remote: Rewrite the HTTP caching client in Netty. Fixes #4481

* This puts in the foundation of HTTP/2 support for remote caching.
* Allows us to remove the Apache HTTP library as a dependency, reducing
the Bazel binary size by 1MiB.

On fast networks (i.e. GCE to GCS) we can see a >2x speed improvement for TLS
throughput. Even from my workstation to GCS I get significant build time
improvements when using Netty's TLS 18s vs 12s.

Closes #4481.

PiperOrigin-RevId: 183411787

1 files changed, 0 insertions, 175 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/remote/blobstore/RestBlobStore.java b/src/main/java/com/google/devtools/build/lib/remote/blobstore/RestBlobStore.java
deleted file mode 100644
index 76d1773623..0000000000
--- a/src/main/java/com/google/devtools/build/lib/remote/blobstore/RestBlobStore.java
+++ /dev/null
@@ -1,175 +0,0 @@
-// 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 com.google.api.client.http.ByteArrayContent;
-import com.google.api.client.http.GenericUrl;
-import com.google.api.client.http.HttpContent;
-import com.google.api.client.http.HttpRequestFactory;
-import com.google.api.client.http.HttpResponse;
-import com.google.api.client.http.InputStreamContent;
-import com.google.api.client.http.apache.ApacheHttpTransport;
-import com.google.auth.Credentials;
-import com.google.auth.http.HttpCredentialsAdapter;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.net.URI;
-import java.net.URISyntaxException;
-import javax.annotation.Nullable;
-import org.apache.http.HttpStatus;
-import org.apache.http.client.config.RequestConfig;
-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 /{ac,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 /{ac,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.
- */
-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 HttpClientBuilder clientFactory;
-  private final ApacheHttpTransport transport;
-  private final HttpRequestFactory requestFactory;
-
-  /**
-   * Creates a new instance.
-   *
-   * @param baseUrl base URL for the remote cache
-   * @param poolSize maximum number of simultaneous connections
-   */
-  public RestBlobStore(String baseUrl, int timeoutMillis, @Nullable Credentials creds)
-      throws IOException {
-    validateUrl(baseUrl);
-    this.baseUrl = baseUrl;
-    PoolingHttpClientConnectionManager connMan = new PoolingHttpClientConnectionManager();
-    // We'll use as many connections as necessary. The connection pool tries to re-use open
-    // connections before creating new ones, so in practice we should have as many connections
-    // as concurrent actions.
-    connMan.setDefaultMaxPerRoute(Integer.MAX_VALUE);
-    connMan.setMaxTotal(Integer.MAX_VALUE);
-    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());
-    transport = new ApacheHttpTransport(clientFactory.build());
-    if (creds != null) {
-      requestFactory = transport.createRequestFactory(new HttpCredentialsAdapter(creds));
-    } else {
-      requestFactory = transport.createRequestFactory();
-    }
-  }
-
-  @Override
-  public void close() {
-    transport.shutdown();
-  }
-
-  @Override
-  public boolean containsKey(String key) throws IOException {
-    throw new UnsupportedOperationException("HTTP Caching does not use this method.");
-  }
-
-  @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 {
-    HttpResponse response = null;
-    try {
-      response =
-          requestFactory
-              .buildGetRequest(new GenericUrl(baseUrl + "/" + urlPrefix + "/" + key))
-              .setThrowExceptionOnExecuteError(false)
-              .execute();
-      int statusCode = response.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.download(out);
-      return true;
-    } finally {
-      if (response != null) {
-        response.disconnect();
-      }
-    }
-  }
-
-  @Override
-  public void put(String key, long length, InputStream in) throws IOException {
-    put(CAS_PREFIX, key, new InputStreamContent("application/octext-stream", in));
-  }
-
-  @Override
-  public void putActionResult(String key, byte[] in) throws IOException, InterruptedException {
-    put(ACTION_CACHE_PREFIX, key, new ByteArrayContent("application/octet-stream", in));
-  }
-
-  private void put(String urlPrefix, String key, HttpContent content) throws IOException {
-    HttpResponse response = null;
-    try {
-      response =
-          requestFactory
-              .buildPutRequest(new GenericUrl(baseUrl + "/" + urlPrefix + "/" + key), content)
-              .setThrowExceptionOnExecuteError(false)
-              .execute();
-      int statusCode = response.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);
-      }
-    } finally {
-      if (response != null) {
-        response.disconnect();
-      }
-    }
-  }
-  
-  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);
-    }
-  }
-}