Using Berkeley DB with PHP
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## Using Berkeley DB with PHP

A PHP 4 extension for this release of Berkeley DB is included in the distribution package. It can either either link directly against the installed Berkeley DB library (which is necessary for running in a non-Apache/mod_php4 environment), or against mod_db4, which provides additional safety when running under Apache/mod_php4.

The PHP extension provides the following classes, which mirror the standard Berkeley DB C++ API.

    class Db4Env {
    	function Db4Env($flags = 0) {}
    	function close($flags = 0) {}
    	function dbremove($txn, $filename, $database = null, $flags = 0) {}
    	function dbrename($txn, $file, $database, $new_database, $flags = 0) {}
    	function open($home, $flags = DB_CREATE  | DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_TXN, $mode = 0666) {}
    	function remove($home, $flags = 0) {}
    	function set_data_dir($directory) {}
    	function txn_begin($parent_txn = null, $flags = 0) {}
    	function txn_checkpoint($kbytes, $minutes, $flags = 0) {}
    }

    class Db4 {
    	function Db4($dbenv = null) {}	// create a new Db4 object using the optional DbEnv
    	function open($txn = null, $file = null, $database = null, $flags = DB_CREATE, $mode = 0) {}
    	function close() {}
    	function del($key, $txn = null) {}
    	function get($key, $txn = null, $flags = 0) {}
    	function pget($key, &$pkey, $txn = null, $flags = 0) {}
    	function get_type() {}	// returns the stringified database type name
    	function stat($txn = null, $flags = 0) {} // returns statistics as an as
    	function join($cursor_list, $flags = 0) {}
    	function sync() {}
    	function truncate($txn = null, $flags = 0) {}
    	function cursor($txn = null, flags = 0) {}
    }

    class Db4Txn {
    	function abort() {}
    	function commit() {}
    	function discard() {}
    	function id() {}
    	function set_timeout($timeout, $flags = 0) {}
    }

    class Db4Cursor {
    	function close() {}
    	function count() {}
    	function del() {}
    	function dup($flags = 0) {}
    	function get($key, $flags = 0) {}
    	function pget($key, &$primary_key, $flags = 0) {}
    	function put($key, $data, $flags = 0) {}
    }

The PHP extension attempts to be "smart" for you by:

1. Auto-committing operations on transactional databases if no explicit Db4Txn object is specified.
2. Performing reference and dependency checking to insure that all resources are closed in the correct order.
3. Supplying default values for flags.

To install this PHP module linked against the mod_db4 framework, perform the following steps:

    % phpize
    % ./configure --with-db4=[Berkeley DB library installation directory] \
    	--with-mod_db4=$APACHE_INCLUDEDIR
    % make
    % make install

Then, in your php.ini file add the following:

    extension=db4.so

This extension will now only run in a SAPI linked into Apache httpd (mod_php4, most likely), and will take advantage of all of its auto-recovery and handle-caching facilities.

To install this php module linked against the Berkeley DB library and not the mod_db4 framework, perform the following steps:

    % phpize
    % ./configure --with-db4=[Berkeley DB library installation directory]
    % make
    % make install

Then in your php.ini file add:

    extension=db4.so

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