1 /* 2 * Copyright 2015 The gRPC Authors 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 17 package io.grpc.internal; 18 19 /** 20 * An interface for a byte buffer that can only be written to. 21 * {@link WritableBuffer}s are a generic way to transfer bytes to 22 * the concrete network transports, like Netty and OkHttp. 23 */ 24 public interface WritableBuffer { 25 26 /** 27 * Appends {@code length} bytes to the buffer from the source 28 * array starting at {@code srcIndex}. 29 * 30 * @throws IndexOutOfBoundsException 31 * if the specified {@code srcIndex} is less than {@code 0}, 32 * if {@code srcIndex + length} is greater than 33 * {@code src.length}, or 34 * if {@code length} is greater than {@link #writableBytes()} 35 */ write(byte[] src, int srcIndex, int length)36 void write(byte[] src, int srcIndex, int length); 37 38 /** 39 * Appends a single byte to the buffer. This is slow so don't call it. 40 */ write(byte b)41 void write(byte b); 42 43 /** 44 * Returns the number of bytes one can write to the buffer. 45 */ writableBytes()46 int writableBytes(); 47 48 /** 49 * Returns the number of bytes one can read from the buffer. 50 */ readableBytes()51 int readableBytes(); 52 53 /** 54 * Releases the buffer, indicating to the {@link WritableBufferAllocator} that 55 * this buffer is no longer used and its resources can be reused. 56 */ release()57 void release(); 58 } 59