public synchronized void put(StoredBlock block) throws BlockStoreException {
try {
Sha256Hash hash = block.getHeader().getHash();
assert blockMap.get(hash) == null : "Attempt to insert duplicate";
// Append to the end of the file. The other fields in StoredBlock will be recalculated when
// it's reloaded.
byte[] bytes = block.getHeader().bitcoinSerialize();
stream.write(bytes);
stream.flush();
blockMap.put(hash, block);
} catch (IOException e) {
throw new BlockStoreException(e);
}
}
public synchronized void setChainHead(StoredBlock chainHead) throws BlockStoreException {
try {
this.chainHead = chainHead.getHeader().getHash();
// Write out new hash to the first 32 bytes of the file past one (first byte is version
// number).
stream.getChannel().write(ByteBuffer.wrap(this.chainHead.getBytes()), 1);
} catch (IOException e) {
throw new BlockStoreException(e);
}
}
@Override
public void put(StoredBlock block) throws BlockStoreException {
final MappedByteBuffer buffer = this.buffer;
if (buffer == null) throw new BlockStoreException("Store closed");
lock.lock();
try {
int cursor = getRingCursor(buffer);
if (cursor == getFileSize()) {
// Wrapped around.
cursor = FILE_PROLOGUE_BYTES;
}
buffer.position(cursor);
Sha256Hash hash = block.getHeader().getHash();
notFoundCache.remove(hash);
buffer.put(hash.getBytes());
block.serializeCompact(buffer);
setRingCursor(buffer, buffer.position());
blockCache.put(hash, block);
} finally {
lock.unlock();
}
}
@Override
public void setChainHead(StoredBlock chainHead) throws BlockStoreException {
final MappedByteBuffer buffer = this.buffer;
if (buffer == null) throw new BlockStoreException("Store closed");
lock.lock();
try {
lastChainHead = chainHead;
byte[] headHash = chainHead.getHeader().getHash().getBytes();
buffer.position(8);
buffer.put(headHash);
} finally {
lock.unlock();
}
}
private void createNewStore(NetworkParameters params, File file) throws BlockStoreException {
// Create a new block store if the file wasn't found or anything went wrong whilst reading.
blockMap.clear();
try {
stream = new FileOutputStream(file, false); // Do not append, create fresh.
stream.write(1); // Version.
} catch (IOException e1) {
// We could not load a block store nor could we create a new one!
throw new BlockStoreException(e1);
}
try {
// Set up the genesis block. When we start out fresh, it is by definition the top of the
// chain.
Block genesis = params.genesisBlock.cloneAsHeader();
StoredBlock storedGenesis = new StoredBlock(genesis, genesis.getWork(), 0);
this.chainHead = storedGenesis.getHeader().getHash();
stream.write(this.chainHead.getBytes());
put(storedGenesis);
} catch (VerificationException e1) {
throw new RuntimeException(e1); // Cannot happen.
} catch (IOException e) {
throw new BlockStoreException(e);
}
}
@Override
@Nullable
public StoredBlock get(Sha256Hash hash) throws BlockStoreException {
final MappedByteBuffer buffer = this.buffer;
if (buffer == null) throw new BlockStoreException("Store closed");
lock.lock();
try {
StoredBlock cacheHit = blockCache.get(hash);
if (cacheHit != null) return cacheHit;
if (notFoundCache.get(hash) != null) return null;
// Starting from the current tip of the ring work backwards until we have either found the
// block or
// wrapped around.
int cursor = getRingCursor(buffer);
final int startingPoint = cursor;
final int fileSize = getFileSize();
final byte[] targetHashBytes = hash.getBytes();
byte[] scratch = new byte[32];
do {
cursor -= RECORD_SIZE;
if (cursor < FILE_PROLOGUE_BYTES) {
// We hit the start, so wrap around.
cursor = fileSize - RECORD_SIZE;
}
// Cursor is now at the start of the next record to check, so read the hash and compare it.
buffer.position(cursor);
buffer.get(scratch);
if (Arrays.equals(scratch, targetHashBytes)) {
// Found the target.
StoredBlock storedBlock = StoredBlock.deserializeCompact(params, buffer);
blockCache.put(hash, storedBlock);
return storedBlock;
}
} while (cursor != startingPoint);
// Not found.
notFoundCache.put(hash, notFoundMarker);
return null;
} catch (ProtocolException e) {
throw new RuntimeException(e); // Cannot happen.
} finally {
lock.unlock();
}
}
private void load(File file) throws IOException, BlockStoreException {
log.info("Reading block store from {}", file);
InputStream input = null;
try {
input = new BufferedInputStream(new FileInputStream(file));
// Read a version byte.
int version = input.read();
if (version == -1) {
// No such file or the file was empty.
throw new FileNotFoundException(file.getName() + " does not exist or is empty");
}
if (version != 1) {
throw new BlockStoreException("Bad version number: " + version);
}
// Chain head pointer is the first thing in the file.
byte[] chainHeadHash = new byte[32];
if (input.read(chainHeadHash) < chainHeadHash.length)
throw new BlockStoreException("Truncated block store: cannot read chain head hash");
this.chainHead = new Sha256Hash(chainHeadHash);
log.info("Read chain head from disk: {}", this.chainHead);
long now = System.currentTimeMillis();
// Rest of file is raw block headers.
byte[] headerBytes = new byte[Block.HEADER_SIZE];
try {
while (true) {
// Read a block from disk.
if (input.read(headerBytes) < 80) {
// End of file.
break;
}
// Parse it.
Block b = new Block(params, headerBytes);
// Look up the previous block it connects to.
StoredBlock prev = get(b.getPrevBlockHash());
StoredBlock s;
if (prev == null) {
// First block in the stored chain has to be treated specially.
if (b.equals(params.genesisBlock)) {
s =
new StoredBlock(
params.genesisBlock.cloneAsHeader(), params.genesisBlock.getWork(), 0);
} else {
throw new BlockStoreException(
"Could not connect "
+ b.getHash().toString()
+ " to "
+ b.getPrevBlockHash().toString());
}
} else {
// Don't try to verify the genesis block to avoid upsetting the unit tests.
b.verifyHeader();
// Calculate its height and total chain work.
s = prev.build(b);
}
// Save in memory.
blockMap.put(b.getHash(), s);
}
} catch (ProtocolException e) {
// Corrupted file.
throw new BlockStoreException(e);
} catch (VerificationException e) {
// Should not be able to happen unless the file contains bad blocks.
throw new BlockStoreException(e);
}
long elapsed = System.currentTimeMillis() - now;
log.info("Block chain read complete in {}ms", elapsed);
} finally {
if (input != null) input.close();
}
}