/*

** 2008 February 09

**

** 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 that is specific to windows.

*/

#include "sqliteInt.h"

#if OS_SYMBIAN               /* This file is used for symbian only */

#define MAX_PATH 260

/*

** A Note About Memory Allocation:

**

** This driver uses malloc()/free() directly rather than going through

** the SQLite-wrappers sqlite3_malloc()/sqlite3_free().  Those wrappers

** are designed for use on embedded systems where memory is scarce and

** malloc failures happen frequently.  Win32 does not typically run on

** embedded systems, and when it does the developers normally have bigger

** problems to worry about than running out of memory.  So there is not

** a compelling need to use the wrappers.

**

** But there is a good reason to not use the wrappers.  If we use the

** wrappers then we will get simulated malloc() failures within this

** driver.  And that causes all kinds of problems for our tests.  We

** could enhance SQLite to deal with simulated malloc failures within

** the OS driver, but the code to deal with those failure would not

** be exercised on Linux (which does not need to malloc() in the driver)

** and so we would have difficulty writing coverage tests for that

** code.  Better to leave the code out, we think.

**

** The point of this discussion is as follows:  When creating a new

** OS layer for an embedded system, if you use this file as an example,

** avoid the use of malloc()/free().  Those routines work ok on windows

** desktops but not so well in embedded systems.

*/

#include <stdlib.h>

#include <string.h>

#include <time.h>

#include <e32std.h>

#include <f32file.h>

#include <charconv.h>

#include <bautils.h>

#include <unistd.h>

/*

** Macros used to determine whether or not to use threads.

*/

#if defined(THREADSAFE) && THREADSAFE

# define SQLITE_W32_THREADS 1

#endif

/*

** Include code that is common to all os_*.c files

*/

#include "os_common.h"

/*

** The symbianFile structure is a subclass of sqlite3_file* specific to the win32

** portability layer.

*/

typedef struct symbianFile symbianFile;

struct symbianFile {

	int isOpen;

  unsigned char locktype; /* Type of lock currently held on this file */

  short sharedLockByte;   /* Randomly chosen byte used as a shared lock */

  char fileName[512];

  RFs session;

  RFile file;

};

/*****************************************************************************

** The next group of routines implement the I/O methods specified

** by the sqlite3_io_methods object.

******************************************************************************/

/*

** Close a file.

**

** It is reported that an attempt to close a handle might sometimes

** fail.  This is a very unreasonable result, but windows is notorious

** for being unreasonable so I do not doubt that it might happen.  If

** the close fails, we pause for 100 milliseconds and try again.  As

** many as MX_CLOSE_ATTEMPT attempts to close the handle are made before

** giving up and returning an error.

*/

#define MX_CLOSE_ATTEMPT 3

int winClose(sqlite3_file *id){

  int rc, cnt = 0;

  symbianFile *pFile = (symbianFile*)id;

  pFile->file.Close();

  pFile->session.Close();

  return SQLITE_OK;

}

/*

** Some microsoft compilers lack this definition.

*/

#ifndef INVALID_SET_FILE_POINTER

# define INVALID_SET_FILE_POINTER ((DWORD)-1)

#endif

/*

** Read data from a file into a buffer.  Return SQLITE_OK if all

** bytes were read successfully and SQLITE_IOERR if anything goes

** wrong.

*/

int winRead(

  sqlite3_file *id,          /* File to read from */

  void *pBuf,                /* Write content into this buffer */

  int amt,                   /* Number of bytes to read */

  sqlite3_int64 offset       /* Begin reading at this offset */

){

  int rc;

  size_t got;

  symbianFile *pFile = (symbianFile*)id;

  assert( id!=0 );

  SimulateIOError(return SQLITE_IOERR_READ);

  TInt tOffset = (TInt)offset;

  rc = pFile->file.Seek(ESeekStart, tOffset);

  if( rc!= KErrNone){

    return SQLITE_FULL;

  }

  HBufC8* buf = HBufC8::NewL(amt) ;

  TPtr8 ptr = buf->Des();

  if (pFile->file.Read(ptr, amt) != KErrNone)

	  {

	    delete buf;

	    return SQLITE_IOERR_READ;

	  }

  got = buf->Length();

  if( got == 0 ){

	  delete buf;

	  TInt size = 0;

	  if (pFile->file.Size(size) != KErrNone) 

	  {

		  return SQLITE_IOERR_READ;

	  }

	  if (size == 0)

	  {

		  return SQLITE_IOERR_SHORT_READ;

	  }

    return SQLITE_IOERR_READ;

 }

  memcpy(pBuf, ptr.Ptr(), got);

  delete buf;

 if( got == amt ){

    return SQLITE_OK;

  }else{

    memset(&((char*)pBuf)[got], 0, amt-got);

    return SQLITE_IOERR_SHORT_READ;

  }

}

/*

** Write data from a buffer into a file.  Return SQLITE_OK on success

** or some other error code on failure.

*/

int winWrite(

  sqlite3_file *id,         /* File to write into */

  const void *pBuf,         /* The bytes to be written */

  int amt,                  /* Number of bytes to write */

  sqlite3_int64 offset      /* Offset into the file to begin writing at */

){

  int rc;

  symbianFile *pFile = (symbianFile*)id;

  assert( id!=0 );

  SimulateIOError(return SQLITE_IOERR_WRITE);

  SimulateDiskfullError(return SQLITE_FULL);

  TInt tOffset = (TInt)offset;

  rc = pFile->file.Seek(ESeekStart, tOffset);

  if( rc!= KErrNone){

    return SQLITE_FULL;

  }

  assert( amt>0 );

  rc = SQLITE_OK;

  TPtrC8 ptr((TUint8 *)pBuf,amt);

  if (pFile->file.Write(ptr, amt) != KErrNone) rc = SQLITE_FULL;

  return rc;

}

/*

** Truncate an open file to a specified size

*/

int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){

  symbianFile *pFile = (symbianFile*)id;

  if (pFile->file.SetSize(nByte) != KErrNone)

  {

	  return SQLITE_IOERR; 

  }

  return SQLITE_OK;

}

#ifdef SQLITE_TEST

/*

** Count the number of fullsyncs and normal syncs.  This is used to test

** that syncs and fullsyncs are occuring at the right times.

*/

int sqlite3_sync_count = 0;

int sqlite3_fullsync_count = 0;

#endif

/*

** Make sure all writes to a particular file are committed to disk.

*/

int winSync(sqlite3_file *id, int flags){

  symbianFile *pFile = (symbianFile*)id;

  OSTRACE3("SYNC %d lock=%d\n", pFile->h, pFile->locktype);

#ifdef SQLITE_TEST

  if( flags & SQLITE_SYNC_FULL ){

    sqlite3_fullsync_count++;

  }

  sqlite3_sync_count++;

#endif

  TInt error = pFile->file.Flush();

  if (error != KErrNone)

  {

    return SQLITE_IOERR;

  }else{

    return SQLITE_OK;

  }

}

/*

** Determine the current size of a file in bytes

*/

int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){

  symbianFile *pFile = (symbianFile*)id;

  TInt size = 0;

  if (pFile->file.Size(size) != KErrNone)

  {

	  return SQLITE_IOERR;

  }

  *pSize = size;

  return SQLITE_OK;

}

/*

** Lock the file with the lock specified by parameter locktype - one

** of the following:

**

**     (1) SHARED_LOCK

**     (2) RESERVED_LOCK

**     (3) PENDING_LOCK

**     (4) EXCLUSIVE_LOCK

**

** Sometimes when requesting one lock state, additional lock states

** are inserted in between.  The locking might fail on one of the later

** transitions leaving the lock state different from what it started but

** still short of its goal.  The following chart shows the allowed

** transitions and the inserted intermediate states:

**

**    UNLOCKED -> SHARED

**    SHARED -> RESERVED

**    SHARED -> (PENDING) -> EXCLUSIVE

**    RESERVED -> (PENDING) -> EXCLUSIVE

**    PENDING -> EXCLUSIVE

**

** This routine will only increase a lock.  The winUnlock() routine

** erases all locks at once and returns us immediately to locking level 0.

** It is not possible to lower the locking level one step at a time.  You

** must go straight to locking level 0.

*/

int winLock(sqlite3_file *id, int locktype){

  int rc = SQLITE_OK;    /* Return code from subroutines */

  int res = 1;           /* Result of a windows lock call */

  int newLocktype;       /* Set pFile->locktype to this value before exiting */

  int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */

  symbianFile *pFile = (symbianFile*)id;

  assert( pFile!=0 );

  OSTRACE5("LOCK %d %d was %d(%d)\n",

          pFile->h, locktype, pFile->locktype, pFile->sharedLockByte);

  // one smartphone only one application can control the database

  TInt size = 0;

  if (pFile->file.Size(size) == KErrNone) return SQLITE_OK;

  return SQLITE_BUSY;

}

/*

** This routine checks if there is a RESERVED lock held on the specified

** file by this or any other process. If such a lock is held, return

** non-zero, otherwise zero.

*/

int winCheckReservedLock(sqlite3_file *id){

  int rc;

  symbianFile *pFile = (symbianFile*)id;

  assert( pFile!=0 );

  if( pFile->locktype>=RESERVED_LOCK ){

    rc = 1;

    OSTRACE3("TEST WR-LOCK %d %d (local)\n", pFile->h, rc);

  }else{

	  TInt size = 0;

	  if (pFile->file.Size(size) == KErrNone) rc = 1;

    OSTRACE3("TEST WR-LOCK %d %d (remote)\n", pFile->h, rc);

  }

  return rc;

}

/*

** Lower the locking level on file descriptor id to locktype.  locktype

** must be either NO_LOCK or SHARED_LOCK.

**

** If the locking level of the file descriptor is already at or below

** the requested locking level, this routine is a no-op.

**

** It is not possible for this routine to fail if the second argument

** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine

** might return SQLITE_IOERR;

*/

int winUnlock(sqlite3_file *id, int locktype){

  int type;

  symbianFile *pFile = (symbianFile*)id;

  int rc = SQLITE_OK;

  assert( pFile!=0 );

  return rc;

}

/*

** Control and query of the open file handle.

*/

int winFileControl(sqlite3_file *id, int op, void *pArg){

  switch( op ){

    case SQLITE_FCNTL_LOCKSTATE: {

      *(int*)pArg = ((symbianFile*)id)->locktype;

      return SQLITE_OK;

    }

  }

  return SQLITE_ERROR;

}

/*

** Return the sector size in bytes of the underlying block device for

** the specified file. This is almost always 512 bytes, but may be

** larger for some devices.

**

** SQLite code assumes this function cannot fail. It also assumes that

** if two files are created in the same file-system directory (i.e.

** a database and its journal file) that the sector size will be the

** same for both.

*/

int winSectorSize(sqlite3_file *id){

  return SQLITE_DEFAULT_SECTOR_SIZE;

}

/*

** Return a vector of device characteristics.

*/

int winDeviceCharacteristics(sqlite3_file *id){

  return 0;

}

/***************************************************************************

** Here ends the I/O methods that form the sqlite3_io_methods object.

**

** The next block of code implements the VFS methods.

****************************************************************************/

void ConvertToUnicode(RFs session, TDes16& aUnicode, const char *str)

{

  CCnvCharacterSetConverter *converter = CCnvCharacterSetConverter::NewL();

  converter->PrepareToConvertToOrFromL(KCharacterSetIdentifierUtf8, session);

  TPtrC8 ptr((const unsigned char*)str);

  int state = CCnvCharacterSetConverter::KStateDefault;

  converter->ConvertToUnicode(aUnicode, ptr, state);

  delete converter;

}

/*

** Open a file.

*/

int winOpen(

  sqlite3_vfs *pVfs,        /* Not used */

  const char *zName,        /* Name of the file (UTF-8) */

  sqlite3_file *id,         /* Write the SQLite file handle here */

  int flags,                /* Open mode flags */

  int *pOutFlags            /* Status return flags */

){

  symbianFile *pFile = (symbianFile*)id;

  TBuf16<MAX_PATH> filename;

  pFile->isOpen = 0;

  memset(pFile, 0, sizeof(*pFile));

  strcpy(pFile->fileName, zName);

  pFile->session.Connect();

  ConvertToUnicode(pFile->session, filename, zName);

  int ret = 0;

  if( flags & SQLITE_OPEN_CREATE ){

    if (BaflUtils::FileExists(pFile->session, filename) == 1)

    	{

  	  ret = pFile->file.Open(pFile->session, filename, EFileStream | EFileWrite);

    	}

    else

    	{

    	ret = pFile->file.Create(pFile->session, filename, EFileStream | EFileWrite);

    	}

  }

  else

  if( flags & SQLITE_OPEN_READWRITE ){

	  ret = pFile->file.Open(pFile->session, filename, EFileStream | EFileWrite);

  }else{

	ret = pFile->file.Open(pFile->session, filename, EFileStream | EFileRead);

  }

  OpenCounter(+1);

  if (ret != KErrNone)

  {

	  return SQLITE_IOERR;

  }

  pFile->isOpen = 1;

  return SQLITE_OK;

}

/*

** Delete the named file.

**

** Note that windows does not allow a file to be deleted if some other

** process has it open.  Sometimes a virus scanner or indexing program

** will open a journal file shortly after it is created in order to do

** whatever does.  While this other process is holding the

** file open, we will be unable to delete it.  To work around this

** problem, we delay 100 milliseconds and try to delete again.  Up

** to MX_DELETION_ATTEMPTs deletion attempts are run before giving

** up and returning an error.

*/

#define MX_DELETION_ATTEMPTS 5

int winDelete(

  sqlite3_vfs *pVfs,          /* Not used on win32 */

  const char *zFilename,      /* Name of file to delete */

  int syncDir                 /* Not used on win32 */

){

  SimulateIOError(return SQLITE_IOERR_DELETE);

  TBuf16<MAX_PATH> filename;

  RFs session;

  session.Connect();

  ConvertToUnicode(session, filename, zFilename);

  BaflUtils::DeleteFile(session, filename);

  OSTRACE2("DELETE \"%s\"\n", zFilename);

  session.Close();

  return SQLITE_OK;

}

/*

** Check the existance and status of a file.

*/

int winAccess(

  sqlite3_vfs *pVfs,         /* Not used on win32 */

  const char *zFilename,     /* Name of file to check */

  int flags                  /* Type of test to make on this file */

){

  TBuf16<MAX_PATH> filename;

  RFs session;

  session.Connect();

  ConvertToUnicode(session, filename, zFilename);

  int ret = BaflUtils::FileExists(session, filename);

  session.Close();

  return ret;

}

/*

** Create a temporary file name in zBuf.  zBuf must be big enough to

** hold at pVfs->mxPathname characters.

*/

int winGetTempname(sqlite3_vfs *pVfs, int nBuf, char *zBuf){

  static char zChars[] =

    "abcdefghijklmnopqrstuvwxyz"

    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

    "0123456789";

  int i, j;

  char zTempPath[MAX_PATH+1];

  if( sqlite3_temp_directory ){

    sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", sqlite3_temp_directory);

  }

  else

  {

  }

  for(i=strlen(zTempPath); i>0 && zTempPath[i-1]=='\\'; i--){}

  zTempPath[i] = 0;

  sqlite3_snprintf(nBuf-30, zBuf,

                   "%s\\"SQLITE_TEMP_FILE_PREFIX, zTempPath);

  j = strlen(zBuf);

  sqlite3Randomness(20, &zBuf[j]);

  for(i=0; i<20; i++, j++){

    zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];

  }

  zBuf[j] = 0;

  OSTRACE2("TEMP FILENAME: %s\n", zBuf);

  return SQLITE_OK; 

}