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diff --git a/bdb/docs/ref/upgrade.3.0/envopen.html b/bdb/docs/ref/upgrade.3.0/envopen.html deleted file mode 100644 index 3c20a0e9e21..00000000000 --- a/bdb/docs/ref/upgrade.3.0/envopen.html +++ /dev/null @@ -1,156 +0,0 @@ -<!--$Id: envopen.so,v 11.12 2000/03/18 21:43:20 bostic Exp $--> -<!--Copyright 1997, 1998, 1999, 2000 by Sleepycat Software, Inc.--> -<!--All rights reserved.--> -<html> -<head> -<title>Berkeley DB Reference Guide: Release 3.0: environment open/close/unlink</title> -<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> -<meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++"> -</head> -<body bgcolor=white> -<table><tr valign=top> -<td><h3><dl><dt>Berkeley DB Reference Guide:<dd>Upgrading Berkeley DB Applications</dl></h3></td> -<td width="1%"><a href="../../ref/upgrade.3.0/intro.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../../ref/toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../../ref/upgrade.3.0/func.html"><img src="../../images/next.gif" alt="Next"></a> -</td></tr></table> -<p> -<h1 align=center>Release 3.0: environment open/close/unlink</h1> -<p>The hardest part of upgrading your application from a 2.X code base to -the 3.0 release is translating the Berkeley DB environment open, close and -remove calls. -<p>There were two logical changes in this part of the Berkeley DB interface. -First, in Berkeley DB 3.0, there are no longer separate structures that -represent each subsystem (e.g., DB_LOCKTAB or DB_TXNMGR) and an overall -DB_ENV environment structure. Instead there is only the -DB_ENV structure. This means that DB_ENV references should -be passed around by your application instead of passing around DB_LOCKTAB -or DB_TXNMGR references. This is likely to be a simple change for most -applications as few applications use the lock_XXX, log_XXX, -memp_XXX or txn_XXX interfaces to create Berkeley DB environments. -<p>The second change is that there are no longer separate open, close, and -unlink interfaces to the -Berkeley DB subsystems, e.g., in previous releases, it was possible to open a -lock subsystem either using db_appinit or using the lock_open call. In -the 3.0 release the XXX_open interfaces to the subsystems have been -removed, and subsystems must now be opened using the 3.0 replacement for the -db_appinit call. -<p>To upgrade your application, first find each place your application opens, -closes and/or removes a Berkeley DB environment. This will be code of the form: -<p><blockquote><pre>db_appinit, db_appexit -lock_open, lock_close, lock_unlink -log_open, log_close, log_unlink -memp_open, memp_close, memp_unlink -txn_open, txn_close, txn_unlink</pre></blockquote> -<p>Each of these groups of calls should be replaced with calls to: -<p><blockquote><pre><a href="../../api_c/env_create.html">db_env_create</a>, <a href="../../api_c/env_open.html">DBENV->open</a>, <a href="../../api_c/env_close.html">DBENV->close</a>, -<a href="../../api_c/env_remove.html">DBENV->remove</a></pre></blockquote> -<p>The <a href="../../api_c/env_create.html">db_env_create</a> call and the call to the <a href="../../api_c/env_open.html">DBENV->open</a> -method replace the db_appinit, lock_open, log_open, memp_open and txn_open -calls. The <a href="../../api_c/env_close.html">DBENV->close</a> method replaces the db_appexit, -lock_close, log_close, memp_close and txn_close calls. The -<a href="../../api_c/env_remove.html">DBENV->remove</a> call replaces the lock_unlink, log_unlink, -memp_unlink and txn_unlink calls. -<p>Here's an example creating a Berkeley DB environment using the 2.X interface: -<p><blockquote><pre>/* - * db_init -- - * Initialize the environment. - */ -DB_ENV * -db_init(home) - char *home; -{ - DB_ENV *dbenv; -<p> - if ((dbenv = (DB_ENV *)calloc(sizeof(DB_ENV), 1)) == NULL) - return (errno); -<p> - if ((errno = db_appinit(home, NULL, dbenv, - DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_TXN | - DB_USE_ENVIRON)) == 0) - return (dbenv); -<p> - free(dbenv); - return (NULL); -}</pre></blockquote> -<p>In the Berkeley DB 3.0 release, this code would be written as: -<p><blockquote><pre>/* - * db_init -- - * Initialize the environment. - */ -int -db_init(home, dbenvp) - char *home; - DB_ENV **dbenvp; -{ - int ret; - DB_ENV *dbenv; -<p> - if ((ret = db_env_create(&dbenv, 0)) != 0) - return (ret); -<p> - if ((ret = dbenv->open(dbenv, home, NULL, - DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_TXN | - DB_USE_ENVIRON, 0)) == 0) { - *dbenvp = dbenv; - return (0); - } -<p> - (void)dbenv->close(dbenv, 0); - return (ret); -}</pre></blockquote> -<p>As you can see, the arguments to db_appinit and to <a href="../../api_c/env_open.html">DBENV->open</a> are -largely the same. There is some minor re-organization: the mapping is -that arguments #1, 2, 3, and 4 to db_appinit become arguments #2, 3, 1 -and 4 to <a href="../../api_c/env_open.html">DBENV->open</a>. There is one additional argument to -<a href="../../api_c/env_open.html">DBENV->open</a>, argument #5. For backward compatibility with the 2.X -Berkeley DB releases, simply set that argument to 0. -<p>It is only slightly more complex to translate calls to XXX_open to the -<a href="../../api_c/env_open.html">DBENV->open</a> method. Here's an example of creating a lock region -using the 2.X interface: -<p><blockquote><pre>lock_open(dir, DB_CREATE, 0664, dbenv, ®ionp);</pre></blockquote> -<p>In the Berkeley DB 3.0 release, this code would be written as: -<p><blockquote><pre>if ((ret = db_env_create(&dbenv, 0)) != 0) - return (ret); -<p> -if ((ret = dbenv->open(dbenv, - dir, NULL, DB_CREATE | DB_INIT_LOCK, 0664)) == 0) { - *dbenvp = dbenv; - return (0); -}</pre></blockquote> -<p>Note that in this example, you no longer need the DB_LOCKTAB structure -reference that was required in Berkeley DB 2.X releases. -<p>The final issue with upgrading the db_appinit call is the DB_MPOOL_PRIVATE -option previously provided for the db_appinit interface. If your -application is using this flag, it should almost certainly use the new -<a href="../../api_c/env_open.html#DB_PRIVATE">DB_PRIVATE</a> flag to the <a href="../../api_c/env_open.html">DBENV->open</a> interface. Regardless, -you should carefully consider this change before converting to use the -<a href="../../api_c/env_open.html#DB_PRIVATE">DB_PRIVATE</a> flag. -<p>Translating db_appexit or XXX_close calls to <a href="../../api_c/env_close.html">DBENV->close</a> is equally -simple. Instead of taking a reference to a per-subsystem structure such -as DB_LOCKTAB or DB_TXNMGR, all calls take a reference to a DB_ENV -structure. The calling sequence is otherwise unchanged. Note that as -the application no longer allocates the memory for the DB_ENV structure, -application code to discard it after the call to db_appexit() is no longer -needed. -<p>Translating XXX_unlink calls to <a href="../../api_c/env_remove.html">DBENV->remove</a> is slightly more complex. -As with <a href="../../api_c/env_close.html">DBENV->close</a>, the call takes a reference to a DB_ENV -structure instead of a per-subsystem structure. The calling sequence is -slightly different, however. Here is an example of removing a lock region -using the 2.X interface: -<p><blockquote><pre>DB_ENV *dbenv; -<p> -ret = lock_unlink(dir, 1, dbenv);</pre></blockquote> -<p>In the Berkeley DB 3.0 release, this code fragment would be written as: -<p><blockquote><pre>DB_ENV *dbenv; -<p> -ret = dbenv->remove(dbenv, dir, NULL, DB_FORCE);</pre></blockquote> -<p>The additional argument to the <a href="../../api_c/env_remove.html">DBENV->remove</a> function is a -configuration argument similar to that previously taken by db_appinit and -now taken by the <a href="../../api_c/env_open.html">DBENV->open</a> method. For backward compatibility -this new argument should simply be set to NULL. The force argument to -XXX_unlink is now a flag value that is set by bitwise inclusively <b>OR</b>'ing it the -<a href="../../api_c/env_remove.html">DBENV->remove</a> flag argument. -<table><tr><td><br></td><td width="1%"><a href="../../ref/upgrade.3.0/intro.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../../ref/toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../../ref/upgrade.3.0/func.html"><img src="../../images/next.gif" alt="Next"></a> -</td></tr></table> -<p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font> -</body> -</html> |