWritable;       /* Bitvec of pages that may be written to the file */
-  u32 *aCksum;             /* Checksum for first nPage pages */
-  int nSync;               /* Number of times journal file has been synced */
-
-  /* Only used by journal file-handles */
-  sqlite3_int64 iMaxOff;   /* Maximum offset written to this transaction */
-
-  jt_file *pNext;          /* All files are stored in a linked list */
-  sqlite3_file *pReal;     /* The file handle for the underlying vfs */
-};
-
-/*
-** Method declarations for jt_file.
-*/
-static int jtClose(sqlite3_file*);
-static int jtRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
-static int jtWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
-static int jtTruncate(sqlite3_file*, sqlite3_int64 size);
-static int jtSync(sqlite3_file*, int flags);
-static int jtFileSize(sqlite3_file*, sqlite3_int64 *pSize);
-static int jtLock(sqlite3_file*, int);
-static int jtUnlock(sqlite3_file*, int);
-static int jtCheckReservedLock(sqlite3_file*, int *);
-static int jtFileControl(sqlite3_file*, int op, void *pArg);
-static int jtSectorSize(sqlite3_file*);
-static int jtDeviceCharacteristics(sqlite3_file*);
-
-/*
-** Method declarations for jt_vfs.
-*/
-static int jtOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
-static int jtDelete(sqlite3_vfs*, const char *zName, int syncDir);
-static int jtAccess(sqlite3_vfs*, const char *zName, int flags, int *);
-static int jtFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
-static void *jtDlOpen(sqlite3_vfs*, const char *zFilename);
-static void jtDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
-static void (*jtDlSym(sqlite3_vfs*,void*, const char *zSymbol))(void);
-static void jtDlClose(sqlite3_vfs*, void*);
-static int jtRandomness(sqlite3_vfs*, int nByte, char *zOut);
-static int jtSleep(sqlite3_vfs*, int microseconds);
-static int jtCurrentTime(sqlite3_vfs*, double*);
-
-static sqlite3_vfs jt_vfs = {
-  1,                             /* iVersion */
-  sizeof(jt_file),               /* szOsFile */
-  JT_MAX_PATHNAME,               /* mxPathname */
-  0,                             /* pNext */
-  JT_VFS_NAME,                   /* zName */
-  0,                             /* pAppData */
-  jtOpen,                        /* xOpen */
-  jtDelete,                      /* xDelete */
-  jtAccess,                      /* xAccess */
-  jtFullPathname,                /* xFullPathname */
-  jtDlOpen,                      /* xDlOpen */
-  jtDlError,                     /* xDlError */
-  jtDlSym,                       /* xDlSym */
-  jtDlClose,                     /* xDlClose */
-  jtRandomness,                  /* xRandomness */
-  jtSleep,                       /* xSleep */
-  jtCurrentTime                  /* xCurrentTime */
-};
-
-static sqlite3_io_methods jt_io_methods = {
-  1,                             /* iVersion */
-  jtClose,                       /* xClose */
-  jtRead,                        /* xRead */
-  jtWrite,                       /* xWrite */
-  jtTruncate,                    /* xTruncate */
-  jtSync,                        /* xSync */
-  jtFileSize,                    /* xFileSize */
-  jtLock,                        /* xLock */
-  jtUnlock,                      /* xUnlock */
-  jtCheckReservedLock,           /* xCheckReservedLock */
-  jtFileControl,                 /* xFileControl */
-  jtSectorSize,                  /* xSectorSize */
-  jtDeviceCharacteristics        /* xDeviceCharacteristics */
-};
-
-struct JtGlobal {
-  sqlite3_vfs *pVfs;             /* Parent VFS */
-  jt_file *pList;                /* List of all open files */
-};
-static struct JtGlobal g = {0, 0};
-
-/*
-** Functions to obtain and relinquish a mutex to protect g.pList. The
-** STATIC_PRNG mutex is reused, purely for the sake of convenience.
-*/
-static void enterJtMutex(void){
-  sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PRNG));
-}
-static void leaveJtMutex(void){
-  sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PRNG));
-}
-
-extern int sqlite3_io_error_pending;
-extern int sqlite3_io_error_hit;
-static void stop_ioerr_simulation(int *piSave, int *piSave2){
-  *piSave = sqlite3_io_error_pending;
-  *piSave2 = sqlite3_io_error_hit;
-  sqlite3_io_error_pending = -1;
-  sqlite3_io_error_hit = 0;
-}
-static void start_ioerr_simulation(int iSave, int iSave2){
-  sqlite3_io_error_pending = iSave;
-  sqlite3_io_error_hit = iSave2;
-}
-
-/*
-** The jt_file pointed to by the argument may or may not be a file-handle
-** open on a main database file. If it is, and a transaction is currently
-** opened on the file, then discard all transaction related data.
-*/
-static void closeTransaction(jt_file *p){
-  sqlite3BitvecDestroy(p->pWritable);
-  sqlite3_free(p->aCksum);
-  p->pWritable = 0;
-  p->aCksum = 0;
-  p->nSync = 0;
-}
-
-/*
-** Close an jt-file.
-*/
-static int jtClose(sqlite3_file *pFile){
-  jt_file **pp;
-  jt_file *p = (jt_file *)pFile;
-
-  closeTransaction(p);
-  enterJtMutex();
-  if( p->zName ){
-    for(pp=&g.pList; *pp!=p; pp=&(*pp)->pNext);
-    *pp = p->pNext;
-  }
-  leaveJtMutex();
-  return sqlite3OsClose(p->pReal);
-}
-
-/*
-** Read data from an jt-file.
-*/
-static int jtRead(
-  sqlite3_file *pFile, 
-  void *zBuf, 
-  int iAmt, 
-  sqlite_int64 iOfst
-){
-  jt_file *p = (jt_file *)pFile;
-  return sqlite3OsRead(p->pReal, zBuf, iAmt, iOfst);
-}
-
-/*
-** Parameter zJournal is the name of a journal file that is currently 
-** open. This function locates and returns the handle opened on the
-** corresponding database file by the pager that currently has the
-** journal file opened. This file-handle is identified by the 
-** following properties:
-**
-**   a) SQLITE_OPEN_MAIN_DB was specified when the file was opened.
-**
-**   b) The file-name specified when the file was opened matches
-**      all but the final 8 characters of the journal file name.
-**
-**   c) There is currently a reserved lock on the file.
-**/
-static jt_file *locateDatabaseHandle(const char *zJournal){
-  jt_file *pMain = 0;
-  enterJtMutex();
-  for(pMain=g.pList; pMain; pMain=pMain->pNext){
-    int nName = strlen(zJournal) - strlen("-journal");
-    if( (pMain->flags&SQLITE_OPEN_MAIN_DB)
-     && (strlen(pMain->zName)==nName)
-     && 0==memcmp(pMain->zName, zJournal, nName)
-     && (pMain->eLock>=SQLITE_LOCK_RESERVED)
-    ){
-      break;
-    }
-  }
-  leaveJtMutex();
-  return pMain;
-}
-
-/*
-** Parameter z points to a buffer of 4 bytes in size containing a 
-** unsigned 32-bit integer stored in big-endian format. Decode the 
-** integer and return its value.
-*/
-static u32 decodeUint32(const unsigned char *z){
-  return (z[0]<<24) + (z[1]<<16) + (z[2]<<8) + z[3];
-}
-
-/*
-** Calculate a checksum from the buffer of length n bytes pointed to
-** by parameter z.
-*/
-static u32 genCksum(const unsigned char *z, int n){
-  int i;
-  u32 cksum = 0;
-  for(i=0; i<n; i++){
-    cksum = cksum + z[i] + (cksum<<3);
-  }
-  return cksum;
-}
-
-/*
-** The first argument, zBuf, points to a buffer containing a 28 byte
-** serialized journal header. This function deserializes four of the
-** integer fields contained in the journal header and writes their
-** values to the output variables.
-**
-** SQLITE_OK is returned if the journal-header is successfully 
-** decoded. Otherwise, SQLITE_ERROR.
-*/
-static int decodeJournalHdr(
-  const unsigned char *zBuf,         /* Input: 28 byte journal header */
-  u32 *pnRec,                        /* Out: Number of journalled records */
-  u32 *pnPage,                       /* Out: Original database page count */
-  u32 *pnSector,                     /* Out: Sector size in bytes */
-  u32 *pnPagesize                    /* Out: Page size in bytes */
-){
-  unsigned char aMagic[] = { 0xd9, 0xd5, 0x05, 0xf9, 0x20, 0xa1, 0x63, 0xd7 };
-  if( memcmp(aMagic, zBuf, 8) ) return SQLITE_ERROR;
-  if( pnRec ) *pnRec = decodeUint32(&zBuf[8]);
-  if( pnPage ) *pnPage = decodeUint32(&zBuf[16]);
-  if( pnSector ) *pnSector = decodeUint32(&zBuf[20]);
-  if( pnPagesize ) *pnPagesize = decodeUint32(&zBuf[24]);
-  return SQLITE_OK;
-}
-
-/*
-** This function is called when a new transaction is opened, just after
-** the first journal-header is written to the journal file.
-*/
-static int openTransaction(jt_file *pMain, jt_file *pJournal){
-  unsigned char *aData;
-  sqlite3_file *p = pMain->pReal;
-  int rc = SQLITE_OK;
-
-  aData = sqlite3_malloc(pMain->nPagesize);
-  pMain->pWritable = sqlite3BitvecCreate(pMain->nPage);
-  pMain->aCksum = sqlite3_malloc(sizeof(u32) * (pMain->nPage + 1));
-  pJournal->iMaxOff = 0;
-
-  if( !pMain->pWritable || !pMain->aCksum || !aData ){
-    rc = SQLITE_IOERR_NOMEM;
-  }else if( pMain->nPage>0 ){
-    u32 iTrunk;
-    int iSave;
-    int iSave2;
-
-    stop_ioerr_simulation(&iSave, &iSave2);
-
-    /* Read the database free-list. Add the page-number for each free-list
-    ** leaf to the jt_file.pWritable bitvec.
-    */
-    rc = sqlite3OsRead(p, aData, pMain->nPagesize, 0);
-    iTrunk = decodeUint32(&aData[32]);
-    while( rc==SQLITE_OK && iTrunk>0 ){
-      u32 nLeaf;
-      u32 iLeaf;
-      sqlite3_int64 iOff = (iTrunk-1)*pMain->nPagesize;
-      rc = sqlite3OsRead(p, aData, pMain->nPagesize, iOff);
-      nLeaf = decodeUint32(&aData[4]);
-      for(iLeaf=0; rc==SQLITE_OK && iLeaf<nLeaf; iLeaf++){
-        u32 pgno = decodeUint32(&aData[8+4*iLeaf]);
-        sqlite3BitvecSet(pMain->pWritable, pgno);
-      }
-      iTrunk = decodeUint32(aData);
-    }
-
-    /* Calculate and store a checksum for each page in the database file. */
-    if( rc==SQLITE_OK ){
-      int ii;
-      for(ii=0; rc==SQLITE_OK && ii<pMain->nPage; ii++){
-        i64 iOff = (i64)(pMain->nPagesize) * (i64)ii;
-        if( iOff==PENDING_BYTE ) continue;
-        rc = sqlite3OsRead(pMain->pReal, aData, pMain->nPagesize, iOff);
-        pMain->aCksum[ii] = genCksum(aData, pMain->nPagesize);
-      }
-    }
-
-    start_ioerr_simulation(iSave, iSave2);
-  }
-
-  sqlite3_free(aData);
-  return rc;
-}
-
-/*
-** The first argument to this function is a handle open on a journal file.
-** This function reads the journal file and adds the page number for each
-** page in the journal to the Bitvec object passed as the second argument.
-*/
-static int readJournalFile(jt_file *p, jt_file *pMain){
-  int rc = SQLITE_OK;
-  unsigned char zBuf[28];
-  sqlite3_file *pReal = p->pReal;
-  sqlite3_int64 iOff = 0;
-  sqlite3_int64 iSize = p->iMaxOff;
-  unsigned char *aPage;
-  int iSave;
-  int iSave2;
-
-  aPage = sqlite3_malloc(pMain->nPagesize);
-  if( !aPage ){
-    return SQLITE_IOERR_NOMEM;
-  }
-
-  stop_ioerr_simulation(&iSave, &iSave2);
-
-  while( rc==SQLITE_OK && iOff<iSize ){
-    u32 nRec, nPage, nSector, nPagesize;
-    u32 ii;
-
-    /* Read and decode the next journal-header from the journal file. */
-    rc = sqlite3OsRead(pReal, zBuf, 28, iOff);
-    if( rc!=SQLITE_OK 
-     || decodeJournalHdr(zBuf, &nRec, &nPage, &nSector, &nPagesize) 
-    ){
-      goto finish_rjf;
-    }
-    iOff += nSector;
-
-    if( nRec==0 ){
-      /* A trick. There might be another journal-header immediately 
-      ** following this one. In this case, 0 records means 0 records, 
-      ** not "read until the end of the file". See also ticket #2565.
-      */
-      if( iSize>=(iOff+nSector) ){
-        rc = sqlite3OsRead(pReal, zBuf, 28, iOff);
-        if( rc!=SQLITE_OK || 0==decodeJournalHdr(zBuf, 0, 0, 0, 0) ){
-          continue;
-        }
-      }
-      nRec = (iSize-iOff) / (pMain->nPagesize+8);
-    }
-
-    /* Read all the records that follow the journal-header just read. */
-    for(ii=0; rc==SQLITE_OK && ii<nRec && iOff<iSize; ii++){
-      u32 pgno;
-      rc = sqlite3OsRead(pReal, zBuf, 4, iOff);
-      if( rc==SQLITE_OK ){
-        pgno = decodeUint32(zBuf);
-        if( pgno>0 && pgno<=pMain->nPage ){
-          if( 0==sqlite3BitvecTest(pMain->pWritable, pgno) ){
-            rc = sqlite3OsRead(pReal, aPage, pMain->nPagesize, iOff+4);
-            if( rc==SQLITE_OK ){
-              u32 cksum = genCksum(aPage, pMain->nPagesize);
-              assert( cksum==pMain->aCksum[pgno-1] );
-            }
-          }
-          sqlite3BitvecSet(pMain->pWritable, pgno);
-        }
-        iOff += (8 + pMain->nPagesize);
-      }
-    }
-
-    iOff = ((iOff + (nSector-1)) / nSector) * nSector;
-  }
-
-finish_rjf:
-  start_ioerr_simulation(iSave, iSave2);
-  sqlite3_free(aPage);
-  if( rc==SQLITE_IOERR_SHORT_READ ){
-    rc = SQLITE_OK;
-  }
-  return rc;
-}
-
-
-/*
-** Write data to an jt-file.
-*/
-static int jtWrite(
-  sqlite3_file *pFile, 
-  const void *zBuf, 
-  int iAmt, 
-  sqlite_int64 iOfst
-){
-  int rc;
-  jt_file *p = (jt_file *)pFile;
-  if( p->flags&SQLITE_OPEN_MAIN_JOURNAL ){
-    if( iOfst==0 ){
-      jt_file *pMain = locateDatabaseHandle(p->zName);
-      assert( pMain );
-  
-      if( iAmt==28 ){
-        /* Zeroing the first journal-file header. This is the end of a
-        ** transaction. */
-        closeTransaction(pMain);
-      }else if( iAmt!=12 ){
-        /* Writing the first journal header to a journal file. This happens
-        ** when a transaction is first started.  */
-        u8 *z = (u8 *)zBuf;
-        pMain->nPage = decodeUint32(&z[16]);
-        pMain->nPagesize = decodeUint32(&z[24]);
-        if( SQLITE_OK!=(rc=openTransaction(pMain, p)) ){
-          return rc;
-        }
-      }
-    }
-    if( p->iMaxOff<(iOfst + iAmt) ){
-      p->iMaxOff = iOfst + iAmt;
-    }
-  }
-
-  if( p->flags&SQLITE_OPEN_MAIN_DB && p->pWritable ){
-    if( iAmt<p->nPagesize 
-     && p->nPagesize%iAmt==0 
-     && iOfst>=(PENDING_BYTE+512) 
-     && iOfst+iAmt<=PENDING_BYTE+p->nPagesize
-    ){
-      /* No-op. This special case is hit when the backup code is copying a
-      ** to a database with a larger page-size than the source database and
-      ** it needs to fill in the non-locking-region part of the original
-      ** pending-byte page.
-      */
-    }else{
-      u32 pgno = iOfst/p->nPagesize + 1;
-      assert( (iAmt==1||iAmt==p->nPagesize) && ((iOfst+iAmt)%p->nPagesize)==0 );
-      assert( pgno<=p->nPage || p->nSync>0 );
-      assert( pgno>p->nPage || sqlite3BitvecTest(p->pWritable, pgno) );
-    }
-  }
-
-  rc = sqlite3OsWrite(p->pReal, zBuf, iAmt, iOfst);
-  if( (p->flags&SQLITE_OPEN_MAIN_JOURNAL) && iAmt==12 ){
-    jt_file *pMain = locateDatabaseHandle(p->zName);
-    int rc2 = readJournalFile(p, pMain);
-    if( rc==SQLITE_OK ) rc = rc2;
-  }
-  return rc;
-}
-
-/*
-** Truncate an jt-file.
-*/
-static int jtTruncate(sqlite3_file *pFile, sqlite_int64 size){
-  jt_file *p = (jt_file *)pFile;
-  if( p->flags&SQLITE_OPEN_MAIN_JOURNAL && size==0 ){
-    /* Truncating a journal file. This is the end of a transaction. */
-    jt_file *pMain = locateDatabaseHandle(p->zName);
-    closeTransaction(pMain);
-  }
-  if( p->flags&SQLITE_OPEN_MAIN_DB && p->pWritable ){
-    u32 pgno;
-    u32 locking_page = (u32)(PENDING_BYTE/p->nPagesize+1);
-    for(pgno=size/p->nPagesize+1; pgno<=p->nPage; pgno++){
-      assert( pgno==locking_page || sqlite3BitvecTest(p->pWritable, pgno) );
-    }
-  }
-  return sqlite3OsTruncate(p->pReal, size);
-}
-
-/*
-** Sync an jt-file.
-*/
-static int jtSync(sqlite3_file *pFile, int flags){
-  jt_file *p = (jt_file *)pFile;
-
-  if( p->flags&SQLITE_OPEN_MAIN_JOURNAL ){
-    int rc;
-    jt_file *pMain;                   /* The associated database file */
-
-    /* The journal file is being synced. At this point, we inspect the 
-    ** contents of the file up to this point and set each bit in the 
-    ** jt_file.pWritable bitvec of the main database file associated with
-    ** this journal file.
-    */
-    pMain = locateDatabaseHandle(p->zName);
-    assert(pMain);
-
-    /* Set the bitvec values */
-    if( pMain->pWritable ){
-      pMain->nSync++;
-      rc = readJournalFile(p, pMain);
-      if( rc!=SQLITE_OK ){
-        return rc;
-      }
-    }
-  }
-
-  return sqlite3OsSync(p->pReal, flags);
-}
-
-/*
-** Return the current file-size of an jt-file.
-*/
-static int jtFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
-  jt_file *p = (jt_file *)pFile;
-  return sqlite3OsFileSize(p->pReal, pSize);
-}
-
-/*
-** Lock an jt-file.
-*/
-static int jtLock(sqlite3_file *pFile, int eLock){
-  int rc;
-  jt_file *p = (jt_file *)pFile;
-  rc = sqlite3OsLock(p->pReal, eLock);
-  if( rc==SQLITE_OK && eLock>p->eLock ){
-    p->eLock = eLock;
-  }
-  return rc;
-}
-
-/*
-** Unlock an jt-file.
-*/
-static int jtUnlock(sqlite3_file *pFile, int eLock){
-  int rc;
-  jt_file *p = (jt_file *)pFile;
-  rc = sqlite3OsUnlock(p->pReal, eLock);
-  if( rc==SQLITE_OK && eLock<p->eLock ){
-    p->eLock = eLock;
-  }
-  return rc;
-}
-
-/*
-** Check if another file-handle holds a RESERVED lock on an jt-file.
-*/
-static int jtCheckReservedLock(sqlite3_file *pFile, int *pResOut){
-  jt_file *p = (jt_file *)pFile;
-  return sqlite3OsCheckReservedLock(p->pReal, pResOut);
-}
-
-/*
-** File control method. For custom operations on an jt-file.
-*/
-static int jtFileControl(sqlite3_file *pFile, int op, void *pArg){
-  jt_file *p = (jt_file *)pFile;
-  return sqlite3OsFileControl(p->pReal, op, pArg);
-}
-
-/*
-** Return the sector-size in bytes for an jt-file.
-*/
-static int jtSectorSize(sqlite3_file *pFile){
-  jt_file *p = (jt_file *)pFile;
-  return sqlite3OsSectorSize(p->pReal);
-}
-
-/*
-** Return the device characteristic flags supported by an jt-file.
-*/
-static int jtDeviceCharacteristics(sqlite3_file *pFile){
-  jt_file *p = (jt_file *)pFile;
-  return sqlite3OsDeviceCharacteristics(p->pReal);
-}
-
-/*
-** Open an jt file handle.
-*/
-static int jtOpen(
-  sqlite3_vfs *pVfs,
-  const char *zName,
-  sqlite3_file *pFile,
-  int flags,
-  int *pOutFlags
-){
-  int rc;
-  jt_file *p = (jt_file *)pFile;
-  pFile->pMethods = 0;
-  p->pReal = (sqlite3_file *)&p[1];
-  p->pReal->pMethods = 0;
-  rc = sqlite3OsOpen(g.pVfs, zName, p->pReal, flags, pOutFlags);
-  assert( rc==SQLITE_OK || p->pReal->pMethods==0 );
-  if( rc==SQLITE_OK ){
-    pFile->pMethods = &jt_io_methods;
-    p->eLock = 0;
-    p->zName = zName;
-    p->flags = flags;
-    p->pNext = 0;
-    p->pWritable = 0;
-    p->aCksum = 0;
-    enterJtMutex();
-    if( zName ){
-      p->pNext = g.pList;
-      g.pList = p;
-    }
-    leaveJtMutex();
-  }
-  return rc;
-}
-
-/*
-** Delete the file located at zPath. If the dirSync argument is true,
-** ensure the file-system modifications are synced to disk before
-** returning.
-*/
-static int jtDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
-  int nPath = strlen(zPath);
-  if( nPath>8 && 0==strcmp("-journal", &zPath[nPath-8]) ){
-    /* Deleting a journal file. The end of a transaction. */
-    jt_file *pMain = locateDatabaseHandle(zPath);
-    if( pMain ){
-      closeTransaction(pMain);
-    }
-  }
-
-  return sqlite3OsDelete(g.pVfs, zPath, dirSync);
-}
-
-/*
-** Test for access permissions. Return true if the requested permission
-** is available, or false otherwise.
-*/
-static int jtAccess(
-  sqlite3_vfs *pVfs, 
-  const char *zPath, 
-  int flags, 
-  int *pResOut
-){
-  return sqlite3OsAccess(g.pVfs, zPath, flags, pResOut);
-}
-
-/*
-** Populate buffer zOut with the full canonical pathname corresponding
-** to the pathname in zPath. zOut is guaranteed to point to a buffer
-** of at least (JT_MAX_PATHNAME+1) bytes.
-*/
-static int jtFullPathname(
-  sqlite3_vfs *pVfs, 
-  const char *zPath, 
-  int nOut, 
-  char *zOut
-){
-  return sqlite3OsFullPathname(g.pVfs, zPath, nOut, zOut);
-}
-
-/*
-** Open the dynamic library located at zPath and return a handle.
-*/
-static void *jtDlOpen(sqlite3_vfs *pVfs, const char *zPath){
-  return g.pVfs->xDlOpen(g.pVfs, zPath);
-}
-
-/*
-** Populate the buffer zErrMsg (size nByte bytes) with a human readable
-** utf-8 string describing the most recent error encountered associated 
-** with dynamic libraries.
-*/
-static void jtDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
-  g.pVfs->xDlError(g.pVfs, nByte, zErrMsg);
-}
-
-/*
-** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
-*/
-static void (*jtDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){
-  return g.pVfs->xDlSym(g.pVfs, p, zSym);
-}
-
-/*
-** Close the dynamic library handle pHandle.
-*/
-static void jtDlClose(sqlite3_vfs *pVfs, void *pHandle){
-  g.pVfs->xDlClose(g.pVfs, pHandle);
-}
-
-/*
-** Populate the buffer pointed to by zBufOut with nByte bytes of 
-** random data.
-*/
-static int jtRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
-  return sqlite3OsRandomness(g.pVfs, nByte, zBufOut);
-}
-
-/*
-** Sleep for nMicro microseconds. Return the number of microseconds 
-** actually slept.
-*/
-static int jtSleep(sqlite3_vfs *pVfs, int nMicro){
-  return sqlite3OsSleep(g.pVfs, nMicro);
-}
-
-/*
-** Return the current time as a Julian Day number in *pTimeOut.
-*/
-static int jtCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
-  return sqlite3OsCurrentTime(g.pVfs, pTimeOut);
-}
-
-/**************************************************************************
-** Start of public API.
-*/
-
-/*
-** Configure the jt VFS as a wrapper around the VFS named by parameter 
-** zWrap. If the isDefault parameter is true, then the jt VFS is installed
-** as the new default VFS for SQLite connections. If isDefault is not
-** true, then the jt VFS is installed as non-default. In this case it
-** is available via its name, "jt".
-*/
-int jt_register(char *zWrap, int isDefault){
-  g.pVfs = sqlite3_vfs_find(zWrap);
-  if( g.pVfs==0 ){
-    return SQLITE_ERROR;
-  }
-  jt_vfs.szOsFile = sizeof(jt_file) + g.pVfs->szOsFile;
-  sqlite3_vfs_register(&jt_vfs, isDefault);
-  return SQLITE_OK;
-}
-
-/*
-** Uninstall the jt VFS, if it is installed.
-*/
-void jt_unregister(void){
-  sqlite3_vfs_unregister(&jt_vfs);
-}
-
-#endif