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transmission/libtransmission/inout.c

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/******************************************************************************
* Copyright (c) 2005 Eric Petit
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*****************************************************************************/
#include "transmission.h"
#ifdef SYS_BEOS
# define fseeko _fseek
#endif
struct tr_io_s
{
tr_torrent_t * tor;
/* Position of pieces
-1 = we haven't started to download this piece yet
n = we have started or completed the piece in slot n */
int * pieceSlot;
/* Pieces in slot
-1 = unused slot
n = piece n */
int * slotPiece;
int slotsUsed;
};
#include "fastresume.h"
/***********************************************************************
* Local prototypes
**********************************************************************/
static int createFiles( tr_io_t * );
static int checkFiles( tr_io_t * );
static void closeFiles( tr_io_t * );
static int readOrWriteBytes( tr_io_t *, uint64_t, int, uint8_t *, int );
static int readOrWriteSlot( tr_io_t * io, int slot, uint8_t * buf,
int * size, int write );
static void findSlotForPiece( tr_io_t *, int );
#define readBytes(io,o,s,b) readOrWriteBytes(io,o,s,b,0)
#define writeBytes(io,o,s,b) readOrWriteBytes(io,o,s,b,1)
#define readSlot(io,sl,b,s) readOrWriteSlot(io,sl,b,s,0)
#define writeSlot(io,sl,b,s) readOrWriteSlot(io,sl,b,s,1)
/***********************************************************************
* tr_ioInit
***********************************************************************
* Open all files we are going to write to
**********************************************************************/
tr_io_t * tr_ioInit( tr_torrent_t * tor )
{
tr_io_t * io;
io = malloc( sizeof( tr_io_t ) );
io->tor = tor;
if( createFiles( io ) || checkFiles( io ) )
{
free( io );
return NULL;
}
return io;
}
/***********************************************************************
* tr_ioRead
***********************************************************************
*
**********************************************************************/
int tr_ioRead( tr_io_t * io, int index, int begin, int length,
uint8_t * buf )
{
uint64_t offset;
tr_info_t * inf = &io->tor->info;
offset = (uint64_t) io->pieceSlot[index] *
(uint64_t) inf->pieceSize + (uint64_t) begin;
return readBytes( io, offset, length, buf );
}
/***********************************************************************
* tr_ioWrite
***********************************************************************
*
**********************************************************************/
int tr_ioWrite( tr_io_t * io, int index, int begin, int length,
uint8_t * buf )
{
tr_torrent_t * tor = io->tor;
tr_info_t * inf = &io->tor->info;
uint64_t offset;
int i;
uint8_t hash[SHA_DIGEST_LENGTH];
uint8_t * pieceBuf;
int pieceSize;
int startBlock, endBlock;
if( io->pieceSlot[index] < 0 )
{
findSlotForPiece( io, index );
tr_inf( "Piece %d: starting in slot %d", index,
io->pieceSlot[index] );
}
offset = (uint64_t) io->pieceSlot[index] *
(uint64_t) inf->pieceSize + (uint64_t) begin;
if( writeBytes( io, offset, length, buf ) )
{
return 1;
}
startBlock = tr_pieceStartBlock( index );
endBlock = startBlock + tr_pieceCountBlocks( index );
for( i = startBlock; i < endBlock; i++ )
{
if( !tr_cpBlockIsComplete( tor->completion, i ) )
{
/* The piece is not complete */
return 0;
}
}
/* The piece is complete, check the hash */
pieceSize = tr_pieceSize( index );
pieceBuf = malloc( pieceSize );
readBytes( io, (uint64_t) io->pieceSlot[index] *
(uint64_t) inf->pieceSize, pieceSize, pieceBuf );
SHA1( pieceBuf, pieceSize, hash );
free( pieceBuf );
if( memcmp( hash, &inf->pieces[20*index], SHA_DIGEST_LENGTH ) )
{
tr_inf( "Piece %d (slot %d): hash FAILED", index,
io->pieceSlot[index] );
/* We will need to reload the whole piece */
for( i = startBlock; i < endBlock; i++ )
{
tr_cpBlockRem( tor->completion, i );
}
}
else
{
tr_inf( "Piece %d (slot %d): hash OK", index,
io->pieceSlot[index] );
tr_cpPieceAdd( tor->completion, index );
}
return 0;
}
void tr_ioClose( tr_io_t * io )
{
closeFiles( io );
fastResumeSave( io );
free( io->pieceSlot );
free( io->slotPiece );
free( io );
}
void tr_ioSaveResume( tr_io_t * io )
{
fastResumeSave( io );
}
/***********************************************************************
* createFiles
***********************************************************************
* Make sure the existing folders/files have correct types and
* permissions, and create missing folders and files
**********************************************************************/
static int createFiles( tr_io_t * io )
{
tr_torrent_t * tor = io->tor;
tr_info_t * inf = &tor->info;
int i;
char * path, * p;
struct stat sb;
FILE * file;
tr_dbg( "Creating files..." );
for( i = 0; i < inf->fileCount; i++ )
{
asprintf( &path, "%s/%s", tor->destination, inf->files[i].name );
/* Create folders */
p = path;
while( ( p = strchr( p, '/' ) ) )
{
*p = '\0';
if( stat( path, &sb ) )
{
/* Folder doesn't exist yet */
mkdir( path, 0755 );
}
else if( ( sb.st_mode & S_IFMT ) != S_IFDIR )
{
/* Node exists but isn't a folder */
printf( "Remove %s, it's in the way.\n", path );
free( path );
return 1;
}
*p = '/';
p++;
}
if( stat( path, &sb ) )
{
/* File doesn't exist yet */
if( !( file = fopen( path, "w" ) ) )
{
tr_err( "Could not create `%s' (%s)", path,
strerror( errno ) );
free( path );
return 1;
}
fclose( file );
}
else if( ( sb.st_mode & S_IFMT ) != S_IFREG )
{
/* Node exists but isn't a file */
printf( "Remove %s, it's in the way.\n", path );
free( path );
return 1;
}
free( path );
}
return 0;
}
/***********************************************************************
* checkFiles
***********************************************************************
* Look for pieces
**********************************************************************/
static int checkFiles( tr_io_t * io )
{
tr_torrent_t * tor = io->tor;
tr_info_t * inf = &tor->info;
int i;
uint8_t * buf;
uint8_t hash[SHA_DIGEST_LENGTH];
io->pieceSlot = malloc( inf->pieceCount * sizeof( int ) );
io->slotPiece = malloc( inf->pieceCount * sizeof( int ) );
if( !fastResumeLoad( io ) )
{
return 0;
}
tr_dbg( "Checking pieces..." );
/* Yet we don't have anything */
memset( io->pieceSlot, 0xFF, inf->pieceCount * sizeof( int ) );
memset( io->slotPiece, 0xFF, inf->pieceCount * sizeof( int ) );
/* Check pieces */
io->slotsUsed = 0;
buf = malloc( inf->pieceSize );
for( i = 0; i < inf->pieceCount; i++ )
{
int size, j;
if( readSlot( io, i, buf, &size ) )
{
break;
}
io->slotsUsed = i + 1;
SHA1( buf, size, hash );
for( j = i; j < inf->pieceCount - 1; j++ )
{
if( !memcmp( hash, &inf->pieces[20*j], SHA_DIGEST_LENGTH ) )
{
io->pieceSlot[j] = i;
io->slotPiece[i] = j;
tr_cpPieceAdd( tor->completion, j );
break;
}
}
if( io->slotPiece[i] > -1 )
{
continue;
}
/* Special case for the last piece */
SHA1( buf, tr_pieceSize( inf->pieceCount - 1 ), hash );
if( !memcmp( hash, &inf->pieces[20 * (inf->pieceCount - 1)],
SHA_DIGEST_LENGTH ) )
{
io->pieceSlot[inf->pieceCount - 1] = i;
io->slotPiece[i] = inf->pieceCount - 1;
tr_cpPieceAdd( tor->completion, inf->pieceCount - 1 );
}
}
free( buf );
return 0;
}
/***********************************************************************
* closeFiles
**********************************************************************/
static void closeFiles( tr_io_t * io )
{
tr_torrent_t * tor = io->tor;
tr_info_t * inf = &tor->info;
int i;
char * path;
for( i = 0; i < inf->fileCount; i++ )
{
asprintf( &path, "%s/%s", tor->destination, inf->files[i].name );
tr_fdFileClose( tor->fdlimit, path );
free( path );
}
}
/***********************************************************************
* readOrWriteBytes
***********************************************************************
*
**********************************************************************/
typedef size_t (* iofunc) ( void *, size_t, size_t, FILE * );
static int readOrWriteBytes( tr_io_t * io, uint64_t offset, int size,
uint8_t * buf, int write )
{
tr_torrent_t * tor = io->tor;
tr_info_t * inf = &tor->info;
int piece = offset / inf->pieceSize;
int begin = offset % inf->pieceSize;
int i, cur;
char * path;
FILE * file;
iofunc readOrWrite = write ? (iofunc) fwrite : (iofunc) fread;
/* Release the torrent lock so the UI can still update itself if
this blocks for a while */
tr_lockUnlock( &tor->lock );
/* We don't ever read or write more than a piece at a time */
if( tr_pieceSize( piece ) < begin + size )
{
tr_err( "readOrWriteBytes: trying to write more than a piece" );
goto fail;
}
/* Find which file we shall start reading/writing in */
for( i = 0; i < inf->fileCount; i++ )
{
if( offset < inf->files[i].length )
{
/* This is the file */
break;
}
offset -= inf->files[i].length;
}
if( i >= inf->fileCount )
{
/* Should not happen */
tr_err( "readOrWriteBytes: offset out of range (%lld, %d, %d)",
offset, size, write );
goto fail;
}
while( size > 0 )
{
/* How much can we put or take with this file */
if( inf->files[i].length < offset + size )
{
cur = (int) ( inf->files[i].length - offset );
}
else
{
cur = size;
}
/* Now let's get a stream on the file... */
asprintf( &path, "%s/%s", tor->destination, inf->files[i].name );
file = tr_fdFileOpen( tor->fdlimit, path );
if( !file )
{
tr_err( "readOrWriteBytes: could not open file '%s'", path );
free( path );
goto fail;
}
free( path );
/* seek to the right offset... */
if( fseeko( file, offset, SEEK_SET ) )
{
goto fail;
}
/* do what we are here to do... */
if( readOrWrite( buf, cur, 1, file ) != 1 )
{
goto fail;
}
/* and close the stream. */
tr_fdFileRelease( tor->fdlimit, file );
/* 'cur' bytes done, 'size - cur' bytes to go with the next file */
i += 1;
offset = 0;
size -= cur;
buf += cur;
}
tr_lockLock( &tor->lock );
return 0;
fail:
tr_lockLock( &tor->lock );
return 1;
}
/***********************************************************************
* readSlot
***********************************************************************
*
**********************************************************************/
static int readOrWriteSlot( tr_io_t * io, int slot, uint8_t * buf,
int * size, int write )
{
tr_torrent_t * tor = io->tor;
tr_info_t * inf = &tor->info;
uint64_t offset = (uint64_t) slot * (uint64_t) inf->pieceSize;
*size = 0;
if( slot == inf->pieceCount - 1 )
{
*size = inf->totalSize % inf->pieceSize;
}
if( !*size )
{
*size = inf->pieceSize;
}
return readOrWriteBytes( io, offset, *size, buf, write );
}
static void invertSlots( tr_io_t * io, int slot1, int slot2 )
{
tr_torrent_t * tor = io->tor;
tr_info_t * inf = &tor->info;
uint8_t * buf1, * buf2;
int piece1, piece2, foo;
buf1 = calloc( inf->pieceSize, 1 );
buf2 = calloc( inf->pieceSize, 1 );
readSlot( io, slot1, buf1, &foo );
readSlot( io, slot2, buf2, &foo );
writeSlot( io, slot1, buf2, &foo );
writeSlot( io, slot2, buf1, &foo );
free( buf1 );
free( buf2 );
piece1 = io->slotPiece[slot1];
piece2 = io->slotPiece[slot2];
io->slotPiece[slot1] = piece2;
io->slotPiece[slot2] = piece1;
if( piece1 >= 0 )
{
io->pieceSlot[piece1] = slot2;
}
if( piece2 >= 0 )
{
io->pieceSlot[piece2] = slot1;
}
}
static void reorderPieces( tr_io_t * io )
{
tr_torrent_t * tor = io->tor;
tr_info_t * inf = &tor->info;
int i, didInvert;
/* Try to move pieces to their final places */
do
{
didInvert = 0;
for( i = 0; i < inf->pieceCount; i++ )
{
if( io->pieceSlot[i] < 0 )
{
/* We haven't started this piece yet */
continue;
}
if( io->pieceSlot[i] == i )
{
/* Already in place */
continue;
}
if( i >= io->slotsUsed )
{
/* File is not big enough yet */
continue;
}
/* Move piece i into slot i */
tr_inf( "invert %d and %d", io->pieceSlot[i], i );
invertSlots( io, i, io->pieceSlot[i] );
didInvert = 1;
}
} while( didInvert );
}
static void findSlotForPiece( tr_io_t * io, int piece )
{
int i;
#if 0
tr_torrent_t * tor = io->tor;
tr_info_t * inf = &tor->info;
tr_dbg( "Entering findSlotForPiece" );
for( i = 0; i < inf->pieceCount; i++ )
printf( "%02d ", io->slotPiece[i] );
printf( "\n" );
for( i = 0; i < inf->pieceCount; i++ )
printf( "%02d ", io->pieceSlot[i] );
printf( "\n" );
#endif
/* Look for an empty slot somewhere */
for( i = 0; i < io->slotsUsed; i++ )
{
if( io->slotPiece[i] < 0 )
{
io->pieceSlot[piece] = i;
io->slotPiece[i] = piece;
goto reorder;
}
}
/* No empty slot, extend the file */
io->pieceSlot[piece] = io->slotsUsed;
io->slotPiece[io->slotsUsed] = piece;
(io->slotsUsed)++;
reorder:
reorderPieces( io );
#if 0
for( i = 0; i < inf->pieceCount; i++ )
printf( "%02d ", io->slotPiece[i] );
printf( "\n" );
for( i = 0; i < inf->pieceCount; i++ )
printf( "%02d ", io->pieceSlot[i] );
printf( "\n" );
printf( "Leaving findSlotForPiece\n" );
#endif
}
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