1 /* 2 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package jdk.incubator.http.internal.hpack; 26 27 import java.nio.ByteBuffer; 28 import java.util.Arrays; 29 30 // 31 // 0 1 2 3 4 5 6 7 32 // +---+---+---+---+---+---+---+---+ 33 // | H | String Length (7+) | 34 // +---+---------------------------+ 35 // | String Data (Length octets) | 36 // +-------------------------------+ 37 // 38 // StringWriter does not require a notion of endOfInput (isLast) in 'write' 39 // methods due to the nature of string representation in HPACK. Namely, the 40 // length of the string is put before string's contents. Therefore the length is 41 // always known beforehand. 42 // 43 // Expected use: 44 // 45 // configure write* (reset configure write*)* 46 // 47 final class StringWriter { 48 49 private static final int NEW = 0; 50 private static final int CONFIGURED = 1; 51 private static final int LENGTH_WRITTEN = 2; 52 private static final int DONE = 4; 53 54 private final IntegerWriter intWriter = new IntegerWriter(); 55 private final Huffman.Writer huffmanWriter = new Huffman.Writer(); 56 private final ISO_8859_1.Writer plainWriter = new ISO_8859_1.Writer(); 57 58 private int state = NEW; 59 private boolean huffman; 60 61 StringWriter configure(CharSequence input, boolean huffman) { 62 return configure(input, 0, input.length(), huffman); 63 } 64 65 StringWriter configure(CharSequence input, int start, int end, 66 boolean huffman) { 67 if (start < 0 || end < 0 || end > input.length() || start > end) { 68 throw new IndexOutOfBoundsException( 69 String.format("input.length()=%s, start=%s, end=%s", 70 input.length(), start, end)); 71 } 72 if (!huffman) { 73 plainWriter.configure(input, start, end); 74 intWriter.configure(end - start, 7, 0b0000_0000); 75 } else { 76 huffmanWriter.from(input, start, end); 77 intWriter.configure(Huffman.INSTANCE.lengthOf(input, start, end), 78 7, 0b1000_0000); 79 } 80 81 this.huffman = huffman; 82 state = CONFIGURED; 83 return this; 84 } 85 86 boolean write(ByteBuffer output) { 87 if (state == DONE) { 88 return true; 89 } 90 if (state == NEW) { 91 throw new IllegalStateException("Configure first"); 92 } 93 if (!output.hasRemaining()) { 94 return false; 95 } 96 if (state == CONFIGURED) { 97 if (intWriter.write(output)) { 98 state = LENGTH_WRITTEN; 99 } else { 100 return false; 101 } 102 } 103 if (state == LENGTH_WRITTEN) { 104 boolean written = huffman 105 ? huffmanWriter.write(output) 106 : plainWriter.write(output); 107 if (written) { 108 state = DONE; 109 return true; 110 } else { 111 return false; 112 } 113 } 114 throw new InternalError(Arrays.toString(new Object[]{state, huffman})); 115 } 116 117 void reset() { 118 intWriter.reset(); 119 if (huffman) { 120 huffmanWriter.reset(); 121 } else { 122 plainWriter.reset(); 123 } 124 state = NEW; 125 } 126 }