/****************************************************************************** * 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. *****************************************************************************/ /*********************************************************************** * Fast resume *********************************************************************** * Format of the resume file: * - 4 bytes: format version (currently 0) * - 4 bytes * number of files: mtimes of files * - 1 bit * number of blocks: whether we have the block or not * - 4 bytes * number of pieces (byte aligned): the pieces that have * been completed or started in each slot * * The name of the resume file is "resume.". * * 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 mtimes will be wrong, * so the files will be scanned). **********************************************************************/ static char * fastResumeFileName( tr_io_t * io ) { char * ret, * p; int i; asprintf( &ret, "%s/resume.%40d", tr_getPrefsDirectory(), 0 ); p = &ret[ strlen( ret ) - 2 * SHA_DIGEST_LENGTH ]; for( i = 0; i < SHA_DIGEST_LENGTH; i++ ) { sprintf( p, "%02x", io->tor->info.hash[i] ); p += 2; } return ret; } static int fastResumeMTimes( tr_io_t * io, int * tab ) { tr_torrent_t * tor = io->tor; tr_info_t * inf = &tor->info; int i; char * path; struct stat sb; for( i = 0; i < inf->fileCount; i++ ) { asprintf( &path, "%s/%s", tor->destination, inf->files[i].name ); if( stat( path, &sb ) ) { tr_err( "Could not stat '%s'", path ); free( path ); return 1; } if( ( sb.st_mode & S_IFMT ) != S_IFREG ) { tr_err( "Wrong st_mode for '%s'", path ); free( path ); return 1; } free( path ); #ifdef SYS_DARWIN tab[i] = ( sb.st_mtimespec.tv_sec & 0x7FFFFFFF ); #else tab[i] = ( sb.st_mtime & 0x7FFFFFFF ); #endif } return 0; } static void fastResumeSave( tr_io_t * io ) { tr_torrent_t * tor = io->tor; tr_info_t * inf = &tor->info; FILE * file; int version = 0; char * path; int * fileMTimes; uint8_t * blockBitfield; /* Get file sizes */ fileMTimes = malloc( inf->fileCount * 4 ); if( fastResumeMTimes( io, fileMTimes ) ) { free( fileMTimes ); return; } /* Create/overwrite the resume file */ path = fastResumeFileName( io ); if( !( file = fopen( path, "w" ) ) ) { tr_err( "Could not open '%s' for writing", path ); free( fileMTimes ); free( path ); return; } /* Write format version */ fwrite( &version, 4, 1, file ); /* Write file mtimes */ fwrite( fileMTimes, 4, inf->fileCount, file ); free( fileMTimes ); /* Build and write the bitfield for blocks */ blockBitfield = tr_cpBlockBitfield( tor->completion ); fwrite( blockBitfield, ( tor->blockCount + 7 ) / 8, 1, file ); /* Write the 'slotPiece' table */ fwrite( io->slotPiece, 4, inf->pieceCount, file ); fclose( file ); tr_dbg( "Resume file '%s' written", path ); free( path ); } static int fastResumeLoad( tr_io_t * io ) { tr_torrent_t * tor = io->tor; tr_info_t * inf = &tor->info; FILE * file; int version = 0; char * path; int * fileMTimes1, * fileMTimes2; int i, j; uint8_t * blockBitfield; int size; /* Open resume file */ path = fastResumeFileName( io ); if( !( file = fopen( path, "r" ) ) ) { tr_inf( "Could not open '%s' for reading", path ); free( path ); return 1; } tr_dbg( "Resume file '%s' loaded", path ); free( path ); /* Check the size */ size = 4 + 4 * inf->fileCount + 4 * inf->pieceCount + ( tor->blockCount + 7 ) / 8; fseek( file, 0, SEEK_END ); if( ftell( file ) != size ) { tr_inf( "Wrong size for resume file (%d bytes, %d expected)", ftell( file ), size ); fclose( file ); return 1; } fseek( file, 0, SEEK_SET ); /* Check format version */ fread( &version, 4, 1, file ); if( version != 0 ) { tr_inf( "Resume file has version %d, not supported", version ); fclose( file ); return 1; } /* Compare file mtimes */ fileMTimes1 = malloc( inf->fileCount * 4 ); if( fastResumeMTimes( io, fileMTimes1 ) ) { free( fileMTimes1 ); fclose( file ); return 1; } fileMTimes2 = malloc( inf->fileCount * 4 ); fread( fileMTimes2, 4, inf->fileCount, file ); if( memcmp( fileMTimes1, fileMTimes2, inf->fileCount * 4 ) ) { tr_inf( "File mtimes don't match" ); free( fileMTimes1 ); free( fileMTimes2 ); fclose( file ); return 1; } free( fileMTimes1 ); free( fileMTimes2 ); /* Load the bitfield for blocks and fill blockHave */ blockBitfield = calloc( ( tor->blockCount + 7 ) / 8, 1 ); fread( blockBitfield, ( tor->blockCount + 7 ) / 8, 1, file ); tr_cpBlockBitfieldSet( tor->completion, blockBitfield ); free( blockBitfield ); /* Load the 'slotPiece' table */ fread( io->slotPiece, 4, inf->pieceCount, file ); fclose( file ); /* Update io->pieceSlot, io->slotsUsed, and tor->bitfield */ io->slotsUsed = 0; for( i = 0; i < inf->pieceCount; i++ ) { io->pieceSlot[i] = -1; for( j = 0; j < inf->pieceCount; j++ ) { if( io->slotPiece[j] == i ) { // tr_dbg( "Has piece %d in slot %d", i, j ); io->pieceSlot[i] = j; io->slotsUsed = MAX( io->slotsUsed, j + 1 ); break; } } } // tr_dbg( "Slot used: %d", io->slotsUsed ); tr_inf( "Fast resuming successful" ); return 0; }