misc_8h-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="l00123"></a>00123         <span class="keywordflow">switch</span> (s_objectState)
<a name="l00124"></a>00124         {
<a name="l00125"></a>00125         <span class="keywordflow">case</span> 0:
<a name="l00126"></a>00126                 s_objectState = 1;
<a name="l00127"></a>00127                 <span class="keywordflow">try</span>
<a name="l00128"></a>00128                 {
<a name="l00129"></a>00129                         s_pObject.<a class="code" href="classsimple__ptr.html#7c4a48ed4ea8b823d14de63fb6d56993">m_p</a> = m_objectFactory();
<a name="l00130"></a>00130                 }
<a name="l00131"></a>00131                 <span class="keywordflow">catch</span>(...)
<a name="l00132"></a>00132                 {
<a name="l00133"></a>00133                         s_objectState = 0;
<a name="l00134"></a>00134                         <span class="keywordflow">throw</span>;
<a name="l00135"></a>00135                 }
<a name="l00136"></a>00136                 s_objectState = 2;
<a name="l00137"></a>00137                 <span class="keywordflow">break</span>;
<a name="l00138"></a>00138         <span class="keywordflow">case</span> 1:
<a name="l00139"></a>00139                 <span class="keywordflow">goto</span> retry;
<a name="l00140"></a>00140         <span class="keywordflow">default</span>:
<a name="l00141"></a>00141                 <span class="keywordflow">break</span>;
<a name="l00142"></a>00142         }
<a name="l00143"></a>00143         <span class="keywordflow">return</span> *s_pObject.<a class="code" href="classsimple__ptr.html#7c4a48ed4ea8b823d14de63fb6d56993">m_p</a>;
<a name="l00144"></a>00144 }
<a name="l00145"></a>00145 
<a name="l00146"></a>00146 <span class="comment">// ************** misc functions ***************</span>
<a name="l00147"></a>00147 
<a name="l00148"></a>00148 <span class="preprocessor">#if (!__STDC_WANT_SECURE_LIB__)</span>
<a name="l00149"></a>00149 <span class="preprocessor"></span><span class="keyword">inline</span> <span class="keywordtype">void</span> memcpy_s(<span class="keywordtype">void</span> *dest, <span class="keywordtype">size_t</span> sizeInBytes, <span class="keyword">const</span> <span class="keywordtype">void</span> *src, <span class="keywordtype">size_t</span> count)
<a name="l00150"></a>00150 {
<a name="l00151"></a>00151         <span class="keywordflow">if</span> (count &gt; sizeInBytes)
<a name="l00152"></a>00152                 <span class="keywordflow">throw</span> <a class="code" href="class_invalid_argument.html" title="exception thrown when an invalid argument is detected">InvalidArgument</a>(<span class="stringliteral">"memcpy_s: buffer overflow"</span>);
<a name="l00153"></a>00153         memcpy(dest, src, count);
<a name="l00154"></a>00154 }
<a name="l00155"></a>00155 
<a name="l00156"></a>00156 <span class="keyword">inline</span> <span class="keywordtype">void</span> memmove_s(<span class="keywordtype">void</span> *dest, <span class="keywordtype">size_t</span> sizeInBytes, <span class="keyword">const</span> <span class="keywordtype">void</span> *src, <span class="keywordtype">size_t</span> count)
<a name="l00157"></a>00157 {
<a name="l00158"></a>00158         <span class="keywordflow">if</span> (count &gt; sizeInBytes)
<a name="l00159"></a>00159                 <span class="keywordflow">throw</span> <a class="code" href="class_invalid_argument.html" title="exception thrown when an invalid argument is detected">InvalidArgument</a>(<span class="stringliteral">"memmove_s: buffer overflow"</span>);
<a name="l00160"></a>00160         memmove(dest, src, count);
<a name="l00161"></a>00161 }
<a name="l00162"></a>00162 <span class="preprocessor">#endif</span>
<a name="l00163"></a>00163 <span class="preprocessor"></span>
<a name="l00164"></a>00164 <span class="comment">// can't use std::min or std::max in MSVC60 or Cygwin 1.1.0</span>
<a name="l00165"></a>00165 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt; <span class="keyword">inline</span> <span class="keyword">const</span> T&amp; STDMIN(<span class="keyword">const</span> T&amp; a, <span class="keyword">const</span> T&amp; b)
<a name="l00166"></a>00166 {
<a name="l00167"></a>00167         <span class="keywordflow">return</span> b &lt; a ? b : a;
<a name="l00168"></a>00168 }
<a name="l00169"></a>00169 
<a name="l00170"></a>00170 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T1, <span class="keyword">class</span> T2&gt; <span class="keyword">inline</span> <span class="keyword">const</span> T1 UnsignedMin(<span class="keyword">const</span> T1&amp; a, <span class="keyword">const</span> T2&amp; b)
<a name="l00171"></a>00171 {
<a name="l00172"></a>00172         CRYPTOPP_COMPILE_ASSERT((<span class="keyword">sizeof</span>(T1)&lt;=<span class="keyword">sizeof</span>(T2) &amp;&amp; T2(-1)&gt;0) || (<span class="keyword">sizeof</span>(T1)&gt;<span class="keyword">sizeof</span>(T2) &amp;&amp; T1(-1)&gt;0));
<a name="l00173"></a>00173         assert(a==0 || a&gt;0);    <span class="comment">// GCC workaround: get rid of the warning "comparison is always true due to limited range of data type"</span>
<a name="l00174"></a>00174         assert(b&gt;=0);
<a name="l00175"></a>00175 
<a name="l00176"></a>00176         <span class="keywordflow">if</span> (<span class="keyword">sizeof</span>(T1)&lt;=<span class="keyword">sizeof</span>(T2))
<a name="l00177"></a>00177                 <span class="keywordflow">return</span> b &lt; (T2)a ? (T1)b : a;
<a name="l00178"></a>00178         <span class="keywordflow">else</span>
<a name="l00179"></a>00179                 <span class="keywordflow">return</span> (T1)b &lt; a ? (T1)b : a;
<a name="l00180"></a>00180 }
<a name="l00181"></a>00181 
<a name="l00182"></a>00182 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt; <span class="keyword">inline</span> <span class="keyword">const</span> T&amp; STDMAX(<span class="keyword">const</span> T&amp; a, <span class="keyword">const</span> T&amp; b)
<a name="l00183"></a>00183 {
<a name="l00184"></a>00184         <span class="keywordflow">return</span> a &lt; b ? b : a;
<a name="l00185"></a>00185 }
<a name="l00186"></a>00186 
<a name="l00187"></a>00187 <span class="preprocessor">#define RETURN_IF_NONZERO(x) size_t returnedValue = x; if (returnedValue) return returnedValue</span>
<a name="l00188"></a>00188 <span class="preprocessor"></span>
<a name="l00189"></a>00189 <span class="comment">// this version of the macro is fastest on Pentium 3 and Pentium 4 with MSVC 6 SP5 w/ Processor Pack</span>
<a name="l00190"></a>00190 <span class="preprocessor">#define GETBYTE(x, y) (unsigned int)byte((x)&gt;&gt;(8*(y)))</span>
<a name="l00191"></a>00191 <span class="preprocessor"></span><span class="comment">// these may be faster on other CPUs/compilers</span>
<a name="l00192"></a>00192 <span class="comment">// #define GETBYTE(x, y) (unsigned int)(((x)&gt;&gt;(8*(y)))&amp;255)</span>
<a name="l00193"></a>00193 <span class="comment">// #define GETBYTE(x, y) (((byte *)&amp;(x))[y])</span>
<a name="l00194"></a>00194 
<a name="l00195"></a>00195 <span class="preprocessor">#define CRYPTOPP_GET_BYTE_AS_BYTE(x, y) byte((x)&gt;&gt;(8*(y)))</span>
<a name="l00196"></a>00196 <span class="preprocessor"></span>
<a name="l00197"></a>00197 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00198"></a>00198 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> Parity(T value)
<a name="l00199"></a>00199 {
<a name="l00200"></a>00200         <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> i=8*<span class="keyword">sizeof</span>(value)/2; i&gt;0; i/=2)
<a name="l00201"></a>00201                 value ^= value &gt;&gt; i;
<a name="l00202"></a>00202         <span class="keywordflow">return</span> (<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span>)value&amp;1;
<a name="l00203"></a>00203 }
<a name="l00204"></a>00204 
<a name="l00205"></a>00205 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00206"></a>00206 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> BytePrecision(<span class="keyword">const</span> T &amp;value)
<a name="l00207"></a>00207 {
<a name="l00208"></a>00208         <span class="keywordflow">if</span> (!value)
<a name="l00209"></a>00209                 <span class="keywordflow">return</span> 0;
<a name="l00210"></a>00210 
<a name="l00211"></a>00211         <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> l=0, h=8*<span class="keyword">sizeof</span>(value);
<a name="l00212"></a>00212 
<a name="l00213"></a>00213         <span class="keywordflow">while</span> (h-l &gt; 8)
<a name="l00214"></a>00214         {
<a name="l00215"></a>00215                 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> t = (l+h)/2;
<a name="l00216"></a>00216                 <span class="keywordflow">if</span> (value &gt;&gt; t)
<a name="l00217"></a>00217                         l = t;
<a name="l00218"></a>00218                 <span class="keywordflow">else</span>
<a name="l00219"></a>00219                         h = t;
<a name="l00220"></a>00220         }
<a name="l00221"></a>00221 
<a name="l00222"></a>00222         <span class="keywordflow">return</span> h/8;
<a name="l00223"></a>00223 }
<a name="l00224"></a>00224 
<a name="l00225"></a>00225 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00226"></a>00226 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> BitPrecision(<span class="keyword">const</span> T &amp;value)
<a name="l00227"></a>00227 {
<a name="l00228"></a>00228         <span class="keywordflow">if</span> (!value)
<a name="l00229"></a>00229                 <span class="keywordflow">return</span> 0;
<a name="l00230"></a>00230 
<a name="l00231"></a>00231         <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> l=0, h=8*<span class="keyword">sizeof</span>(value);
<a name="l00232"></a>00232 
<a name="l00233"></a>00233         <span class="keywordflow">while</span> (h-l &gt; 1)
<a name="l00234"></a>00234         {
<a name="l00235"></a>00235                 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> t = (l+h)/2;
<a name="l00236"></a>00236                 <span class="keywordflow">if</span> (value &gt;&gt; t)
<a name="l00237"></a>00237                         l = t;
<a name="l00238"></a>00238                 <span class="keywordflow">else</span>
<a name="l00239"></a>00239                         h = t;
<a name="l00240"></a>00240         }
<a name="l00241"></a>00241 
<a name="l00242"></a>00242         <span class="keywordflow">return</span> h;
<a name="l00243"></a>00243 }
<a name="l00244"></a>00244 
<a name="l00245"></a>00245 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T&gt;
<a name="l00246"></a>00246 <span class="keyword">inline</span> T Crop(T value, <span class="keywordtype">size_t</span> size)
<a name="l00247"></a>00247 {
<a name="l00248"></a>00248         <span class="keywordflow">if</span> (size &lt; 8*<span class="keyword">sizeof</span>(value))
<a name="l00249"></a>00249         <span class="keywordflow">return</span> T(value &amp; ((T(1) &lt;&lt; size) - 1));
<a name="l00250"></a>00250         <span class="keywordflow">else</span>
<a name="l00251"></a>00251                 <span class="keywordflow">return</span> value;
<a name="l00252"></a>00252 }
<a name="l00253"></a>00253 
<a name="l00254"></a>00254 <span class="keyword">template</span> &lt;<span class="keyword">class</span> T1, <span class="keyword">class</span> T2&gt;
<a name="l00255"></a>00255 <span class="keyword">inline</span> <span class="keywordtype">bool</span> SafeConvert(T1 from, T2 &amp;to)
<a name="l00256"></a>00256 {
<a name="l00257"></a>00257         to = (T2)from;
<a name="l00258"></a>00258         <span class="keywordflow">if</span> (from != to || (from &gt; 0) != (to &gt; 0))
<a name="l00259"></a>00259                 <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00260"></a>00260         <span class="keywordflow">return</span> <span class="keyword">true</span>;
<a name="l00261"></a>00261 }
<a name="l00262"></a>00262 
<a name="l00263"></a>00263 <span class="keyword">inline</span> <span class="keywordtype">size_t</span> BitsToBytes(<span class="keywordtype">size_t</span> bitCount)
<a name="l00264"></a>00264 {
<a name="l00265"></a>00265         <span class="keywordflow">return</span> ((bitCount+7)/(8));