CacheFileWithCachepublic class CacheFileWithCache extends Object implements CacheFile
| Fields Summary |
|---|
| private static final byte | SS_CACHE | | private static final LogIDs | LOGID | | protected static Comparator | comparator | | protected static boolean | TRACE | | protected static final boolean | TRACE_CACHE_CONTENTS | | protected static final int | READAHEAD_LOW_LIMIT | | protected static final int | READAHEAD_HIGH_LIMIT | | protected static final int | READAHEAD_HISTORY | | protected CacheFileManagerImpl | manager | | protected FMFile | file | | protected int | access_mode | | protected TOTorrentFile | torrent_file | | protected TOTorrent | torrent | | protected long | file_offset_in_torrent | | protected long[] | read_history | | protected int | read_history_next | | protected TreeSet | cache | | protected int | current_read_ahead_size | | protected static final int | READ_AHEAD_STATS_WAIT_TICKS | | protected int | read_ahead_stats_wait | | protected Average | read_ahead_made_average | | protected Average | read_ahead_used_average | | protected long | read_ahead_bytes_made | | protected long | last_read_ahead_bytes_made | | protected long | read_ahead_bytes_used | | protected long | last_read_ahead_bytes_used | | protected int | piece_size | | protected int | piece_offset | | protected AEMonitor | this_mon | | protected volatile CacheFileManagerException | pending_exception |
| Constructors Summary |
|---|
protected CacheFileWithCache(CacheFileManagerImpl _manager, FMFile _file, TOTorrentFile _torrent_file)
manager = _manager;
file = _file;
Arrays.fill( read_history, -1 );
if ( _torrent_file != null ){
torrent_file = _torrent_file;
torrent = torrent_file.getTorrent();
piece_size = (int)torrent.getPieceLength();
for (int i=0;i<torrent.getFiles().length;i++){
TOTorrentFile f = torrent.getFiles()[i];
if ( f == torrent_file ){
break;
}
file_offset_in_torrent += f.getLength();
}
piece_offset = piece_size - (int)( file_offset_in_torrent % piece_size );
if ( piece_offset == piece_size ){
piece_offset = 0;
}
current_read_ahead_size = Math.min( READAHEAD_LOW_LIMIT, piece_size );
}
|
| Methods Summary |
|---|
| protected void | checkPendingException()
if ( pending_exception != null ){
throw( pending_exception );
}
| | public void | clearCache()
flushCachePublic(true, -1);
| | public void | close()
// we've got to always close the file here, even if the flush fails
boolean fm_file_closed = false;
try{
flushCachePublic( true, -1 );
file.close();
fm_file_closed = true;
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
}finally{
if ( !fm_file_closed ){
try{
file.close();
}catch( Throwable e ){
// we're already on our way out via exception, no need to
// throw a new one
}
}
manager.closeFile( this );
}
| | public long | compareLength(long compare_to)
try{
// we can optimise this if the file's already big enough as cache entries can
// only make it bigger
long physical_length = file.getLength();
long res = physical_length - compare_to;
if ( res >= 0 ){
return( res );
}
return( getLength() - compare_to );
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
return( 0 );
}
| | public void | delete()
try{
file.delete();
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
}
| | public void | ensureOpen(java.lang.String reason)
try{
// no cache flush required here
file.ensureOpen( reason );
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
}
| | public boolean | exists()
return( file.exists());
| | public void | flushCache()
try{
flushCachePublic( false, -1 );
file.flush();
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
}
| | protected void | flushCache(long file_position, long length, boolean release_entries, long minimum_to_release, long oldest_dirty_time, long min_chunk_size)
try{
flushCacheSupport( file_position, length, release_entries, minimum_to_release, oldest_dirty_time, min_chunk_size );
}catch( CacheFileManagerException e ){
if ( !release_entries ){
// make sure we release the offending buffer entries otherwise they'll hang around
// in memory causing grief when the next attempt it made to flush them...
flushCacheSupport( 0, -1, true, -1, 0, -1 );
}
throw( e );
}
| | protected void | flushCache(long file_start_position, boolean release_entries, long minumum_to_release)
if ( manager.isCacheEnabled()){
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID, "flushCache: " + getName()
+ ", rel = " + release_entries + ", min = " + minumum_to_release));
flushCache( file_start_position, -1, release_entries, minumum_to_release, 0, -1 );
}
| | protected void | flushCachePublic(boolean release_entries, long minumum_to_release)
checkPendingException();
flushCache(0, release_entries, minumum_to_release );
| | protected void | flushCacheSupport(long file_position, long length, boolean release_entries, long minimum_to_release, long oldest_dirty_time, long min_chunk_size)
try{
this_mon.enter();
if ( cache.size() == 0 ){
return;
}
Iterator it = cache.iterator();
Throwable last_failure = null;
long entry_total_released = 0;
List multi_block_entries = new ArrayList();
long multi_block_start = -1;
long multi_block_next = -1;
while( it.hasNext()){
CacheEntry entry = (CacheEntry)it.next();
long entry_file_position = entry.getFilePosition();
int entry_length = entry.getLength();
if ( entry_file_position + entry_length <= file_position ){
// to the left
continue;
}else if ( length != -1 && file_position + length <= entry_file_position ){
// to the right, give up
break;
}
// overlap!!!!
// we're going to deal with this entry one way or another. In particular if
// we are releasing entries then this is guaranteed to be released, either directly
// or via a flush if dirty
boolean dirty = entry.isDirty();
try{
if ( dirty &&
( oldest_dirty_time == 0 ||
entry.getLastUsed() < oldest_dirty_time )){
if ( multi_block_start == -1 ){
// start of day
multi_block_start = entry_file_position;
multi_block_next = entry_file_position + entry_length;
multi_block_entries.add( entry );
}else if ( multi_block_next == entry_file_position ){
// continuation, add in
multi_block_next = entry_file_position + entry_length;
multi_block_entries.add( entry );
}else{
// we've got a gap - flush current and start another series
// set up ready for next block in case the flush fails - we try
// and flush as much as possible in the face of failure
boolean skip_chunk = false;
if ( min_chunk_size != -1 ){
if ( release_entries ){
Debug.out( "CacheFile: can't use min chunk with release option" );
}else{
skip_chunk = multi_block_next - multi_block_start < min_chunk_size;
}
}
List f_multi_block_entries = multi_block_entries;
long f_multi_block_start = multi_block_start;
long f_multi_block_next = multi_block_next;
multi_block_start = entry_file_position;
multi_block_next = entry_file_position + entry_length;
multi_block_entries = new ArrayList();
multi_block_entries.add( entry );
if ( skip_chunk ){
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID,
"flushCache: skipping " + multi_block_entries.size()
+ " entries, [" + multi_block_start + ","
+ multi_block_next + "] as too small"));
}else{
multiBlockFlush(
f_multi_block_entries,
f_multi_block_start,
f_multi_block_next,
release_entries );
}
}
}
}catch( Throwable e ){
last_failure = e;
}finally{
if ( release_entries ){
it.remove();
// if it is dirty it will be released when the flush is done
if ( !dirty ){
manager.releaseCacheSpace( entry );
}
entry_total_released += entry.getLength();
if ( minimum_to_release != -1 && entry_total_released > minimum_to_release ){
// if this entry needs flushing this is done outside the loop
break;
}
}
}
}
if ( multi_block_start != -1 ){
boolean skip_chunk = false;
if ( min_chunk_size != -1 ){
if ( release_entries ){
Debug.out( "CacheFile: can't use min chunk with release option" );
}else{
skip_chunk = multi_block_next - multi_block_start < min_chunk_size;
}
}
if ( skip_chunk ){
if (TRACE)
Logger
.log(new LogEvent(torrent, LOGID, "flushCache: skipping "
+ multi_block_entries.size() + " entries, ["
+ multi_block_start + "," + multi_block_next
+ "] as too small"));
}else{
multiBlockFlush(
multi_block_entries,
multi_block_start,
multi_block_next,
release_entries );
}
}
if ( last_failure != null ){
if ( last_failure instanceof CacheFileManagerException ){
throw((CacheFileManagerException)last_failure );
}
throw( new CacheFileManagerException( this,"cache flush failed", last_failure ));
}
}finally{
this_mon.exit();
}
| | protected void | flushOldDirtyData(long oldest_dirty_time, long min_chunk_size)
if ( manager.isCacheEnabled()){
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID, "flushOldDirtyData: "
+ getName()));
flushCache( 0, -1, false, -1, oldest_dirty_time, min_chunk_size );
}
| | protected void | flushOldDirtyData(long oldest_dirty_time)
flushOldDirtyData( oldest_dirty_time, -1 );
| | public int | getAccessMode()
return( access_mode );
| | protected void | getBytesInCache(boolean[] toModify, long[] absoluteOffsets, long[] lengths)
final long baseOffset = file_offset_in_torrent;
int i = 0;
long first = absoluteOffsets[0];
long last = absoluteOffsets[absoluteOffsets.length-1]+lengths[lengths.length-1];
// chunk might span file boundaries
long lastEnd = Math.max(absoluteOffsets[0],baseOffset);
while(absoluteOffsets[i]+lengths[i] < baseOffset)
i++;
boolean doSkipping = true;
try {
this_mon.enter();
Iterator it = cache.iterator();
while(it.hasNext())
{
CacheEntry entry = (CacheEntry)it.next();
long startPos = entry.getFilePosition()+baseOffset;
long endPos = startPos+entry.getLength();
// the following check ensures that we are within the interesting region
if(startPos < first)
continue; // skip forward until we reach a chunk
// perform skipping from the previous round
if(doSkipping)
while(i < absoluteOffsets.length && absoluteOffsets[i] < startPos)
{
toModify[i] = false;
i++;
}
if(i >= absoluteOffsets.length)
break;
doSkipping = false;
if(startPos >= absoluteOffsets[i] && endPos >= absoluteOffsets[i]+lengths[i])
{ // chunk completely falls into cache entry -> don't invalidate
i++;
doSkipping = true;
} else if(startPos >= lastEnd)
{ // chunk spans multiple cache entries AND we skipped -> invalidate
doSkipping = true;
} else if(startPos >= absoluteOffsets[i]+lengths[i])
{ // end of a spanning chunk -> don't invalidate
i++;
doSkipping = true;
}
if(endPos > last)
break;
lastEnd = endPos;
}
} finally {
this_mon.exit();
}
if(doSkipping) // we fell through the loop but there's still cleanup to do
while(i<absoluteOffsets.length)
{
if(absoluteOffsets[i]+lengths[i] < baseOffset || absoluteOffsets[i] > baseOffset+torrent_file.getLength())
{
i++;
continue;
}
toModify[i] = false;
i++;
}
| | protected FMFile | getFMFile()
return( file );
| | public long | getLength()
// not sure of the difference between "size" and "length" here. Old code
// used to use "size" so I'm going to carry on for the moment in case
// there is some weirdness here
try{
// bug found here with "incremental creation" failing with lots of hash
// fails. Caused by the reported length not taking into account the cache
// entries that have yet to be flushed.
if ( manager.isCacheEnabled()){
try{
this_mon.enter();
long physical_size = file.getLength();
Iterator it = cache.iterator();
// last entry is furthest down the file
while( it.hasNext()){
CacheEntry entry = (CacheEntry)it.next();
if ( !it.hasNext()){
long entry_file_position = entry.getFilePosition();
int entry_length = entry.getLength();
long logical_size = entry_file_position + entry_length;
if ( logical_size > physical_size ){
physical_size = logical_size;
}
}
}
return( physical_size );
}finally{
this_mon.exit();
}
}else{
return( file.getLength());
}
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
return( 0 );
}
| | protected java.lang.String | getName()
return( file.getName());
| | public int | getStorageType()
return( file.getStorageType()==FMFile.FT_COMPACT?CT_COMPACT:CT_LINEAR );
| | public TOTorrentFile | getTorrentFile()
return( torrent_file );
| | public boolean | isOpen()
return( file.isOpen());
| | public void | moveFile(java.io.File new_file)
try{
flushCachePublic( true, -1 );
file.moveFile( new_file );
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
}
| | protected void | multiBlockFlush(java.util.List multi_block_entries, long multi_block_start, long multi_block_next, boolean release_entries)
boolean write_ok = false;
try{
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID, "multiBlockFlush: writing "
+ multi_block_entries.size() + " entries, [" + multi_block_start
+ "," + multi_block_next + "," + release_entries + "]"));
DirectByteBuffer[] buffers = new DirectByteBuffer[ multi_block_entries.size()];
long expected_per_entry_write = 0;
for (int i=0;i<buffers.length;i++){
CacheEntry entry = (CacheEntry)multi_block_entries.get(i);
// sanitity check - we should always be flushing entire entries
DirectByteBuffer buffer = entry.getBuffer();
if ( buffer.limit(SS_CACHE) - buffer.position(SS_CACHE) != entry.getLength()){
throw( new CacheFileManagerException( this,"flush: inconsistent entry length, position wrong" ));
}
expected_per_entry_write += entry.getLength();
buffers[i] = buffer;
}
long expected_overall_write = multi_block_next - multi_block_start;
if ( expected_per_entry_write != expected_overall_write ){
throw( new CacheFileManagerException( this,"flush: inconsistent write length, entrys = " + expected_per_entry_write + " overall = " + expected_overall_write ));
}
getFMFile().write( buffers, multi_block_start );
manager.fileBytesWritten( expected_overall_write );
write_ok = true;
}catch( FMFileManagerException e ){
throw( new CacheFileManagerException( this,"flush fails", e ));
}finally{
for (int i=0;i<multi_block_entries.size();i++){
CacheEntry entry = (CacheEntry)multi_block_entries.get(i);
if ( release_entries ){
manager.releaseCacheSpace( entry );
}else{
entry.resetBufferPosition();
if ( write_ok ){
entry.setClean();
}
}
}
}
| | public void | read(DirectByteBuffer[] buffers, long position, short policy)
for (int i=0;i<buffers.length;i++){
DirectByteBuffer buffer = buffers[i];
int len = buffer.remaining( DirectByteBuffer.SS_CACHE );
try{
read( buffer, position, policy );
position += len;
}catch( CacheFileManagerException e ){
throw( new CacheFileManagerException( this, e.getMessage(), e, i ));
}
}
| | public void | read(DirectByteBuffer buffer, long position, short policy)
boolean read_cache = ( policy & CP_READ_CACHE ) != 0;
boolean flush = ( policy & CP_FLUSH ) != 0;
if ( flush ){
int file_buffer_position = buffer.position(DirectByteBuffer.SS_CACHE);
int file_buffer_limit = buffer.limit(DirectByteBuffer.SS_CACHE);
int read_length = file_buffer_limit - file_buffer_position;
flushCache( position, read_length, false, -1, 0, -1 );
}
readCache( buffer, position, false, !read_cache );
| | protected void | readCache(DirectByteBuffer file_buffer, long file_position, boolean recursive, boolean disable_read_cache)
checkPendingException();
final int file_buffer_position = file_buffer.position(SS_CACHE);
final int file_buffer_limit = file_buffer.limit(SS_CACHE);
final int read_length = file_buffer_limit - file_buffer_position;
try{
if ( manager.isCacheEnabled()){
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID, "readCache: " + getName()
+ ", " + file_position + " - "
+ (file_position + read_length - 1) + ":" + file_buffer_position
+ "/" + file_buffer_limit));
if ( read_length == 0 ){
return; // nothing to do
}
long writing_file_position = file_position;
int writing_left = read_length;
boolean ok = true;
int used_entries = 0;
long used_read_ahead = 0;
// if we can totally satisfy the read from the cache, then use it
// otherwise flush the cache (not so smart here to only read missing)
try{
this_mon.enter();
// record the position of the byte *following* the end of this read
read_history[read_history_next++] = file_position + read_length;
if ( read_history_next == READAHEAD_HISTORY ){
read_history_next = 0;
}
Iterator it = cache.iterator();
while( ok && writing_left > 0 && it.hasNext()){
CacheEntry entry = (CacheEntry)it.next();
long entry_file_position = entry.getFilePosition();
int entry_length = entry.getLength();
if ( entry_file_position > writing_file_position ){
// data missing at the start of the read section
ok = false;
break;
}else if ( entry_file_position + entry_length <= writing_file_position ){
// not got there yet
}else{
// copy required amount into read buffer
int skip = (int)(writing_file_position - entry_file_position);
int available = entry_length - skip;
if ( available > writing_left ){
available = writing_left;
}
DirectByteBuffer entry_buffer = entry.getBuffer();
int entry_buffer_position = entry_buffer.position(SS_CACHE);
int entry_buffer_limit = entry_buffer.limit(SS_CACHE);
try{
entry_buffer.limit( SS_CACHE, entry_buffer_position + skip + available );
entry_buffer.position( SS_CACHE, entry_buffer_position + skip );
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID, "cacheRead: using "
+ entry.getString() + "["
+ entry_buffer.position(SS_CACHE) + "/"
+ entry_buffer.limit(SS_CACHE) + "]" + "to write to ["
+ file_buffer.position(SS_CACHE) + "/"
+ file_buffer.limit(SS_CACHE) + "]"));
used_entries++;
file_buffer.put( SS_CACHE, entry_buffer );
manager.cacheEntryUsed( entry );
}finally{
entry_buffer.limit( SS_CACHE, entry_buffer_limit );
entry_buffer.position( SS_CACHE, entry_buffer_position );
}
writing_file_position += available;
writing_left -= available;
if ( entry.getType() == CacheEntry.CT_READ_AHEAD ){
used_read_ahead += available;
}
}
}
}finally{
if ( ok ){
read_ahead_bytes_used += used_read_ahead;
}
this_mon.exit();
}
if ( ok && writing_left == 0 ){
// only record this as a cache read hit if we haven't just read the
// data from the file system
if ( !recursive ){
manager.cacheBytesRead( read_length );
}
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID,
"cacheRead: cache use ok [entries = " + used_entries + "]"));
}else{
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID,
"cacheRead: cache use fails, reverting to plain read"));
// reset in case we've done some partial reads
file_buffer.position( SS_CACHE, file_buffer_position );
// If read-ahead fails then we resort to a straight read
// Read-ahead can fail if a cache-flush fails (e.g. out of disk space
// on a file belonging to a different torrent than this.
// We don't want such a failure to break this read operation
for (int i=0;i<2;i++){
try{
boolean do_read_ahead =
i == 0 && // first time round
!recursive &&
!disable_read_cache &&
manager.isReadCacheEnabled() &&
read_length < current_read_ahead_size &&
file_position + current_read_ahead_size <= file.getLength();
if ( do_read_ahead ){
// only read ahead if this is a continuation of a prior read within history
do_read_ahead = false;
for (int j=0;j<READAHEAD_HISTORY;j++){
if ( read_history[j] == file_position ){
do_read_ahead = true;
break;
}
}
}
int actual_read_ahead = current_read_ahead_size;
if ( do_read_ahead ){
// don't read ahead over the end of a piece
int request_piece_offset = (int)((file_position - piece_offset ) % piece_size);
if ( request_piece_offset < 0 ){
request_piece_offset += piece_size;
}
//System.out.println( "request offset = " + request_piece_offset );
int data_left = piece_size - request_piece_offset;
if ( data_left < actual_read_ahead ){
actual_read_ahead = data_left;
// no point in using read-ahead logic if actual read ahead
// smaller or same as request size!
if ( actual_read_ahead <= read_length ){
do_read_ahead = false;
}
//System.out.println( " trimmed to " + data_left );
}
}
if ( do_read_ahead ){
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID,
"\tperforming read-ahead"));
DirectByteBuffer cache_buffer =
DirectByteBufferPool.getBuffer( DirectByteBuffer.AL_CACHE_READ, actual_read_ahead );
boolean buffer_cached = false;
try{
// must allocate space OUTSIDE sync block (see manager for details)
CacheEntry entry =
manager.allocateCacheSpace(
CacheEntry.CT_READ_AHEAD,
this,
cache_buffer, file_position, actual_read_ahead );
entry.setClean();
try{
this_mon.enter();
// flush before read so that any bits in cache get re-read correctly on read
flushCache( file_position, actual_read_ahead, true, -1, 0, -1 );
getFMFile().read( cache_buffer, file_position );
read_ahead_bytes_made += actual_read_ahead;
manager.fileBytesRead( actual_read_ahead );
cache_buffer.position( SS_CACHE, 0 );
cache.add( entry );
manager.addCacheSpace( entry );
}finally{
this_mon.exit();
}
buffer_cached = true;
}finally{
if ( !buffer_cached ){
// if the read operation failed, and hence the buffer
// wasn't added to the cache, then release it here
cache_buffer.returnToPool();
}
}
// recursively read from the cache, should hit the data we just read although
// there is the possibility that it could be flushed before then - hence the
// recursion flag that will avoid this happening next time around
readCache( file_buffer, file_position, true, disable_read_cache );
}else{
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID,
"\tnot performing read-ahead"));
try{
this_mon.enter();
flushCache( file_position, read_length, true, -1, 0, -1 );
getFMFile().read( file_buffer, file_position );
}finally{
this_mon.exit();
}
manager.fileBytesRead( read_length );
}
break;
}catch( CacheFileManagerException e ){
if ( i == 1 ){
throw( e );
}
}catch( FMFileManagerException e ){
if ( i == 1 ){
manager.rethrow(this,e);
}
}
}
}
}else{
try{
getFMFile().read( file_buffer, file_position );
manager.fileBytesRead( read_length );
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
}
}
}finally{
if ( AEDiagnostics.CHECK_DUMMY_FILE_DATA ){
long temp_position = file_position + file_offset_in_torrent;
file_buffer.position( SS_CACHE, file_buffer_position );
while( file_buffer.hasRemaining( SS_CACHE )){
byte v = file_buffer.get( SS_CACHE );
if ((byte)temp_position != v ){
System.out.println( "readCache: read is bad at " + temp_position +
": expected = " + (byte)temp_position + ", actual = " + v );
file_buffer.position( SS_CACHE, file_buffer_limit );
break;
}
temp_position++;
}
}
}
| | public void | setAccessMode(int mode)
try{
this_mon.enter();
if ( access_mode != mode ){
flushCachePublic( false, -1 );
}
file.setAccessMode( mode==CF_READ?FMFile.FM_READ:FMFile.FM_WRITE );
access_mode = mode;
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
}finally{
this_mon.exit();
}
| | public void | setLength(long length)
try{
// flush in case length change will invalidate cache data (unlikely but possible)
flushCachePublic( true, -1 );
file.setLength( length );
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
}
| | protected void | setPendingException(CacheFileManagerException e)
pending_exception = e;
| | public void | setStorageType(int type)
try{
this_mon.enter();
if ( getStorageType() != type ){
flushCachePublic( false, -1 );
}
file.setStorageType( type==CT_COMPACT?FMFile.FT_COMPACT:FMFile.FT_LINEAR );
}catch( FMFileManagerException e ){
manager.rethrow(this,e);
}finally{
this_mon.exit();
}
| | protected void | updateStats()
long made = read_ahead_bytes_made;
long used = read_ahead_bytes_used;
long made_diff = made - last_read_ahead_bytes_made;
long used_diff = used - last_read_ahead_bytes_used;
read_ahead_made_average.addValue( made_diff );
read_ahead_used_average.addValue( used_diff );
last_read_ahead_bytes_made = made;
last_read_ahead_bytes_used = used;
// give changes made to read ahead size a chance to work through the stats
// before recalculating
if ( --read_ahead_stats_wait == 0 ){
read_ahead_stats_wait = READ_AHEAD_STATS_WAIT_TICKS;
// see if we need to adjust the read-ahead size
double made_average = read_ahead_made_average.getAverage();
double used_average = read_ahead_used_average.getAverage();
// if used average > 75% of made average then increase
double ratio = used_average*100/made_average;
if ( ratio > 0.75 ){
current_read_ahead_size += 16*1024;
// no bigger than a piece
current_read_ahead_size = Math.min( current_read_ahead_size, piece_size );
// no bigger than the fixed max size
current_read_ahead_size = Math.min( current_read_ahead_size, READAHEAD_HIGH_LIMIT );
// no bigger than a 16th of the cache, in case its really small (e.g. 1M)
current_read_ahead_size = Math.min( current_read_ahead_size, (int)(manager.getCacheSize()/16 ));
}else if ( ratio < 0.5 ){
current_read_ahead_size -= 16*1024;
// no smaller than the min
current_read_ahead_size = Math.max( current_read_ahead_size, READAHEAD_LOW_LIMIT );
}
}
// System.out.println( "read-ahead: done = " + read_ahead_bytes_made + ", used = " + read_ahead_bytes_used + ", done_av = " + read_ahead_made_average.getAverage() + ", used_av = " + read_ahead_used_average.getAverage()+ ", size = " + current_read_ahead_size );
| | public void | write(DirectByteBuffer buffer, long position)
writeCache( buffer, position, false );
| | public void | write(DirectByteBuffer[] buffers, long position)
for (int i=0;i<buffers.length;i++){
DirectByteBuffer buffer = buffers[i];
int len = buffer.remaining( DirectByteBuffer.SS_CACHE );
try{
write( buffer, position );
position += len;
}catch( CacheFileManagerException e ){
throw( new CacheFileManagerException( this, e.getMessage(), e, i ));
}
}
| | public void | writeAndHandoverBuffer(DirectByteBuffer buffer, long position)
writeCache( buffer, position, true );
| | public void | writeAndHandoverBuffers(DirectByteBuffer[] buffers, long position)
for (int i=0;i<buffers.length;i++){
DirectByteBuffer buffer = buffers[i];
int len = buffer.remaining( DirectByteBuffer.SS_CACHE );
try{
writeAndHandoverBuffer( buffer, position );
position += len;
}catch( CacheFileManagerException e ){
throw( new CacheFileManagerException( this, e.getMessage(), e, i ));
}
}
| | protected void | writeCache(DirectByteBuffer file_buffer, long file_position, boolean buffer_handed_over)
checkPendingException();
boolean buffer_cached = false;
boolean failed = false;
try{
int file_buffer_position = file_buffer.position(SS_CACHE);
int file_buffer_limit = file_buffer.limit(SS_CACHE);
int write_length = file_buffer_limit - file_buffer_position;
if ( write_length == 0 ){
return; // nothing to do
}
if ( AEDiagnostics.CHECK_DUMMY_FILE_DATA ){
long temp_position = file_position + file_offset_in_torrent;
while( file_buffer.hasRemaining( SS_CACHE )){
byte v = file_buffer.get( SS_CACHE );
if ((byte)temp_position != v ){
System.out.println( "writeCache: write is bad at " + temp_position +
": expected = " + (byte)temp_position + ", actual = " + v );
break;
}
temp_position++;
}
file_buffer.position( SS_CACHE, file_buffer_position );
}
if ( manager.isWriteCacheEnabled() ){
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID, "writeCache: " + getName()
+ ", " + file_position + " - "
+ (file_position + write_length - 1) + ":" + file_buffer_position
+ "/" + file_buffer_limit));
// if the data is smaller than a piece and not handed over
// then it is most
// likely apart of a piece at the start or end of a file. If
// so, copy it
// and insert the copy into cache
if ( ( !buffer_handed_over ) &&
write_length < piece_size ){
if (TRACE)
Logger.log(new LogEvent(torrent, LOGID,
" making copy of non-handedover buffer"));
DirectByteBuffer cache_buffer = DirectByteBufferPool.getBuffer( DirectByteBuffer.AL_CACHE_WRITE, write_length );
cache_buffer.put( SS_CACHE, file_buffer );
cache_buffer.position( SS_CACHE, 0 );
// make it look like this buffer has been handed over
file_buffer = cache_buffer;
file_buffer_position = 0;
file_buffer_limit = write_length;
buffer_handed_over = true;
}
if ( buffer_handed_over ){
// cache this write, allocate outside sync block (see manager for details)
CacheEntry entry =
manager.allocateCacheSpace(
CacheEntry.CT_DATA_WRITE,
this,
file_buffer,
file_position,
write_length );
try{
this_mon.enter();
if ( access_mode != CF_WRITE ){
throw( new CacheFileManagerException( this,"Write failed - cache file is read only" ));
}
// if we are overwriting stuff already in the cache then force-write overlapped
// data (easiest solution as this should only occur on hash-fails)
// do the flush and add sychronized to avoid possibility of another
// thread getting in-between and adding same block thus causing mutiple entries
// for same space
flushCache( file_position, write_length, true, -1, 0, -1 );
cache.add( entry );
manager.addCacheSpace( entry );
}finally{
this_mon.exit();
}
manager.cacheBytesWritten( write_length );
buffer_cached = true;
}else{
// not handed over, invalidate any cache that exists for the area
// as it is now out of date
try{
this_mon.enter();
flushCache( file_position, write_length, true, -1, 0, -1 );
getFMFile().write( file_buffer, file_position );
}finally{
this_mon.exit();
}
manager.fileBytesWritten( write_length );
}
}else{
getFMFile().write( file_buffer, file_position );
manager.fileBytesWritten( write_length );
}
}catch( CacheFileManagerException e ){
failed = true;
throw( e );
}catch( FMFileManagerException e ){
failed = true;
manager.rethrow(this,e);
}finally{
if ( buffer_handed_over ){
if ( !(failed || buffer_cached )){
file_buffer.returnToPool();
}
}
}
|
|
