/**
* Serializes the source, target and feature data structures into interlinked binary files. Target
* is written first, into a skeletal (node don't carry any data) upward-pointing trie, updating
* the linking source trie nodes with the position once it is known. Source and feature data are
* written simultaneously. The source structure is written into a downward-pointing trie and
* stores the rule's lhs as well as links to the target and feature stream. The feature stream is
* prompted to write out a block
*
* @param source_trie
* @param target_trie
* @param feature_buffer
* @param id
* @throws IOException
*/
private PackingFileTuple flush(
PackingTrie<SourceValue> source_trie,
PackingTrie<TargetValue> target_trie,
FeatureBuffer feature_buffer,
AlignmentBuffer alignment_buffer,
int id)
throws IOException {
// Make a slice object for this piece of the grammar.
PackingFileTuple slice = new PackingFileTuple("slice_" + String.format("%05d", id));
// Pull out the streams for source, target and data output.
DataOutputStream source_stream = slice.getSourceOutput();
DataOutputStream target_stream = slice.getTargetOutput();
DataOutputStream target_lookup_stream = slice.getTargetLookupOutput();
DataOutputStream feature_stream = slice.getFeatureOutput();
DataOutputStream alignment_stream = slice.getAlignmentOutput();
Queue<PackingTrie<TargetValue>> target_queue;
Queue<PackingTrie<SourceValue>> source_queue;
// The number of bytes both written into the source stream and
// buffered in the source queue.
int source_position;
// The number of bytes written into the target stream.
int target_position;
// Add trie root into queue, set target position to 0 and set cumulated
// size to size of trie root.
target_queue = new LinkedList<PackingTrie<TargetValue>>();
target_queue.add(target_trie);
target_position = 0;
// Target lookup table for trie levels.
int current_level_size = 1;
int next_level_size = 0;
ArrayList<Integer> target_lookup = new ArrayList<Integer>();
// Packing loop for upwards-pointing target trie.
while (!target_queue.isEmpty()) {
// Pop top of queue.
PackingTrie<TargetValue> node = target_queue.poll();
// Register that this is where we're writing the node to.
node.address = target_position;
// Tell source nodes that we're writing to this position in the file.
for (TargetValue tv : node.values) tv.parent.target = node.address;
// Write link to parent.
if (node.parent != null) target_stream.writeInt(node.parent.address);
else target_stream.writeInt(-1);
target_stream.writeInt(node.symbol);
// Enqueue children.
for (int k : node.children.descendingKeySet()) {
PackingTrie<TargetValue> child = node.children.get(k);
target_queue.add(child);
}
target_position += node.size(false, true);
next_level_size += node.children.descendingKeySet().size();
current_level_size--;
if (current_level_size == 0) {
target_lookup.add(target_position);
current_level_size = next_level_size;
next_level_size = 0;
}
}
target_lookup_stream.writeInt(target_lookup.size());
for (int i : target_lookup) target_lookup_stream.writeInt(i);
target_lookup_stream.close();
// Setting up for source and data writing.
source_queue = new LinkedList<PackingTrie<SourceValue>>();
source_queue.add(source_trie);
source_position = source_trie.size(true, false);
source_trie.address = target_position;
// Ready data buffers for writing.
feature_buffer.initialize();
if (packAlignments) alignment_buffer.initialize();
// Packing loop for downwards-pointing source trie.
while (!source_queue.isEmpty()) {
// Pop top of queue.
PackingTrie<SourceValue> node = source_queue.poll();
// Write number of children.
source_stream.writeInt(node.children.size());
// Write links to children.
for (int k : node.children.descendingKeySet()) {
PackingTrie<SourceValue> child = node.children.get(k);
// Enqueue child.
source_queue.add(child);
// Child's address will be at the current end of the queue.
child.address = source_position;
// Advance cumulated size by child's size.
source_position += child.size(true, false);
// Write the link.
source_stream.writeInt(k);
source_stream.writeInt(child.address);
}
// Write number of data items.
source_stream.writeInt(node.values.size());
// Write lhs and links to target and data.
for (SourceValue sv : node.values) {
int feature_block_index = feature_buffer.write(sv.data);
if (packAlignments) {
int alignment_block_index = alignment_buffer.write(sv.data);
if (alignment_block_index != feature_block_index) {
logger.severe("Block index mismatch.");
throw new RuntimeException(
"Block index mismatch: alignment ("
+ alignment_block_index
+ ") and features ("
+ feature_block_index
+ ") don't match.");
}
}
source_stream.writeInt(sv.lhs);
source_stream.writeInt(sv.target);
source_stream.writeInt(feature_block_index);
}
}
// Flush the data stream.
feature_buffer.flush(feature_stream);
if (packAlignments) alignment_buffer.flush(alignment_stream);
target_stream.close();
source_stream.close();
feature_stream.close();
if (packAlignments) alignment_stream.close();
return slice;
}
