transmission/libtransmission/inout.c

431 lines
11 KiB
C

/*
* This file Copyright (C) 2007 Charles Kerr <charles@rebelbase.com>
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2(b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*
* $Id$
*/
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "transmission.h"
#include "completion.h"
#include "crypto.h"
#include "fastresume.h"
#include "fdlimit.h"
#include "inout.h"
#include "list.h"
#include "platform.h"
#include "peer-mgr.h"
#include "utils.h"
/****
***** Low-level IO functions
****/
#ifdef WIN32
#define lseek _lseeki64
#endif
enum { TR_IO_READ, TR_IO_WRITE };
static int
readOrWriteBytes( const tr_torrent * tor,
int ioMode,
int fileIndex,
uint64_t fileOffset,
void * buf,
size_t buflen )
{
const tr_info * info = &tor->info;
const tr_file * file = &info->files[fileIndex];
typedef size_t (* iofunc) ( int, void *, size_t );
iofunc func = ioMode == TR_IO_READ ? (iofunc)read : (iofunc)write;
char path[MAX_PATH_LENGTH];
struct stat sb;
int fd = -1;
int ret;
assert( 0<=fileIndex && fileIndex<info->fileCount );
assert( !file->length || (fileOffset < file->length));
assert( fileOffset + buflen <= file->length );
tr_buildPath ( path, sizeof(path), tor->destination, file->name, NULL );
if( !file->length )
return 0;
else if ((ioMode==TR_IO_READ) && stat( path, &sb ) ) /* does file exist? */
ret = tr_ioErrorFromErrno ();
else if ((fd = tr_fdFileCheckout ( path, ioMode==TR_IO_WRITE )) < 0)
ret = fd;
else if( lseek( fd, (off_t)fileOffset, SEEK_SET ) == ((off_t)-1) )
ret = TR_ERROR_IO_OTHER;
else if( func( fd, buf, buflen ) != buflen )
ret = tr_ioErrorFromErrno( );
else
ret = TR_OK;
if( fd >= 0 )
tr_fdFileReturn( fd );
return ret;
}
static void
findFileLocation( const tr_torrent * tor,
int pieceIndex,
int pieceOffset,
int * fileIndex,
uint64_t * fileOffset )
{
const tr_info * info = &tor->info;
int i;
uint64_t piecePos = ((uint64_t)pieceIndex * info->pieceSize) + pieceOffset;
assert( 0<=pieceIndex && pieceIndex < info->pieceCount );
assert( 0<=tor->info.pieceSize );
assert( pieceOffset < tr_torPieceCountBytes( tor, pieceIndex ) );
assert( piecePos < info->totalSize );
for( i=0; info->files[i].length<=piecePos; ++i )
piecePos -= info->files[i].length;
*fileIndex = i;
*fileOffset = piecePos;
assert( 0<=*fileIndex && *fileIndex<info->fileCount );
assert( *fileOffset < info->files[i].length );
}
#ifdef WIN32
static int
ensureMinimumFileSize( const tr_torrent * tor,
int fileIndex,
uint64_t minBytes )
{
int fd;
int ret;
struct stat sb;
const tr_file * file = &tor->info.files[fileIndex];
char path[MAX_PATH_LENGTH];
assert( 0<=fileIndex && fileIndex<tor->info.fileCount );
assert( minBytes <= file->length );
tr_buildPath( path, sizeof(path), tor->destination, file->name, NULL );
fd = tr_fdFileCheckout( path, TRUE );
if( fd < 0 ) /* bad fd */
ret = fd;
else if (fstat (fd, &sb) ) /* how big is the file? */
ret = tr_ioErrorFromErrno ();
else if (sb.st_size >= (off_t)minBytes) /* already big enough */
ret = TR_OK;
else if (!ftruncate( fd, minBytes )) /* grow it */
ret = TR_OK;
else /* couldn't grow it */
ret = tr_ioErrorFromErrno ();
if( fd >= 0 )
tr_fdFileReturn( fd );
return ret;
}
#endif
static int
readOrWritePiece( tr_torrent * tor,
int ioMode,
int pieceIndex,
int pieceOffset,
uint8_t * buf,
size_t buflen )
{
int ret = 0;
int fileIndex;
uint64_t fileOffset;
const tr_info * info = &tor->info;
assert( 0<=pieceIndex && pieceIndex<tor->info.pieceCount );
assert( buflen <= (size_t) tr_torPieceCountBytes( tor, pieceIndex ) );
findFileLocation ( tor, pieceIndex, pieceOffset, &fileIndex, &fileOffset );
while( buflen && !ret )
{
const tr_file * file = &info->files[fileIndex];
const uint64_t bytesThisPass = MIN( buflen, file->length - fileOffset );
#ifdef WIN32
if( ioMode == TR_IO_WRITE )
ret = ensureMinimumFileSize( tor, fileIndex,
fileOffset + bytesThisPass );
if( !ret )
#endif
ret = readOrWriteBytes( tor, ioMode,
fileIndex, fileOffset, buf, bytesThisPass );
buf += bytesThisPass;
buflen -= bytesThisPass;
fileIndex++;
fileOffset = 0;
}
return ret;
}
int
tr_ioRead( tr_torrent * tor,
int pieceIndex,
int begin,
int len,
uint8_t * buf )
{
return readOrWritePiece( tor, TR_IO_READ, pieceIndex, begin, buf, len );
}
int
tr_ioWrite( tr_torrent * tor,
int pieceIndex,
int begin,
int len,
const uint8_t * buf )
{
return readOrWritePiece( tor, TR_IO_WRITE, pieceIndex, begin, (void*)buf, len );
}
/****
*****
****/
static int
tr_ioRecalculateHash( tr_torrent * tor,
int pieceIndex,
uint8_t * setme )
{
int n;
int ret;
uint8_t * buf;
const tr_info * info;
assert( tor != NULL );
assert( setme != NULL );
assert( 0<=pieceIndex && pieceIndex<tor->info.pieceCount );
info = &tor->info;
n = tr_torPieceCountBytes( tor, pieceIndex );
buf = tr_new( uint8_t, n );
ret = tr_ioRead( tor, pieceIndex, 0, n, buf );
if( !ret )
tr_sha1( setme, buf, n, NULL );
tr_free( buf );
return ret;
}
static int
checkPiece( tr_torrent * tor, int pieceIndex )
{
uint8_t hash[SHA_DIGEST_LENGTH];
const int ret = tr_ioRecalculateHash( tor, pieceIndex, hash )
|| memcmp( hash, tor->info.pieces[pieceIndex].hash, SHA_DIGEST_LENGTH );
tr_dbg ("torrent [%s] piece %d hash check: %s",
tor->info.name, pieceIndex, (ret?"FAILED":"OK"));
return ret;
}
/**
***
**/
int
tr_ioHash( tr_torrent * tor, int pieceIndex )
{
int ret;
const int success = !checkPiece( tor, pieceIndex );
if( success )
{
tr_dbg( "Piece %d hash OK", pieceIndex );
tr_cpPieceAdd( tor->completion, pieceIndex );
ret = TR_OK;
}
else
{
tr_err( "Piece %d hash FAILED", pieceIndex );
tr_cpPieceRem( tor->completion, pieceIndex );
ret = TR_ERROR;
}
tr_peerMgrSetBlame( tor->handle->peerMgr, tor->info.hash,
pieceIndex, success );
return ret;
}
/**
***
**/
struct recheck_node
{
tr_torrent * torrent;
tr_recheck_done_cb recheck_done_cb;
};
static void
fireCheckDone( tr_torrent * torrent,
tr_recheck_done_cb recheck_done_cb )
{
if( recheck_done_cb != NULL )
(*recheck_done_cb)( torrent );
}
static struct recheck_node currentNode;
static tr_list * recheckList = NULL;
static tr_thread * recheckThread = NULL;
static int stopCurrent = FALSE;
static tr_lock* getRecheckLock( void )
{
static tr_lock * lock = NULL;
if( lock == NULL )
lock = tr_lockNew( );
return lock;
}
static void
recheckThreadFunc( void * unused UNUSED )
{
for( ;; )
{
int i;
tr_torrent * tor;
struct recheck_node * node;
tr_lockLock( getRecheckLock( ) );
stopCurrent = FALSE;
node = (struct recheck_node*) recheckList ? recheckList->data : NULL;
if( node == NULL ) {
currentNode.torrent = NULL;
break;
}
currentNode = *node;
tor = currentNode.torrent;
tr_list_remove_data( &recheckList, node );
tr_free( node );
tr_lockUnlock( getRecheckLock( ) );
if( tor->uncheckedPieces == NULL ) {
tor->recheckState = TR_RECHECK_NONE;
fireCheckDone( tor, currentNode.recheck_done_cb );
continue;
}
tor->recheckState = TR_RECHECK_NOW;
/* remove the unchecked pieces from completion... */
for( i=0; i<tor->info.pieceCount; ++i )
if( tr_bitfieldHas( tor->uncheckedPieces, i ) )
tr_cpPieceRem( tor->completion, i );
tr_inf( "Verifying some pieces of \"%s\"", tor->info.name );
for( i=0; i<tor->info.pieceCount && !stopCurrent; ++i )
{
if( !tr_bitfieldHas( tor->uncheckedPieces, i ) )
continue;
tr_torrentSetHasPiece( tor, i, !checkPiece( tor, i ) );
tr_bitfieldRem( tor->uncheckedPieces, i );
}
tor->recheckState = TR_RECHECK_NONE;
if( !stopCurrent )
{
tr_bitfieldFree( tor->uncheckedPieces );
tor->uncheckedPieces = NULL;
tr_fastResumeSave( tor );
fireCheckDone( tor, currentNode.recheck_done_cb );
}
}
recheckThread = NULL;
tr_lockUnlock( getRecheckLock( ) );
}
void
tr_ioRecheckAdd( tr_torrent * tor,
tr_recheck_done_cb recheck_done_cb )
{
if( !tr_bitfieldCountTrueBits( tor->uncheckedPieces ) )
{
/* doesn't need to be checked... */
recheck_done_cb( tor );
}
else
{
struct recheck_node * node;
node = tr_new( struct recheck_node, 1 );
node->torrent = tor;
node->recheck_done_cb = recheck_done_cb;
tr_lockLock( getRecheckLock( ) );
tor->recheckState = recheckList ? TR_RECHECK_WAIT : TR_RECHECK_NOW;
tr_list_append( &recheckList, node );
if( recheckThread == NULL )
recheckThread = tr_threadNew( recheckThreadFunc, NULL, "recheckThreadFunc" );
tr_lockUnlock( getRecheckLock( ) );
}
}
static int
compareRecheckByTorrent( const void * va, const void * vb )
{
const struct recheck_node * a = va;
const tr_torrent * b = vb;
return a->torrent - b;
}
void
tr_ioRecheckRemove( tr_torrent * tor )
{
tr_lock * lock = getRecheckLock( );
tr_lockLock( lock );
if( tor == currentNode.torrent )
{
stopCurrent = TRUE;
while( stopCurrent )
{
tr_lockUnlock( lock );
tr_wait( 100 );
tr_lockLock( lock );
}
}
else
{
tr_free( tr_list_remove( &recheckList, tor, compareRecheckByTorrent ) );
tor->recheckState = TR_RECHECK_NONE;
}
tr_lockUnlock( lock );
}