1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // Derived from: 6 // mozilla/netwerk/protocol/http/src/nsHttpChunkedDecoder.h 7 // The license block is: 8 /* ***** BEGIN LICENSE BLOCK ***** 9 * Version: MPL 1.1/GPL 2.0/LGPL 2.1 10 * 11 * The contents of this file are subject to the Mozilla Public License Version 12 * 1.1 (the "License"); you may not use this file except in compliance with 13 * the License. You may obtain a copy of the License at 14 * http://www.mozilla.org/MPL/ 15 * 16 * Software distributed under the License is distributed on an "AS IS" basis, 17 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 18 * for the specific language governing rights and limitations under the 19 * License. 20 * 21 * The Original Code is Mozilla. 22 * 23 * The Initial Developer of the Original Code is 24 * Netscape Communications. 25 * Portions created by the Initial Developer are Copyright (C) 2001 26 * the Initial Developer. All Rights Reserved. 27 * 28 * Contributor(s): 29 * Darin Fisher <darin (at) netscape.com> (original author) 30 * 31 * Alternatively, the contents of this file may be used under the terms of 32 * either the GNU General Public License Version 2 or later (the "GPL"), or 33 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), 34 * in which case the provisions of the GPL or the LGPL are applicable instead 35 * of those above. If you wish to allow use of your version of this file only 36 * under the terms of either the GPL or the LGPL, and not to allow others to 37 * use your version of this file under the terms of the MPL, indicate your 38 * decision by deleting the provisions above and replace them with the notice 39 * and other provisions required by the GPL or the LGPL. If you do not delete 40 * the provisions above, a recipient may use your version of this file under 41 * the terms of any one of the MPL, the GPL or the LGPL. 42 * 43 * ***** END LICENSE BLOCK ***** */ 44 45 #ifndef NET_HTTP_HTTP_CHUNKED_DECODER_H_ 46 #define NET_HTTP_HTTP_CHUNKED_DECODER_H_ 47 48 #include <string> 49 50 #include "net/base/net_export.h" 51 52 namespace net { 53 54 // From RFC2617 section 3.6.1, the chunked transfer coding is defined as: 55 // 56 // Chunked-Body = *chunk 57 // last-chunk 58 // trailer 59 // CRLF 60 // chunk = chunk-size [ chunk-extension ] CRLF 61 // chunk-data CRLF 62 // chunk-size = 1*HEX 63 // last-chunk = 1*("0") [ chunk-extension ] CRLF 64 // 65 // chunk-extension = *( ";" chunk-ext-name [ "=" chunk-ext-val ] ) 66 // chunk-ext-name = token 67 // chunk-ext-val = token | quoted-string 68 // chunk-data = chunk-size(OCTET) 69 // trailer = *(entity-header CRLF) 70 // 71 // The chunk-size field is a string of hex digits indicating the size of the 72 // chunk. The chunked encoding is ended by any chunk whose size is zero, 73 // followed by the trailer, which is terminated by an empty line. 74 // 75 // NOTE: This implementation does not bother to parse trailers since they are 76 // not used on the web. 77 // 78 class NET_EXPORT_PRIVATE HttpChunkedDecoder { 79 public: 80 // The maximum length of |line_buf_| between calls to FilterBuff(). 81 // Exposed for tests. 82 static const size_t kMaxLineBufLen; 83 84 HttpChunkedDecoder(); 85 86 // Indicates that a previous call to FilterBuf encountered the final CRLF. 87 bool reached_eof() const { return reached_eof_; } 88 89 // Returns the number of bytes after the final CRLF. 90 int bytes_after_eof() const { return bytes_after_eof_; } 91 92 // Called to filter out the chunk markers from buf and to check for end-of- 93 // file. This method modifies |buf| inline if necessary to remove chunk 94 // markers. The return value indicates the final size of decoded data stored 95 // in |buf|. Call reached_eof() after this method to check if end-of-file 96 // was encountered. 97 int FilterBuf(char* buf, int buf_len); 98 99 private: 100 // Scans |buf| for the next chunk delimiter. This method returns the number 101 // of bytes consumed from |buf|. If found, |chunk_remaining_| holds the 102 // value for the next chunk size. 103 int ScanForChunkRemaining(const char* buf, int buf_len); 104 105 // Converts string |start| of length |len| to a numeric value. 106 // |start| is a string of type "chunk-size" (hex string). 107 // If the conversion succeeds, returns true and places the result in |out|. 108 static bool ParseChunkSize(const char* start, int len, int* out); 109 110 // Indicates the number of bytes remaining for the current chunk. 111 int chunk_remaining_; 112 113 // A small buffer used to store a partial chunk marker. 114 std::string line_buf_; 115 116 // True if waiting for the terminal CRLF of a chunk's data. 117 bool chunk_terminator_remaining_; 118 119 // Set to true when FilterBuf encounters the last-chunk. 120 bool reached_last_chunk_; 121 122 // Set to true when FilterBuf encounters the final CRLF. 123 bool reached_eof_; 124 125 // The number of extraneous unfiltered bytes after the final CRLF. 126 int bytes_after_eof_; 127 }; 128 129 } // namespace net 130 131 #endif // NET_HTTP_HTTP_CHUNKED_DECODER_H_ 132
