1 /* 2 * Copyright (C) 2014 Square, Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package okio; 17 18 import java.io.Closeable; 19 import java.io.Flushable; 20 import java.io.IOException; 21 22 /** 23 * Receives a stream of bytes. Use this interface to write data wherever it's 24 * needed: to the network, storage, or a buffer in memory. Sinks may be layered 25 * to transform received data, such as to compress, encrypt, throttle, or add 26 * protocol framing. 27 * 28 * <p>Most application code shouldn't operate on a sink directly, but rather 29 * {@link BufferedSink} which is both more efficient and more convenient. Use 30 * {@link Okio#buffer(Sink)} to wrap any sink with a buffer. 31 * 32 * <p>Sinks are easy to test: just use an {@link Buffer} in your tests, and 33 * read from it to confirm it received the data that was expected. 34 * 35 * <h3>Comparison with OutputStream</h3> 36 * This interface is functionally equivalent to {@link java.io.OutputStream}. 37 * 38 * <p>{@code OutputStream} requires multiple layers when emitted data is 39 * heterogeneous: a {@code DataOutputStream} for primitive values, a {@code 40 * BufferedOutputStream} for buffering, and {@code OutputStreamWriter} for 41 * charset encoding. This class uses {@code BufferedSink} for all of the above. 42 * 43 * <p>Sink is also easier to layer: there is no {@linkplain 44 * java.io.OutputStream#write(int) single-byte write} method that is awkward to 45 * implement efficiently. 46 * 47 * <h3>Interop with OutputStream</h3> 48 * Use {@link Okio#sink} to adapt an {@code OutputStream} to a sink. Use {@link 49 * BufferedSink#outputStream} to adapt a sink to an {@code OutputStream}. 50 */ 51 public interface Sink extends Closeable, Flushable { 52 /** Removes {@code byteCount} bytes from {@code source} and appends them to this. */ 53 void write(Buffer source, long byteCount) throws IOException; 54 55 /** Pushes all buffered bytes to their final destination. */ 56 @Override void flush() throws IOException; 57 58 /** Returns the timeout for this sink. */ 59 Timeout timeout(); 60 61 /** 62 * Pushes all buffered bytes to their final destination and releases the 63 * resources held by this sink. It is an error to write a closed sink. It is 64 * safe to close a sink more than once. 65 */ 66 @Override void close() throws IOException; 67 } 68
