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transmission/libtransmission/fastresume.c

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/******************************************************************************
* $Id$
*
* Copyright (c) 2005-2007 Transmission authors and contributors
*
* 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.
*****************************************************************************/
/***********************************************************************
* Fast resume
***********************************************************************
* The format of the resume file is a 4 byte format version (currently 1),
* followed by several variable-sized blocks of data. Each block is
* preceded by a 1 byte ID and a 4 byte length. The currently recognized
* IDs are defined below by the FR_ID_* macros. The length does not include
* the 5 bytes for the ID and length.
*
* The name of the resume file is "resume.<hash>-<tag>", although
* older files with a name of "resume.<hash>" will be recognized if
* the former doesn't exist.
*
* All values are stored in the native endianness. Moving a
* libtransmission resume file from an architecture to another will not
* work, although it will not hurt either (the version will be wrong,
* so the resume file will not be read).
**********************************************************************/
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <event.h>
#include "transmission.h"
#include "completion.h"
#include "fastresume.h"
#include "peer-mgr.h"
#include "platform.h"
#include "utils.h"
/* time_t can be 32 or 64 bits... for consistency we'll hardwire 64 */
typedef uint64_t tr_time_t;
enum
{
/* number of bytes downloaded */
FR_ID_DOWNLOADED = 2,
/* number of bytes uploaded */
FR_ID_UPLOADED = 3,
/* progress data:
* - 4 bytes * number of files: mtimes of files
* - 1 bit * number of blocks: whether we have the block or not */
FR_ID_PROGRESS = 5,
/* dnd and priority
* char * number of files: l,n,h for low, normal, high priority
* char * number of files: t,f for DND flags */
FR_ID_PRIORITY = 6,
/* transfer speeds
* uint32_t: dl speed rate to use when the mode is single
* uint32_t: dl's tr_speedlimit
* uint32_t: ul speed rate to use when the mode is single
* uint32_t: ul's tr_speedlimit
*/
FR_ID_SPEED = 8,
/* active
* char: 't' if running, 'f' if paused
*/
FR_ID_RUN = 9,
/* number of corrupt bytes downloaded */
FR_ID_CORRUPT = 10,
/* IPs and ports of connectable peers */
FR_ID_PEERS = 11,
/* destination of the torrent: zero-terminated string */
FR_ID_DESTINATION = 12,
/* pex flag
* 't' if pex is enabled, 'f' if disabled */
FR_ID_PEX = 13
};
/* macros for the length of various pieces of the progress data */
#define FR_MTIME_LEN( t ) \
( sizeof(tr_time_t) * (t)->info.fileCount )
#define FR_BLOCK_BITFIELD_LEN( t ) \
( ( (t)->blockCount + 7 ) / 8 )
#define FR_PROGRESS_LEN( t ) \
( FR_MTIME_LEN( t ) + FR_BLOCK_BITFIELD_LEN( t ) )
#define FR_SPEED_LEN (2 * (sizeof(uint16_t) + sizeof(uint8_t) ) )
static void
fastResumeFileName( char * buf, size_t buflen, const tr_torrent * tor, int tag )
{
const char * cacheDir = tr_getCacheDirectory ();
const char * hash = tor->info.hashString;
if( !tag )
{
tr_buildPath( buf, buflen, cacheDir, hash, NULL );
}
else
{
char base[1024];
snprintf( base, sizeof(base), "%s-%s", hash, tor->handle->tag );
tr_buildPath( buf, buflen, cacheDir, base, NULL );
}
}
static tr_time_t*
getMTimes( const tr_torrent * tor, int * setme_n )
{
int i;
const int n = tor->info.fileCount;
tr_time_t * m = calloc( n, sizeof(tr_time_t) );
for( i=0; i<n; ++i ) {
char fname[MAX_PATH_LENGTH];
struct stat sb;
tr_buildPath( fname, sizeof(fname),
tor->destination, tor->info.files[i].name, NULL );
if ( !stat( fname, &sb ) && S_ISREG( sb.st_mode ) ) {
#ifdef SYS_DARWIN
m[i] = sb.st_mtimespec.tv_sec;
#else
m[i] = sb.st_mtime;
#endif
}
}
*setme_n = n;
return m;
}
static void
fastResumeWriteData( uint8_t id,
const void * data,
uint32_t size,
uint32_t count,
FILE * file )
{
uint32_t datalen = size * count;
fwrite( &id, 1, 1, file );
fwrite( &datalen, 4, 1, file );
fwrite( data, size, count, file );
}
void
tr_fastResumeSave( const tr_torrent * tor )
{
char path[MAX_PATH_LENGTH];
FILE * file;
const int version = 1;
uint64_t total;
fastResumeFileName( path, sizeof path, tor, 1 );
file = fopen( path, "wb+" );
if( NULL == file ) {
tr_err( "Couldn't open '%s' for writing", path );
return;
}
/* Write format version */
fwrite( &version, 4, 1, file );
if( TRUE ) /* FR_ID_DESTINATION */
{
const char * d = tor->destination ? tor->destination : "";
const int byteCount = strlen( d ) + 1;
fastResumeWriteData( FR_ID_DESTINATION, d, 1, byteCount, file );
}
/* Write progress data */
if (1) {
int n;
tr_time_t * mtimes;
uint8_t * buf = malloc( FR_PROGRESS_LEN( tor ) );
uint8_t * walk = buf;
const tr_bitfield * bitfield;
/* mtimes */
mtimes = getMTimes( tor, &n );
memcpy( walk, mtimes, n*sizeof(tr_time_t) );
walk += n * sizeof(tr_time_t);
/* completion bitfield */
bitfield = tr_cpBlockBitfield( tor->completion );
assert( (unsigned)FR_BLOCK_BITFIELD_LEN( tor ) == bitfield->len );
memcpy( walk, bitfield->bits, bitfield->len );
walk += bitfield->len;
/* write it */
assert( walk-buf == (int)FR_PROGRESS_LEN( tor ) );
fastResumeWriteData( FR_ID_PROGRESS, buf, 1, walk-buf, file );
/* cleanup */
free( mtimes );
free( buf );
}
/* Write the priorities and DND flags */
if( TRUE )
{
int i;
const int n = tor->info.fileCount;
char * buf = tr_new0( char, n*2 );
char * walk = buf;
/* priorities */
for( i=0; i<n; ++i ) {
char ch;
const int priority = tor->info.files[i].priority;
switch( priority ) {
case TR_PRI_LOW: ch = 'l'; break; /* low */
case TR_PRI_HIGH: ch = 'h'; break; /* high */
default: ch = 'n'; break; /* normal */
};
*walk++ = ch;
}
/* dnd flags */
for( i=0; i<n; ++i )
*walk++ = tor->info.files[i].dnd ? 't' : 'f';
/* write it */
assert( walk - buf == 2*n );
fastResumeWriteData( FR_ID_PRIORITY, buf, 1, walk-buf, file );
/* cleanup */
tr_free( buf );
}
/* Write the torrent ul/dl speed caps */
if( TRUE )
{
const int len = FR_SPEED_LEN;
char * buf = tr_new0( char, len );
char * walk = buf;
uint16_t i16;
uint8_t i8;
i16 = (uint16_t) tr_torrentGetSpeedLimit( tor, TR_DOWN );
memcpy( walk, &i16, 2 ); walk += 2;
i8 = (uint8_t) tr_torrentGetSpeedMode( tor, TR_DOWN );
memcpy( walk, &i8, 1 ); walk += 1;
i16 = (uint16_t) tr_torrentGetSpeedLimit( tor, TR_UP );
memcpy( walk, &i16, 2 ); walk += 2;
i8 = (uint8_t) tr_torrentGetSpeedMode( tor, TR_UP );
memcpy( walk, &i8, 1 ); walk += 1;
assert( walk - buf == len );
fastResumeWriteData( FR_ID_SPEED, buf, 1, walk-buf, file );
tr_free( buf );
}
if( TRUE ) /* FR_ID_PEX */
{
const char flag = tor->pexDisabled ? 'f' : 't';
fastResumeWriteData( FR_ID_PEX, &flag, 1, 1, file );
}
if( TRUE ) /* FR_ID_RUN */
{
const char is_running = tor->isRunning ? 't' : 'f';
fastResumeWriteData( FR_ID_RUN, &is_running, 1, 1, file );
}
/* Write download and upload totals */
total = tor->downloadedCur + tor->downloadedPrev;
fastResumeWriteData( FR_ID_DOWNLOADED, &total, 8, 1, file );
total = tor->uploadedCur + tor->uploadedPrev;
fastResumeWriteData( FR_ID_UPLOADED, &total, 8, 1, file );
total = tor->corruptCur + tor->corruptPrev;
fastResumeWriteData( FR_ID_CORRUPT, &total, 8, 1, file );
if( !tor->info.isPrivate )
{
tr_pex * pex;
const int count = tr_peerMgrGetPeers( tor->handle->peerMgr,
tor->info.hash,
&pex );
if( count > 0 )
fastResumeWriteData( FR_ID_PEERS, pex, sizeof(tr_pex), count, file );
tr_free( pex );
}
fclose( file );
tr_dbg( "Wrote resume file for '%s'", tor->info.name );
}
/***
****
***/
static uint64_t
internalIdToPublicBitfield( uint8_t id )
{
uint64_t ret = 0;
switch( id )
{
case FR_ID_DOWNLOADED: ret = TR_FR_DOWNLOADED; break;
case FR_ID_UPLOADED: ret = TR_FR_UPLOADED; break;
case FR_ID_PROGRESS: ret = TR_FR_PROGRESS; break;
case FR_ID_PRIORITY: ret = TR_FR_PRIORITY; break;
case FR_ID_SPEED: ret = TR_FR_SPEEDLIMIT; break;
case FR_ID_RUN: ret = TR_FR_RUN; break;
case FR_ID_CORRUPT: ret = TR_FR_CORRUPT; break;
case FR_ID_PEERS: ret = TR_FR_PEERS; break;
case FR_ID_DESTINATION: ret = TR_FR_DESTINATION; break;
case FR_ID_PEX: ret = TR_FR_PEX; break;
}
return ret;
}
static void
readBytes( void * target, const uint8_t ** source, size_t byteCount )
{
memcpy( target, *source, byteCount );
*source += byteCount;
}
static uint64_t
parseDownloaded( tr_torrent * tor, const uint8_t * buf, uint32_t len )
{
if( len != sizeof(uint64_t) )
return 0;
readBytes( &tor->downloadedPrev, &buf, sizeof(uint64_t) );
return TR_FR_DOWNLOADED;
}
static uint64_t
parseUploaded( tr_torrent * tor, const uint8_t * buf, uint32_t len )
{
if( len != sizeof(uint64_t) )
return 0;
readBytes( &tor->uploadedPrev, &buf, sizeof(uint64_t) );
return TR_FR_UPLOADED;
}
static uint64_t
parseCorrupt( tr_torrent * tor, const uint8_t * buf, uint32_t len )
{
if( len != sizeof(uint64_t) )
return 0;
readBytes( &tor->corruptPrev, &buf, sizeof(uint64_t) );
return TR_FR_CORRUPT;
}
static uint64_t
parseProgress( const tr_torrent * tor,
const uint8_t * buf,
uint32_t len,
tr_bitfield * uncheckedPieces )
{
int i;
uint64_t ret = 0;
if( len == FR_PROGRESS_LEN( tor ) )
{
int n;
tr_bitfield bitfield;
/* compare file mtimes */
tr_time_t * curMTimes = getMTimes( tor, &n );
const uint8_t * walk = buf;
const tr_time_t * oldMTimes = (const tr_time_t *) walk;
for( i=0; i<n; ++i ) {
if ( !curMTimes[i] || ( curMTimes[i] != oldMTimes[i] ) ) {
const tr_file * file = &tor->info.files[i];
tr_dbg( "File '%s' mtimes differ-- flagging pieces [%d..%d] for recheck",
file->name, file->firstPiece, file->lastPiece);
tr_bitfieldAddRange( uncheckedPieces,
file->firstPiece, file->lastPiece+1 );
}
}
free( curMTimes );
walk += n * sizeof(tr_time_t);
/* get the completion bitfield */
memset( &bitfield, 0, sizeof bitfield );
bitfield.len = FR_BLOCK_BITFIELD_LEN( tor );
bitfield.bits = (uint8_t*) walk;
tr_cpBlockBitfieldSet( tor->completion, &bitfield );
ret = TR_FR_PROGRESS;
}
/* the files whose mtimes are wrong,
remove from completion pending a recheck... */
for( i=0; i<tor->info.pieceCount; ++i )
if( tr_bitfieldHas( uncheckedPieces, i ) )
tr_cpPieceRem( tor->completion, i );
return ret;
}
static uint64_t
parsePriorities( tr_torrent * tor, const uint8_t * buf, uint32_t len )
{
uint64_t ret = 0;
if( len == (uint32_t)(2 * tor->info.fileCount) )
{
const size_t n = tor->info.fileCount;
const size_t len = 2 * n;
int *dnd = NULL, dndCount = 0;
int *dl = NULL, dlCount = 0;
size_t i;
const uint8_t * walk = buf;
/* set file priorities */
for( i=0; i<n; ++i ) {
tr_priority_t priority;
const char ch = *walk++;
switch( ch ) {
case 'l': priority = TR_PRI_LOW; break;
case 'h': priority = TR_PRI_HIGH; break;
default: priority = TR_PRI_NORMAL; break;
}
tor->info.files[i].priority = priority;
}
/* set the dnd flags */
dl = tr_new( int, len );
dnd = tr_new( int, len );
for( i=0; i<n; ++i )
if( *walk++ == 't' ) /* 't' means the DND flag is true */
dnd[dndCount++] = i;
else
dl[dlCount++] = i;
if( dndCount )
tr_torrentSetFileDLs ( tor, dnd, dndCount, FALSE );
if( dlCount )
tr_torrentSetFileDLs ( tor, dl, dlCount, TRUE );
tr_free( dnd );
tr_free( dl );
ret = TR_FR_PRIORITY;
}
return ret;
}
static uint64_t
parseSpeedLimit( tr_torrent * tor, const uint8_t * buf, uint32_t len )
{
uint64_t ret = 0;
if( len == FR_SPEED_LEN )
{
uint8_t i8;
uint16_t i16;
readBytes( &i16, &buf, sizeof(i16) );
tr_torrentSetSpeedLimit( tor, TR_DOWN, i16 );
readBytes( &i8, &buf, sizeof(i8) );
tr_torrentSetSpeedMode( tor, TR_DOWN, (tr_speedlimit)i8 );
readBytes( &i16, &buf, sizeof(i16) );
tr_torrentSetSpeedLimit( tor, TR_UP, i16 );
readBytes( &i8, &buf, sizeof(i8) );
tr_torrentSetSpeedMode( tor, TR_UP, (tr_speedlimit)i8 );
ret = TR_FR_SPEEDLIMIT;
}
return ret;
}
static uint64_t
parseRun( tr_torrent * tor, const uint8_t * buf, uint32_t len )
{
if( len != 1 )
return 0;
tor->isRunning = *buf=='t';
return TR_FR_RUN;
}
static uint64_t
parsePex( tr_torrent * tor, const uint8_t * buf, uint32_t len )
{
if( len != 1 )
return 0;
tor->pexDisabled = *buf!='t';
return TR_FR_PEX;
}
static uint64_t
parsePeers( tr_torrent * tor, const uint8_t * buf, uint32_t len )
{
uint64_t ret = 0;
if( !tor->info.isPrivate )
{
const int count = len / sizeof(tr_pex);
tr_peerMgrAddPex( tor->handle->peerMgr,
tor->info.hash,
TR_PEER_FROM_CACHE,
(tr_pex*)buf, count );
tr_dbg( "found %i peers in resume file", count );
ret = TR_FR_PEERS;
}
return ret;
}
static uint64_t
parseDestination( tr_torrent * tor, const uint8_t * buf, uint32_t len,
const char * destination, int argIsFallback )
{
if( argIsFallback )
tor->destination = tr_strdup( len ? (const char*)buf : destination );
else
tor->destination = tr_strdup( len ? destination : (const char*)buf );
return TR_FR_DESTINATION;
}
static uint64_t
parseVersion1( tr_torrent * tor, const uint8_t * buf, const uint8_t * end,
uint64_t fieldsToLoad,
tr_bitfield * uncheckedPieces,
const char * destination, int argIsFallback )
{
uint64_t ret = 0;
while( end-buf >= 5 )
{
uint8_t id;
uint32_t len;
readBytes( &id, &buf, sizeof(id) );
readBytes( &len, &buf, sizeof(len) );
if( fieldsToLoad & internalIdToPublicBitfield( id ) ) switch( id )
{
case FR_ID_DOWNLOADED: ret |= parseDownloaded( tor, buf, len ); break;
case FR_ID_UPLOADED: ret |= parseUploaded( tor, buf, len ); break;
case FR_ID_PROGRESS: ret |= parseProgress( tor, buf, len, uncheckedPieces ); break;
case FR_ID_PRIORITY: ret |= parsePriorities( tor, buf, len ); break;
case FR_ID_SPEED: ret |= parseSpeedLimit( tor, buf, len ); break;
case FR_ID_RUN: ret |= parseRun( tor, buf, len ); break;
case FR_ID_CORRUPT: ret |= parseCorrupt( tor, buf, len ); break;
case FR_ID_PEERS: ret |= parsePeers( tor, buf, len ); break;
case FR_ID_PEX: ret |= parsePex( tor, buf, len ); break;
case FR_ID_DESTINATION: ret |= parseDestination( tor, buf, len, destination, argIsFallback ); break;
default: tr_dbg( "Skipping unknown resume code %d", (int)id ); break;
}
buf += len;
}
return ret;
}
static uint8_t*
loadResumeFile( const tr_torrent * tor, size_t * len )
{
uint8_t * ret = NULL;
char path[MAX_PATH_LENGTH];
const char * cacheDir = tr_getCacheDirectory ();
const char * hash = tor->info.hashString;
if( !ret && tor->handle->tag )
{
char base[1024];
snprintf( base, sizeof(base), "%s-%s", hash, tor->handle->tag );
tr_buildPath( path, sizeof(path), cacheDir, base, NULL );
ret = tr_loadFile( path, len );
}
if( !ret )
{
tr_buildPath( path, sizeof(path), cacheDir, hash, NULL );
ret = tr_loadFile( path, len );
}
return ret;
}
static uint64_t
fastResumeLoadImpl ( tr_torrent * tor,
uint64_t fieldsToLoad,
tr_bitfield * uncheckedPieces,
const char * destination,
int argIsFallback )
{
uint64_t ret = 0;
size_t size = 0;
uint8_t * buf = loadResumeFile( tor, &size );
if( !buf )
tr_inf( "Couldn't read resume file for '%s'", tor->info.name );
else {
const uint8_t * walk = buf;
const uint8_t * end = walk + size;
if( end - walk >= 4 ) {
uint32_t version;
readBytes( &version, &walk, sizeof(version) );
if( version == 1 )
ret |= parseVersion1 ( tor, walk, end, fieldsToLoad, uncheckedPieces, destination, argIsFallback );
else
tr_inf( "Unsupported resume file %d for '%s'", version, tor->info.name );
}
tr_free( buf );
}
return ret;
}
uint64_t
tr_fastResumeLoad( tr_torrent * tor,
uint64_t fieldsToLoad,
tr_bitfield * uncheckedPieces,
const char * destination,
int argIsFallback )
{
const uint64_t ret = fastResumeLoadImpl( tor, fieldsToLoad, uncheckedPieces, destination, argIsFallback );
if( ! ( ret & TR_FR_PROGRESS ) )
tr_bitfieldAddRange( uncheckedPieces, 0, tor->info.pieceCount );
if( !tor->destination )
tor->destination = tr_strdup( destination );
return ret;
}
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