zinflate_8cpp-source.html

Crypto++是一个非常强大的密码学库,主要是功能全

00143 }
00144 
00145 <span class="keywordtype">void</span> HuffmanDecoder::FillCacheEntry(LookupEntry &amp;entry, code_t normalizedCode)<span class="keyword"> const</span>
00146 <span class="keyword"></span>{
00147         normalizedCode &amp;= m_normalizedCacheMask;
00148         <span class="keyword">const</span> CodeInfo &amp;codeInfo = *(std::upper_bound(m_codeToValue.begin(), m_codeToValue.end(), normalizedCode, CodeLessThan())-1);
00149         <span class="keywordflow">if</span> (codeInfo.len &lt;= m_cacheBits)
00150         {
00151                 entry.type = 1;
00152                 entry.value = codeInfo.value;
00153                 entry.len = codeInfo.len;
00154         }
00155         <span class="keywordflow">else</span>
00156         {
00157                 entry.begin = &amp;codeInfo;
00158                 <span class="keyword">const</span> CodeInfo *last = &amp; *(std::upper_bound(m_codeToValue.begin(), m_codeToValue.end(), normalizedCode + ~m_normalizedCacheMask, CodeLessThan())-1);
00159                 <span class="keywordflow">if</span> (codeInfo.len == last-&gt;len)
00160                 {
00161                         entry.type = 2;
00162                         entry.len = codeInfo.len;
00163                 }
00164                 <span class="keywordflow">else</span>
00165                 {
00166                         entry.type = 3;
00167                         entry.end = last+1;
00168                 }
00169         }
00170 }
00171 
00172 <span class="keyword">inline</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> HuffmanDecoder::Decode(code_t code, <span class="comment">/* out */</span> value_t &amp;value)<span class="keyword"> const</span>
00173 <span class="keyword"></span>{
00174         assert(m_codeToValue.size() &gt; 0);
00175         LookupEntry &amp;entry = m_cache[code &amp; m_cacheMask];
00176 
00177         code_t normalizedCode;
00178         <span class="keywordflow">if</span> (entry.type != 1)
00179                 normalizedCode = BitReverse(code);
00180 
00181         <span class="keywordflow">if</span> (entry.type == 0)
00182                 FillCacheEntry(entry, normalizedCode);
00183 
00184         <span class="keywordflow">if</span> (entry.type == 1)
00185         {
00186                 value = entry.value;
00187                 <span class="keywordflow">return</span> entry.len;
00188         }
00189         <span class="keywordflow">else</span>
00190         {
00191                 <span class="keyword">const</span> CodeInfo &amp;codeInfo = (entry.type == 2)
00192                         ? entry.begin[(normalizedCode &lt;&lt; m_cacheBits) &gt;&gt; (MAX_CODE_BITS - (entry.len - m_cacheBits))]
00193                         : *(std::upper_bound(entry.begin, entry.end, normalizedCode, CodeLessThan())-1);
00194                 value = codeInfo.value;
00195                 <span class="keywordflow">return</span> codeInfo.len;
00196         }
00197 }
00198 
00199 <span class="keywordtype">bool</span> HuffmanDecoder::Decode(<a class="code" href="class_low_first_bit_reader.html">LowFirstBitReader</a> &amp;reader, value_t &amp;value)<span class="keyword"> const</span>
00200 <span class="keyword"></span>{
00201         reader.<a class="code" href="class_low_first_bit_reader.html#_low_first_bit_readera4">FillBuffer</a>(m_maxCodeBits);
00202         <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> codeBits = Decode(reader.<a class="code" href="class_low_first_bit_reader.html#_low_first_bit_readera3">PeekBuffer</a>(), value);
00203         <span class="keywordflow">if</span> (codeBits &gt; reader.<a class="code" href="class_low_first_bit_reader.html#_low_first_bit_readera2">BitsBuffered</a>())
00204                 <span class="keywordflow">return</span> <span class="keyword">false</span>;
00205         reader.<a class="code" href="class_low_first_bit_reader.html#_low_first_bit_readera6">SkipBits</a>(codeBits);
00206         <span class="keywordflow">return</span> <span class="keyword">true</span>;
00207 }
00208 
00209 <span class="comment">// *************************************************************</span>
00210 
<a name="l00211"></a><a class="code" href="class_inflator.html#_inflatora0">00211</a> <a class="code" href="class_inflator.html#_inflatora0">Inflator::Inflator</a>(<a class="code" href="class_buffered_transformation.html">BufferedTransformation</a> *attachment, <span class="keywordtype">bool</span> repeat, <span class="keywordtype">int</span> propagation)
00212         : AutoSignaling&lt;<a class="code" href="class_filter.html">Filter</a>&gt;(attachment, propagation)
00213         , m_state(PRE_STREAM), m_repeat(repeat)
00214         , m_decodersInitializedWithFixedCodes(false), m_reader(m_inQueue)
00215 {
00216 }
00217 
00218 <span class="keywordtype">void</span> Inflator::IsolatedInitialize(<span class="keyword">const</span> <a class="code" href="class_name_value_pairs.html">NameValuePairs</a> &amp;parameters)
00219 {
00220         m_state = PRE_STREAM;
00221         parameters.<a class="code" href="class_name_value_pairs.html#_x_t_r___d_ha39">GetValue</a>(<span class="stringliteral">"Repeat"</span>, m_repeat);
00222         m_inQueue.<a class="code" href="class_byte_queue.html#_d_e_r_set_encodera17">Clear</a>();
00223         m_reader.<a class="code" href="class_low_first_bit_reader.html#_low_first_bit_readera6">SkipBits</a>(m_reader.<a class="code" href="class_low_first_bit_reader.html#_low_first_bit_readera2">BitsBuffered</a>());
00224 }
00225 
00226 <span class="keyword">inline</span> <span class="keywordtype">void</span> Inflator::OutputByte(byte b)
00227 {
00228         m_window[m_current++] = b;
00229         <span class="keywordflow">if</span> (m_current == m_window.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>())
00230         {
00231                 ProcessDecompressedData(m_window + m_lastFlush, m_window.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>() - m_lastFlush);
00232                 m_lastFlush = 0;
00233                 m_current = 0;
00234         }
00235         <span class="keywordflow">if</span> (m_maxDistance &lt; m_window.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>())
00236                 m_maxDistance++;
00237 }
00238 
00239 <span class="keywordtype">void</span> Inflator::OutputString(<span class="keyword">const</span> byte *string, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> length)
00240 {
00241         <span class="keywordflow">while</span> (length--)
00242                 OutputByte(*string++);
00243 }
00244 
00245 <span class="keywordtype">void</span> Inflator::OutputPast(<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> length, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> distance)
00246 {
00247         <span class="keywordflow">if</span> (distance &gt; m_maxDistance)
00248                 <span class="keywordflow">throw</span> BadBlockErr();
00249         <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> start;
00250         <span class="keywordflow">if</span> (m_current &gt; distance)
00251                 start = m_current - distance;
00252         <span class="keywordflow">else</span>
00253                 start = m_current + m_window.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>() - distance;
00254 
00255         <span class="keywordflow">if</span> (start + length &gt; m_window.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>())
00256         {
00257                 <span class="keywordflow">for</span> (; start &lt; m_window.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>(); start++, length--)
00258                         OutputByte(m_window[start]);
00259                 start = 0;
00260         }
00261 
00262         <span class="keywordflow">if</span> (start + length &gt; m_current || m_current + length &gt;= m_window.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>())
00263         {
00264                 <span class="keywordflow">while</span> (length--)
00265                         OutputByte(m_window[start++]);
00266         }
00267         <span class="keywordflow">else</span>
00268         {
00269                 memcpy(m_window + m_current, m_window + start, length);
00270                 m_current += length;
00271                 m_maxDistance = STDMIN((<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span>)m_window.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>(), m_maxDistance + length);
00272         }
00273 }
00274 
<a name="l00275"></a><a class="code" href="class_inflator.html#_zlib_decompressora3">00275</a> <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> <a class="code" href="class_inflator.html#_zlib_decompressora3">Inflator::Put2</a>(<span class="keyword">const</span> byte *inString, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> length, <span class="keywordtype">int</span> messageEnd, <span class="keywordtype">bool</span> blocking)
00276 {
00277         <span class="keywordflow">if</span> (!blocking)
00278                 <span class="keywordflow">throw</span> BlockingInputOnly(<span class="stringliteral">"Inflator"</span>);
00279 
00280         <a class="code" href="class_lazy_putter.html">LazyPutter</a> lp(m_inQueue, inString, length);
00281         ProcessInput(messageEnd != 0);
00282 
00283         <span class="keywordflow">if</span> (messageEnd)
00284                 <span class="keywordflow">if</span> (!(m_state == PRE_STREAM || m_state == AFTER_END))
00285                         <span class="keywordflow">throw</span> UnexpectedEndErr();
00286 
00287         Output(0, NULL, 0, messageEnd, blocking);
00288         <span class="keywordflow">return</span> 0;
00289 }
00290 
00291 <span class="keywordtype">bool</span> Inflator::IsolatedFlush(<span class="keywordtype">bool</span> hardFlush, <span class="keywordtype">bool</span> blocking)