Adding upstream version 3.40.1.upstream/3.40.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 672 insertions, 0 deletions

diff --git a/ext/misc/appendvfs.c b/ext/misc/appendvfs.c
new file mode 100644
index 0000000..eb9ed01
--- /dev/null
+++ b/ext/misc/appendvfs.c
@@ -0,0 +1,672 @@
+/*
+** 2017-10-20
+**
+** 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 implements a VFS shim that allows an SQLite database to be
+** appended onto the end of some other file, such as an executable.
+**
+** A special record must appear at the end of the file that identifies the
+** file as an appended database and provides the offset to the first page
+** of the exposed content. (Or, it is the length of the content prefix.)
+** For best performance page 1 should be located at a disk page boundary,
+** though that is not required.
+**
+** When opening a database using this VFS, the connection might treat
+** the file as an ordinary SQLite database, or it might treat it as a
+** database appended onto some other file.  The decision is made by
+** applying the following rules in order:
+**
+**  (1)  An empty file is an ordinary database.
+**
+**  (2)  If the file ends with the appendvfs trailer string
+**       "Start-Of-SQLite3-NNNNNNNN" that file is an appended database.
+**
+**  (3)  If the file begins with the standard SQLite prefix string
+**       "SQLite format 3", that file is an ordinary database.
+**
+**  (4)  If none of the above apply and the SQLITE_OPEN_CREATE flag is
+**       set, then a new database is appended to the already existing file.
+**
+**  (5)  Otherwise, SQLITE_CANTOPEN is returned.
+**
+** To avoid unnecessary complications with the PENDING_BYTE, the size of
+** the file containing the database is limited to 1GiB. (1073741824 bytes)
+** This VFS will not read or write past the 1GiB mark.  This restriction
+** might be lifted in future versions.  For now, if you need a larger
+** database, then keep it in a separate file.
+**
+** If the file being opened is a plain database (not an appended one), then
+** this shim is a pass-through into the default underlying VFS. (rule 3)
+**/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <string.h>
+#include <assert.h>
+
+/* The append mark at the end of the database is:
+**
+**     Start-Of-SQLite3-NNNNNNNN
+**     123456789 123456789 12345
+**
+** The NNNNNNNN represents a 64-bit big-endian unsigned integer which is
+** the offset to page 1, and also the length of the prefix content.
+*/
+#define APND_MARK_PREFIX     "Start-Of-SQLite3-"
+#define APND_MARK_PREFIX_SZ  17
+#define APND_MARK_FOS_SZ      8
+#define APND_MARK_SIZE       (APND_MARK_PREFIX_SZ+APND_MARK_FOS_SZ)
+
+/*
+** Maximum size of the combined prefix + database + append-mark.  This
+** must be less than 0x40000000 to avoid locking issues on Windows.
+*/
+#define APND_MAX_SIZE  (0x40000000)
+
+/*
+** Try to align the database to an even multiple of APND_ROUNDUP bytes.
+*/
+#ifndef APND_ROUNDUP
+#define APND_ROUNDUP 4096
+#endif
+#define APND_ALIGN_MASK         ((sqlite3_int64)(APND_ROUNDUP-1))
+#define APND_START_ROUNDUP(fsz) (((fsz)+APND_ALIGN_MASK) & ~APND_ALIGN_MASK)
+
+/*
+** Forward declaration of objects used by this utility
+*/
+typedef struct sqlite3_vfs ApndVfs;
+typedef struct ApndFile ApndFile;
+
+/* Access to a lower-level VFS that (might) implement dynamic loading,
+** access to randomness, etc.
+*/
+#define ORIGVFS(p)  ((sqlite3_vfs*)((p)->pAppData))
+#define ORIGFILE(p) ((sqlite3_file*)(((ApndFile*)(p))+1))
+
+/* An open appendvfs file
+**
+** An instance of this structure describes the appended database file.
+** A separate sqlite3_file object is always appended. The appended
+** sqlite3_file object (which can be accessed using ORIGFILE()) describes
+** the entire file, including the prefix, the database, and the
+** append-mark.
+**
+** The structure of an AppendVFS database is like this:
+**
+**   +-------------+---------+----------+-------------+
+**   | prefix-file | padding | database | append-mark |
+**   +-------------+---------+----------+-------------+
+**                           ^          ^
+**                           |          |
+**                         iPgOne      iMark
+**
+**
+** "prefix file" -  file onto which the database has been appended.
+** "padding"     -  zero or more bytes inserted so that "database"
+**                  starts on an APND_ROUNDUP boundary
+** "database"    -  The SQLite database file
+** "append-mark" -  The 25-byte "Start-Of-SQLite3-NNNNNNNN" that indicates
+**                  the offset from the start of prefix-file to the start
+**                  of "database".
+**
+** The size of the database is iMark - iPgOne.
+**
+** The NNNNNNNN in the "Start-Of-SQLite3-NNNNNNNN" suffix is the value
+** of iPgOne stored as a big-ending 64-bit integer.
+**
+** iMark will be the size of the underlying file minus 25 (APND_MARKSIZE).
+** Or, iMark is -1 to indicate that it has not yet been written.
+*/
+struct ApndFile {
+  sqlite3_file base;        /* Subclass.  MUST BE FIRST! */
+  sqlite3_int64 iPgOne;     /* Offset to the start of the database */
+  sqlite3_int64 iMark;      /* Offset of the append mark.  -1 if unwritten */
+  /* Always followed by another sqlite3_file that describes the whole file */
+};
+
+/*
+** Methods for ApndFile
+*/
+static int apndClose(sqlite3_file*);
+static int apndRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
+static int apndWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
+static int apndTruncate(sqlite3_file*, sqlite3_int64 size);
+static int apndSync(sqlite3_file*, int flags);
+static int apndFileSize(sqlite3_file*, sqlite3_int64 *pSize);
+static int apndLock(sqlite3_file*, int);
+static int apndUnlock(sqlite3_file*, int);
+static int apndCheckReservedLock(sqlite3_file*, int *pResOut);
+static int apndFileControl(sqlite3_file*, int op, void *pArg);
+static int apndSectorSize(sqlite3_file*);
+static int apndDeviceCharacteristics(sqlite3_file*);
+static int apndShmMap(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
+static int apndShmLock(sqlite3_file*, int offset, int n, int flags);
+static void apndShmBarrier(sqlite3_file*);
+static int apndShmUnmap(sqlite3_file*, int deleteFlag);
+static int apndFetch(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
+static int apndUnfetch(sqlite3_file*, sqlite3_int64 iOfst, void *p);
+
+/*
+** Methods for ApndVfs
+*/
+static int apndOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
+static int apndDelete(sqlite3_vfs*, const char *zName, int syncDir);
+static int apndAccess(sqlite3_vfs*, const char *zName, int flags, int *);
+static int apndFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
+static void *apndDlOpen(sqlite3_vfs*, const char *zFilename);
+static void apndDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
+static void (*apndDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void);
+static void apndDlClose(sqlite3_vfs*, void*);
+static int apndRandomness(sqlite3_vfs*, int nByte, char *zOut);
+static int apndSleep(sqlite3_vfs*, int microseconds);
+static int apndCurrentTime(sqlite3_vfs*, double*);
+static int apndGetLastError(sqlite3_vfs*, int, char *);
+static int apndCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);
+static int apndSetSystemCall(sqlite3_vfs*, const char*,sqlite3_syscall_ptr);
+static sqlite3_syscall_ptr apndGetSystemCall(sqlite3_vfs*, const char *z);
+static const char *apndNextSystemCall(sqlite3_vfs*, const char *zName);
+
+static sqlite3_vfs apnd_vfs = {
+  3,                            /* iVersion (set when registered) */
+  0,                            /* szOsFile (set when registered) */
+  1024,                         /* mxPathname */
+  0,                            /* pNext */
+  "apndvfs",                    /* zName */
+  0,                            /* pAppData (set when registered) */ 
+  apndOpen,                     /* xOpen */
+  apndDelete,                   /* xDelete */
+  apndAccess,                   /* xAccess */
+  apndFullPathname,             /* xFullPathname */
+  apndDlOpen,                   /* xDlOpen */
+  apndDlError,                  /* xDlError */
+  apndDlSym,                    /* xDlSym */
+  apndDlClose,                  /* xDlClose */
+  apndRandomness,               /* xRandomness */
+  apndSleep,                    /* xSleep */
+  apndCurrentTime,              /* xCurrentTime */
+  apndGetLastError,             /* xGetLastError */
+  apndCurrentTimeInt64,         /* xCurrentTimeInt64 */
+  apndSetSystemCall,            /* xSetSystemCall */
+  apndGetSystemCall,            /* xGetSystemCall */
+  apndNextSystemCall            /* xNextSystemCall */
+};
+
+static const sqlite3_io_methods apnd_io_methods = {
+  3,                              /* iVersion */
+  apndClose,                      /* xClose */
+  apndRead,                       /* xRead */
+  apndWrite,                      /* xWrite */
+  apndTruncate,                   /* xTruncate */
+  apndSync,                       /* xSync */
+  apndFileSize,                   /* xFileSize */
+  apndLock,                       /* xLock */
+  apndUnlock,                     /* xUnlock */
+  apndCheckReservedLock,          /* xCheckReservedLock */
+  apndFileControl,                /* xFileControl */
+  apndSectorSize,                 /* xSectorSize */
+  apndDeviceCharacteristics,      /* xDeviceCharacteristics */
+  apndShmMap,                     /* xShmMap */
+  apndShmLock,                    /* xShmLock */
+  apndShmBarrier,                 /* xShmBarrier */
+  apndShmUnmap,                   /* xShmUnmap */
+  apndFetch,                      /* xFetch */
+  apndUnfetch                     /* xUnfetch */
+};
+
+/*
+** Close an apnd-file.
+*/
+static int apndClose(sqlite3_file *pFile){
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xClose(pFile);
+}
+
+/*
+** Read data from an apnd-file.
+*/
+static int apndRead(
+  sqlite3_file *pFile, 
+  void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  ApndFile *paf = (ApndFile *)pFile;
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xRead(pFile, zBuf, iAmt, paf->iPgOne+iOfst);
+}
+
+/*
+** Add the append-mark onto what should become the end of the file.
+*  If and only if this succeeds, internal ApndFile.iMark is updated.
+*  Parameter iWriteEnd is the appendvfs-relative offset of the new mark.
+*/
+static int apndWriteMark(
+  ApndFile *paf,
+  sqlite3_file *pFile,
+  sqlite_int64 iWriteEnd
+){
+  sqlite_int64 iPgOne = paf->iPgOne;
+  unsigned char a[APND_MARK_SIZE];
+  int i = APND_MARK_FOS_SZ;
+  int rc;
+  assert(pFile == ORIGFILE(paf));
+  memcpy(a, APND_MARK_PREFIX, APND_MARK_PREFIX_SZ);
+  while( --i >= 0 ){
+    a[APND_MARK_PREFIX_SZ+i] = (unsigned char)(iPgOne & 0xff);
+    iPgOne >>= 8;
+  }
+  iWriteEnd += paf->iPgOne;
+  if( SQLITE_OK==(rc = pFile->pMethods->xWrite
+                  (pFile, a, APND_MARK_SIZE, iWriteEnd)) ){
+    paf->iMark = iWriteEnd;
+  }
+  return rc;
+}
+
+/*
+** Write data to an apnd-file.
+*/
+static int apndWrite(
+  sqlite3_file *pFile,
+  const void *zBuf,
+  int iAmt,
+  sqlite_int64 iOfst
+){
+  ApndFile *paf = (ApndFile *)pFile;
+  sqlite_int64 iWriteEnd = iOfst + iAmt;
+  if( iWriteEnd>=APND_MAX_SIZE ) return SQLITE_FULL;
+  pFile = ORIGFILE(pFile);
+  /* If append-mark is absent or will be overwritten, write it. */
+  if( paf->iMark < 0 || paf->iPgOne + iWriteEnd > paf->iMark ){
+    int rc = apndWriteMark(paf, pFile, iWriteEnd);
+    if( SQLITE_OK!=rc ) return rc;
+  }
+  return pFile->pMethods->xWrite(pFile, zBuf, iAmt, paf->iPgOne+iOfst);
+}
+
+/*
+** Truncate an apnd-file.
+*/
+static int apndTruncate(sqlite3_file *pFile, sqlite_int64 size){
+  ApndFile *paf = (ApndFile *)pFile;
+  pFile = ORIGFILE(pFile);
+  /* The append mark goes out first so truncate failure does not lose it. */
+  if( SQLITE_OK!=apndWriteMark(paf, pFile, size) ) return SQLITE_IOERR;
+  /* Truncate underlying file just past append mark */
+  return pFile->pMethods->xTruncate(pFile, paf->iMark+APND_MARK_SIZE);
+}
+
+/*
+** Sync an apnd-file.
+*/
+static int apndSync(sqlite3_file *pFile, int flags){
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xSync(pFile, flags);
+}
+
+/*
+** Return the current file-size of an apnd-file.
+** If the append mark is not yet there, the file-size is 0.
+*/
+static int apndFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
+  ApndFile *paf = (ApndFile *)pFile;
+  *pSize = ( paf->iMark >= 0 )? (paf->iMark - paf->iPgOne) : 0;
+  return SQLITE_OK;
+}
+
+/*
+** Lock an apnd-file.
+*/
+static int apndLock(sqlite3_file *pFile, int eLock){
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xLock(pFile, eLock);
+}
+
+/*
+** Unlock an apnd-file.
+*/
+static int apndUnlock(sqlite3_file *pFile, int eLock){
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xUnlock(pFile, eLock);
+}
+
+/*
+** Check if another file-handle holds a RESERVED lock on an apnd-file.
+*/
+static int apndCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xCheckReservedLock(pFile, pResOut);
+}
+
+/*
+** File control method. For custom operations on an apnd-file.
+*/
+static int apndFileControl(sqlite3_file *pFile, int op, void *pArg){
+  ApndFile *paf = (ApndFile *)pFile;
+  int rc;
+  pFile = ORIGFILE(pFile);
+  if( op==SQLITE_FCNTL_SIZE_HINT ) *(sqlite3_int64*)pArg += paf->iPgOne;
+  rc = pFile->pMethods->xFileControl(pFile, op, pArg);
+  if( rc==SQLITE_OK && op==SQLITE_FCNTL_VFSNAME ){
+    *(char**)pArg = sqlite3_mprintf("apnd(%lld)/%z", paf->iPgOne,*(char**)pArg);
+  }
+  return rc;
+}
+
+/*
+** Return the sector-size in bytes for an apnd-file.
+*/
+static int apndSectorSize(sqlite3_file *pFile){
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xSectorSize(pFile);
+}
+
+/*
+** Return the device characteristic flags supported by an apnd-file.
+*/
+static int apndDeviceCharacteristics(sqlite3_file *pFile){
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xDeviceCharacteristics(pFile);
+}
+
+/* Create a shared memory file mapping */
+static int apndShmMap(
+  sqlite3_file *pFile,
+  int iPg,
+  int pgsz,
+  int bExtend,
+  void volatile **pp
+){
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xShmMap(pFile,iPg,pgsz,bExtend,pp);
+}
+
+/* Perform locking on a shared-memory segment */
+static int apndShmLock(sqlite3_file *pFile, int offset, int n, int flags){
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xShmLock(pFile,offset,n,flags);
+}
+
+/* Memory barrier operation on shared memory */
+static void apndShmBarrier(sqlite3_file *pFile){
+  pFile = ORIGFILE(pFile);
+  pFile->pMethods->xShmBarrier(pFile);
+}
+
+/* Unmap a shared memory segment */
+static int apndShmUnmap(sqlite3_file *pFile, int deleteFlag){
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xShmUnmap(pFile,deleteFlag);
+}
+
+/* Fetch a page of a memory-mapped file */
+static int apndFetch(
+  sqlite3_file *pFile,
+  sqlite3_int64 iOfst,
+  int iAmt,
+  void **pp
+){
+  ApndFile *p = (ApndFile *)pFile;
+  if( p->iMark < 0 || iOfst+iAmt > p->iMark ){
+    return SQLITE_IOERR; /* Cannot read what is not yet there. */
+  }
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xFetch(pFile, iOfst+p->iPgOne, iAmt, pp);
+}
+
+/* Release a memory-mapped page */
+static int apndUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){
+  ApndFile *p = (ApndFile *)pFile;
+  pFile = ORIGFILE(pFile);
+  return pFile->pMethods->xUnfetch(pFile, iOfst+p->iPgOne, pPage);
+}
+
+/*
+** Try to read the append-mark off the end of a file.  Return the
+** start of the appended database if the append-mark is present.
+** If there is no valid append-mark, return -1;
+**
+** An append-mark is only valid if the NNNNNNNN start-of-database offset
+** indicates that the appended database contains at least one page.  The
+** start-of-database value must be a multiple of 512.
+*/
+static sqlite3_int64 apndReadMark(sqlite3_int64 sz, sqlite3_file *pFile){
+  int rc, i;
+  sqlite3_int64 iMark;
+  int msbs = 8 * (APND_MARK_FOS_SZ-1);
+  unsigned char a[APND_MARK_SIZE];
+
+  if( APND_MARK_SIZE!=(sz & 0x1ff) ) return -1;
+  rc = pFile->pMethods->xRead(pFile, a, APND_MARK_SIZE, sz-APND_MARK_SIZE);
+  if( rc ) return -1;
+  if( memcmp(a, APND_MARK_PREFIX, APND_MARK_PREFIX_SZ)!=0 ) return -1;
+  iMark = ((sqlite3_int64)(a[APND_MARK_PREFIX_SZ] & 0x7f)) << msbs;
+  for(i=1; i<8; i++){
+    msbs -= 8;
+    iMark |= (sqlite3_int64)a[APND_MARK_PREFIX_SZ+i]<<msbs;
+  }
+  if( iMark > (sz - APND_MARK_SIZE - 512) ) return -1;
+  if( iMark & 0x1ff ) return -1;
+  return iMark;
+}
+
+static const char apvfsSqliteHdr[] = "SQLite format 3";
+/*
+** Check to see if the file is an appendvfs SQLite database file.
+** Return true iff it is such. Parameter sz is the file's size.
+*/
+static int apndIsAppendvfsDatabase(sqlite3_int64 sz, sqlite3_file *pFile){
+  int rc;
+  char zHdr[16];
+  sqlite3_int64 iMark = apndReadMark(sz, pFile);
+  if( iMark>=0 ){
+    /* If file has the correct end-marker, the expected odd size, and the
+    ** SQLite DB type marker where the end-marker puts it, then it
+    ** is an appendvfs database.
+    */
+    rc = pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), iMark);
+    if( SQLITE_OK==rc
+     && memcmp(zHdr, apvfsSqliteHdr, sizeof(zHdr))==0
+     && (sz & 0x1ff) == APND_MARK_SIZE
+     && sz>=512+APND_MARK_SIZE
+    ){
+      return 1; /* It's an appendvfs database */
+    }
+  }
+  return 0;
+}
+
+/*
+** Check to see if the file is an ordinary SQLite database file.
+** Return true iff so. Parameter sz is the file's size.
+*/
+static int apndIsOrdinaryDatabaseFile(sqlite3_int64 sz, sqlite3_file *pFile){
+  char zHdr[16];
+  if( apndIsAppendvfsDatabase(sz, pFile) /* rule 2 */
+   || (sz & 0x1ff) != 0
+   || SQLITE_OK!=pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), 0)
+   || memcmp(zHdr, apvfsSqliteHdr, sizeof(zHdr))!=0
+  ){
+    return 0;
+  }else{
+    return 1;
+  }
+}
+
+/*
+** Open an apnd file handle.
+*/
+static int apndOpen(
+  sqlite3_vfs *pApndVfs,
+  const char *zName,
+  sqlite3_file *pFile,
+  int flags,
+  int *pOutFlags
+){
+  ApndFile *pApndFile = (ApndFile*)pFile;
+  sqlite3_file *pBaseFile = ORIGFILE(pFile);
+  sqlite3_vfs *pBaseVfs = ORIGVFS(pApndVfs);
+  int rc;
+  sqlite3_int64 sz = 0;
+  if( (flags & SQLITE_OPEN_MAIN_DB)==0 ){
+    /* The appendvfs is not to be used for transient or temporary databases.
+    ** Just use the base VFS open to initialize the given file object and
+    ** open the underlying file. (Appendvfs is then unused for this file.)
+    */
+    return pBaseVfs->xOpen(pBaseVfs, zName, pFile, flags, pOutFlags);
+  }
+  memset(pApndFile, 0, sizeof(ApndFile));
+  pFile->pMethods = &apnd_io_methods;
+  pApndFile->iMark = -1;    /* Append mark not yet written */
+
+  rc = pBaseVfs->xOpen(pBaseVfs, zName, pBaseFile, flags, pOutFlags);
+  if( rc==SQLITE_OK ){
+    rc = pBaseFile->pMethods->xFileSize(pBaseFile, &sz);
+    if( rc ){
+      pBaseFile->pMethods->xClose(pBaseFile);
+    }
+  }
+  if( rc ){
+    pFile->pMethods = 0;
+    return rc;
+  }
+  if( apndIsOrdinaryDatabaseFile(sz, pBaseFile) ){
+    /* The file being opened appears to be just an ordinary DB. Copy
+    ** the base dispatch-table so this instance mimics the base VFS. 
+    */
+    memmove(pApndFile, pBaseFile, pBaseVfs->szOsFile);
+    return SQLITE_OK;
+  }
+  pApndFile->iPgOne = apndReadMark(sz, pFile);
+  if( pApndFile->iPgOne>=0 ){
+    pApndFile->iMark = sz - APND_MARK_SIZE; /* Append mark found */
+    return SQLITE_OK;
+  }
+  if( (flags & SQLITE_OPEN_CREATE)==0 ){
+    pBaseFile->pMethods->xClose(pBaseFile);
+    rc = SQLITE_CANTOPEN;
+    pFile->pMethods = 0;
+  }else{
+    /* Round newly added appendvfs location to #define'd page boundary. 
+    ** Note that nothing has yet been written to the underlying file.
+    ** The append mark will be written along with first content write.
+    ** Until then, paf->iMark value indicates it is not yet written.
+    */
+    pApndFile->iPgOne = APND_START_ROUNDUP(sz);
+  }
+  return rc;
+}
+
+/*
+** Delete an apnd file.
+** For an appendvfs, this could mean delete the appendvfs portion,
+** leaving the appendee as it was before it gained an appendvfs.
+** For now, this code deletes the underlying file too.
+*/
+static int apndDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  return ORIGVFS(pVfs)->xDelete(ORIGVFS(pVfs), zPath, dirSync);
+}
+
+/*
+** All other VFS methods are pass-thrus.
+*/
+static int apndAccess(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int flags, 
+  int *pResOut
+){
+  return ORIGVFS(pVfs)->xAccess(ORIGVFS(pVfs), zPath, flags, pResOut);
+}
+static int apndFullPathname(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int nOut, 
+  char *zOut
+){
+  return ORIGVFS(pVfs)->xFullPathname(ORIGVFS(pVfs),zPath,nOut,zOut);
+}
+static void *apndDlOpen(sqlite3_vfs *pVfs, const char *zPath){
+  return ORIGVFS(pVfs)->xDlOpen(ORIGVFS(pVfs), zPath);
+}
+static void apndDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
+  ORIGVFS(pVfs)->xDlError(ORIGVFS(pVfs), nByte, zErrMsg);
+}
+static void (*apndDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){
+  return ORIGVFS(pVfs)->xDlSym(ORIGVFS(pVfs), p, zSym);
+}
+static void apndDlClose(sqlite3_vfs *pVfs, void *pHandle){
+  ORIGVFS(pVfs)->xDlClose(ORIGVFS(pVfs), pHandle);
+}
+static int apndRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
+  return ORIGVFS(pVfs)->xRandomness(ORIGVFS(pVfs), nByte, zBufOut);
+}
+static int apndSleep(sqlite3_vfs *pVfs, int nMicro){
+  return ORIGVFS(pVfs)->xSleep(ORIGVFS(pVfs), nMicro);
+}
+static int apndCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
+  return ORIGVFS(pVfs)->xCurrentTime(ORIGVFS(pVfs), pTimeOut);
+}
+static int apndGetLastError(sqlite3_vfs *pVfs, int a, char *b){
+  return ORIGVFS(pVfs)->xGetLastError(ORIGVFS(pVfs), a, b);
+}
+static int apndCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){
+  return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p);
+}
+static int apndSetSystemCall(
+  sqlite3_vfs *pVfs,
+  const char *zName,
+  sqlite3_syscall_ptr pCall
+){
+  return ORIGVFS(pVfs)->xSetSystemCall(ORIGVFS(pVfs),zName,pCall);
+}
+static sqlite3_syscall_ptr apndGetSystemCall(
+  sqlite3_vfs *pVfs,
+  const char *zName
+){
+  return ORIGVFS(pVfs)->xGetSystemCall(ORIGVFS(pVfs),zName);
+}
+static const char *apndNextSystemCall(sqlite3_vfs *pVfs, const char *zName){
+  return ORIGVFS(pVfs)->xNextSystemCall(ORIGVFS(pVfs), zName);
+}
+
+  
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+/* 
+** This routine is called when the extension is loaded.
+** Register the new VFS.
+*/
+int sqlite3_appendvfs_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  sqlite3_vfs *pOrig;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;
+  (void)db;
+  pOrig = sqlite3_vfs_find(0);
+  if( pOrig==0 ) return SQLITE_ERROR;
+  apnd_vfs.iVersion = pOrig->iVersion;
+  apnd_vfs.pAppData = pOrig;
+  apnd_vfs.szOsFile = pOrig->szOsFile + sizeof(ApndFile);
+  rc = sqlite3_vfs_register(&apnd_vfs, 0);
+#ifdef APPENDVFS_TEST
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_auto_extension((void(*)(void))apndvfsRegister);
+  }
+#endif
+  if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY;
+  return rc;
+}