mobile/android/thirdparty/ch/boye/httpclientandroidlib/client/entity/DeflateDecompressingEntity.java@fc2d59ddac77 (annotated)
mobile/android/thirdparty/ch/boye/httpclientandroidlib/client/entity/DeflateDecompressingEntity.java
Wed, 31 Dec 2014 07:22:50 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 07:22:50 +0100
- branch
- TOR_BUG_3246
- changeset 4
- fc2d59ddac77
- permissions
- -rw-r--r--
Correct previous dual key logic pending first delivery installment.
| michael@0 | 1 | /* |
| michael@0 | 2 | * ==================================================================== |
| michael@0 | 3 | * |
| michael@0 | 4 | * Licensed to the Apache Software Foundation (ASF) under one or more |
| michael@0 | 5 | * contributor license agreements. See the NOTICE file distributed with |
| michael@0 | 6 | * this work for additional information regarding copyright ownership. |
| michael@0 | 7 | * The ASF licenses this file to You under the Apache License, Version 2.0 |
| michael@0 | 8 | * (the "License"); you may not use this file except in compliance with |
| michael@0 | 9 | * the License. You may obtain a copy of the License at |
| michael@0 | 10 | * |
| michael@0 | 11 | * http://www.apache.org/licenses/LICENSE-2.0 |
| michael@0 | 12 | * |
| michael@0 | 13 | * Unless required by applicable law or agreed to in writing, software |
| michael@0 | 14 | * distributed under the License is distributed on an "AS IS" BASIS, |
| michael@0 | 15 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| michael@0 | 16 | * See the License for the specific language governing permissions and |
| michael@0 | 17 | * limitations under the License. |
| michael@0 | 18 | * ==================================================================== |
| michael@0 | 19 | * |
| michael@0 | 20 | * This software consists of voluntary contributions made by many |
| michael@0 | 21 | * individuals on behalf of the Apache Software Foundation. For more |
| michael@0 | 22 | * information on the Apache Software Foundation, please see |
| michael@0 | 23 | * <http://www.apache.org/>. |
| michael@0 | 24 | * |
| michael@0 | 25 | */ |
| michael@0 | 26 | package ch.boye.httpclientandroidlib.client.entity; |
| michael@0 | 27 | |
| michael@0 | 28 | import java.io.IOException; |
| michael@0 | 29 | import java.io.InputStream; |
| michael@0 | 30 | import java.io.PushbackInputStream; |
| michael@0 | 31 | import java.util.zip.DataFormatException; |
| michael@0 | 32 | import java.util.zip.Inflater; |
| michael@0 | 33 | import java.util.zip.InflaterInputStream; |
| michael@0 | 34 | |
| michael@0 | 35 | import ch.boye.httpclientandroidlib.Header; |
| michael@0 | 36 | import ch.boye.httpclientandroidlib.HttpEntity; |
| michael@0 | 37 | import ch.boye.httpclientandroidlib.entity.HttpEntityWrapper; |
| michael@0 | 38 | |
| michael@0 | 39 | /** |
| michael@0 | 40 | * {@link HttpEntityWrapper} responsible for handling deflate Content Coded responses. In RFC2616 |
| michael@0 | 41 | * terms, <code>deflate</code> means a <code>zlib</code> stream as defined in RFC1950. Some server |
| michael@0 | 42 | * implementations have misinterpreted RFC2616 to mean that a <code>deflate</code> stream as |
| michael@0 | 43 | * defined in RFC1951 should be used (or maybe they did that since that's how IE behaves?). It's |
| michael@0 | 44 | * confusing that <code>deflate</code> in HTTP 1.1 means <code>zlib</code> streams rather than |
| michael@0 | 45 | * <code>deflate</code> streams. We handle both types in here, since that's what is seen on the |
| michael@0 | 46 | * internet. Moral - prefer <code>gzip</code>! |
| michael@0 | 47 | * |
| michael@0 | 48 | * @see GzipDecompressingEntity |
| michael@0 | 49 | * |
| michael@0 | 50 | * @since 4.1 |
| michael@0 | 51 | */ |
| michael@0 | 52 | public class DeflateDecompressingEntity extends DecompressingEntity { |
| michael@0 | 53 | |
| michael@0 | 54 | /** |
| michael@0 | 55 | * Creates a new {@link DeflateDecompressingEntity} which will wrap the specified |
| michael@0 | 56 | * {@link HttpEntity}. |
| michael@0 | 57 | * |
| michael@0 | 58 | * @param entity |
| michael@0 | 59 | * a non-null {@link HttpEntity} to be wrapped |
| michael@0 | 60 | */ |
| michael@0 | 61 | public DeflateDecompressingEntity(final HttpEntity entity) { |
| michael@0 | 62 | super(entity); |
| michael@0 | 63 | } |
| michael@0 | 64 | |
| michael@0 | 65 | /** |
| michael@0 | 66 | * Returns the non-null InputStream that should be returned to by all requests to |
| michael@0 | 67 | * {@link #getContent()}. |
| michael@0 | 68 | * |
| michael@0 | 69 | * @return a non-null InputStream |
| michael@0 | 70 | * @throws IOException if there was a problem |
| michael@0 | 71 | */ |
| michael@0 | 72 | @Override |
| michael@0 | 73 | InputStream getDecompressingInputStream(final InputStream wrapped) throws IOException { |
| michael@0 | 74 | /* |
| michael@0 | 75 | * A zlib stream will have a header. |
| michael@0 | 76 | * |
| michael@0 | 77 | * CMF | FLG [| DICTID ] | ...compressed data | ADLER32 | |
| michael@0 | 78 | * |
| michael@0 | 79 | * * CMF is one byte. |
| michael@0 | 80 | * |
| michael@0 | 81 | * * FLG is one byte. |
| michael@0 | 82 | * |
| michael@0 | 83 | * * DICTID is four bytes, and only present if FLG.FDICT is set. |
| michael@0 | 84 | * |
| michael@0 | 85 | * Sniff the content. Does it look like a zlib stream, with a CMF, etc? c.f. RFC1950, |
| michael@0 | 86 | * section 2.2. http://tools.ietf.org/html/rfc1950#page-4 |
| michael@0 | 87 | * |
| michael@0 | 88 | * We need to see if it looks like a proper zlib stream, or whether it is just a deflate |
| michael@0 | 89 | * stream. RFC2616 calls zlib streams deflate. Confusing, isn't it? That's why some servers |
| michael@0 | 90 | * implement deflate Content-Encoding using deflate streams, rather than zlib streams. |
| michael@0 | 91 | * |
| michael@0 | 92 | * We could start looking at the bytes, but to be honest, someone else has already read |
| michael@0 | 93 | * the RFCs and implemented that for us. So we'll just use the JDK libraries and exception |
| michael@0 | 94 | * handling to do this. If that proves slow, then we could potentially change this to check |
| michael@0 | 95 | * the first byte - does it look like a CMF? What about the second byte - does it look like |
| michael@0 | 96 | * a FLG, etc. |
| michael@0 | 97 | */ |
| michael@0 | 98 | |
| michael@0 | 99 | /* We read a small buffer to sniff the content. */ |
| michael@0 | 100 | byte[] peeked = new byte[6]; |
| michael@0 | 101 | |
| michael@0 | 102 | PushbackInputStream pushback = new PushbackInputStream(wrapped, peeked.length); |
| michael@0 | 103 | |
| michael@0 | 104 | int headerLength = pushback.read(peeked); |
| michael@0 | 105 | |
| michael@0 | 106 | if (headerLength == -1) { |
| michael@0 | 107 | throw new IOException("Unable to read the response"); |
| michael@0 | 108 | } |
| michael@0 | 109 | |
| michael@0 | 110 | /* We try to read the first uncompressed byte. */ |
| michael@0 | 111 | byte[] dummy = new byte[1]; |
| michael@0 | 112 | |
| michael@0 | 113 | Inflater inf = new Inflater(); |
| michael@0 | 114 | |
| michael@0 | 115 | try { |
| michael@0 | 116 | int n; |
| michael@0 | 117 | while ((n = inf.inflate(dummy)) == 0) { |
| michael@0 | 118 | if (inf.finished()) { |
| michael@0 | 119 | |
| michael@0 | 120 | /* Not expecting this, so fail loudly. */ |
| michael@0 | 121 | throw new IOException("Unable to read the response"); |
| michael@0 | 122 | } |
| michael@0 | 123 | |
| michael@0 | 124 | if (inf.needsDictionary()) { |
| michael@0 | 125 | |
| michael@0 | 126 | /* Need dictionary - then it must be zlib stream with DICTID part? */ |
| michael@0 | 127 | break; |
| michael@0 | 128 | } |
| michael@0 | 129 | |
| michael@0 | 130 | if (inf.needsInput()) { |
| michael@0 | 131 | inf.setInput(peeked); |
| michael@0 | 132 | } |
| michael@0 | 133 | } |
| michael@0 | 134 | |
| michael@0 | 135 | if (n == -1) { |
| michael@0 | 136 | throw new IOException("Unable to read the response"); |
| michael@0 | 137 | } |
| michael@0 | 138 | |
| michael@0 | 139 | /* |
| michael@0 | 140 | * We read something without a problem, so it's a valid zlib stream. Just need to reset |
| michael@0 | 141 | * and return an unused InputStream now. |
| michael@0 | 142 | */ |
| michael@0 | 143 | pushback.unread(peeked, 0, headerLength); |
| michael@0 | 144 | return new InflaterInputStream(pushback); |
| michael@0 | 145 | } catch (DataFormatException e) { |
| michael@0 | 146 | |
| michael@0 | 147 | /* Presume that it's an RFC1951 deflate stream rather than RFC1950 zlib stream and try |
| michael@0 | 148 | * again. */ |
| michael@0 | 149 | pushback.unread(peeked, 0, headerLength); |
| michael@0 | 150 | return new InflaterInputStream(pushback, new Inflater(true)); |
| michael@0 | 151 | } |
| michael@0 | 152 | } |
| michael@0 | 153 | |
| michael@0 | 154 | /** |
| michael@0 | 155 | * {@inheritDoc} |
| michael@0 | 156 | */ |
| michael@0 | 157 | @Override |
| michael@0 | 158 | public Header getContentEncoding() { |
| michael@0 | 159 | |
| michael@0 | 160 | /* This HttpEntityWrapper has dealt with the Content-Encoding. */ |
| michael@0 | 161 | return null; |
| michael@0 | 162 | } |
| michael@0 | 163 | |
| michael@0 | 164 | /** |
| michael@0 | 165 | * {@inheritDoc} |
| michael@0 | 166 | */ |
| michael@0 | 167 | @Override |
| michael@0 | 168 | public long getContentLength() { |
| michael@0 | 169 | |
| michael@0 | 170 | /* Length of inflated content is unknown. */ |
| michael@0 | 171 | return -1; |
| michael@0 | 172 | } |
| michael@0 | 173 | |
| michael@0 | 174 | } |
