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<h1>TcaRegistry.cc</h1><a href="TcaRegistry_8cc.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/*</span>
<a name="l00002"></a>00002 <span class="comment"> * Copyright 2005-2006 University of Waterloo</span>
<a name="l00003"></a>00003 <span class="comment"> * </span>
<a name="l00004"></a>00004 <span class="comment"> * Licensed under the Apache License, Version 2.0 (the "License");</span>
<a name="l00005"></a>00005 <span class="comment"> * you may not use this file except in compliance with the License.</span>
<a name="l00006"></a>00006 <span class="comment"> * You may obtain a copy of the License at</span>
<a name="l00007"></a>00007 <span class="comment"> * </span>
<a name="l00008"></a>00008 <span class="comment"> * http://www.apache.org/licenses/LICENSE-2.0</span>
<a name="l00009"></a>00009 <span class="comment"> * </span>
<a name="l00010"></a>00010 <span class="comment"> * Unless required by applicable law or agreed to in writing, software</span>
<a name="l00011"></a>00011 <span class="comment"> * distributed under the License is distributed on an "AS IS" BASIS,</span>
<a name="l00012"></a>00012 <span class="comment"> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</span>
<a name="l00013"></a>00013 <span class="comment"> * See the License for the specific language governing permissions and</span>
<a name="l00014"></a>00014 <span class="comment"> * limitations under the License.</span>
<a name="l00015"></a>00015 <span class="comment"> */</span>
<a name="l00016"></a>00016
<a name="l00017"></a>00017 <span class="preprocessor">#ifdef HAVE_CONFIG_H</span>
<a name="l00018"></a>00018 <span class="preprocessor"></span><span class="preprocessor"># include <<a class="code" href="dtn-config_8h.html">dtn-config.h</a>></span>
<a name="l00019"></a>00019 <span class="preprocessor">#endif</span>
<a name="l00020"></a>00020 <span class="preprocessor"></span>
<a name="l00021"></a>00021 <span class="preprocessor">#include "libs/gateway_prot.h"</span>
<a name="l00022"></a>00022 <span class="preprocessor">#include "libs/gateway_rpc.h"</span>
<a name="l00023"></a>00023 <span class="preprocessor">#include "libs/sha1.h"</span>
<a name="l00024"></a>00024 <span class="preprocessor">#include "<a class="code" href="TcaRegistry_8h.html">TcaRegistry.h</a>"</span>
<a name="l00025"></a>00025
<a name="l00026"></a><a class="code" href="TcaRegistry_8cc.html#cc62737c809c0d2cc74192ef8a279fba">00026</a> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span>* <a class="code" href="TcaRegistry_8cc.html#cc62737c809c0d2cc74192ef8a279fba">APP_STRING</a> = <span class="stringliteral">"tca"</span>;
<a name="l00027"></a><a class="code" href="TcaRegistry_8cc.html#89b40b413c0afcf8ea0d793c3cda6345">00027</a> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">char</span>* <a class="code" href="TcaRegistry_8cc.html#89b40b413c0afcf8ea0d793c3cda6345">CLIB_STRING</a> = <span class="stringliteral">"rpcgen"</span>;
<a name="l00028"></a>00028
<a name="l00029"></a><a class="code" href="TcaRegistry_8cc.html#d046473c9a6a6101455401593725490c">00029</a> <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">int</span> <a class="code" href="TcaRegistry_8cc.html#d046473c9a6a6101455401593725490c">DHT_KEYLEN</a> = 20; <span class="comment">// number of uints in a key</span>
<a name="l00030"></a>00030
<a name="l00031"></a>00031
<a name="l00032"></a>00032 <span class="comment">// hash a key s, from original long-string form, down to 20-byte key</span>
<a name="l00033"></a>00033 <span class="comment">// usable in the dht</span>
<a name="l00034"></a>00034 <span class="keyword">static</span> <span class="keywordtype">void</span>
<a name="l00035"></a><a class="code" href="TcaRegistry_8cc.html#e0c7b207b3253033c3edaead394cafcb">00035</a> <a class="code" href="TcaRegistry_8cc.html#e0c7b207b3253033c3edaead394cafcb">hash</a>(<span class="keyword">const</span> std::string& s, uint8 digest[<a class="code" href="TcaRegistry_8cc.html#d046473c9a6a6101455401593725490c">DHT_KEYLEN</a>])
<a name="l00036"></a>00036 {
<a name="l00037"></a>00037 <span class="comment">// Use sha1 hash of endpointid to get a (probably) unique 20-byte key</span>
<a name="l00038"></a>00038 sha1_context ctx;
<a name="l00039"></a>00039 sha1_starts(&ctx);
<a name="l00040"></a>00040 sha1_update(&ctx, (<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>*)(s.c_str()), s.length());
<a name="l00041"></a>00041 sha1_finish(&ctx, digest);
<a name="l00042"></a>00042 }
<a name="l00043"></a>00043
<a name="l00044"></a>00044
<a name="l00045"></a>00045 <span class="comment">/*</span>
<a name="l00046"></a>00046 <span class="comment">static void</span>
<a name="l00047"></a>00047 <span class="comment">dump_digest(uint8 digest[DHT_KEYLEN])</span>
<a name="l00048"></a>00048 <span class="comment">{</span>
<a name="l00049"></a>00049 <span class="comment"> printf("digest=");</span>
<a name="l00050"></a>00050 <span class="comment"> for (int i=0; i<DHT_KEYLEN; ++i) printf("%c", digest[i]);</span>
<a name="l00051"></a>00051 <span class="comment"> printf("\n");</span>
<a name="l00052"></a>00052 <span class="comment">}</span>
<a name="l00053"></a>00053 <span class="comment">*/</span>
<a name="l00054"></a>00054
<a name="l00056"></a>00056 <span class="comment">// class TcaRegistry</span>
<a name="l00057"></a>00057
<a name="l00058"></a>00058
<a name="l00059"></a>00059 <span class="keywordtype">bool</span>
<a name="l00060"></a><a class="code" href="classTcaRegistry.html#21873416b1875b3e7a0d0fcfd7b17920">00060</a> <a class="code" href="classTcaRegistry.html#21873416b1875b3e7a0d0fcfd7b17920">TcaRegistry::init_nodes</a>()
<a name="l00061"></a>00061 {
<a name="l00062"></a>00062 <span class="comment">// Construct list of available DHT nodes, hard coded at the moment.</span>
<a name="l00063"></a>00063 <span class="comment">// TODO: Do something smarter here, like go to OpenDHT site and read</span>
<a name="l00064"></a>00064 <span class="comment">// the current list of DHT nodes. Or read them from a local file that</span>
<a name="l00065"></a>00065 <span class="comment">// somebody actively maintains.</span>
<a name="l00066"></a>00066
<a name="l00067"></a>00067 <span class="comment">// To make this fast as possible for testing, cut this list down to just</span>
<a name="l00068"></a>00068 <span class="comment">// a few. For greater reliability and scalability, use more nodes.</span>
<a name="l00069"></a>00069 <a class="code" href="classTcaRegistry.html#e82a6a30383d413c48dab6f42e05359f">dht_nodes_</a>.push_back(std::string(<span class="stringliteral">"cloudburst.uwaterloo.ca"</span>));
<a name="l00070"></a>00070 <a class="code" href="classTcaRegistry.html#e82a6a30383d413c48dab6f42e05359f">dht_nodes_</a>.push_back(std::string(<span class="stringliteral">"blast.uwaterloo.ca"</span>));
<a name="l00071"></a>00071
<a name="l00072"></a>00072 <span class="comment">// Other known nodes:</span>
<a name="l00073"></a>00073 <span class="comment">/*</span>
<a name="l00074"></a>00074 <span class="comment"> dht_nodes_.push_back(std::string("lefthand.eecs.harvard.edu"));</span>
<a name="l00075"></a>00075 <span class="comment"> dht_nodes_.push_back(std::string("node2.lbnl.nodes.planet-lab.org"));</span>
<a name="l00076"></a>00076 <span class="comment"> dht_nodes_.push_back(std::string("pl1.cs.utk.edu"));</span>
<a name="l00077"></a>00077 <span class="comment"> dht_nodes_.push_back(std::string("pl1.ece.toronto.edu"));</span>
<a name="l00078"></a>00078 <span class="comment"> dht_nodes_.push_back(std::string("planetlab2.cnds.jhu.edu"));</span>
<a name="l00079"></a>00079 <span class="comment"> dht_nodes_.push_back(std::string("ricepl-3.cs.rice.edu"));</span>
<a name="l00080"></a>00080 <span class="comment"> dht_nodes_.push_back(std::string("pli2-pa-3.hpl.hp.com"));</span>
<a name="l00081"></a>00081 <span class="comment"> dht_nodes_.push_back(std::string("planetlab10.millennium.berkeley.edu"));</span>
<a name="l00082"></a>00082 <span class="comment"> */</span>
<a name="l00083"></a>00083
<a name="l00084"></a>00084 <span class="keywordflow">return</span> <span class="keyword">true</span>;
<a name="l00085"></a>00085 }
<a name="l00086"></a>00086
<a name="l00087"></a>00087
<a name="l00088"></a>00088 <span class="keywordtype">bool</span>
<a name="l00089"></a><a class="code" href="classTcaRegistry.html#bd88a1e563fbd1313c0a0352ef402f5a">00089</a> <a class="code" href="classTcaRegistry.html#bd88a1e563fbd1313c0a0352ef402f5a">TcaRegistry::init_addrs</a>()
<a name="l00090"></a>00090 {
<a name="l00091"></a>00091 <span class="comment">// First pass at "something smarter"... </span>
<a name="l00092"></a>00092 <span class="comment">// Test each dht node and keep only the nodes that are awake.</span>
<a name="l00093"></a>00093
<a name="l00094"></a>00094 <span class="comment">// Usage Note: It would be good to call this function periodically</span>
<a name="l00095"></a>00095 <span class="comment">// to refresh the list of "good" nodes.</span>
<a name="l00096"></a>00096
<a name="l00097"></a>00097 printf(<span class="stringliteral">"Initializing TcaRegistry...\n"</span>);
<a name="l00098"></a>00098
<a name="l00099"></a>00099 <a class="code" href="classTcaRegistry.html#7804c7c7c3f8f9e1760927ecb5bb67b7">last_node_</a> = 0;
<a name="l00100"></a>00100
<a name="l00101"></a>00101 sockaddr_in addr;
<a name="l00102"></a>00102 <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> i=0; i<<a class="code" href="classTcaRegistry.html#e82a6a30383d413c48dab6f42e05359f">dht_nodes_</a>.size(); ++i)
<a name="l00103"></a>00103 {
<a name="l00104"></a>00104 <span class="keywordflow">if</span> (test_node(<a class="code" href="classTcaRegistry.html#e82a6a30383d413c48dab6f42e05359f">dht_nodes_</a>[i].c_str(), &addr))
<a name="l00105"></a>00105 {
<a name="l00106"></a>00106 <span class="comment">// it's a keeper</span>
<a name="l00107"></a>00107 <a class="code" href="classTcaRegistry.html#9b6c22afe1829c0a331a0deef147932b">dht_addrs_</a>.push_back(addr);
<a name="l00108"></a>00108 }
<a name="l00109"></a>00109 }
<a name="l00110"></a>00110
<a name="l00111"></a>00111 <span class="keywordflow">if</span> (<a class="code" href="classTcaRegistry.html#9b6c22afe1829c0a331a0deef147932b">dht_addrs_</a>.size() == 0) <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00112"></a>00112
<a name="l00113"></a>00113 printf(<span class="stringliteral">"...dht nodes available = %zu / %zu\n"</span>,
<a name="l00114"></a>00114 <a class="code" href="classTcaRegistry.html#9b6c22afe1829c0a331a0deef147932b">dht_addrs_</a>.size(), <a class="code" href="classTcaRegistry.html#e82a6a30383d413c48dab6f42e05359f">dht_nodes_</a>.size());
<a name="l00115"></a>00115 <span class="keywordflow">return</span> <span class="keyword">true</span>;
<a name="l00116"></a>00116 }
<a name="l00117"></a>00117
<a name="l00118"></a>00118
<a name="l00119"></a>00119
<a name="l00120"></a>00120 <span class="comment">// write a registry record</span>
<a name="l00121"></a>00121
<a name="l00122"></a>00122 <span class="keywordtype">bool</span>
<a name="l00123"></a><a class="code" href="classTcaRegistry.html#7058ce3cde01133881d41a5c5c96958b">00123</a> <a class="code" href="classTcaRegistry.html#7058ce3cde01133881d41a5c5c96958b">TcaRegistry::write</a>(<span class="keyword">const</span> <a class="code" href="classRegRecord.html">RegRecord</a>& rr, <span class="keywordtype">int</span> ttl)
<a name="l00124"></a>00124 {
<a name="l00125"></a>00125 CLIENT* p_node = <a class="code" href="classTcaRegistry.html#603cc7229960d91b6e8d5f054b806957">get_node</a>();
<a name="l00126"></a>00126 <span class="keywordflow">if</span> (p_node == NULL) <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00127"></a>00127
<a name="l00128"></a>00128 <span class="comment">// printf("TcaRegistry::write: using node %d\n", int(p_node));</span>
<a name="l00129"></a>00129
<a name="l00130"></a>00130 uint8 key[<a class="code" href="TcaRegistry_8cc.html#d046473c9a6a6101455401593725490c">DHT_KEYLEN</a>];
<a name="l00131"></a>00131 <a class="code" href="TcaRegistry_8cc.html#e0c7b207b3253033c3edaead394cafcb">hash</a>(rr.<a class="code" href="classRegRecord.html#5674d7072a743fa2fa0278b1bfe95f1f">host_</a>, key);
<a name="l00132"></a>00132 <span class="comment">// dump_digest(key);</span>
<a name="l00133"></a>00133
<a name="l00134"></a>00134 bamboo_put_args args;
<a name="l00135"></a>00135 memset(&args, 0, <span class="keyword">sizeof</span>(args));
<a name="l00136"></a>00136
<a name="l00137"></a>00137 args.application = <span class="keyword">const_cast<</span><span class="keywordtype">char</span>*<span class="keyword">></span>(<a class="code" href="TcaRegistry_8cc.html#cc62737c809c0d2cc74192ef8a279fba">APP_STRING</a>);
<a name="l00138"></a>00138 args.client_library = <span class="keyword">const_cast<</span><span class="keywordtype">char</span>*<span class="keyword">></span>(<a class="code" href="TcaRegistry_8cc.html#89b40b413c0afcf8ea0d793c3cda6345">CLIB_STRING</a>);
<a name="l00139"></a>00139 memcpy(args.key, key, <a class="code" href="TcaRegistry_8cc.html#d046473c9a6a6101455401593725490c">DHT_KEYLEN</a>);
<a name="l00140"></a>00140
<a name="l00141"></a>00141 args.value.bamboo_value_len = rr.<a class="code" href="classRegRecord.html#73b5a145105ac1d526d436af014b82cd">link_addr_</a>.length() + 1;
<a name="l00142"></a>00142 args.value.bamboo_value_val = <span class="keyword">const_cast<</span><span class="keywordtype">char</span>*<span class="keyword">></span>(rr.<a class="code" href="classRegRecord.html#73b5a145105ac1d526d436af014b82cd">link_addr_</a>.c_str());
<a name="l00143"></a>00143
<a name="l00144"></a>00144 args.ttl_sec = ttl;
<a name="l00145"></a>00145
<a name="l00146"></a>00146 <span class="comment">// TODO: Append other fields? Like timestamp of entry/refresh?</span>
<a name="l00147"></a>00147
<a name="l00148"></a>00148 bamboo_stat* res = bamboo_dht_proc_put_2(&args, p_node);
<a name="l00149"></a>00149 <span class="comment">// printf("TcaRegistry::write: put return code = %d\n", int(*res));</span>
<a name="l00150"></a>00150
<a name="l00151"></a>00151 <span class="keywordflow">return</span> (*res == BAMBOO_OK);
<a name="l00152"></a>00152 }
<a name="l00153"></a>00153
<a name="l00154"></a>00154
<a name="l00155"></a>00155
<a name="l00156"></a>00156 <span class="comment">// read a registry record</span>
<a name="l00157"></a>00157 <span class="comment">// rr.eid_ must be primed with the endpointid of the node to lookup</span>
<a name="l00158"></a>00158
<a name="l00159"></a>00159 <span class="keywordtype">bool</span>
<a name="l00160"></a><a class="code" href="classTcaRegistry.html#da5526f5cb51fae130787d3f0f33d9b2">00160</a> <a class="code" href="classTcaRegistry.html#da5526f5cb51fae130787d3f0f33d9b2">TcaRegistry::read</a>(<a class="code" href="classRegRecord.html">RegRecord</a>& rr)
<a name="l00161"></a>00161 {
<a name="l00162"></a>00162 CLIENT* p_node = <a class="code" href="classTcaRegistry.html#603cc7229960d91b6e8d5f054b806957">get_node</a>();
<a name="l00163"></a>00163 <span class="keywordflow">if</span> (p_node == NULL) <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00164"></a>00164
<a name="l00165"></a>00165 <span class="comment">// printf("TcaRegistry::read: using node %d\n", int(p_node));</span>
<a name="l00166"></a>00166
<a name="l00167"></a>00167 uint8 key[<a class="code" href="TcaRegistry_8cc.html#d046473c9a6a6101455401593725490c">DHT_KEYLEN</a>];
<a name="l00168"></a>00168 <a class="code" href="TcaRegistry_8cc.html#e0c7b207b3253033c3edaead394cafcb">hash</a>(rr.<a class="code" href="classRegRecord.html#5674d7072a743fa2fa0278b1bfe95f1f">host_</a>, key);
<a name="l00169"></a>00169 <span class="comment">// dump_digest(key);</span>
<a name="l00170"></a>00170
<a name="l00171"></a>00171 bamboo_get_args args;
<a name="l00172"></a>00172 memset(&args, 0, <span class="keyword">sizeof</span>(args));
<a name="l00173"></a>00173
<a name="l00174"></a>00174 args.application = <span class="keyword">const_cast<</span><span class="keywordtype">char</span>*<span class="keyword">></span>(<a class="code" href="TcaRegistry_8cc.html#cc62737c809c0d2cc74192ef8a279fba">APP_STRING</a>);
<a name="l00175"></a>00175 args.client_library = <span class="keyword">const_cast<</span><span class="keywordtype">char</span>*<span class="keyword">></span>(<a class="code" href="TcaRegistry_8cc.html#89b40b413c0afcf8ea0d793c3cda6345">CLIB_STRING</a>);
<a name="l00176"></a>00176 memcpy(args.key, key, <a class="code" href="TcaRegistry_8cc.html#d046473c9a6a6101455401593725490c">DHT_KEYLEN</a>);
<a name="l00177"></a>00177
<a name="l00178"></a>00178 <span class="comment">// Note: to here, this function is identical to write()</span>
<a name="l00179"></a>00179
<a name="l00180"></a>00180 args.maxvals = 1;
<a name="l00181"></a>00181
<a name="l00182"></a>00182 bamboo_get_res* res = bamboo_dht_proc_get_2(&args, p_node);
<a name="l00183"></a>00183 <span class="keywordflow">if</span> (res == NULL)
<a name="l00184"></a>00184 {
<a name="l00185"></a>00185 printf(<span class="stringliteral">"TcaRegistry::read: get returned NULL\n"</span>);
<a name="l00186"></a>00186 <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00187"></a>00187 }
<a name="l00188"></a>00188
<a name="l00189"></a>00189 <span class="keywordtype">int</span> n_values = res->values.values_len;
<a name="l00190"></a>00190
<a name="l00191"></a>00191 <span class="keywordflow">if</span> (n_values != 1)
<a name="l00192"></a>00192 {
<a name="l00193"></a>00193 <span class="comment">// printf("TcaRegistry::read: get returned %d values\n", n_values);</span>
<a name="l00194"></a>00194 <span class="keywordflow">return</span> <span class="keyword">false</span>;
<a name="l00195"></a>00195 }
<a name="l00196"></a>00196
<a name="l00197"></a>00197 bamboo_value* p_val = &res->values.values_val[0];
<a name="l00198"></a>00198
<a name="l00199"></a>00199 rr.<a class="code" href="classRegRecord.html#73b5a145105ac1d526d436af014b82cd">link_addr_</a> = p_val->bamboo_value_val;
<a name="l00200"></a>00200 printf(<span class="stringliteral">"TcaRegistry::read: succeeded! value=%s\n"</span>, rr.<a class="code" href="classRegRecord.html#73b5a145105ac1d526d436af014b82cd">link_addr_</a>.c_str());
<a name="l00201"></a>00201
<a name="l00202"></a>00202 <span class="keywordflow">return</span> <span class="keyword">true</span>;
<a name="l00203"></a>00203 }
<a name="l00204"></a>00204
<a name="l00205"></a>00205
<a name="l00206"></a>00206 <span class="comment">/*</span>
<a name="l00207"></a>00207 <span class="comment">// This version gets nodes by dns name -- inneficient because of dns</span>
<a name="l00208"></a>00208 <span class="comment">// lookup, and also bad because the node in question may not be alive.</span>
<a name="l00209"></a>00209 <span class="comment">CLIENT*</span>
<a name="l00210"></a>00210 <span class="comment">TcaRegistry::get_node()</span>
<a name="l00211"></a>00211 <span class="comment">{</span>
<a name="l00212"></a>00212 <span class="comment"> // Get next available node. We deliberately spread the load around</span>
<a name="l00213"></a>00213 <span class="comment"> // among all availabe nodes, and also tolerate missing nodes.</span>
<a name="l00214"></a>00214 <span class="comment"></span>
<a name="l00215"></a>00215 <span class="comment"> CLIENT* p_node = NULL;</span>
<a name="l00216"></a>00216 <span class="comment"></span>
<a name="l00217"></a>00217 <span class="comment"> for (unsigned int i = last_node_ + 1; i != last_node_; ++i)</span>
<a name="l00218"></a>00218 <span class="comment"> {</span>
<a name="l00219"></a>00219 <span class="comment"> if (i == dht_nodes_.size()) i = 0;</span>
<a name="l00220"></a>00220 <span class="comment"> p_node = get_connection(dht_nodes_[i].c_str());</span>
<a name="l00221"></a>00221 <span class="comment"> if (p_node)</span>
<a name="l00222"></a>00222 <span class="comment"> {</span>
<a name="l00223"></a>00223 <span class="comment"> printf("TcaRegistry::get_node: using node %s\n",</span>
<a name="l00224"></a>00224 <span class="comment"> dht_nodes_[i].c_str());</span>
<a name="l00225"></a>00225 <span class="comment"> last_node_ = i;</span>
<a name="l00226"></a>00226 <span class="comment"> break;</span>
<a name="l00227"></a>00227 <span class="comment"> }</span>
<a name="l00228"></a>00228 <span class="comment"> }</span>
<a name="l00229"></a>00229 <span class="comment"></span>
<a name="l00230"></a>00230 <span class="comment"> return p_node;</span>
<a name="l00231"></a>00231 <span class="comment">}</span>
<a name="l00232"></a>00232 <span class="comment">*/</span>
<a name="l00233"></a>00233
<a name="l00234"></a>00234
<a name="l00235"></a>00235 CLIENT*
<a name="l00236"></a><a class="code" href="classTcaRegistry.html#603cc7229960d91b6e8d5f054b806957">00236</a> <a class="code" href="classTcaRegistry.html#603cc7229960d91b6e8d5f054b806957">TcaRegistry::get_node</a>()
<a name="l00237"></a>00237 {
<a name="l00238"></a>00238 <span class="comment">// Get next available node. We deliberately spread the load around</span>
<a name="l00239"></a>00239 <span class="comment">// among all availabe nodes, and also tolerate missing nodes.</span>
<a name="l00240"></a>00240 <span class="comment">//</span>
<a name="l00241"></a>00241 <span class="comment">// This version uses the addrs list which saves a dns lookup.</span>
<a name="l00242"></a>00242 <span class="comment">// Also, the addrs list is only populated with the nodes that are alive</span>
<a name="l00243"></a>00243 <span class="comment">// at startup, so there's less chance of failed attempts.</span>
<a name="l00244"></a>00244
<a name="l00245"></a>00245 CLIENT* p_node = NULL;
<a name="l00246"></a>00246
<a name="l00247"></a>00247 <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> i = <a class="code" href="classTcaRegistry.html#7804c7c7c3f8f9e1760927ecb5bb67b7">last_node_</a> + 1; i != <a class="code" href="classTcaRegistry.html#7804c7c7c3f8f9e1760927ecb5bb67b7">last_node_</a>; ++i)
<a name="l00248"></a>00248 {
<a name="l00249"></a>00249 <span class="keywordflow">if</span> (i == <a class="code" href="classTcaRegistry.html#9b6c22afe1829c0a331a0deef147932b">dht_addrs_</a>.size()) i = 0;
<a name="l00250"></a>00250 p_node = get_connection(&<a class="code" href="classTcaRegistry.html#9b6c22afe1829c0a331a0deef147932b">dht_addrs_</a>[i]);
<a name="l00251"></a>00251 <span class="keywordflow">if</span> (p_node)
<a name="l00252"></a>00252 {
<a name="l00253"></a>00253 <a class="code" href="classTcaRegistry.html#7804c7c7c3f8f9e1760927ecb5bb67b7">last_node_</a> = i;
<a name="l00254"></a>00254 <span class="keywordflow">break</span>;
<a name="l00255"></a>00255 }
<a name="l00256"></a>00256 }
<a name="l00257"></a>00257
<a name="l00258"></a>00258 <span class="keywordflow">return</span> p_node;
<a name="l00259"></a>00259 }
<a name="l00260"></a>00260
<a name="l00261"></a>00261
<a name="l00262"></a>00262
</pre></div></div>
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