com.qcloud.cos.internal.eventstreaming.Message Maven / Gradle / Ivy
/*
* Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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.
* According to cos feature, we modify some class，comment, field name, etc.
*/
package com.qcloud.cos.internal.eventstreaming;
import static java.lang.String.format;
import com.qcloud.cos.exception.CosClientException;
import com.qcloud.cos.exception.CRC32MismatchException;
import com.qcloud.cos.utils.Base64;
import com.qcloud.cos.utils.StringUtils;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.zip.CRC32;
import java.util.zip.CheckedOutputStream;
import java.util.zip.Checksum;
/**
* An eventstream message.
*/
public class Message {
private static final int TRAILING_CRC_LENGTH = 4;
static final int MESSAGE_OVERHEAD = Prelude.LENGTH_WITH_CRC + TRAILING_CRC_LENGTH;
private final Map headers;
private final byte[] payload;
public Message(Map headers, byte[] payload) {
this.headers = headers;
this.payload = payload.clone();
}
public Map getHeaders() {
return headers;
}
public byte[] getPayload() {
return payload.clone();
}
public static Message decode(ByteBuffer buf) {
Prelude prelude = Prelude.decode(buf);
int totalLength = prelude.getTotalLength();
validateMessageCrc(buf, totalLength);
buf.position(buf.position() + Prelude.LENGTH_WITH_CRC);
long headersLength = prelude.getHeadersLength();
byte[] headerBytes = new byte[Utils.toIntExact(headersLength)];
buf.get(headerBytes);
Map headers = decodeHeaders(ByteBuffer.wrap(headerBytes));
byte[] payload = new byte[Utils.toIntExact(totalLength - MESSAGE_OVERHEAD - headersLength)];
buf.get(payload);
buf.getInt(); // skip past the message CRC
return new Message(headers, payload);
}
private static void validateMessageCrc(ByteBuffer buf, int totalLength) {
Checksum crc = new CRC32();
Checksums.update(crc, (ByteBuffer) buf.duplicate().limit(buf.position() + totalLength - 4));
long computedMessageCrc = crc.getValue();
long wireMessageCrc = Utils.toUnsignedLong(buf.getInt(buf.position() + totalLength - 4));
if (wireMessageCrc != computedMessageCrc) {
throw new CosClientException(new CRC32MismatchException(
format("Message checksum failure: expected 0x%x, computed 0x%x", wireMessageCrc, computedMessageCrc)));
}
}
static Map decodeHeaders(ByteBuffer buf) {
Map headers = new HashMap();
while (buf.hasRemaining()) {
Header header = Header.decode(buf);
headers.put(header.getName(), header.getValue());
}
return Collections.unmodifiableMap(headers);
}
public ByteBuffer toByteBuffer() {
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
encode(baos);
baos.close();
return ByteBuffer.wrap(baos.toByteArray());
} catch (IOException e) {
throw new RuntimeException(e);
}
}
public void encode(OutputStream os) {
try {
CheckedOutputStream checkedOutputStream = new CheckedOutputStream(os, new CRC32());
encodeOrThrow(checkedOutputStream);
long messageCrc = checkedOutputStream.getChecksum().getValue();
os.write((int) (0xFF & messageCrc >> 24));
os.write((int) (0xFF & messageCrc >> 16));
os.write((int) (0xFF & messageCrc >> 8));
os.write((int) (0xFF & messageCrc));
os.flush();
} catch (IOException ex) {
throw new RuntimeException(ex);
}
}
private void encodeOrThrow(OutputStream os) throws IOException {
ByteArrayOutputStream headersAndPayload = new ByteArrayOutputStream();
{
DataOutputStream dos = new DataOutputStream(headersAndPayload);
for (Entry entry : headers.entrySet()) {
Header.encode(entry, dos);
}
dos.write(payload);
dos.flush();
}
int totalLength = Prelude.LENGTH_WITH_CRC + headersAndPayload.size() + 4;
{
byte[] preludeBytes = getPrelude(totalLength);
Checksum crc = new CRC32();
crc.update(preludeBytes, 0, preludeBytes.length);
DataOutputStream dos = new DataOutputStream(os);
dos.write(preludeBytes);
long value = crc.getValue();
int value1 = (int) value;
dos.writeInt(value1);
dos.flush();
}
headersAndPayload.writeTo(os);
}
private byte[] getPrelude(int totalLength) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream(8);
DataOutputStream dos = new DataOutputStream(baos);
int headerLength = totalLength - Message.MESSAGE_OVERHEAD - payload.length;
dos.writeInt(totalLength);
dos.writeInt(headerLength);
dos.close();
return baos.toByteArray();
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Message message = (Message) o;
if (!headers.equals(message.headers)) return false;
return Arrays.equals(payload, message.payload);
}
@Override
public int hashCode() {
int result = headers.hashCode();
result = 31 * result + Arrays.hashCode(payload);
return result;
}
@Override
public String toString() {
StringBuilder ret = new StringBuilder();
for (Entry entry : headers.entrySet()) {
ret.append(entry.getKey());
ret.append(": ");
ret.append(entry.getValue().toString());
ret.append('\n');
}
ret.append('\n');
HeaderValue contentTypeHeader = headers.get("content-type");
if (contentTypeHeader == null) {
contentTypeHeader = HeaderValue.fromString("application/octet-stream");
}
String contentType = contentTypeHeader.getString();
if (contentType.contains("json") || contentType.contains("text")) {
ret.append(new String(payload, StringUtils.UTF8));
} else {
ret.append(Base64.encodeAsString(payload));
}
ret.append('\n');
return ret.toString();
}
}