private void write(FileStorage fileStorage, long pos, ByteBuffer buffer) {
try {
fileStorage.writeFully(pos, buffer);
} catch (IllegalStateException e) {
panic(e);
throw e;
}
}
/** Commit and save all changes, if there are any, and compact the storage if needed. */
public void writeInBackground(int autoCommitDelay) {
if (closed) {
return;
}
// could also commit when there are many unsaved pages,
// but according to a test it doesn't really help
long time = getTimeSinceCreation();
if (time <= lastCommitTime + autoCommitDelay) {
return;
}
if (hasUnsavedChanges()) {
try {
commitAndSave();
} catch (Exception e) {
if (backgroundExceptionHandler != null) {
backgroundExceptionHandler.uncaughtException(null, e);
return;
}
}
}
if (autoCompactFillRate > 0 && lastChunk != null && lastChunk.fileStorage != null) {
FileStorage fileStorage = lastChunk.fileStorage;
try {
// whether there were file read or write operations since
// the last time
boolean fileOps;
long fileOpCount = fileStorage.getWriteCount() + fileStorage.getReadCount();
if (autoCompactLastFileOpCount != fileOpCount) {
fileOps = true;
} else {
fileOps = false;
}
// use a lower fill rate if there were any file operations
int fillRate = fileOps ? autoCompactFillRate / 3 : autoCompactFillRate;
// TODO how to avoid endless compaction if there is a bug
// in the bookkeeping?
compact(fillRate, autoCommitMemory);
autoCompactLastFileOpCount = fileStorage.getWriteCount() + fileStorage.getReadCount();
} catch (Exception e) {
if (backgroundExceptionHandler != null) {
backgroundExceptionHandler.uncaughtException(null, e);
}
}
}
}
private synchronized BTreeChunk readChunkHeader(int chunkId) {
FileStorage fileStorage = getFileStorage(chunkId);
BTreeChunk chunk = null;
ByteBuffer chunkHeaderBlocks = fileStorage.readFully(0, CHUNK_HEADER_SIZE);
byte[] buff = new byte[BLOCK_SIZE];
for (int i = 0; i <= BLOCK_SIZE; i += BLOCK_SIZE) {
chunkHeaderBlocks.get(buff);
try {
String s = new String(buff, 0, BLOCK_SIZE, DataUtils.LATIN).trim();
HashMap<String, String> m = DataUtils.parseMap(s);
int blockSize = DataUtils.readHexInt(m, "blockSize", BLOCK_SIZE);
if (blockSize != BLOCK_SIZE) {
throw DataUtils.newIllegalStateException(
DataUtils.ERROR_UNSUPPORTED_FORMAT,
"Block size {0} is currently not supported",
blockSize);
}
int check = DataUtils.readHexInt(m, "fletcher", 0);
m.remove("fletcher");
s = s.substring(0, s.lastIndexOf("fletcher") - 1);
byte[] bytes = s.getBytes(DataUtils.LATIN);
int checksum = DataUtils.getFletcher32(bytes, bytes.length);
if (check != checksum) {
continue;
}
chunk = BTreeChunk.fromString(s);
break;
} catch (Exception e) {
continue;
}
}
if (chunk == null) {
throw DataUtils.newIllegalStateException(
DataUtils.ERROR_FILE_CORRUPT, "Storage header is corrupt: {0}", fileStorage);
}
chunk.fileStorage = fileStorage;
chunks.put(chunk.id, chunk);
return chunk;
}
private FileStorage getFileStorage(int chunkId) {
String chunkFileName = btreeStorageName + File.separator + chunkId + AOStorage.SUFFIX_AO_FILE;
FileStorage fileStorage = new FileStorage();
fileStorage.open(chunkFileName, map.config);
return fileStorage;
}
