/*
* Copyright (C) 2011 The Android Open Source Project
*
* 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 com.android.volley.toolbox;
import android.os.SystemClock;
import com.android.volley.AuthFailureError;
import com.android.volley.Cache;
import com.android.volley.Cache.Entry;
import com.android.volley.ClientError;
import com.android.volley.Header;
import com.android.volley.Network;
import com.android.volley.NetworkError;
import com.android.volley.NetworkResponse;
import com.android.volley.NoConnectionError;
import com.android.volley.Request;
import com.android.volley.RetryPolicy;
import com.android.volley.ServerError;
import com.android.volley.TimeoutError;
import com.android.volley.VolleyError;
import com.android.volley.VolleyLog;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.SocketTimeoutException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
/** A network performing Volley requests over an {@link HttpStack}. */
public class BasicNetwork implements Network {
protected static final boolean DEBUG = VolleyLog.DEBUG;
private static final int SLOW_REQUEST_THRESHOLD_MS = 3000;
private static final int DEFAULT_POOL_SIZE = 4096;
/**
* @deprecated Should never have been exposed in the API. This field may be removed in a future
* release of Volley.
*/
@Deprecated protected final HttpStack mHttpStack;
private final BaseHttpStack mBaseHttpStack;
protected final ByteArrayPool mPool;
/**
* @param httpStack HTTP stack to be used
* @deprecated use {@link #BasicNetwork(BaseHttpStack)} instead to avoid depending on Apache
* HTTP. This method may be removed in a future release of Volley.
*/
@Deprecated
public BasicNetwork(HttpStack httpStack) {
// If a pool isn't passed in, then build a small default pool that will give us a lot of
// benefit and not use too much memory.
this(httpStack, new ByteArrayPool(DEFAULT_POOL_SIZE));
}
/**
* @param httpStack HTTP stack to be used
* @param pool a buffer pool that improves GC performance in copy operations
* @deprecated use {@link #BasicNetwork(BaseHttpStack, ByteArrayPool)} instead to avoid
* depending on Apache HTTP. This method may be removed in a future release of Volley.
*/
@Deprecated
public BasicNetwork(HttpStack httpStack, ByteArrayPool pool) {
mHttpStack = httpStack;
mBaseHttpStack = new AdaptedHttpStack(httpStack);
mPool = pool;
}
/** @param httpStack HTTP stack to be used */
public BasicNetwork(BaseHttpStack httpStack) {
// If a pool isn't passed in, then build a small default pool that will give us a lot of
// benefit and not use too much memory.
this(httpStack, new ByteArrayPool(DEFAULT_POOL_SIZE));
}
/**
* @param httpStack HTTP stack to be used
* @param pool a buffer pool that improves GC performance in copy operations
*/
public BasicNetwork(BaseHttpStack httpStack, ByteArrayPool pool) {
mBaseHttpStack = httpStack;
// Populate mHttpStack for backwards compatibility, since it is a protected field. However,
// we won't use it directly here, so clients which don't access it directly won't need to
// depend on Apache HTTP.
mHttpStack = httpStack;
mPool = pool;
}
@Override
public NetworkResponse performRequest(Request<?> request) throws VolleyError {
long requestStart = SystemClock.elapsedRealtime();
while (true) {
HttpResponse httpResponse = null;
byte[] responseContents = null;
List<Header> responseHeaders = Collections.emptyList();
try {
// Gather headers.
Map<String, String> additionalRequestHeaders =
getCacheHeaders(request.getCacheEntry());
httpResponse = mBaseHttpStack.executeRequest(request, additionalRequestHeaders);
int statusCode = httpResponse.getStatusCode();
responseHeaders = httpResponse.getHeaders();
// Handle cache validation.
if (statusCode == HttpURLConnection.HTTP_NOT_MODIFIED) {
Entry entry = request.getCacheEntry();
if (entry == null) {
return new NetworkResponse(
HttpURLConnection.HTTP_NOT_MODIFIED,
/* data= */ null,
/* notModified= */ true,
SystemClock.elapsedRealtime() - requestStart,
responseHeaders);
}
// Combine cached and response headers so the response will be complete.
List<Header> combinedHeaders = combineHeaders(responseHeaders, entry);
return new NetworkResponse(
HttpURLConnection.HTTP_NOT_MODIFIED,
entry.data,
/* notModified= */ true,
SystemClock.elapsedRealtime() - requestStart,
combinedHeaders);
}
// Some responses such as 204s do not have content. We must check.
InputStream inputStream = httpResponse.getContent();
if (inputStream != null) {
responseContents =
inputStreamToBytes(inputStream, httpResponse.getContentLength());
} else {
// Add 0 byte response as a way of honestly representing a
// no-content request.
responseContents = new byte[0];
}
// if the request is slow, log it.
long requestLifetime = SystemClock.elapsedRealtime() - requestStart;
logSlowRequests(requestLifetime, request, responseContents, statusCode);
if (statusCode < 200 || statusCode > 299) {
throw new IOException();
}
return new NetworkResponse(
statusCode,
responseContents,
/* notModified= */ false,
SystemClock.elapsedRealtime() - requestStart,
responseHeaders);
} catch (SocketTimeoutException e) {
attemptRetryOnException("socket", request, new TimeoutError());
} catch (MalformedURLException e) {
throw new RuntimeException("Bad URL " + request.getUrl(), e);
} catch (IOException e) {
int statusCode;
if (httpResponse != null) {
statusCode = httpResponse.getStatusCode();
} else {
if (request.shouldRetryConnectionErrors()) {
attemptRetryOnException("connection", request, new NoConnectionError(e));
continue;
} else {
throw new NoConnectionError(e);
}
}
VolleyLog.e("Unexpected response code %d for %s", statusCode, request.getUrl());
NetworkResponse networkResponse;
if (responseContents != null) {
networkResponse =
new NetworkResponse(
statusCode,
responseContents,
/* notModified= */ false,
SystemClock.elapsedRealtime() - requestStart,
responseHeaders);
if (statusCode == HttpURLConnection.HTTP_UNAUTHORIZED
|| statusCode == HttpURLConnection.HTTP_FORBIDDEN) {
attemptRetryOnException(
"auth", request, new AuthFailureError(networkResponse));
} else if (statusCode >= 400 && statusCode <= 499) {
// Don't retry other client errors.
throw new ClientError(networkResponse);
} else if (statusCode >= 500 && statusCode <= 599) {
if (request.shouldRetryServerErrors()) {
attemptRetryOnException(
"server", request, new ServerError(networkResponse));
} else {
throw new ServerError(networkResponse);
}
} else {
// 3xx? No reason to retry.
throw new ServerError(networkResponse);
}
} else {
attemptRetryOnException("network", request, new NetworkError());
}
}
}
}
/** Logs requests that took over SLOW_REQUEST_THRESHOLD_MS to complete. */
private void logSlowRequests(
long requestLifetime, Request<?> request, byte[] responseContents, int statusCode) {
if (DEBUG || requestLifetime > SLOW_REQUEST_THRESHOLD_MS) {
VolleyLog.d(
"HTTP response for request=<%s> [lifetime=%d], [size=%s], "
+ "[rc=%d], [retryCount=%s]",
request,
requestLifetime,
responseContents != null ? responseContents.length : "null",
statusCode,
request.getRetryPolicy().getCurrentRetryCount());
}
}
/**
* Attempts to prepare the request for a retry. If there are no more attempts remaining in the
* request's retry policy, a timeout exception is thrown.
*
* @param request The request to use.
*/
private static void attemptRetryOnException(
String logPrefix, Request<?> request, VolleyError exception) throws VolleyError {
RetryPolicy retryPolicy = request.getRetryPolicy();
int oldTimeout = request.getTimeoutMs();
try {
retryPolicy.retry(exception);
} catch (VolleyError e) {
request.addMarker(
String.format("%s-timeout-giveup [timeout=%s]", logPrefix, oldTimeout));
throw e;
}
request.addMarker(String.format("%s-retry [timeout=%s]", logPrefix, oldTimeout));
}
private Map<String, String> getCacheHeaders(Cache.Entry entry) {
// If there's no cache entry, we're done.
if (entry == null) {
return Collections.emptyMap();
}
Map<String, String> headers = new HashMap<>();
if (entry.etag != null) {
headers.put("If-None-Match", entry.etag);
}
if (entry.lastModified > 0) {
headers.put(
"If-Modified-Since", HttpHeaderParser.formatEpochAsRfc1123(entry.lastModified));
}
return headers;
}
protected void logError(String what, String url, long start) {
long now = SystemClock.elapsedRealtime();
VolleyLog.v("HTTP ERROR(%s) %d ms to fetch %s", what, (now - start), url);
}
/** Reads the contents of an InputStream into a byte[]. */
private byte[] inputStreamToBytes(InputStream in, int contentLength)
throws IOException, ServerError {
PoolingByteArrayOutputStream bytes = new PoolingByteArrayOutputStream(mPool, contentLength);
byte[] buffer = null;
try {
if (in == null) {
throw new ServerError();
}
buffer = mPool.getBuf(1024);
int count;
while ((count = in.read(buffer)) != -1) {
bytes.write(buffer, 0, count);
}
return bytes.toByteArray();
} finally {
try {
// Close the InputStream and release the resources by "consuming the content".
if (in != null) {
in.close();
}
} catch (IOException e) {
// This can happen if there was an exception above that left the stream in
// an invalid state.
VolleyLog.v("Error occurred when closing InputStream");
}
mPool.returnBuf(buffer);
bytes.close();
}
}
/**
* Converts Headers[] to Map<String, String>.
*
* @deprecated Should never have been exposed in the API. This method may be removed in a future
* release of Volley.
*/
@Deprecated
protected static Map<String, String> convertHeaders(Header[] headers) {
Map<String, String> result = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
for (int i = 0; i < headers.length; i++) {
result.put(headers[i].getName(), headers[i].getValue());
}
return result;
}
/**
* Combine cache headers with network response headers for an HTTP 304 response.
*
* <p>An HTTP 304 response does not have all header fields. We have to use the header fields
* from the cache entry plus the new ones from the response. See also:
* http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.5
*
* @param responseHeaders Headers from the network response.
* @param entry The cached response.
* @return The combined list of headers.
*/
private static List<Header> combineHeaders(List<Header> responseHeaders, Entry entry) {
// First, create a case-insensitive set of header names from the network
// response.
Set<String> headerNamesFromNetworkResponse = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
if (!responseHeaders.isEmpty()) {
for (Header header : responseHeaders) {
headerNamesFromNetworkResponse.add(header.getName());
}
}
// Second, add headers from the cache entry to the network response as long as
// they didn't appear in the network response, which should take precedence.
List<Header> combinedHeaders = new ArrayList<>(responseHeaders);
if (entry.allResponseHeaders != null) {
if (!entry.allResponseHeaders.isEmpty()) {
for (Header header : entry.allResponseHeaders) {
if (!headerNamesFromNetworkResponse.contains(header.getName())) {
combinedHeaders.add(header);
}
}
}
} else {
// Legacy caches only have entry.responseHeaders.
if (!entry.responseHeaders.isEmpty()) {
for (Map.Entry<String, String> header : entry.responseHeaders.entrySet()) {
if (!headerNamesFromNetworkResponse.contains(header.getKey())) {
combinedHeaders.add(new Header(header.getKey(), header.getValue()));
}
}
}
}
return combinedHeaders;
}
}
