| // Copyright 2022 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| package org.chromium.net.apihelpers; |
| |
| import androidx.annotation.Nullable; |
| |
| import org.chromium.net.CronetException; |
| import org.chromium.net.UrlResponseInfo; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.nio.ByteBuffer; |
| import java.nio.channels.Channels; |
| import java.nio.channels.WritableByteChannel; |
| import java.util.LinkedHashSet; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * An abstract Cronet callback that reads the entire body to memory and optionally deserializes the |
| * body before passing it back to the issuer of the HTTP request. |
| * |
| * <p>The requester can subscribe for updates about the request by adding completion mListeners on |
| * the callback. When the request reaches a terminal state, the mListeners are informed in order of |
| * addition. |
| * |
| * @param <T> the response body type |
| */ |
| public abstract class InMemoryTransformCronetCallback<T> extends ImplicitFlowControlCallback { |
| private static final String CONTENT_LENGTH_HEADER_NAME = "Content-Length"; |
| // See ArrayList.MAX_ARRAY_SIZE for reasoning. |
| private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; |
| |
| private ByteArrayOutputStream mResponseBodyStream; |
| private WritableByteChannel mResponseBodyChannel; |
| |
| /** The set of listeners observing the associated request. */ |
| private final Set<CronetRequestCompletionListener<? super T>> mListeners = |
| new LinkedHashSet<>(); |
| |
| /** |
| * Transforms (deserializes) the plain full body into a user-defined object. |
| * |
| * <p>It is assumed that the implementing classes handle edge cases (such as empty and malformed |
| * bodies) appropriately. Cronet doesn't inspects the objects and passes them (or any |
| * exceptions) along to the issuer of the request. |
| */ |
| protected abstract T transformBodyBytes(UrlResponseInfo info, byte[] bodyBytes); |
| |
| /** |
| * Adds a completion listener. All listeners are informed when the request reaches a terminal |
| * state, in order of addition. If a listener is added multiple times, it will only be called |
| * once according to the first time it was added. |
| * |
| * @see CronetRequestCompletionListener |
| */ |
| public ImplicitFlowControlCallback addCompletionListener( |
| CronetRequestCompletionListener<? super T> listener) { |
| mListeners.add(listener); |
| return this; |
| } |
| |
| @Override |
| protected final void onResponseStarted(UrlResponseInfo info) { |
| long bodyLength = getBodyLength(info); |
| if (bodyLength > MAX_ARRAY_SIZE) { |
| throw new IllegalArgumentException( |
| "The body is too large and wouldn't fit in a byte array!"); |
| } |
| // bodyLength returns -1 if the header can't be parsed, also ignore obviously bogus values |
| if (bodyLength >= 0) { |
| mResponseBodyStream = new ByteArrayOutputStream((int) bodyLength); |
| } else { |
| mResponseBodyStream = new ByteArrayOutputStream(); |
| } |
| mResponseBodyChannel = Channels.newChannel(mResponseBodyStream); |
| } |
| |
| @Override |
| protected final void onBodyChunkRead(UrlResponseInfo info, ByteBuffer bodyChunk) |
| throws Exception { |
| mResponseBodyChannel.write(bodyChunk); |
| } |
| |
| @Override |
| protected final void onSucceeded(UrlResponseInfo info) { |
| T body = transformBodyBytes(info, mResponseBodyStream.toByteArray()); |
| for (CronetRequestCompletionListener<? super T> callback : mListeners) { |
| callback.onSucceeded(info, body); |
| } |
| } |
| |
| @Override |
| protected final void onFailed(@Nullable UrlResponseInfo info, CronetException exception) { |
| for (CronetRequestCompletionListener<? super T> callback : mListeners) { |
| callback.onFailed(info, exception); |
| } |
| } |
| |
| @Override |
| protected final void onCanceled(@Nullable UrlResponseInfo info) { |
| for (CronetRequestCompletionListener<? super T> callback : mListeners) { |
| callback.onCanceled(info); |
| } |
| } |
| |
| /** Returns the numerical value of the Content-Length header, or -1 if not set or invalid. */ |
| private static long getBodyLength(UrlResponseInfo info) { |
| List<String> contentLengthHeader = info.getAllHeaders().get(CONTENT_LENGTH_HEADER_NAME); |
| if (contentLengthHeader == null || contentLengthHeader.size() != 1) { |
| return -1; |
| } |
| try { |
| return Long.parseLong(contentLengthHeader.get(0)); |
| } catch (NumberFormatException e) { |
| return -1; |
| } |
| } |
| } |