HttpByteArrayCacheEntrySerializer.java
/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.hc.client5.http.impl.cache;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.time.Instant;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import org.apache.hc.client5.http.async.methods.SimpleHttpResponse;
import org.apache.hc.client5.http.cache.HttpCacheEntry;
import org.apache.hc.client5.http.cache.HttpCacheEntrySerializer;
import org.apache.hc.client5.http.cache.HttpCacheStorageEntry;
import org.apache.hc.client5.http.cache.Resource;
import org.apache.hc.client5.http.cache.ResourceIOException;
import org.apache.hc.core5.annotation.Contract;
import org.apache.hc.core5.annotation.ThreadingBehavior;
import org.apache.hc.core5.http.ClassicHttpResponse;
import org.apache.hc.core5.http.Header;
import org.apache.hc.core5.http.HttpVersion;
import org.apache.hc.core5.http.ParseException;
import org.apache.hc.core5.http.impl.io.AbstractMessageParser;
import org.apache.hc.core5.http.impl.io.AbstractMessageWriter;
import org.apache.hc.core5.http.impl.io.SessionInputBufferImpl;
import org.apache.hc.core5.http.impl.io.SessionOutputBufferImpl;
import org.apache.hc.core5.http.io.SessionOutputBuffer;
import org.apache.hc.core5.http.message.BasicLineFormatter;
import org.apache.hc.core5.http.message.BasicLineParser;
import org.apache.hc.core5.http.message.HeaderGroup;
import org.apache.hc.core5.http.message.LineFormatter;
import org.apache.hc.core5.http.message.LineParser;
import org.apache.hc.core5.http.message.RequestLine;
import org.apache.hc.core5.http.message.StatusLine;
import org.apache.hc.core5.util.CharArrayBuffer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This class implements the {@link HttpCacheEntrySerializer} interface, which defines the contract for HTTP cache
* entry serialization and deserialization. It also includes a default buffer size of 8192 bytes, which can be
* overridden by specifying a different buffer size in the constructor.
*
* @since 5.4
*/
@Contract(threading = ThreadingBehavior.STATELESS)
public class HttpByteArrayCacheEntrySerializer implements HttpCacheEntrySerializer<byte[]> {
private static final Logger LOG = LoggerFactory.getLogger(HttpByteArrayCacheEntrySerializer.class);
/**
* The default buffer size used for I/O operations, set to 8192 bytes.
*/
private static final int DEFAULT_BUFFER_SIZE = 8192;
static final String HC_CACHE_VERSION = "1.0";
static final String HC_CACHE_VERSION_LINE = "HttpClient CacheEntry " + HC_CACHE_VERSION;
static final String HC_CACHE_KEY = "HC-Key";
static final String HC_CACHE_LENGTH = "HC-Resource-Length";
static final String HC_REQUEST_INSTANT = "HC-Request-Instant";
static final String HC_RESPONSE_INSTANT = "HC-Response-Instant";
static final String HC_VARIANT = "HC-Variant";
/**
* Default instance of {@link HttpByteArrayCacheEntrySerializer}.
*/
public static final HttpByteArrayCacheEntrySerializer INSTANCE = new HttpByteArrayCacheEntrySerializer();
private final LineParser lineParser;
private final LineFormatter lineFormatter;
private final int bufferSize;
/**
* Constructs a HttpByteArrayCacheEntrySerializer with the specified buffer size.
*
* @param bufferSize the buffer size to use for serialization and deserialization.
*/
public HttpByteArrayCacheEntrySerializer(final int bufferSize) {
this.lineParser = BasicLineParser.INSTANCE;
this.lineFormatter = BasicLineFormatter.INSTANCE;
this.bufferSize = bufferSize > 0 ? bufferSize : DEFAULT_BUFFER_SIZE;
}
/**
* Constructs a new instance of {@code HttpByteArrayCacheEntrySerializer} with a default buffer size.
*
* @see #DEFAULT_BUFFER_SIZE
*/
public HttpByteArrayCacheEntrySerializer() {
this(DEFAULT_BUFFER_SIZE);
}
/**
* Serializes an HttpCacheStorageEntry object into a byte array using an HTTP-like format.
* <p>
* The metadata is encoded into HTTP pseudo-headers for storage.
*
* @param storageEntry the HttpCacheStorageEntry to serialize.
* @return the byte array containing the serialized HttpCacheStorageEntry.
* @throws ResourceIOException if there is an error during serialization.
*/
@Override
public byte[] serialize(final HttpCacheStorageEntry storageEntry) throws ResourceIOException {
final String key = storageEntry.getKey();
final HttpCacheEntry cacheEntry = storageEntry.getContent();
final Resource resource = cacheEntry.getResource();
try (ByteArrayOutputStream out = new ByteArrayOutputStream((resource != null ? (int) resource.length() : 0) + DEFAULT_BUFFER_SIZE)) {
final SessionOutputBuffer outputBuffer = new SessionOutputBufferImpl(bufferSize);
final CharArrayBuffer line = new CharArrayBuffer(DEFAULT_BUFFER_SIZE);
line.append(HC_CACHE_VERSION_LINE);
outputBuffer.writeLine(line, out);
line.clear();
line.append(HC_CACHE_KEY);
line.append(": ");
line.append(key);
outputBuffer.writeLine(line, out);
if (resource != null) {
line.clear();
line.append(HC_CACHE_LENGTH);
line.append(": ");
line.append(asStr(resource.length()));
outputBuffer.writeLine(line, out);
}
line.clear();
line.append(HC_REQUEST_INSTANT);
line.append(": ");
line.append(asStr(cacheEntry.getRequestInstant()));
outputBuffer.writeLine(line, out);
line.clear();
line.append(HC_RESPONSE_INSTANT);
line.append(": ");
line.append(asStr(cacheEntry.getResponseInstant()));
outputBuffer.writeLine(line, out);
for (final String variant : cacheEntry.getVariants()) {
line.clear();
line.append(HC_VARIANT);
line.append(": ");
line.append(variant);
outputBuffer.writeLine(line, out);
}
line.clear();
outputBuffer.writeLine(line, out);
line.clear();
final RequestLine requestLine = new RequestLine(cacheEntry.getRequestMethod(), cacheEntry.getRequestURI(), HttpVersion.HTTP_1_1);
lineFormatter.formatRequestLine(line, requestLine);
outputBuffer.writeLine(line, out);
for (final Iterator<Header> it = cacheEntry.requestHeaderIterator(); it.hasNext(); ) {
line.clear();
lineFormatter.formatHeader(line, it.next());
outputBuffer.writeLine(line, out);
}
line.clear();
outputBuffer.writeLine(line, out);
line.clear();
final StatusLine statusLine = new StatusLine(HttpVersion.HTTP_1_1, cacheEntry.getStatus(), "");
lineFormatter.formatStatusLine(line, statusLine);
outputBuffer.writeLine(line, out);
for (final Iterator<Header> it = cacheEntry.headerIterator(); it.hasNext(); ) {
line.clear();
lineFormatter.formatHeader(line, it.next());
outputBuffer.writeLine(line, out);
}
line.clear();
outputBuffer.writeLine(line, out);
outputBuffer.flush(out);
if (resource != null) {
out.write(resource.get());
}
out.flush();
final byte[] bytes = out.toByteArray();
if (LOG.isDebugEnabled()) {
LOG.debug("Serialized cache entry with key {} and {} bytes", key, bytes.length);
}
return bytes;
} catch (final IOException ex) {
throw new ResourceIOException("Exception while serializing cache entry", ex);
}
}
/**
* Deserializes a byte array representation of an HTTP cache storage entry into an instance of
* {@link HttpCacheStorageEntry}.
*
* @param serializedObject the byte array representation of the HTTP cache storage entry
* @return the deserialized HTTP cache storage entry
* @throws ResourceIOException if an error occurs during deserialization
*/
@Override
public HttpCacheStorageEntry deserialize(final byte[] serializedObject) throws ResourceIOException {
if (serializedObject == null || serializedObject.length == 0) {
throw new ResourceIOException("Serialized object is null or empty");
}
try (final InputStream in = new ByteArrayInputStream(serializedObject)) {
final SessionInputBufferImpl inputBuffer = new SessionInputBufferImpl(bufferSize);
final CharArrayBuffer line = new CharArrayBuffer(DEFAULT_BUFFER_SIZE);
checkReadResult(inputBuffer.readLine(line, in));
final String versionLine = line.toString();
if (!versionLine.equals(HC_CACHE_VERSION_LINE)) {
throw new ResourceIOException("Unexpected cache entry version line");
}
String storageKey = null;
long length = -1;
Instant requestDate = null;
Instant responseDate = null;
final Set<String> variants = new HashSet<>();
while (true) {
line.clear();
checkReadResult(inputBuffer.readLine(line, in));
if (line.isEmpty()) {
break;
}
final Header header = lineParser.parseHeader(line);
final String name = header.getName();
final String value = header.getValue();
if (name.equalsIgnoreCase(HC_CACHE_KEY)) {
storageKey = value;
} else if (name.equalsIgnoreCase(HC_CACHE_LENGTH)) {
length = asLong(value);
} else if (name.equalsIgnoreCase(HC_REQUEST_INSTANT)) {
requestDate = asInstant(value);
} else if (name.equalsIgnoreCase(HC_RESPONSE_INSTANT)) {
responseDate = asInstant(value);
} else if (name.equalsIgnoreCase(HC_VARIANT)) {
variants.add(value);
} else {
throw new ResourceIOException("Unexpected header entry");
}
}
if (storageKey == null || requestDate == null || responseDate == null) {
throw new ResourceIOException("Invalid cache header format");
}
line.clear();
checkReadResult(inputBuffer.readLine(line, in));
final RequestLine requestLine = lineParser.parseRequestLine(line);
final HeaderGroup requestHeaders = new HeaderGroup();
while (true) {
line.clear();
checkReadResult(inputBuffer.readLine(line, in));
if (line.isEmpty()) {
break;
}
requestHeaders.addHeader(lineParser.parseHeader(line));
}
line.clear();
checkReadResult(inputBuffer.readLine(line, in));
final StatusLine statusLine = lineParser.parseStatusLine(line);
final HeaderGroup responseHeaders = new HeaderGroup();
while (true) {
line.clear();
checkReadResult(inputBuffer.readLine(line, in));
if (line.isEmpty()) {
break;
}
responseHeaders.addHeader(lineParser.parseHeader(line));
}
final Resource resource;
if (length != -1) {
int off = 0;
int remaining = (int) length;
final byte[] buf = new byte[remaining];
while (remaining > 0) {
final int i = inputBuffer.read(buf, off, remaining, in);
if (i > 0) {
off += i;
remaining -= i;
}
if (i == -1) {
throw new ResourceIOException("Unexpected end of cache content");
}
}
resource = new HeapResource(buf);
} else {
resource = null;
}
if (inputBuffer.read(in) != -1) {
throw new ResourceIOException("Unexpected content at the end of cache content");
}
final HttpCacheEntry httpCacheEntry = new HttpCacheEntry(
requestDate,
responseDate,
requestLine.getMethod(),
requestLine.getUri(),
requestHeaders,
statusLine.getStatusCode(),
responseHeaders,
resource,
!variants.isEmpty() ? variants : null
);
if (LOG.isDebugEnabled()) {
LOG.debug("Returning deserialized cache entry with storage key '{}'", httpCacheEntry);
}
return new HttpCacheStorageEntry(storageKey, httpCacheEntry);
} catch (final ResourceIOException ex) {
throw ex;
} catch (final ParseException ex) {
throw new ResourceIOException("Invalid cache header format", ex);
} catch (final IOException ex) {
throw new ResourceIOException("I/O error deserializing cache entry", ex);
}
}
private static String asStr(final long value) {
return Long.toString(value);
}
private static String asStr(final Instant instant) {
return Long.toString(instant.toEpochMilli());
}
private static long asLong(final String value) throws ResourceIOException {
try {
return Long.parseLong(value);
} catch (final NumberFormatException ex) {
throw new ResourceIOException("Invalid cache header format");
}
}
private static Instant asInstant(final String value) throws ResourceIOException {
return Instant.ofEpochMilli(asLong(value));
}
private static void checkReadResult(final int n) throws ResourceIOException {
if (n == -1) {
throw new ResourceIOException("Unexpected end of stream");
}
}
/**
* @return null
* @deprecated Do not use.
*/
@Deprecated
protected InputStream makeByteArrayInputStream(final byte[] bytes) {
return null;
}
/**
* @return null
* @deprecated Do not use.
*/
@Deprecated
protected AbstractMessageParser<ClassicHttpResponse> makeHttpResponseParser() {
return null;
}
/**
* @return null
* @deprecated Do not use.
*/
@Deprecated
protected AbstractMessageWriter<SimpleHttpResponse> makeHttpResponseWriter(final SessionOutputBuffer outputBuffer) {
return null;
}
}