public void reset() {
block.reset();
entryCount = 0;
restartPositions.clear();
restartPositions.add(0); // first restart point must be 0
restartBlockEntryCount = 0;
lastKey = null;
finished = false;
}
public BlockBuilder(int estimatedSize, int blockRestartInterval, Comparator<Slice> comparator) {
Preconditions.checkArgument(estimatedSize >= 0, "estimatedSize is negative");
Preconditions.checkArgument(blockRestartInterval >= 0, "blockRestartInterval is negative");
Preconditions.checkNotNull(comparator, "comparator is null");
this.block = new DynamicSliceOutput(estimatedSize);
this.blockRestartInterval = blockRestartInterval;
this.comparator = comparator;
restartPositions = new IntVector(32);
restartPositions.add(0); // first restart point must be 0
}
public void add(Slice key, Slice value) {
Preconditions.checkNotNull(key, "key is null");
Preconditions.checkNotNull(value, "value is null");
Preconditions.checkState(!finished, "block is finished");
Preconditions.checkPositionIndex(restartBlockEntryCount, blockRestartInterval);
Preconditions.checkArgument(
lastKey == null || comparator.compare(key, lastKey) > 0,
"key %s must be greater than last key %s",
key,
lastKey);
int sharedKeyBytes = 0;
if (restartBlockEntryCount < blockRestartInterval) {
sharedKeyBytes = calculateSharedBytes(key, lastKey);
} else {
// restart prefix compression
restartPositions.add(block.size());
restartBlockEntryCount = 0;
}
int nonSharedKeyBytes = key.length() - sharedKeyBytes;
// write "<shared><non_shared><value_size>"
VariableLengthQuantity.writeVariableLengthInt(sharedKeyBytes, block);
VariableLengthQuantity.writeVariableLengthInt(nonSharedKeyBytes, block);
VariableLengthQuantity.writeVariableLengthInt(value.length(), block);
// write non-shared key bytes
block.writeBytes(key, sharedKeyBytes, nonSharedKeyBytes);
// write value bytes
block.writeBytes(value, 0, value.length());
// update last key
lastKey = key;
// update state
entryCount++;
restartBlockEntryCount++;
}
