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Make some fields static/final as a memory optimization. Thanks to Andreas for his suggestions.

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Fix a bug that affected Windows machines by always closing files on the exception propagation path.
This commit is contained in:
Mike Hearn 2011-09-05 12:17:54 +00:00
parent 098671ffba
commit f4e54046f0
1 changed files with 29 additions and 26 deletions
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55
src/com/google/bitcoin/store/BoundedOverheadBlockStore.java
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@ -61,7 +61,7 @@ public class BoundedOverheadBlockStore implements BlockStore {
//
// We don't care about the value in this cache. It is always notFoundMarker. Unfortunately LinkedHashSet does not
// provide the removeEldestEntry control.
private StoredBlock notFoundMarker;
private final StoredBlock notFoundMarker = new StoredBlock(null, null, -1);
private LinkedHashMap<Sha256Hash, StoredBlock> notFoundCache = new LinkedHashMap<Sha256Hash, StoredBlock>() {
@Override
protected boolean removeEldestEntry(Map.Entry<Sha256Hash, StoredBlock> entry) {
@ -70,14 +70,14 @@ public class BoundedOverheadBlockStore implements BlockStore {
};
private Sha256Hash chainHead;
private NetworkParameters params;
private final NetworkParameters params;
private FileChannel channel;
private static class Record {
// A BigInteger representing the total amount of work done so far on this chain. As of May 2011 it takes 8
// bytes to represent this field, so 16 bytes should be plenty for a long time.
private static final int CHAIN_WORK_BYTES = 16;
private final byte[] EMPTY_BYTES = new byte[CHAIN_WORK_BYTES];
private static final byte[] EMPTY_BYTES = new byte[CHAIN_WORK_BYTES];
private int height; // 4 bytes
private byte[] chainWork; // 16 bytes
@ -91,8 +91,7 @@ public class BoundedOverheadBlockStore implements BlockStore {
blockHeader = new byte[Block.HEADER_SIZE];
}
// This should be static but the language does not allow for it.
public void write(FileChannel channel, StoredBlock block) throws IOException {
public static void write(FileChannel channel, StoredBlock block) throws IOException {
ByteBuffer buf = ByteBuffer.allocate(Record.SIZE);
buf.putInt(block.getHeight());
byte[] chainWorkBytes = block.getChainWork().toByteArray();
@ -141,7 +140,6 @@ public class BoundedOverheadBlockStore implements BlockStore {
public BoundedOverheadBlockStore(NetworkParameters params, File file) throws BlockStoreException {
this.params = params;
notFoundMarker = new StoredBlock(null, null, -1);
try {
load(file);
} catch (Exception e) {
@ -182,33 +180,38 @@ public class BoundedOverheadBlockStore implements BlockStore {
private void load(File file) throws IOException, BlockStoreException {
log.info("Reading block store from {}", file);
this.file = new RandomAccessFile(file, "rw");
channel = this.file.getChannel();
// Read a version byte.
int version = this.file.read();
if (version == -1) {
// No such file or the file was empty.
throw new FileNotFoundException(file.getName() + " does not exist or is empty");
try {
channel = this.file.getChannel();
// Read a version byte.
int version = this.file.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 != FILE_FORMAT_VERSION) {
throw new BlockStoreException("Bad version number: " + version);
}
// Chain head pointer is the first thing in the file.
byte[] chainHeadHash = new byte[32];
if (this.file.read(chainHeadHash) < chainHeadHash.length)
throw new BlockStoreException("Truncated store: could not read chain head hash.");
this.chainHead = new Sha256Hash(chainHeadHash);
log.info("Read chain head from disk: {}", this.chainHead);
channel.position(channel.size() - Record.SIZE);
} catch (IOException e) {
this.file.close();
throw e;
} catch (BlockStoreException e) {
this.file.close();
throw e;
}
if (version != FILE_FORMAT_VERSION) {
throw new BlockStoreException("Bad version number: " + version);
}
// Chain head pointer is the first thing in the file.
byte[] chainHeadHash = new byte[32];
if (this.file.read(chainHeadHash) < chainHeadHash.length)
throw new BlockStoreException("Truncated store: could not read chain head hash.");
this.chainHead = new Sha256Hash(chainHeadHash);
log.info("Read chain head from disk: {}", this.chainHead);
channel.position(channel.size() - Record.SIZE);
}
// TODO: This is ugly, fixinate!
private Record dummyRecord = new Record();
public synchronized void put(StoredBlock block) throws BlockStoreException {
try {
Sha256Hash hash = block.getHeader().getHash();
// Append to the end of the file.
dummyRecord.write(channel, block);
Record.write(channel, block);
blockCache.put(hash, block);
} catch (IOException e) {
throw new BlockStoreException(e);