1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // 4 // Use of this source code is governed by a BSD-style 5 // license that can be found in the LICENSE file or at 6 // https://developers.google.com/open-source/licenses/bsd 7 8 package com.google.protobuf; 9 10 import java.util.Collection; 11 import java.util.List; 12 13 /** 14 * An interface extending {@code List<String>} that also provides access to the items of the list as 15 * UTF8-encoded ByteString or byte[] objects. This is used by the protocol buffer implementation to 16 * support lazily converting bytes parsed over the wire to String objects until needed and also 17 * increases the efficiency of serialization if the String was never requested as the ByteString or 18 * byte[] is already cached. The ByteString methods are used in immutable API only and byte[] 19 * methods used in mutable API only for they use different representations for string/bytes fields. 20 * 21 * @author jonp@google.com (Jon Perlow) 22 */ 23 public interface LazyStringList extends ProtocolStringList { 24 25 /** 26 * Returns the element at the specified position in this list as a ByteString. 27 * 28 * @param index index of the element to return 29 * @return the element at the specified position in this list 30 * @throws IndexOutOfBoundsException if the index is out of range ({@code index < 0 || index >= 31 * size()}) 32 */ getByteString(int index)33 ByteString getByteString(int index); 34 35 /** 36 * Returns the element at the specified position in this list as an Object that will either be a 37 * String or a ByteString. 38 * 39 * @param index index of the element to return 40 * @return the element at the specified position in this list 41 * @throws IndexOutOfBoundsException if the index is out of range ({@code index < 0 || index >= 42 * size()}) 43 */ getRaw(int index)44 Object getRaw(int index); 45 46 /** 47 * Returns the element at the specified position in this list as byte[]. 48 * 49 * @param index index of the element to return 50 * @return the element at the specified position in this list 51 * @throws IndexOutOfBoundsException if the index is out of range ({@code index < 0 || index >= 52 * size()}) 53 */ getByteArray(int index)54 byte[] getByteArray(int index); 55 56 /** 57 * Appends the specified element to the end of this list (optional operation). 58 * 59 * @param element element to be appended to this list 60 * @throws UnsupportedOperationException if the <tt>add</tt> operation is not supported by this 61 * list 62 */ add(ByteString element)63 void add(ByteString element); 64 65 /** 66 * Appends the specified element to the end of this list (optional operation). 67 * 68 * @param element element to be appended to this list 69 * @throws UnsupportedOperationException if the <tt>add</tt> operation is not supported by this 70 * list 71 */ add(byte[] element)72 void add(byte[] element); 73 74 /** 75 * Replaces the element at the specified position in this list with the specified element 76 * (optional operation). 77 * 78 * @param index index of the element to replace 79 * @param element the element to be stored at the specified position 80 * @throws UnsupportedOperationException if the <tt>set</tt> operation is not supported by this 81 * list IndexOutOfBoundsException if the index is out of range ({@code index < 0 || index >= 82 * size()}) 83 */ set(int index, ByteString element)84 void set(int index, ByteString element); 85 86 /** 87 * Replaces the element at the specified position in this list with the specified element 88 * (optional operation). 89 * 90 * @param index index of the element to replace 91 * @param element the element to be stored at the specified position 92 * @throws UnsupportedOperationException if the <tt>set</tt> operation is not supported by this 93 * list IndexOutOfBoundsException if the index is out of range ({@code index < 0 || index >= 94 * size()}) 95 */ set(int index, byte[] element)96 void set(int index, byte[] element); 97 98 /** 99 * Appends all elements in the specified ByteString collection to the end of this list. 100 * 101 * @param c collection whose elements are to be added to this list 102 * @return true if this list changed as a result of the call 103 * @throws UnsupportedOperationException if the <tt>addAllByteString</tt> operation is not 104 * supported by this list 105 */ addAllByteString(Collection<? extends ByteString> c)106 boolean addAllByteString(Collection<? extends ByteString> c); 107 108 /** 109 * Appends all elements in the specified byte[] collection to the end of this list. 110 * 111 * @param c collection whose elements are to be added to this list 112 * @return true if this list changed as a result of the call 113 * @throws UnsupportedOperationException if the <tt>addAllByteArray</tt> operation is not 114 * supported by this list 115 */ addAllByteArray(Collection<byte[]> c)116 boolean addAllByteArray(Collection<byte[]> c); 117 118 /** 119 * Returns an unmodifiable List of the underlying elements, each of which is either a {@code 120 * String} or its equivalent UTF-8 encoded {@code ByteString} or byte[]. It is an error for the 121 * caller to modify the returned List, and attempting to do so will result in an {@link 122 * UnsupportedOperationException}. 123 */ getUnderlyingElements()124 List<?> getUnderlyingElements(); 125 126 /** 127 * Merges all elements from another LazyStringList into this one. This method differs from {@link 128 * #addAll(Collection)} on that underlying byte arrays are copied instead of reference shared. 129 * Immutable API doesn't need to use this method as byte[] is not used there at all. 130 */ mergeFrom(LazyStringList other)131 void mergeFrom(LazyStringList other); 132 133 /** 134 * Returns a mutable view of this list. Changes to the view will be made into the original list. 135 * This method is used in mutable API only. 136 */ asByteArrayList()137 List<byte[]> asByteArrayList(); 138 139 /** Returns an unmodifiable view of the list. */ getUnmodifiableView()140 LazyStringList getUnmodifiableView(); 141 } 142