net.spy.memcached.protocol.ascii.BTreeGetByPositionOperationImpl Maven / Gradle / Ivy
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/*
* arcus-java-client : Arcus Java client
* Copyright 2010-2014 NAVER Corp.
* Copyright 2014-2021 JaM2in Co., Ltd.
*
* 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.Buffer;
import java.nio.ByteBuffer;
import java.util.Collection;
import java.util.Collections;
import net.spy.memcached.KeyUtil;
import net.spy.memcached.collection.BTreeGetByPosition;
import net.spy.memcached.collection.CollectionResponse;
import net.spy.memcached.ops.APIType;
import net.spy.memcached.ops.BTreeGetByPositionOperation;
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;
public class BTreeGetByPositionOperationImpl extends OperationImpl implements
BTreeGetByPositionOperation {
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 NOT_FOUND = new CollectionOperationStatus(
false, "NOT_FOUND", CollectionResponse.NOT_FOUND);
private static final OperationStatus UNREADABLE = new CollectionOperationStatus(
false, "UNREADABLE", CollectionResponse.UNREADABLE);
private static final OperationStatus TYPE_MISMATCH = new CollectionOperationStatus(
false, "TYPE_MISMATCH", CollectionResponse.TYPE_MISMATCH);
private static final OperationStatus NOT_FOUND_ELEMENT = new CollectionOperationStatus(
false, "NOT_FOUND_ELEMENT", CollectionResponse.NOT_FOUND_ELEMENT);
protected final String key;
protected final BTreeGetByPosition get;
protected int flags = 0;
protected int count = 0;
protected int pos = 0;
protected int posDiff = 0;
protected byte[] data = null;
protected int readOffset = 0;
protected byte lookingFor = '\0';
protected int spaceCount = 0;
private Boolean hasEFlag = null;
public BTreeGetByPositionOperationImpl(String key,
BTreeGetByPosition get, OperationCallback cb) {
super(cb);
this.key = key;
this.get = get;
setAPIType(APIType.BOP_GBP);
setOperationType(OperationType.READ);
}
@Override
public BTreeGetByPosition getGet() {
return get;
}
@Override
public void handleLine(String line) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("Got line %s", line);
}
/*
VALUE \r\n
[] \r\n
[ ... ]
END\r\n
*/
if (line.startsWith("VALUE ")) {
String[] stuff = line.split(" ");
assert stuff.length == 3;
assert "VALUE".equals(stuff[0]);
flags = Integer.parseInt(stuff[1]);
count = Integer.parseInt(stuff[2]);
if (count > 0) {
// position counter
pos = get.isReversed() ? get.getPosTo() + count - 1 : get.getPosFrom();
posDiff = get.isReversed() ? -1 : 1;
// start to read actual data
setReadType(OperationReadType.DATA);
}
} else {
OperationStatus status = matchStatus(line, END, NOT_FOUND,
UNREADABLE, TYPE_MISMATCH, NOT_FOUND_ELEMENT);
if (getLogger().isDebugEnabled()) {
getLogger().debug(status);
}
getCallback().receivedStatus(status);
transitionState(OperationState.COMPLETE);
return;
}
}
@Override
public void handleRead(ByteBuffer bb) {
// Decode a data header.
if (lookingFor == '\0' && data == null) {
for (int i = 0; bb.remaining() > 0; i++) {
byte b = bb.get();
// Handle spaces to parse the header.
if (b == ' ') {
// One-time check to find if this responses have eflags.
if (hasEFlag == null && spaceCount == BTreeGetByPosition.HEADER_EFLAG_POSITION) {
String[] chunk = new String(byteBuffer.toByteArray())
.split(" ");
if (chunk[BTreeGetByPosition.HEADER_EFLAG_POSITION].startsWith("0x")) {
hasEFlag = true;
} else {
hasEFlag = false;
}
}
spaceCount++;
// Parse the value header.
// FIXME this is not cool... please fix this :-(
int spaceReduced = (hasEFlag != null && hasEFlag) ? 1 : 0;
if (get.headerReady(spaceCount - spaceReduced)) {
// [] \r\n
get.decodeItemHeader(new String(byteBuffer.toByteArray()));
data = new byte[get.getDataLength()];
byteBuffer.reset();
spaceCount = 0;
hasEFlag = null;
break;
}
}
// Ready to finish.
if (b == '\r') {
continue;
}
// Finish the operation.
if (b == '\n') {
OperationStatus status = matchStatus(byteBuffer.toString(),
END, NOT_FOUND, UNREADABLE, TYPE_MISMATCH,
NOT_FOUND_ELEMENT);
if (getLogger().isDebugEnabled()) {
getLogger().debug("Get complete!");
}
getCallback().receivedStatus(status);
transitionState(OperationState.COMPLETE);
data = null;
break;
}
// Write to the result ByteBuffer
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;
if (getLogger().isDebugEnabled()) {
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);
if (getLogger().isDebugEnabled()) {
getLogger().debug("Reading %d bytes", toRead);
}
bb.get(data, readOffset, toRead);
readOffset += toRead;
}
if (lookingFor == '\0' && readOffset == data.length) {
// put an element data.
BTreeGetByPositionOperation.Callback cb =
(BTreeGetByPositionOperation.Callback) getCallback();
cb.gotData(key, flags, pos, get.getBkey(), get.getEflag(), data);
// next position.
pos += posDiff;
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;
}
}
}
@Override
public void initialize() {
String cmd = get.getCommand();
String args = get.stringify();
ByteBuffer bb = ByteBuffer.allocate(cmd.length() + KeyUtil.getKeyBytes(key).length
+ args.length() + 16);
setArguments(bb, cmd, key, args);
((Buffer) 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);
}
@Override
public boolean isBulkOperation() {
return false;
}
@Override
public boolean isPipeOperation() {
return false;
}
}