1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mobile/android/base/sync/JSONRecordFetcher.java Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,143 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +package org.mozilla.gecko.sync;
1.9 +
1.10 +import java.util.concurrent.CountDownLatch;
1.11 +import java.util.concurrent.TimeUnit;
1.12 +
1.13 +import org.mozilla.gecko.background.common.log.Logger;
1.14 +import org.mozilla.gecko.sync.delegates.JSONRecordFetchDelegate;
1.15 +import org.mozilla.gecko.sync.net.AuthHeaderProvider;
1.16 +import org.mozilla.gecko.sync.net.SyncStorageRecordRequest;
1.17 +import org.mozilla.gecko.sync.net.SyncStorageRequestDelegate;
1.18 +import org.mozilla.gecko.sync.net.SyncStorageResponse;
1.19 +
1.20 +/**
1.21 + * An object which fetches a chunk of JSON from a URI, using certain credentials,
1.22 + * and informs its delegate of the result.
1.23 + */
1.24 +public class JSONRecordFetcher {
1.25 + private static final long DEFAULT_AWAIT_TIMEOUT_MSEC = 2 * 60 * 1000; // Two minutes.
1.26 + private static final String LOG_TAG = "JSONRecordFetcher";
1.27 +
1.28 + protected final AuthHeaderProvider authHeaderProvider;
1.29 + protected final String uri;
1.30 + protected JSONRecordFetchDelegate delegate;
1.31 +
1.32 + public JSONRecordFetcher(final String uri, final AuthHeaderProvider authHeaderProvider) {
1.33 + if (uri == null) {
1.34 + throw new IllegalArgumentException("uri must not be null");
1.35 + }
1.36 + this.uri = uri;
1.37 + this.authHeaderProvider = authHeaderProvider;
1.38 + }
1.39 +
1.40 + protected String getURI() {
1.41 + return this.uri;
1.42 + }
1.43 +
1.44 + private class JSONFetchHandler implements SyncStorageRequestDelegate {
1.45 +
1.46 + // SyncStorageRequestDelegate methods for fetching.
1.47 + @Override
1.48 + public AuthHeaderProvider getAuthHeaderProvider() {
1.49 + return authHeaderProvider;
1.50 + }
1.51 +
1.52 + public String ifUnmodifiedSince() {
1.53 + return null;
1.54 + }
1.55 +
1.56 + public void handleRequestSuccess(SyncStorageResponse response) {
1.57 + if (response.wasSuccessful()) {
1.58 + try {
1.59 + delegate.handleSuccess(response.jsonObjectBody());
1.60 + } catch (Exception e) {
1.61 + handleRequestError(e);
1.62 + }
1.63 + return;
1.64 + }
1.65 + handleRequestFailure(response);
1.66 + }
1.67 +
1.68 + @Override
1.69 + public void handleRequestFailure(SyncStorageResponse response) {
1.70 + delegate.handleFailure(response);
1.71 + }
1.72 +
1.73 + @Override
1.74 + public void handleRequestError(Exception ex) {
1.75 + delegate.handleError(ex);
1.76 + }
1.77 + }
1.78 +
1.79 + public void fetch(final JSONRecordFetchDelegate delegate) {
1.80 + this.delegate = delegate;
1.81 + try {
1.82 + final SyncStorageRecordRequest r = new SyncStorageRecordRequest(this.getURI());
1.83 + r.delegate = new JSONFetchHandler();
1.84 + r.get();
1.85 + } catch (Exception e) {
1.86 + delegate.handleError(e);
1.87 + }
1.88 + }
1.89 +
1.90 + private class LatchedJSONRecordFetchDelegate implements JSONRecordFetchDelegate {
1.91 + public ExtendedJSONObject body = null;
1.92 + public Exception exception = null;
1.93 + private CountDownLatch latch;
1.94 +
1.95 + public LatchedJSONRecordFetchDelegate(CountDownLatch latch) {
1.96 + this.latch = latch;
1.97 + }
1.98 +
1.99 + @Override
1.100 + public void handleFailure(SyncStorageResponse response) {
1.101 + this.exception = new HTTPFailureException(response);
1.102 + latch.countDown();
1.103 + }
1.104 +
1.105 + @Override
1.106 + public void handleError(Exception e) {
1.107 + this.exception = e;
1.108 + latch.countDown();
1.109 + }
1.110 +
1.111 + @Override
1.112 + public void handleSuccess(ExtendedJSONObject body) {
1.113 + this.body = body;
1.114 + latch.countDown();
1.115 + }
1.116 + }
1.117 +
1.118 + /**
1.119 + * Fetch the info record, blocking until it returns.
1.120 + * @return the info record.
1.121 + */
1.122 + public ExtendedJSONObject fetchBlocking() throws HTTPFailureException, Exception {
1.123 + CountDownLatch latch = new CountDownLatch(1);
1.124 + LatchedJSONRecordFetchDelegate delegate = new LatchedJSONRecordFetchDelegate(latch);
1.125 + this.delegate = delegate;
1.126 + this.fetch(delegate);
1.127 +
1.128 + // Sanity wait: the resource itself will time out and throw after two
1.129 + // minutes, so we just want to avoid coding errors causing us to block
1.130 + // endlessly.
1.131 + if (!latch.await(DEFAULT_AWAIT_TIMEOUT_MSEC, TimeUnit.MILLISECONDS)) {
1.132 + Logger.warn(LOG_TAG, "Interrupted fetching info record.");
1.133 + throw new InterruptedException("info fetch timed out.");
1.134 + }
1.135 +
1.136 + if (delegate.body != null) {
1.137 + return delegate.body;
1.138 + }
1.139 +
1.140 + if (delegate.exception != null) {
1.141 + throw delegate.exception;
1.142 + }
1.143 +
1.144 + throw new Exception("Unknown error.");
1.145 + }
1.146 +}
1.147 \ No newline at end of file
