Java MemorySegment.putShort方法代码示例

import org.apache.flink.core.memory.MemorySegment; //导入方法依赖的package包/类
protected void initTable(int numBuckets, byte numPartitions) {
	final int bucketsPerSegment = this.bucketsPerSegmentMask + 1;
	final int numSegs = (numBuckets >>> this.bucketsPerSegmentBits) + ( (numBuckets & this.bucketsPerSegmentMask) == 0 ? 0 : 1);
	final MemorySegment[] table = new MemorySegment[numSegs];
	
	ensureNumBuffersReturned(numSegs);
	
	// go over all segments that are part of the table
	for (int i = 0, bucket = 0; i < numSegs && bucket < numBuckets; i++) {
		final MemorySegment seg = getNextBuffer();
		
		// go over all buckets in the segment
		for (int k = 0; k < bucketsPerSegment && bucket < numBuckets; k++, bucket++) {
			final int bucketOffset = k * HASH_BUCKET_SIZE;	
			
			// compute the partition that the bucket corresponds to
			final byte partition = assignPartition(bucket, numPartitions);
			
			// initialize the header fields
			seg.put(bucketOffset + HEADER_PARTITION_OFFSET, partition);
			seg.put(bucketOffset + HEADER_STATUS_OFFSET, BUCKET_STATUS_IN_MEMORY);
			seg.putShort(bucketOffset + HEADER_COUNT_OFFSET, (short) 0);
			seg.putLong(bucketOffset + HEADER_FORWARD_OFFSET, BUCKET_FORWARD_POINTER_NOT_SET);
			seg.putShort(bucketOffset + HEADER_PROBED_FLAGS_OFFSET, (short) 0);
		}
		
		table[i] = seg;
	}
	this.buckets = table;
	this.numBuckets = numBuckets;
	
	if (useBloomFilters) {
		initBloomFilter(numBuckets);
	}
}
 

import org.apache.flink.core.memory.MemorySegment; //导入方法依赖的package包/类
private void writeSegment(MemorySegment segment, int writePosition, boolean lastSegment) throws IOException
{
	segment.putShort(0, HEADER_MAGIC_NUMBER);
	segment.putShort(HEADER_FLAGS_OFFSET, lastSegment ? FLAG_LAST_BLOCK : 0);
	segment.putInt(HEAD_BLOCK_LENGTH_OFFSET, writePosition);
	
	this.writer.writeBlock(segment);
	this.bytesBeforeSegment += writePosition - HEADER_LENGTH;
}
 

import org.apache.flink.core.memory.MemorySegment; //导入方法依赖的package包/类
@Test
public void testBucketsNotFulfillSegment() throws Exception {
	final int NUM_KEYS = 10000;
	final int BUILD_VALS_PER_KEY = 3;
	final int PROBE_VALS_PER_KEY = 10;

	// create a build input that gives 30000 pairs with 3 values sharing the same key
	MutableObjectIterator<IntPair> buildInput = new UniformIntPairGenerator(NUM_KEYS, BUILD_VALS_PER_KEY, false);

	// create a probe input that gives 100000 pairs with 10 values sharing a key
	MutableObjectIterator<IntPair> probeInput = new UniformIntPairGenerator(NUM_KEYS, PROBE_VALS_PER_KEY, true);

	// allocate the memory for the HashTable
	List<MemorySegment> memSegments;
	try {
		// 33 is minimum number of pages required to perform hash join this inputs
		memSegments = this.memManager.allocatePages(MEM_OWNER, 33);
	}
	catch (MemoryAllocationException maex) {
		fail("Memory for the Join could not be provided.");
		return;
	}

	// For FLINK-2545, the buckets data may not fulfill it's buffer, for example, the buffer may contains 256 buckets,
	// while hash table only assign 250 bucket on it. The unused buffer bytes may contains arbitrary data, which may
	// influence hash table if forget to skip it. To mock this, put the invalid bucket data(partition=1, inMemory=true, count=-1)
	// at the end of buffer.
	for (MemorySegment segment : memSegments) {
		int newBucketOffset = segment.size() - 128;
		// initialize the header fields
		segment.put(newBucketOffset + 0, (byte)0);
		segment.put(newBucketOffset + 1, (byte)0);
		segment.putShort(newBucketOffset + 2, (short) -1);
		segment.putLong(newBucketOffset + 4, ~0x0L);
	}

	// ----------------------------------------------------------------------------------------

	final MutableHashTable<IntPair, IntPair> join = new MutableHashTable<IntPair, IntPair>(
		this.pairBuildSideAccesssor, this.pairProbeSideAccesssor,
		this.pairBuildSideComparator, this.pairProbeSideComparator, this.pairComparator,
		memSegments, ioManager);
	join.open(buildInput, probeInput);

	final IntPair recordReuse = new IntPair();
	int numRecordsInJoinResult = 0;

	while (join.nextRecord()) {
		MutableObjectIterator<IntPair> buildSide = join.getBuildSideIterator();
		while (buildSide.next(recordReuse) != null) {
			numRecordsInJoinResult++;
		}
	}
	Assert.assertEquals("Wrong number of records in join result.", NUM_KEYS * BUILD_VALS_PER_KEY * PROBE_VALS_PER_KEY, numRecordsInJoinResult);

	join.close();
	this.memManager.release(join.getFreedMemory());
}