net.spy.memcached.protocol.ascii.ExtendedBTreeGetOperationImpl Maven / Gradle / Ivy

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/*
 * arcus-java-client : Arcus Java client
 * Copyright 2010-2014 NAVER Corp.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.spy.memcached.protocol.ascii;

import java.io.ByteArrayOutputStream;
import java.nio.ByteBuffer;
import java.util.Collection;
import java.util.Collections;

import net.spy.memcached.KeyUtil;
import net.spy.memcached.collection.ExtendedBTreeGet;
import net.spy.memcached.collection.CollectionGet;
import net.spy.memcached.collection.CollectionResponse;
import net.spy.memcached.ops.APIType;
import net.spy.memcached.ops.ExtendedBTreeGetOperation;
import net.spy.memcached.ops.CollectionOperationStatus;
import net.spy.memcached.ops.OperationCallback;
import net.spy.memcached.ops.OperationState;
import net.spy.memcached.ops.OperationStatus;
import net.spy.memcached.ops.OperationType;

/**
 * Operation to retrieve collection data in a memcached server.
 */
public class ExtendedBTreeGetOperationImpl extends OperationImpl
	implements ExtendedBTreeGetOperation {

	private final ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();

	private static final OperationStatus GET_CANCELED = new CollectionOperationStatus(
			false, "collection canceled", CollectionResponse.CANCELED);

	private static final OperationStatus END = new CollectionOperationStatus(
			true, "END", CollectionResponse.END);
	private static final OperationStatus TRIMMED = new CollectionOperationStatus(
			true, "TRIMMED", CollectionResponse.TRIMMED);
	private static final OperationStatus DELETED = new CollectionOperationStatus(
			true, "DELETED", CollectionResponse.DELETED);
	private static final OperationStatus DELETED_DROPPED = new CollectionOperationStatus(
			true, "DELETED_DROPPED", CollectionResponse.DELETED_DROPPED);
	private static final OperationStatus NOT_FOUND = new CollectionOperationStatus(
			false, "NOT_FOUND", CollectionResponse.NOT_FOUND);
	private static final OperationStatus NOT_FOUND_ELEMENT = new CollectionOperationStatus(
			false, "NOT_FOUND_ELEMENT", CollectionResponse.NOT_FOUND_ELEMENT);
	private static final OperationStatus OUT_OF_RANGE = new CollectionOperationStatus(
			false, "OUT_OF_RANGE", CollectionResponse.OUT_OF_RANGE);
	private static final OperationStatus TYPE_MISMATCH = new CollectionOperationStatus(
			false, "TYPE_MISMATCH", CollectionResponse.TYPE_MISMATCH);
	private static final OperationStatus BKEY_MISMATCH = new CollectionOperationStatus(
			false, "BKEY_MISMATCH", CollectionResponse.BKEY_MISMATCH);
	private static final OperationStatus UNREADABLE = new CollectionOperationStatus(
			false, "UNREADABLE", CollectionResponse.UNREADABLE);

	protected final String key;
	protected final CollectionGet collectionGet;

	protected int flags = 0;
	protected int count = 0;
	protected byte[] data = null;
	protected int readOffset = 0;
	protected byte lookingFor = '\0';
	protected int spaceCount = 0;

	public ExtendedBTreeGetOperationImpl(String key, CollectionGet collectionGet,
			OperationCallback cb) {
		super(cb);
		this.key = key;
		this.collectionGet = collectionGet;
		if (this.collectionGet instanceof ExtendedBTreeGet)
			setAPIType(APIType.BOP_GET);
		if (collectionGet.isDelete())
			setOperationType(OperationType.WRITE);
		else
			setOperationType(OperationType.READ);
	}

	/**
	 * VALUE  \r\n
	 */
	public void handleLine(String line) {
		if (line.startsWith("VALUE ")) {
			// Response header
			getLogger().debug("Got line %s", line);

			String[] stuff = line.split(" ");
			assert "VALUE".equals(stuff[0]);

			flags = Integer.parseInt(stuff[1]);
			count = Integer.parseInt(stuff[2]);

			setReadType(OperationReadType.DATA);
		} else {
			OperationStatus status = matchStatus(line, END, TRIMMED, DELETED,
					DELETED_DROPPED, NOT_FOUND, NOT_FOUND_ELEMENT,
					OUT_OF_RANGE, TYPE_MISMATCH, BKEY_MISMATCH, UNREADABLE);
			getLogger().debug(status);
			getCallback().receivedStatus(status);
			transitionState(OperationState.COMPLETE);
			return;
		}
	}

	@Override
	public final void handleRead(ByteBuffer bb) {
		// Decode a collection data header.
		if (lookingFor == '\0' && data == null) {
			for (int i=0; bb.remaining() > 0; i++) {
				byte b = bb.get();

				// Handle spaces.
				if (b == ' ') {
					spaceCount++;
					if (collectionGet.headerReady(spaceCount)) {
						collectionGet.decodeItemHeader(new String(byteBuffer.toByteArray()));
						byteBuffer.reset();

						if (collectionGet.headerReady(spaceCount)
								&& collectionGet.eachRecordParseCompleted()) {
//							if (collectionGet.getElementFlag() != null) {
//								collectionGet.setHeaderCount(collectionGet
//										.getHeaderCount() - 1);
//							}
							data = new byte[collectionGet.getDataLength()];
							spaceCount = 0;
							break;
						}
					}
				}

				// Ready to finish.
				if (b == '\r') {
					continue;
				}

				// Finish the operation.
				if (b == '\n') {
					OperationStatus status = matchStatus(byteBuffer.toString(),
							END, TRIMMED, DELETED, DELETED_DROPPED, NOT_FOUND,
							NOT_FOUND_ELEMENT, OUT_OF_RANGE, TYPE_MISMATCH,
							BKEY_MISMATCH, UNREADABLE);

					getLogger().debug("Get complete!");
					getCallback().receivedStatus(status);
					transitionState(OperationState.COMPLETE);
					data = null;
					break;
				}

				byteBuffer.write(b);
			}
			return;
		}

		// Read data
		assert key != null;
		assert data != null;
		// This will be the case, because we'll clear them when it's not.
		assert readOffset <= data.length
			: "readOffset is " + readOffset + " data.length is " + data.length;

		getLogger().debug("readOffset: %d, length: %d", readOffset, data.length);

		if (lookingFor == '\0') {
			int toRead = data.length - readOffset;
			int available = bb.remaining();
			toRead = Math.min(toRead, available);

			getLogger().debug("Reading %d bytes", toRead);

			bb.get(data, readOffset, toRead);
			readOffset += toRead;
		}

		if (lookingFor == '\0' && readOffset == data.length) {
			ExtendedBTreeGetOperation.Callback cb =
				(ExtendedBTreeGetOperation.Callback) getCallback();
			cb.gotData(key, ((ExtendedBTreeGet) collectionGet).getLongSubkey(),
					collectionGet.getElementFlag(), flags, data);
			lookingFor = '\r';
		}

		if (lookingFor != '\0' && bb.hasRemaining()) {
			do {
				byte tmp = bb.get();
				assert tmp == lookingFor : "Expecting " + lookingFor + ", got "
					+ (char)tmp;

				switch (lookingFor) {
				case '\r': lookingFor = '\n'; break;
				case '\n': lookingFor = '\0'; break;
				default:
					assert false : "Looking for unexpected char: "
						+ (char)lookingFor;
				}
			} while (lookingFor != '\0' && bb.hasRemaining());

			if (lookingFor == '\0') {
				data = null;
				readOffset = 0;
			}
		}
	}

	public void initialize() {
		String cmd = collectionGet.getCommand();
		String args = collectionGet.stringify();
		ByteBuffer bb = ByteBuffer.allocate(KeyUtil.getKeyBytes(key).length
				+ cmd.length() + args.length() + 16);

		setArguments(bb, cmd, key, args);
		bb.flip();
		setBuffer(bb);

		if (getLogger().isDebugEnabled()) {
			getLogger().debug("Request in ascii protocol: "
					+ (new String(bb.array())).replace("\r\n", "\\r\\n"));
		}
	}

	@Override
	protected void wasCancelled() {
		getCallback().receivedStatus(GET_CANCELED);
	}

	public Collection getKeys() {
		return Collections.singleton(key);
	}

	public CollectionGet getGet() {
		return collectionGet;
	}
}