zinflate_8cpp-source.html

著名的密码库Crypto++的文档 C++语言的杰作。程序员必备。

<a name="l00343"></a>00343                         <span class="keywordflow">if</span> (!DecodeBody())
<a name="l00344"></a>00344                                 <span class="keywordflow">return</span>;
<a name="l00345"></a>00345                         <span class="keywordflow">break</span>;
<a name="l00346"></a>00346                 <span class="keywordflow">case</span> POST_STREAM:
<a name="l00347"></a>00347                         <span class="keywordflow">if</span> (!flush &amp;&amp; <a class="code" href="class_inflator.html#e219ede9a3c7342d6c9262f87c8a571d">m_inQueue</a>.<a class="code" href="class_byte_queue.html#003ce4b0f9525589327800d0a14b455f">CurrentSize</a>() &lt; MaxPoststreamTailSize())
<a name="l00348"></a>00348                                 <span class="keywordflow">return</span>;
<a name="l00349"></a>00349                         ProcessPoststreamTail();
<a name="l00350"></a>00350                         m_state = m_repeat ? PRE_STREAM : AFTER_END;
<a name="l00351"></a>00351                         <a class="code" href="class_filter.html#a05cdcaa161f2131cf4d5dcb8903e11f">Output</a>(0, NULL, 0, <a class="code" href="class_auto_signaling.html#011dc89743a4790bdd2ddefd9f176766">GetAutoSignalPropagation</a>(), <span class="keyword">true</span>);   <span class="comment">// TODO: non-blocking</span>
<a name="l00352"></a>00352                         <span class="keywordflow">if</span> (<a class="code" href="class_inflator.html#e219ede9a3c7342d6c9262f87c8a571d">m_inQueue</a>.<a class="code" href="class_byte_queue.html#c218d4b07fe058306a00475222869aaa">IsEmpty</a>())
<a name="l00353"></a>00353                                 <span class="keywordflow">return</span>;
<a name="l00354"></a>00354                         <span class="keywordflow">break</span>;
<a name="l00355"></a>00355                 <span class="keywordflow">case</span> AFTER_END:
<a name="l00356"></a>00356                         <a class="code" href="class_inflator.html#e219ede9a3c7342d6c9262f87c8a571d">m_inQueue</a>.<a class="code" href="class_buffered_transformation.html#91c4526148274ae9cb68803bb2d2a2aa" title="move transferMax bytes of the buffered output to target as input">TransferTo</a>(*<a class="code" href="class_filter.html#c8fc888888b2dad88bf64fc703044a93" title="returns the object immediately attached to this object or NULL for no attachment">AttachedTransformation</a>());
<a name="l00357"></a>00357                         <span class="keywordflow">return</span>;
<a name="l00358"></a>00358                 }
<a name="l00359"></a>00359         }
<a name="l00360"></a>00360 }
<a name="l00361"></a>00361 
<a name="l00362"></a>00362 <span class="keywordtype">void</span> Inflator::DecodeHeader()
<a name="l00363"></a>00363 {
<a name="l00364"></a>00364         <span class="keywordflow">if</span> (!m_reader.<a class="code" href="class_low_first_bit_reader.html#7c2250f093883488eefb6d498aa1c510">FillBuffer</a>(3))
<a name="l00365"></a>00365                 <span class="keywordflow">throw</span> UnexpectedEndErr();
<a name="l00366"></a>00366         m_eof = m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(1) != 0;
<a name="l00367"></a>00367         m_blockType = (byte)m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(2);
<a name="l00368"></a>00368         <span class="keywordflow">switch</span> (m_blockType)
<a name="l00369"></a>00369         {
<a name="l00370"></a>00370         <span class="keywordflow">case</span> 0: <span class="comment">// stored</span>
<a name="l00371"></a>00371                 {
<a name="l00372"></a>00372                 m_reader.<a class="code" href="class_low_first_bit_reader.html#7127a720aeefbc1d91dddefc694538c6">SkipBits</a>(m_reader.<a class="code" href="class_low_first_bit_reader.html#62533059d5572cf7dfc5bcb7d308bec6">BitsBuffered</a>() % 8);
<a name="l00373"></a>00373                 <span class="keywordflow">if</span> (!m_reader.<a class="code" href="class_low_first_bit_reader.html#7c2250f093883488eefb6d498aa1c510">FillBuffer</a>(32))
<a name="l00374"></a>00374                         <span class="keywordflow">throw</span> UnexpectedEndErr();
<a name="l00375"></a>00375                 m_storedLen = (word16)m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(16);
<a name="l00376"></a>00376                 word16 nlen = (word16)m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(16);
<a name="l00377"></a>00377                 <span class="keywordflow">if</span> (nlen != (word16)~m_storedLen)
<a name="l00378"></a>00378                         <span class="keywordflow">throw</span> BadBlockErr();
<a name="l00379"></a>00379                 <span class="keywordflow">break</span>;
<a name="l00380"></a>00380                 }
<a name="l00381"></a>00381         <span class="keywordflow">case</span> 1: <span class="comment">// fixed codes</span>
<a name="l00382"></a>00382                 m_nextDecode = LITERAL;
<a name="l00383"></a>00383                 <span class="keywordflow">break</span>;
<a name="l00384"></a>00384         <span class="keywordflow">case</span> 2: <span class="comment">// dynamic codes</span>
<a name="l00385"></a>00385                 {
<a name="l00386"></a>00386                 <span class="keywordflow">if</span> (!m_reader.<a class="code" href="class_low_first_bit_reader.html#7c2250f093883488eefb6d498aa1c510">FillBuffer</a>(5+5+4))
<a name="l00387"></a>00387                         <span class="keywordflow">throw</span> UnexpectedEndErr();
<a name="l00388"></a>00388                 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> hlit = m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(5);
<a name="l00389"></a>00389                 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> hdist = m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(5);
<a name="l00390"></a>00390                 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> hclen = m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(4);
<a name="l00391"></a>00391 
<a name="l00392"></a>00392                 <a class="code" href="class_fixed_size_sec_block.html" title="a SecBlock with fixed size, allocated statically">FixedSizeSecBlock&lt;unsigned int, 286+32&gt;</a> codeLengths;
<a name="l00393"></a>00393                 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> i;
<a name="l00394"></a>00394                 <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> border[] = {    <span class="comment">// Order of the bit length code lengths</span>
<a name="l00395"></a>00395                         16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
<a name="l00396"></a>00396                 std::fill(codeLengths.<a class="code" href="class_sec_block.html#11a05906688172579cd3520816799446">begin</a>(), codeLengths+19, 0);
<a name="l00397"></a>00397                 <span class="keywordflow">for</span> (i=0; i&lt;hclen+4; i++)
<a name="l00398"></a>00398                         codeLengths[border[i]] = m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(3);
<a name="l00399"></a>00399 
<a name="l00400"></a>00400                 <span class="keywordflow">try</span>
<a name="l00401"></a>00401                 {
<a name="l00402"></a>00402                         <a class="code" href="class_huffman_decoder.html" title="Huffman Decoder.">HuffmanDecoder</a> codeLengthDecoder(codeLengths, 19);
<a name="l00403"></a>00403                         <span class="keywordflow">for</span> (i = 0; i &lt; hlit+257+hdist+1; )
<a name="l00404"></a>00404                         {
<a name="l00405"></a>00405                                 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> k, count, repeater;
<a name="l00406"></a>00406                                 <span class="keywordtype">bool</span> result = codeLengthDecoder.Decode(m_reader, k);
<a name="l00407"></a>00407                                 <span class="keywordflow">if</span> (!result)
<a name="l00408"></a>00408                                         <span class="keywordflow">throw</span> UnexpectedEndErr();
<a name="l00409"></a>00409                                 <span class="keywordflow">if</span> (k &lt;= 15)
<a name="l00410"></a>00410                                 {
<a name="l00411"></a>00411                                         count = 1;
<a name="l00412"></a>00412                                         repeater = k;
<a name="l00413"></a>00413                                 }
<a name="l00414"></a>00414                                 <span class="keywordflow">else</span> <span class="keywordflow">switch</span> (k)
<a name="l00415"></a>00415                                 {
<a name="l00416"></a>00416                                 <span class="keywordflow">case</span> 16:
<a name="l00417"></a>00417                                         <span class="keywordflow">if</span> (!m_reader.<a class="code" href="class_low_first_bit_reader.html#7c2250f093883488eefb6d498aa1c510">FillBuffer</a>(2))
<a name="l00418"></a>00418                                                 <span class="keywordflow">throw</span> UnexpectedEndErr();
<a name="l00419"></a>00419                                         count = 3 + m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(2);
<a name="l00420"></a>00420                                         <span class="keywordflow">if</span> (i == 0)
<a name="l00421"></a>00421                                                 <span class="keywordflow">throw</span> BadBlockErr();
<a name="l00422"></a>00422                                         repeater = codeLengths[i-1];
<a name="l00423"></a>00423                                         <span class="keywordflow">break</span>;
<a name="l00424"></a>00424                                 <span class="keywordflow">case</span> 17:
<a name="l00425"></a>00425                                         <span class="keywordflow">if</span> (!m_reader.<a class="code" href="class_low_first_bit_reader.html#7c2250f093883488eefb6d498aa1c510">FillBuffer</a>(3))
<a name="l00426"></a>00426                                                 <span class="keywordflow">throw</span> UnexpectedEndErr();
<a name="l00427"></a>00427                                         count = 3 + m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(3);
<a name="l00428"></a>00428                                         repeater = 0;
<a name="l00429"></a>00429                                         <span class="keywordflow">break</span>;
<a name="l00430"></a>00430                                 <span class="keywordflow">case</span> 18:
<a name="l00431"></a>00431                                         <span class="keywordflow">if</span> (!m_reader.<a class="code" href="class_low_first_bit_reader.html#7c2250f093883488eefb6d498aa1c510">FillBuffer</a>(7))
<a name="l00432"></a>00432                                                 <span class="keywordflow">throw</span> UnexpectedEndErr();
<a name="l00433"></a>00433                                         count = 11 + m_reader.<a class="code" href="class_low_first_bit_reader.html#ecfd76bf8814829b75d9d4f6592a4625">GetBits</a>(7);
<a name="l00434"></a>00434                                         repeater = 0;
<a name="l00435"></a>00435                                         <span class="keywordflow">break</span>;
<a name="l00436"></a>00436                                 }
<a name="l00437"></a>00437                                 <span class="keywordflow">if</span> (i + count &gt; hlit+257+hdist+1)
<a name="l00438"></a>00438                                         <span class="keywordflow">throw</span> BadBlockErr();
<a name="l00439"></a>00439                                 std::fill(codeLengths + i, codeLengths + i + count, repeater);
<a name="l00440"></a>00440                                 i += count;
<a name="l00441"></a>00441                         }
<a name="l00442"></a>00442                         m_dynamicLiteralDecoder.<a class="code" href="class_huffman_decoder.html#66275670f30366de75c3bcb506c657f5">Initialize</a>(codeLengths, hlit+257);
<a name="l00443"></a>00443                         <span class="keywordflow">if</span> (hdist == 0 &amp;&amp; codeLengths[hlit+257] == 0)
<a name="l00444"></a>00444                         {
<a name="l00445"></a>00445                                 <span class="keywordflow">if</span> (hlit != 0)  <span class="comment">// a single zero distance code length means all literals</span>
<a name="l00446"></a>00446                                         <span class="keywordflow">throw</span> BadBlockErr();
<a name="l00447"></a>00447                         }
<a name="l00448"></a>00448                         <span class="keywordflow">else</span>
<a name="l00449"></a>00449                                 m_dynamicDistanceDecoder.<a class="code" href="class_huffman_decoder.html#66275670f30366de75c3bcb506c657f5">Initialize</a>(codeLengths+hlit+257, hdist+1);
<a name="l00450"></a>00450                         m_nextDecode = LITERAL;
<a name="l00451"></a>00451                 }
<a name="l00452"></a>00452                 <span class="keywordflow">catch</span> (<a class="code" href="class_huffman_decoder_1_1_err.html">HuffmanDecoder::Err</a> &amp;)
<a name="l00453"></a>00453                 {
<a name="l00454"></a>00454                         <span class="keywordflow">throw</span> BadBlockErr();
<a name="l00455"></a>00455                 }
<a name="l00456"></a>00456                 <span class="keywordflow">break</span>;
<a name="l00457"></a>00457                 }
<a name="l00458"></a>00458         <span class="keywordflow">default</span>:
<a name="l00459"></a>00459                 <span class="keywordflow">throw</span> BadBlockErr();    <span class="comment">// reserved block type</span>
<a name="l00460"></a>00460         }
<a name="l00461"></a>00461         m_state = DECODING_BODY;
<a name="l00462"></a>00462 }
<a name="l00463"></a>00463