mv com/google/domain/registry google/registry

This change renames directories in preparation for the great package
rename. The repository is now in a broken state because the code
itself hasn't been updated. However this should ensure that git
correctly preserves history for each file.

java/google/registry/gcs/GcsUtils.java

@@ -0,0 +1,101 @@
+// Copyright 2016 The Domain Registry 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.domain.registry.gcs;
+
+import static com.google.common.collect.Iterables.getLast;
+
+import com.google.appengine.tools.cloudstorage.GcsFileMetadata;
+import com.google.appengine.tools.cloudstorage.GcsFileOptions;
+import com.google.appengine.tools.cloudstorage.GcsFileOptions.Builder;
+import com.google.appengine.tools.cloudstorage.GcsFilename;
+import com.google.appengine.tools.cloudstorage.GcsService;
+import com.google.common.base.Splitter;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.net.MediaType;
+import com.google.domain.registry.config.ConfigModule.Config;
+import com.google.domain.registry.util.FormattingLogger;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.nio.channels.Channels;
+
+import javax.annotation.CheckReturnValue;
+import javax.inject.Inject;
+
+/** Utilities for working with Google Cloud Storage. */
+public final class GcsUtils {
+
+  private static final FormattingLogger logger = FormattingLogger.getLoggerForCallerClass();
+
+  private static final ImmutableMap<String, MediaType> EXTENSIONS =
+      new ImmutableMap.Builder<String, MediaType>()
+          .put("ghostryde", MediaType.APPLICATION_BINARY)
+          .put("length", MediaType.PLAIN_TEXT_UTF_8)
+          .put("json", MediaType.JSON_UTF_8)
+          .build();
+
+  private final GcsService gcsService;
+  private final int bufferSize;
+
+  @Inject
+  public GcsUtils(GcsService gcsService, @Config("gcsBufferSize") int bufferSize) {
+    this.gcsService = gcsService;
+    this.bufferSize = bufferSize;
+  }
+
+  /** Opens a GCS file for reading as an {@link InputStream} with prefetching. */
+  @CheckReturnValue
+  public InputStream openInputStream(GcsFilename filename) {
+    return Channels.newInputStream(gcsService.openPrefetchingReadChannel(filename, 0, bufferSize));
+  }
+
+  /** Opens a GCS file for writing as an {@link OutputStream}, overwriting existing files. */
+  @CheckReturnValue
+  public OutputStream openOutputStream(GcsFilename filename) throws IOException {
+    return Channels.newOutputStream(gcsService.createOrReplace(filename, getOptions(filename)));
+  }
+
+  /** Creates a GCS file with the given byte contents, overwriting existing files. */
+  public void createFromBytes(GcsFilename filename, byte[] bytes) throws IOException {
+    gcsService.createOrReplace(filename, getOptions(filename), ByteBuffer.wrap(bytes));
+  }
+
+  /** Returns {@code true} if a file exists and is non-empty on Google Cloud Storage. */
+  public boolean existsAndNotEmpty(GcsFilename file) {
+    GcsFileMetadata metadata;
+    try {
+      metadata = gcsService.getMetadata(file);
+    } catch (IOException e) {
+      logger.warning(e, "Failed to check if GCS file exists");
+      return false;
+    }
+    if (metadata == null) {
+      return false;
+    }
+    return metadata.getLength() > 0;
+  }
+
+  /** Determines most appropriate {@link GcsFileOptions} based on filename extension. */
+  private static GcsFileOptions getOptions(GcsFilename filename) {
+    Builder builder = new GcsFileOptions.Builder().cacheControl("no-cache");
+    MediaType mediaType = EXTENSIONS.get(getLast(Splitter.on('.').split(filename.getObjectName())));
+    if (mediaType != null) {
+      builder = builder.mimeType(mediaType.type());
+    }
+    return builder.build();
+  }
+}