ChunkedDecoder.cc 4.1 KB

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  1. /* <!-- copyright */
  2. /*
  3. * aria2 - The high speed download utility
  4. *
  5. * Copyright (C) 2006 Tatsuhiro Tsujikawa
  6. *
  7. * This program is free software; you can redistribute it and/or modify
  8. * it under the terms of the GNU General Public License as published by
  9. * the Free Software Foundation; either version 2 of the License, or
  10. * (at your option) any later version.
  11. *
  12. * This program is distributed in the hope that it will be useful,
  13. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15. * GNU General Public License for more details.
  16. *
  17. * You should have received a copy of the GNU General Public License
  18. * along with this program; if not, write to the Free Software
  19. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20. *
  21. * In addition, as a special exception, the copyright holders give
  22. * permission to link the code of portions of this program with the
  23. * OpenSSL library under certain conditions as described in each
  24. * individual source file, and distribute linked combinations
  25. * including the two.
  26. * You must obey the GNU General Public License in all respects
  27. * for all of the code used other than OpenSSL. If you modify
  28. * file(s) with this exception, you may extend this exception to your
  29. * version of the file(s), but you are not obligated to do so. If you
  30. * do not wish to do so, delete this exception statement from your
  31. * version. If you delete this exception statement from all source
  32. * files in the program, then also delete it here.
  33. */
  34. /* copyright --> */
  35. #include "ChunkedDecoder.h"
  36. #include "util.h"
  37. #include "message.h"
  38. #include "DlAbortEx.h"
  39. #include "StringFormat.h"
  40. #include "A2STR.h"
  41. namespace aria2 {
  42. const std::string ChunkedDecoder::NAME("ChunkedDecoder");
  43. ChunkedDecoder::ChunkedDecoder():chunkSize_(0), state_(READ_SIZE) {}
  44. ChunkedDecoder::~ChunkedDecoder() {}
  45. void ChunkedDecoder::init() {}
  46. static bool readChunkSize(uint64_t& chunkSize, std::string& in)
  47. {
  48. std::string::size_type crlfPos = in.find(A2STR::CRLF);
  49. if(crlfPos == std::string::npos) {
  50. return false;
  51. }
  52. std::string::size_type extPos = in.find(A2STR::SEMICOLON_C);
  53. if(extPos == std::string::npos || crlfPos < extPos) {
  54. extPos = crlfPos;
  55. }
  56. chunkSize = util::parseULLInt(in.substr(0, extPos), 16);
  57. in.erase(0, crlfPos+2);
  58. return true;
  59. }
  60. static bool readTrailer(std::string& in)
  61. {
  62. std::string::size_type crlfPos = in.find(A2STR::CRLF);
  63. if(crlfPos == std::string::npos) {
  64. return false;
  65. }
  66. if(crlfPos == 0) {
  67. return true;
  68. } else {
  69. if(in.size() > crlfPos+3) {
  70. if(in[crlfPos+2] == '\r' && in[crlfPos+3] == '\n') {
  71. return true;
  72. } else {
  73. throw DL_ABORT_EX("No CRLF at the end of chunk stream.");
  74. }
  75. } else {
  76. return false;
  77. }
  78. }
  79. }
  80. static bool readData(std::string& out, uint64_t& chunkSize, std::string& in)
  81. {
  82. uint64_t readlen = std::min(chunkSize, static_cast<uint64_t>(in.size()));
  83. out.append(in.begin(), in.begin()+readlen);
  84. in.erase(0, readlen);
  85. chunkSize -= readlen;
  86. if(chunkSize == 0 && in.size() >= 2) {
  87. if(in.find(A2STR::CRLF) == 0) {
  88. in.erase(0, 2);
  89. return true;
  90. } else {
  91. throw DL_ABORT_EX(EX_INVALID_CHUNK_SIZE);
  92. }
  93. } else {
  94. return false;
  95. }
  96. }
  97. std::string ChunkedDecoder::decode(const unsigned char* inbuf, size_t inlen)
  98. {
  99. buf_.append(&inbuf[0], &inbuf[inlen]);
  100. std::string outbuf;
  101. while(1) {
  102. if(state_ == READ_SIZE) {
  103. if(readChunkSize(chunkSize_, buf_)) {
  104. if(chunkSize_ == 0) {
  105. state_ = READ_TRAILER;
  106. } else {
  107. state_ = READ_DATA;
  108. }
  109. } else {
  110. break;
  111. }
  112. } else if(state_ == READ_DATA) {
  113. if(readData(outbuf, chunkSize_, buf_)) {
  114. state_ = READ_SIZE;
  115. } else {
  116. break;
  117. }
  118. } else if(state_ == READ_TRAILER) {
  119. if(readTrailer(buf_)) {
  120. state_ = STREAM_END;
  121. break;
  122. } else {
  123. break;
  124. }
  125. }
  126. }
  127. return outbuf;
  128. }
  129. bool ChunkedDecoder::finished()
  130. {
  131. return state_ == STREAM_END;
  132. }
  133. void ChunkedDecoder::release() {}
  134. const std::string& ChunkedDecoder::getName() const
  135. {
  136. return NAME;
  137. }
  138. } // namespace aria2