/*
* 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.
*/
package com.squareup.okhttp.internal.http;
import com.squareup.okhttp.Address;
import com.squareup.okhttp.Connection;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.OkResponseCache;
import com.squareup.okhttp.ResponseSource;
import com.squareup.okhttp.TunnelRequest;
import com.squareup.okhttp.internal.Dns;
import com.squareup.okhttp.internal.Platform;
import com.squareup.okhttp.internal.Util;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.CacheRequest;
import java.net.CacheResponse;
import java.net.CookieHandler;
import java.net.HttpURLConnection;
import java.net.Proxy;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.UnknownHostException;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.zip.GZIPInputStream;
import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLSocketFactory;
import static com.squareup.okhttp.internal.Util.EMPTY_BYTE_ARRAY;
import static com.squareup.okhttp.internal.Util.getDefaultPort;
import static com.squareup.okhttp.internal.Util.getEffectivePort;
/**
* Handles a single HTTP request/response pair. Each HTTP engine follows this
* lifecycle:
* <ol>
* <li>It is created.
* <li>The HTTP request message is sent with sendRequest(). Once the request
* is sent it is an error to modify the request headers. After
* sendRequest() has been called the request body can be written to if
* it exists.
* <li>The HTTP response message is read with readResponse(). After the
* response has been read the response headers and body can be read.
* All responses have a response body input stream, though in some
* instances this stream is empty.
* </ol>
*
* <p>The request and response may be served by the HTTP response cache, by the
* network, or by both in the event of a conditional GET.
*
* <p>This class may hold a socket connection that needs to be released or
* recycled. By default, this socket connection is held when the last byte of
* the response is consumed. To release the connection when it is no longer
* required, use {@link #automaticallyReleaseConnectionToPool()}.
*/
public class HttpEngine {
private static final CacheResponse GATEWAY_TIMEOUT_RESPONSE = new CacheResponse() {
@Override public Map<String, List<String>> getHeaders() throws IOException {
Map<String, List<String>> result = new HashMap<String, List<String>>();
result.put(null, Collections.singletonList("HTTP/1.1 504 Gateway Timeout"));
return result;
}
@Override public InputStream getBody() throws IOException {
return new ByteArrayInputStream(EMPTY_BYTE_ARRAY);
}
};
public static final int HTTP_CONTINUE = 100;
protected final Policy policy;
protected final OkHttpClient client;
protected final String method;
private ResponseSource responseSource;
protected Connection connection;
protected RouteSelector routeSelector;
private OutputStream requestBodyOut;
private Transport transport;
private InputStream responseTransferIn;
private InputStream responseBodyIn;
private CacheResponse cacheResponse;
private CacheRequest cacheRequest;
/** The time when the request headers were written, or -1 if they haven't been written yet. */
long sentRequestMillis = -1;
/** Whether the connection has been established. */
boolean connected;
/**
* True if this client added an "Accept-Encoding: gzip" header field and is
* therefore responsible for also decompressing the transfer stream.
*/
private boolean transparentGzip;
final URI uri;
final RequestHeaders requestHeaders;
/** Null until a response is received from the network or the cache. */
ResponseHeaders responseHeaders;
// The cache response currently being validated on a conditional get. Null
// if the cached response doesn't exist or doesn't need validation. If the
// conditional get succeeds, these will be used for the response headers and
// body. If it fails, these be closed and set to null.
private ResponseHeaders cachedResponseHeaders;
private InputStream cachedResponseBody;
/**
* True if the socket connection should be released to the connection pool
* when the response has been fully read.
*/
private boolean automaticallyReleaseConnectionToPool;
/** True if the socket connection is no longer needed by this engine. */
private boolean connectionReleased;
/**
* @param requestHeaders the client's supplied request headers. This class
* creates a private copy that it can mutate.
* @param connection the connection used for an intermediate response
* immediately prior to this request/response pair, such as a same-host
* redirect. This engine assumes ownership of the connection and must
* release it when it is unneeded.
*/
public HttpEngine(OkHttpClient client, Policy policy, String method, RawHeaders requestHeaders,
Connection connection, RetryableOutputStream requestBodyOut) throws IOException {
this.client = client;
this.policy = policy;
this.method = method;
this.connection = connection;
this.requestBodyOut = requestBodyOut;
try {
uri = Platform.get().toUriLenient(policy.getURL());
} catch (URISyntaxException e) {
throw new IOException(e.getMessage());
}
this.requestHeaders = new RequestHeaders(uri, new RawHeaders(requestHeaders));
}
public URI getUri() {
return uri;
}
/**
* Figures out what the response source will be, and opens a socket to that
* source if necessary. Prepares the request headers and gets ready to start
* writing the request body if it exists.
*/
public final void sendRequest() throws IOException {
if (responseSource != null) {
return;
}
prepareRawRequestHeaders();
initResponseSource();
OkResponseCache responseCache = client.getOkResponseCache();
if (responseCache != null) {
responseCache.trackResponse(responseSource);
}
// The raw response source may require the network, but the request
// headers may forbid network use. In that case, dispose of the network
// response and use a GATEWAY_TIMEOUT response instead, as specified
// by http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.4.
if (requestHeaders.isOnlyIfCached() && responseSource.requiresConnection()) {
if (responseSource == ResponseSource.CONDITIONAL_CACHE) {
Util.closeQuietly(cachedResponseBody);
}
this.responseSource = ResponseSource.CACHE;
this.cacheResponse = GATEWAY_TIMEOUT_RESPONSE;
RawHeaders rawResponseHeaders = RawHeaders.fromMultimap(cacheResponse.getHeaders(), true);
setResponse(new ResponseHeaders(uri, rawResponseHeaders), cacheResponse.getBody());
}
if (responseSource.requiresConnection()) {
sendSocketRequest();
} else if (connection != null) {
client.getConnectionPool().recycle(connection);
connection = null;
}
}
/**
* Initialize the source for this response. It may be corrected later if the
* request headers forbids network use.
*/
private void initResponseSource() throws IOException {
responseSource = ResponseSource.NETWORK;
if (!policy.getUseCaches()) return;
OkResponseCache responseCache = client.getOkResponseCache();
if (responseCache == null) return;
CacheResponse candidate = responseCache.get(
uri, method, requestHeaders.getHeaders().toMultimap(false));
if (candidate == null) return;
Map<String, List<String>> responseHeadersMap = candidate.getHeaders();
cachedResponseBody = candidate.getBody();
if (!acceptCacheResponseType(candidate)
|| responseHeadersMap == null
|| cachedResponseBody == null) {
Util.closeQuietly(cachedResponseBody);
return;
}
RawHeaders rawResponseHeaders = RawHeaders.fromMultimap(responseHeadersMap, true);
cachedResponseHeaders = new ResponseHeaders(uri, rawResponseHeaders);
long now = System.currentTimeMillis();
this.responseSource = cachedResponseHeaders.chooseResponseSource(now, requestHeaders);
if (responseSource == ResponseSource.CACHE) {
this.cacheResponse = candidate;
setResponse(cachedResponseHeaders, cachedResponseBody);
} else if (responseSource == ResponseSource.CONDITIONAL_CACHE) {
this.cacheResponse = candidate;
} else if (responseSource == ResponseSource.NETWORK) {
Util.closeQuietly(cachedResponseBody);
} else {
throw new AssertionError();
}
}
private void sendSocketRequest() throws IOException {
if (connection == null) {
connect();
}
if (transport != null) {
throw new IllegalStateException();
}
transport = (Transport) connection.newTransport(this);
if (hasRequestBody() && requestBodyOut == null) {
// Create a request body if we don't have one already. We'll already
// have one if we're retrying a failed POST.
requestBodyOut = transport.createRequestBody();
}
}
/** Connect to the origin server either directly or via a proxy. */
protected final void connect() throws IOException {
if (connection != null) {
return;
}
if (routeSelector == null) {
String uriHost = uri.getHost();
if (uriHost == null) {
throw new UnknownHostException(uri.toString());
}
SSLSocketFactory sslSocketFactory = null;
HostnameVerifier hostnameVerifier = null;
if (uri.getScheme().equalsIgnoreCase("https")) {
sslSocketFactory = client.getSslSocketFactory();
hostnameVerifier = client.getHostnameVerifier();
}
Address address = new Address(uriHost, getEffectivePort(uri), sslSocketFactory,
hostnameVerifier, client.getAuthenticator(), client.getProxy(), client.getTransports());
routeSelector = new RouteSelector(address, uri, client.getProxySelector(),
client.getConnectionPool(), Dns.DEFAULT, client.getRoutesDatabase());
}
connection = routeSelector.next(method);
if (!connection.isConnected()) {
connection.connect(client.getConnectTimeout(), client.getReadTimeout(), getTunnelConfig());
client.getConnectionPool().maybeShare(connection);
client.getRoutesDatabase().connected(connection.getRoute());
} else if (!connection.isSpdy()) {
connection.updateReadTimeout(client.getReadTimeout());
}
connected(connection);
if (connection.getRoute().getProxy() != client.getProxy()) {
// Update the request line if the proxy changed; it may need a host name.
requestHeaders.getHeaders().setRequestLine(getRequestLine());
}
}
/**
* Called after a socket connection has been created or retrieved from the
* pool. Subclasses use this hook to get a reference to the TLS data.
*/
protected void connected(Connection connection) {
policy.setSelectedProxy(connection.getRoute().getProxy());
connected = true;
}
/**
* Called immediately before the transport transmits HTTP request headers.
* This is used to observe the sent time should the request be cached.
*/
public void writingRequestHeaders() {
if (sentRequestMillis != -1) {
throw new IllegalStateException();
}
sentRequestMillis = System.currentTimeMillis();
}
/**
* @param body the response body, or null if it doesn't exist or isn't
* available.
*/
private void setResponse(ResponseHeaders headers, InputStream body) throws IOException {
if (this.responseBodyIn != null) {
throw new IllegalStateException();
}
this.responseHeaders = headers;
if (body != null) {
initContentStream(body);
}
}
boolean hasRequestBody() {
return method.equals("POST") || method.equals("PUT") || method.equals("PATCH");
}
/** Returns the request body or null if this request doesn't have a body. */
public final OutputStream getRequestBody() {
if (responseSource == null) {
throw new IllegalStateException();
}
return requestBodyOut;
}
public final boolean hasResponse() {
return responseHeaders != null;
}
public final RequestHeaders getRequestHeaders() {
return requestHeaders;
}
public final ResponseHeaders getResponseHeaders() {
if (responseHeaders == null) {
throw new IllegalStateException();
}
return responseHeaders;
}
public final int getResponseCode() {
if (responseHeaders == null) {
throw new IllegalStateException();
}
return responseHeaders.getHeaders().getResponseCode();
}
public final InputStream getResponseBody() {
if (responseHeaders == null) {
throw new IllegalStateException();
}
return responseBodyIn;
}
public final CacheResponse getCacheResponse() {
return cacheResponse;
}
public final Connection getConnection() {
return connection;
}
/**
* Returns true if {@code cacheResponse} is of the right type. This
* condition is necessary but not sufficient for the cached response to
* be used.
*/
protected boolean acceptCacheResponseType(CacheResponse cacheResponse) {
return true;
}
private void maybeCache() throws IOException {
// Are we caching at all?
if (!policy.getUseCaches()) return;
OkResponseCache responseCache = client.getOkResponseCache();
if (responseCache == null) return;
HttpURLConnection connectionToCache = policy.getHttpConnectionToCache();
// Should we cache this response for this request?
if (!responseHeaders.isCacheable(requestHeaders)) {
responseCache.maybeRemove(connectionToCache.getRequestMethod(), uri);
return;
}
// Offer this request to the cache.
cacheRequest = responseCache.put(uri, connectionToCache);
}
/**
* Cause the socket connection to be released to the connection pool when
* it is no longer needed. If it is already unneeded, it will be pooled
* immediately. Otherwise the connection is held so that redirects can be
* handled by the same connection.
*/
public final void automaticallyReleaseConnectionToPool() {
automaticallyReleaseConnectionToPool = true;
if (connection != null && connectionReleased) {
client.getConnectionPool().recycle(connection);
connection = null;
}
}
/**
* Releases this engine so that its resources may be either reused or
* closed. Also call {@link #automaticallyReleaseConnectionToPool} unless
* the connection will be used to follow a redirect.
*/
public final void release(boolean streamCanceled) {
// If the response body comes from the cache, close it.
if (responseBodyIn == cachedResponseBody) {
Util.closeQuietly(responseBodyIn);
}
if (!connectionReleased && connection != null) {
connectionReleased = true;
if (transport == null
|| !transport.makeReusable(streamCanceled, requestBodyOut, responseTransferIn)) {
Util.closeQuietly(connection);
connection = null;
} else if (automaticallyReleaseConnectionToPool) {
client.getConnectionPool().recycle(connection);
connection = null;
}
}
}
private void initContentStream(InputStream transferStream) throws IOException {
responseTransferIn = transferStream;
if (transparentGzip && responseHeaders.isContentEncodingGzip()) {
// If the response was transparently gzipped, remove the gzip header field
// so clients don't double decompress. http://b/3009828
//
// Also remove the Content-Length in this case because it contains the
// length 528 of the gzipped response. This isn't terribly useful and is
// dangerous because 529 clients can query the content length, but not
// the content encoding.
responseHeaders.stripContentEncoding();
responseHeaders.stripContentLength();
responseBodyIn = new GZIPInputStream(transferStream);
} else {
responseBodyIn = transferStream;
}
}
/**
* Returns true if the response must have a (possibly 0-length) body.
* See RFC 2616 section 4.3.
*/
public final boolean hasResponseBody() {
int responseCode = responseHeaders.getHeaders().getResponseCode();
// HEAD requests never yield a body regardless of the response headers.
if (method.equals("HEAD")) {
return false;
}
if ((responseCode < HTTP_CONTINUE || responseCode >= 200)
&& responseCode != HttpURLConnectionImpl.HTTP_NO_CONTENT
&& responseCode != HttpURLConnectionImpl.HTTP_NOT_MODIFIED) {
return true;
}
// If the Content-Length or Transfer-Encoding headers disagree with the
// response code, the response is malformed. For best compatibility, we
// honor the headers.
if (responseHeaders.getContentLength() != -1 || responseHeaders.isChunked()) {
return true;
}
return false;
}
/**
* Populates requestHeaders with defaults and cookies.
*
* <p>This client doesn't specify a default {@code Accept} header because it
* doesn't know what content types the application is interested in.
*/
private void prepareRawRequestHeaders() throws IOException {
requestHeaders.getHeaders().setRequestLine(getRequestLine());
if (requestHeaders.getUserAgent() == null) {
requestHeaders.setUserAgent(getDefaultUserAgent());
}
if (requestHeaders.getHost() == null) {
requestHeaders.setHost(getOriginAddress(policy.getURL()));
}
if ((connection == null || connection.getHttpMinorVersion() != 0)
&& requestHeaders.getConnection() == null) {
requestHeaders.setConnection("Keep-Alive");
}
if (requestHeaders.getAcceptEncoding() == null) {
transparentGzip = true;
requestHeaders.setAcceptEncoding("gzip");
}
if (hasRequestBody() && requestHeaders.getContentType() == null) {
requestHeaders.setContentType("application/x-www-form-urlencoded");
}
long ifModifiedSince = policy.getIfModifiedSince();
if (ifModifiedSince != 0) {
requestHeaders.setIfModifiedSince(new Date(ifModifiedSince));
}
CookieHandler cookieHandler = client.getCookieHandler();
if (cookieHandler != null) {
requestHeaders.addCookies(
cookieHandler.get(uri, requestHeaders.getHeaders().toMultimap(false)));
}
}
/**
* Returns the request status line, like "GET / HTTP/1.1". This is exposed
* to the application by {@link HttpURLConnectionImpl#getHeaderFields}, so
* it needs to be set even if the transport is SPDY.
*/
String getRequestLine() {
String protocol =
(connection == null || connection.getHttpMinorVersion() != 0) ? "HTTP/1.1" : "HTTP/1.0";
return method + " " + requestString() + " " + protocol;
}
private String requestString() {
URL url = policy.getURL();
if (includeAuthorityInRequestLine()) {
return url.toString();
} else {
return requestPath(url);
}
}
/**
* Returns the path to request, like the '/' in 'GET / HTTP/1.1'. Never
* empty, even if the request URL is. Includes the query component if it
* exists.
*/
public static String requestPath(URL url) {
String fileOnly = url.getFile();
if (fileOnly == null) {
return "/";
} else if (!fileOnly.startsWith("/")) {
return "/" + fileOnly;
} else {
return fileOnly;
}
}
/**
* Returns true if the request line should contain the full URL with host
* and port (like "GET http://android.com/foo HTTP/1.1") or only the path
* (like "GET /foo HTTP/1.1").
*
* <p>This is non-final because for HTTPS it's never necessary to supply the
* full URL, even if a proxy is in use.
*/
protected boolean includeAuthorityInRequestLine() {
return connection == null
? policy.usingProxy() // A proxy was requested.
: connection.getRoute().getProxy().type() == Proxy.Type.HTTP; // A proxy was selected.
}
public static String getDefaultUserAgent() {
String agent = System.getProperty("http.agent");
return agent != null ? agent : ("Java" + System.getProperty("java.version"));
}
public static String getOriginAddress(URL url) {
int port = url.getPort();
String result = url.getHost();
if (port > 0 && port != getDefaultPort(url.getProtocol())) {
result = result + ":" + port;
}
return result;
}
/**
* Flushes the remaining request header and body, parses the HTTP response
* headers and starts reading the HTTP response body if it exists.
*/
public final void readResponse() throws IOException {
if (hasResponse()) {
responseHeaders.setResponseSource(responseSource);
return;
}
if (responseSource == null) {
throw new IllegalStateException("readResponse() without sendRequest()");
}
if (!responseSource.requiresConnection()) {
return;
}
if (sentRequestMillis == -1) {
if (requestBodyOut instanceof RetryableOutputStream) {
int contentLength = ((RetryableOutputStream) requestBodyOut).contentLength();
requestHeaders.setContentLength(contentLength);
}
transport.writeRequestHeaders();
}
if (requestBodyOut != null) {
requestBodyOut.close();
if (requestBodyOut instanceof RetryableOutputStream) {
transport.writeRequestBody((RetryableOutputStream) requestBodyOut);
}
}
transport.flushRequest();
responseHeaders = transport.readResponseHeaders();
responseHeaders.setLocalTimestamps(sentRequestMillis, System.currentTimeMillis());
responseHeaders.setResponseSource(responseSource);
if (responseSource == ResponseSource.CONDITIONAL_CACHE) {
if (cachedResponseHeaders.validate(responseHeaders)) {
release(false);
ResponseHeaders combinedHeaders = cachedResponseHeaders.combine(responseHeaders);
this.responseHeaders = combinedHeaders;
// Update the cache after applying the combined headers but before initializing the content
// stream, otherwise the Content-Encoding header (if present) will be stripped from the
// combined headers and not end up in the cache file if transparent gzip compression is
// turned on.
OkResponseCache responseCache = client.getOkResponseCache();
responseCache.trackConditionalCacheHit();
responseCache.update(cacheResponse, policy.getHttpConnectionToCache());
initContentStream(cachedResponseBody);
return;
} else {
Util.closeQuietly(cachedResponseBody);
}
}
if (hasResponseBody()) {
maybeCache(); // reentrant. this calls into user code which may call back into this!
}
initContentStream(transport.getTransferStream(cacheRequest));
}
protected TunnelRequest getTunnelConfig() {
return null;
}
public void receiveHeaders(RawHeaders headers) throws IOException {
CookieHandler cookieHandler = client.getCookieHandler();
if (cookieHandler != null) {
cookieHandler.put(uri, headers.toMultimap(true));
}
}
}