1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml"> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 6 <title>open_env</title> 7 <link rel="stylesheet" href="apiReference.css" type="text/css" /> 8 <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> 9 <link rel="start" href="index.html" title="Berkeley DB C++ Standard Template Library API Reference" /> 10 <link rel="up" href="dbstl_global_functions.html" title="Chapter 1. Dbstl Global Public Functions" /> 11 <link rel="prev" href="stldbstl_global_functionsopen_db.html" title="open_db" /> 12 <link rel="next" href="stldbstl_global_functionsalloc_mutex.html" title="alloc_mutex" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center"> 19open_env 20</th> 21 </tr> 22 <tr> 23 <td width="20%" align="left"><a accesskey="p" href="stldbstl_global_functionsopen_db.html">Prev</a> </td> 24 <th width="60%" align="center">Chapter 1. 25 Dbstl Global Public Functions </th> 26 <td width="20%" align="right"> <a accesskey="n" href="stldbstl_global_functionsalloc_mutex.html">Next</a></td> 27 </tr> 28 </table> 29 <hr /> 30 </div> 31 <div class="sect1" lang="en" xml:lang="en"> 32 <div class="titlepage"> 33 <div> 34 <div> 35 <h2 class="title" style="clear: both"><a id="stldbstl_global_functionsopen_env"></a> 36open_env 37</h2> 38 </div> 39 </div> 40 </div> 41 <div class="sect2" lang="en" xml:lang="en"> 42 <div class="titlepage"> 43 <div> 44 <div> 45 <h3 class="title"><a id="func_details"></a> 46Function Details</h3> 47 </div> 48 </div> 49 </div> 50 <pre class="programlisting"> 51 DbEnv* open_env(const char *env_home, u_int32_t set_flags, 52 u_int32_t oflags=DB_CREATE|DB_INIT_MPOOL, u_int32_t cachesize=4 *1024 *1024, 53 int mode=0644, 54 u_int32_t cflags=0) 55 </pre> 56 <div class="sect3" lang="en" xml:lang="en"> 57 <div class="titlepage"></div> 58 <p>Helper function to open an environment and register it into dbstl for the calling thread. </p> 59 <p>Users still need to register it in any other thread if it is shared by multiple threads, via <a class="link" href="stldbstl_global_functionsregister_db_env.html" title="register_db_env">register_db_env()</a> 60 function above. Users don't need to delete or free the memory of the returned object, dbstl will take care of that.</p> 61 <p>When you don't use <a class="link" href="stldbstl_global_functionsopen_env.html" title="open_env">dbstl::open_env()</a> 62 but explicitly call DB C++ API to open an environment, you must new the DbEnv object, rather than create it on stack, and you must delete the DbEnv object by yourself. </p> 63 </div> 64 <div class="sect3" lang="en" xml:lang="en"> 65 <div class="titlepage"> 66 <div> 67 <div> 68 <h4 class="title"><a id="id1543179"></a> 69Parameters</h4> 70 </div> 71 </div> 72 </div> 73 <div class="sect4" lang="en" xml:lang="en"> 74 <div class="titlepage"> 75 <div> 76 <div> 77 <h5 class="title"><a id="id1542999"></a> 78 oflags </h5> 79 </div> 80 </div> 81 </div> 82 <p>Environment open flags, passed to DbEnv::open. </p> 83 </div> 84 <div class="sect4" lang="en" xml:lang="en"> 85 <div class="titlepage"> 86 <div> 87 <div> 88 <h5 class="title"><a id="id1542532"></a> 89 set_flags </h5> 90 </div> 91 </div> 92 </div> 93 <p>Flags to set to the created environment before opening it. </p> 94 </div> 95 <div class="sect4" lang="en" xml:lang="en"> 96 <div class="titlepage"> 97 <div> 98 <div> 99 <h5 class="title"><a id="id1543037"></a> 100 mode </h5> 101 </div> 102 </div> 103 </div> 104 <p>Environment region files mode, passed to DbEnv::open. </p> 105 </div> 106 <div class="sect4" lang="en" xml:lang="en"> 107 <div class="titlepage"> 108 <div> 109 <div> 110 <h5 class="title"><a id="id1542303"></a> 111 cflags </h5> 112 </div> 113 </div> 114 </div> 115 <p>DbEnv constructor creation flags, passed to DbEnv::DbEnv. </p> 116 </div> 117 <div class="sect4" lang="en" xml:lang="en"> 118 <div class="titlepage"> 119 <div> 120 <div> 121 <h5 class="title"><a id="id1543261"></a> 122 cachesize </h5> 123 </div> 124 </div> 125 </div> 126 <p>Environment cache size, by default 4M bytes. </p> 127 </div> 128 <div class="sect4" lang="en" xml:lang="en"> 129 <div class="titlepage"> 130 <div> 131 <div> 132 <h5 class="title"><a id="id1541001"></a> 133 env_home </h5> 134 </div> 135 </div> 136 </div> 137 <p>Environment home directory, it must exist. Passed to DbEnv::open. </p> 138 </div> 139 </div> 140 <div class="sect3" lang="en" xml:lang="en"> 141 <div class="titlepage"> 142 <div> 143 <div> 144 <h4 class="title"><a id="id1543262"></a> 145Return Value</h4> 146 </div> 147 </div> 148 </div> 149 <p>The opened database environment handle. </p> 150 </div> 151 <div class="sect3" lang="en" xml:lang="en"> 152 <div class="titlepage"> 153 <div> 154 <div> 155 <h4 class="title"><a id="id1543277"></a> 156See Also</h4> 157 </div> 158 </div> 159 </div> 160 <p> 161 </p> 162 <p><a class="link" href="stldbstl_global_functionsregister_db_env.html" title="register_db_env">register_db_env(DbEnv *)</a> 163; </p> 164 <p><a class="link" href="stldbstl_global_functionsopen_db.html" title="open_db">open_db</a> 165; </p> 166 <p> </p> 167 </div> 168 </div> 169 <div class="sect2" lang="en" xml:lang="en"> 170 <div class="titlepage"> 171 <div> 172 <div> 173 <h3 class="title"><a id="id1543305"></a> 174Class</h3> 175 </div> 176 </div> 177 </div> 178 <p> 179 <a class="link" href="dbstl_global_functions.html" title="Chapter 1. Dbstl Global Public Functions"> 180 dbstl_global_functions</a> 181 </p> 182 </div> 183 </div> 184 <div class="navfooter"> 185 <hr /> 186 <table width="100%" summary="Navigation footer"> 187 <tr> 188 <td width="40%" align="left"><a accesskey="p" href="stldbstl_global_functionsopen_db.html">Prev</a> </td> 189 <td width="20%" align="center"> 190 <a accesskey="u" href="dbstl_global_functions.html">Up</a> 191 </td> 192 <td width="40%" align="right"> <a accesskey="n" href="stldbstl_global_functionsalloc_mutex.html">Next</a></td> 193 </tr> 194 <tr> 195 <td width="40%" align="left" valign="top"> 196open_db 197 </td> 198 <td width="20%" align="center"> 199 <a accesskey="h" href="index.html">Home</a> 200 </td> 201 <td width="40%" align="right" valign="top"> 202alloc_mutex 203</td> 204 </tr> 205 </table> 206 </div> 207 </body> 208</html> 209