/* returns 0 on success, or an errno on failure */
static int
readOrWriteBytes( const tr_torrent * tor,
int ioMode,
tr_file_index_t 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;
struct stat sb;
int fd = -1;
int err;
int fileExists;
assert( tor->downloadDir && *tor->downloadDir );
assert( fileIndex < info->fileCount );
assert( !file->length || ( fileOffset < file->length ) );
assert( fileOffset + buflen <= file->length );
path = tr_buildPath( tor->downloadDir, file->name, NULL );
fileExists = !stat( path, &sb );
tr_free( path );
if( !file->length )
return 0;
if( ( ioMode == TR_IO_READ ) && !fileExists ) /* does file exist? */
err = errno;
else if( ( fd = tr_fdFileCheckout ( tor->downloadDir, file->name, ioMode == TR_IO_WRITE, !file->dnd, file->length ) ) < 0 )
err = errno;
else if( tr_lseek( fd, (int64_t)fileOffset, SEEK_SET ) == -1 )
err = errno;
else if( func( fd, buf, buflen ) != buflen )
err = errno;
else
err = 0;
if( ( !err ) && ( !fileExists ) && ( ioMode == TR_IO_WRITE ) )
tr_statsFileCreated( tor->session );
if( fd >= 0 )
tr_fdFileReturn( fd );
return err;
}
static tr_bool
verifyTorrent( tr_torrent * tor, tr_bool * stopFlag )
{
SHA_CTX sha;
int fd = -1;
int64_t filePos = 0;
tr_bool changed = 0;
tr_bool hadPiece = 0;
uint32_t piecePos = 0;
uint32_t pieceBytesRead = 0;
tr_file_index_t fileIndex = 0;
tr_piece_index_t pieceIndex = 0;
const int64_t buflen = tor->info.pieceSize;
uint8_t * buffer = tr_new( uint8_t, buflen );
#ifdef STOPWATCH
time_t now = time( NULL );
#endif
SHA1_Init( &sha );
while( !*stopFlag && ( pieceIndex < tor->info.pieceCount ) )
{
int64_t leftInPiece;
int64_t leftInFile;
int64_t bytesThisPass;
const tr_file * file = &tor->info.files[fileIndex];
/* if we're starting a new piece... */
if( piecePos == 0 )
{
hadPiece = tr_cpPieceIsComplete( &tor->completion, pieceIndex );
/* fprintf( stderr, "starting piece %d of %d\n", (int)pieceIndex, (int)tor->info.pieceCount ); */
}
/* if we're starting a new file... */
if( !filePos && (fd<0) )
{
char * filename = tr_buildPath( tor->downloadDir, file->name, NULL );
fd = tr_open_file_for_scanning( filename );
/* fprintf( stderr, "opening file #%d (%s) -- %d\n", fileIndex, filename, fd ); */
tr_free( filename );
}
/* figure out how much we can read this pass */
leftInPiece = tr_torPieceCountBytes( tor, pieceIndex ) - piecePos;
leftInFile = file->length - filePos;
bytesThisPass = MIN( leftInFile, leftInPiece );
bytesThisPass = MIN( bytesThisPass, buflen );
/* fprintf( stderr, "reading this pass: %d\n", (int)bytesThisPass ); */
/* read a bit */
if( (fd>=0) && tr_lseek( fd, filePos, SEEK_SET ) != -1 ) {
const int64_t numRead = read( fd, buffer, bytesThisPass );
if( numRead > 0 )
pieceBytesRead += numRead;
if( numRead == bytesThisPass )
SHA1_Update( &sha, buffer, numRead );
}
/* move our offsets */
leftInPiece -= bytesThisPass;
leftInFile -= bytesThisPass;
piecePos += bytesThisPass;
filePos += bytesThisPass;
/* if we're finishing a piece... */
if( leftInPiece == 0 )
{
tr_bool hasPiece;
uint8_t hash[SHA_DIGEST_LENGTH];
SHA1_Final( hash, &sha );
hasPiece = !memcmp( hash, tor->info.pieces[pieceIndex].hash, SHA_DIGEST_LENGTH );
/* fprintf( stderr, "do the hashes match? %s\n", (hasPiece?"yes":"no") ); */
if( hasPiece ) {
tr_torrentSetHasPiece( tor, pieceIndex, TRUE );
if( !hadPiece )
changed = TRUE;
} else if( hadPiece ) {
tr_torrentSetHasPiece( tor, pieceIndex, FALSE );
changed = TRUE;
}
tr_torrentSetPieceChecked( tor, pieceIndex, TRUE );
tor->anyDate = time( NULL );
/* going full-throttle on a verify can choke other processes'
* disk IO, so wait a fwe msec between pieces.
* The msec is arbitrary, and the "if" clause is to make sure we
* don't slow down verification of files that don't exist */
if( pieceBytesRead == tr_torPieceCountBytes( tor, pieceIndex ) )
tr_wait( 50 );
SHA1_Init( &sha );
++pieceIndex;
piecePos = 0;
pieceBytesRead = 0;
}
/* if we're finishing a file... */
if( leftInFile == 0 )
{
/* fprintf( stderr, "closing file\n" ); */
if( fd >= 0 ) {
tr_close_file( fd );
fd = -1;
}
++fileIndex;
filePos = 0;
}
}
/* cleanup */
if( fd >= 0 )
tr_close_file( fd );
tr_free( buffer );
#ifdef STOPWATCH
{
time_t now2 = time( NULL );
fprintf( stderr, "it took %d seconds to verify %"PRIu64" bytes (%"PRIu64" bytes per second)\n",
(int)(now2-now), tor->info.totalSize, (uint64_t)(tor->info.totalSize/(1+(now2-now))) );
}
#endif
return changed;
}
