1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // http://code.google.com/p/protobuf/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 package com.google.protobuf.micro; 32 33 import com.google.protobuf.micro.CodedOutputStreamMicro; 34 import java.io.IOException; 35 36 /** 37 * Abstract interface implemented by Protocol Message objects. 38 * 39 * @author wink (at) google.com Wink Saville 40 */ 41 public abstract class MessageMicro { 42 /** 43 * Get the number of bytes required to encode this message. 44 * Returns the cached size or calls getSerializedSize which 45 * sets the cached size. This is used internally when serializing 46 * so the size is only computed once. If a member is modified 47 * then this could be stale call getSerializedSize if in doubt. 48 */ 49 abstract public int getCachedSize(); 50 51 /** 52 * Computes the number of bytes required to encode this message. 53 * The size is cached and the cached result can be retrieved 54 * using getCachedSize(). 55 */ 56 abstract public int getSerializedSize(); 57 58 /** 59 * Serializes the message and writes it to {@code output}. This does not 60 * flush or close the stream. 61 */ 62 abstract public void writeTo(CodedOutputStreamMicro output) throws java.io.IOException; 63 64 /** 65 * Parse {@code input} as a message of this type and merge it with the 66 * message being built. 67 */ 68 abstract public MessageMicro mergeFrom(final CodedInputStreamMicro input) throws IOException; 69 70 /** 71 * Serialize to a byte array. 72 * @return byte array with the serialized data. 73 */ 74 public byte[] toByteArray() { 75 final byte[] result = new byte[getSerializedSize()]; 76 toByteArray(result, 0, result.length); 77 return result; 78 } 79 80 /** 81 * Serialize to a byte array starting at offset through length. The 82 * method getSerializedSize must have been called prior to calling 83 * this method so the proper length is know. If an attempt to 84 * write more than length bytes OutOfSpaceException will be thrown 85 * and if length bytes are not written then IllegalStateException 86 * is thrown. 87 * @return byte array with the serialized data. 88 */ 89 public void toByteArray(byte [] data, int offset, int length) { 90 try { 91 final CodedOutputStreamMicro output = CodedOutputStreamMicro.newInstance(data, offset, length); 92 writeTo(output); 93 output.checkNoSpaceLeft(); 94 } catch (IOException e) { 95 throw new RuntimeException("Serializing to a byte array threw an IOException " 96 + "(should never happen)."); 97 } 98 } 99 100 /** 101 * Parse {@code data} as a message of this type and merge it with the 102 * message being built. 103 */ 104 public MessageMicro mergeFrom(final byte[] data) throws InvalidProtocolBufferMicroException { 105 return mergeFrom(data, 0, data.length); 106 } 107 108 /** 109 * Parse {@code data} as a message of this type and merge it with the 110 * message being built. 111 */ 112 public MessageMicro mergeFrom(final byte[] data, final int off, final int len) 113 throws InvalidProtocolBufferMicroException { 114 try { 115 final CodedInputStreamMicro input = CodedInputStreamMicro.newInstance(data, off, len); 116 mergeFrom(input); 117 input.checkLastTagWas(0); 118 return this; 119 } catch (InvalidProtocolBufferMicroException e) { 120 throw e; 121 } catch (IOException e) { 122 throw new RuntimeException("Reading from a byte array threw an IOException (should " 123 + "never happen)."); 124 } 125 } 126 127 /** 128 * Called by subclasses to parse an unknown field. 129 * @return {@code true} unless the tag is an end-group tag. 130 */ 131 protected boolean parseUnknownField( 132 final CodedInputStreamMicro input, 133 final int tag) throws IOException { 134 return input.skipField(tag); 135 } 136 } 137
