| // Copyright 2014 Google Inc. 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.server; |
| |
| import com.google.common.base.Preconditions; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.UnsupportedEncodingException; |
| |
| /** |
| * This class models a response from the {@link RPCServer}. This is a |
| * tuple of an error message and the exit status. The encoding of the response |
| * is extremely simple {@link #toString()}: |
| * |
| * <ul><li>Iff a message is present, the wire format is |
| * <pre>message + '\n' + exit code as string + '\n'</pre> |
| * </li> |
| * <li>Otherwise it's just the exit code as string + '\n'</li> |
| * </ul> |
| */ |
| final class ServerResponse { |
| |
| /** |
| * Parses an input string into a {@link ServerResponse} object. |
| */ |
| public static ServerResponse parseFrom(String input) { |
| if (input.charAt(input.length() - 1) != '\n') { |
| String msg = "Response must end with newline (" + input + ")"; |
| throw new IllegalArgumentException(msg); |
| } |
| int newlineAt = input.lastIndexOf('\n', input.length() - 2); |
| |
| final String exitStatusString; |
| final String errorMessage; |
| if (newlineAt == -1) { |
| errorMessage = ""; |
| exitStatusString = input.substring(0, input.length() - 1); |
| } else { |
| errorMessage = input.substring(0, newlineAt); |
| exitStatusString = input.substring(newlineAt + 1, input.length() - 1); |
| } |
| |
| return new ServerResponse(errorMessage, Integer.parseInt(exitStatusString)); |
| } |
| |
| /** |
| * Parses {@code bytes} into a {@link ServerResponse} instance, assuming |
| * Latin 1 encoding. |
| */ |
| public static ServerResponse parseFrom(byte[] bytes) { |
| try { |
| return parseFrom(new String(bytes, "ISO-8859-1")); |
| } catch (UnsupportedEncodingException e) { |
| throw new AssertionError(e); // Latin 1 is everywhere. |
| } |
| } |
| |
| /** |
| * Parses {@code bytes} into a {@link ServerResponse} instance, assuming |
| * Latin 1 encoding. |
| */ |
| public static ServerResponse parseFrom(ByteArrayOutputStream bytes) { |
| return parseFrom(bytes.toByteArray()); |
| } |
| |
| private final String errorMessage; |
| private final int exitStatus; |
| |
| /** |
| * Construct a new instance given an error message and an exit status. |
| */ |
| public ServerResponse(String errorMessage, int exitStatus) { |
| Preconditions.checkNotNull(errorMessage); |
| this.errorMessage = errorMessage; |
| this.exitStatus = exitStatus; |
| } |
| |
| /** |
| * The wire representation of this response object. |
| */ |
| @Override |
| public String toString() { |
| if (errorMessage.length() == 0) { |
| return Integer.toString(exitStatus) + '\n'; |
| } |
| return errorMessage + '\n' + Integer.toString(exitStatus) + '\n'; |
| } |
| |
| @Override |
| public boolean equals(Object other) { |
| if (other == null || !(other instanceof ServerResponse)) return false; |
| ServerResponse otherResponse = (ServerResponse) other; |
| return exitStatus == otherResponse.exitStatus |
| && errorMessage.equals(otherResponse.errorMessage); |
| } |
| |
| @Override |
| public int hashCode() { |
| return exitStatus * 31 ^ errorMessage.hashCode(); |
| } |
| |
| } |