Java tutorial
// Copyright 2017 The Bazel Authors. All rights reserved. // // 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.google.devtools.build.lib.remote.blobstore; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.URI; import java.net.URISyntaxException; import org.apache.http.HttpEntity; import org.apache.http.HttpStatus; import org.apache.http.client.HttpClient; import org.apache.http.client.config.RequestConfig; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpHead; import org.apache.http.client.methods.HttpPut; import org.apache.http.entity.ByteArrayEntity; import org.apache.http.entity.ContentType; import org.apache.http.entity.InputStreamEntity; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.impl.conn.PoolingHttpClientConnectionManager; /** * Implementation of {@link SimpleBlobStore} with a REST service. The REST service needs to * support the following HTTP methods. * * <p>PUT /{actioncache,cas}/1234 HTTP/1.1 PUT method is used to upload a blob with a base16 key. * In this example the key is 1234. Valid status codes are 200, 201, 202 and 204. * * <p>GET /{actioncache,cas}/1234 HTTP/1.1 GET method fetches a blob with the specified key. In this * example the key is 1234. A status code of 200 should be followed by the content of blob. Status * code of 404 or 204 means the key cannot be found. * * <p>HEAD /{actioncache,cas}/1234 HTTP/1.1 HEAD method checks to see if the specified key exists in * the blob store. A status code of 200 indicates the key is found in the blob store. A status code * of 404 indicates the key is not found in the blob store. */ public final class RestBlobStore implements SimpleBlobStore { private static final String ACTION_CACHE_PREFIX = "ac"; private static final String CAS_PREFIX = "cas"; private final String baseUrl; private final PoolingHttpClientConnectionManager connMan; private final HttpClientBuilder clientFactory; /** * Creates a new instance. * * @param baseUrl base URL for the remote cache * @param poolSize maximum number of simultaneous connections */ public RestBlobStore(String baseUrl, int poolSize, int timeoutMillis) throws IOException { validateUrl(baseUrl); this.baseUrl = baseUrl; connMan = new PoolingHttpClientConnectionManager(); connMan.setDefaultMaxPerRoute(poolSize); connMan.setMaxTotal(poolSize); clientFactory = HttpClientBuilder.create(); clientFactory.setConnectionManager(connMan); clientFactory.setConnectionManagerShared(true); clientFactory.setDefaultRequestConfig(RequestConfig.custom() // Timeout to establish a connection. .setConnectTimeout(timeoutMillis) // Timeout between reading data. .setSocketTimeout(timeoutMillis).build()); } @Override public void close() { connMan.close(); } @Override public boolean containsKey(String key) throws IOException { HttpClient client = clientFactory.build(); HttpHead head = new HttpHead(baseUrl + "/" + CAS_PREFIX + "/" + key); return client.execute(head, response -> { int statusCode = response.getStatusLine().getStatusCode(); return HttpStatus.SC_OK == statusCode; }); } @Override public boolean get(String key, OutputStream out) throws IOException { return get(CAS_PREFIX, key, out); } @Override public boolean getActionResult(String key, OutputStream out) throws IOException, InterruptedException { return get(ACTION_CACHE_PREFIX, key, out); } private boolean get(String urlPrefix, String key, OutputStream out) throws IOException { HttpClient client = clientFactory.build(); HttpGet get = new HttpGet(baseUrl + "/" + urlPrefix + "/" + key); return client.execute(get, response -> { int statusCode = response.getStatusLine().getStatusCode(); if (HttpStatus.SC_NOT_FOUND == statusCode || HttpStatus.SC_NO_CONTENT == statusCode) { return false; } if (HttpStatus.SC_OK != statusCode) { throw new IOException("GET failed with status code " + statusCode); } response.getEntity().writeTo(out); return true; }); } @Override public void put(String key, long length, InputStream in) throws IOException { put(CAS_PREFIX, key, new InputStreamEntity(in, length, ContentType.APPLICATION_OCTET_STREAM)); } @Override public void putActionResult(String key, byte[] in) throws IOException, InterruptedException { put(ACTION_CACHE_PREFIX, key, new ByteArrayEntity(in, ContentType.APPLICATION_OCTET_STREAM)); } private void put(String urlPrefix, String key, HttpEntity entity) throws IOException { HttpClient client = clientFactory.build(); HttpPut put = new HttpPut(baseUrl + "/" + urlPrefix + "/" + key); put.setEntity(entity); client.execute(put, (response) -> { int statusCode = response.getStatusLine().getStatusCode(); // Accept more than SC_OK to be compatible with Nginx WebDav module. if (HttpStatus.SC_OK != statusCode && HttpStatus.SC_ACCEPTED != statusCode && HttpStatus.SC_CREATED != statusCode && HttpStatus.SC_NO_CONTENT != statusCode) { throw new IOException("PUT failed with status code " + statusCode); } return null; }); } private void validateUrl(String url) throws IOException { try { new URI(url); } catch (URISyntaxException e) { throw new IOException("Failed to parse remote REST cache URL: " + baseUrl, e); } } }