ldap_cache.3

开放源码的ldap系统

.TH LDAP_CACHE 3 "22 September 1998" "OpenLDAP LDVERSION"
.\" $OpenLDAP: pkg/ldap/doc/man/man3/ldap_cache.3,v 1.2.12.3 2001/06/14 00:05:14 kurt Exp $
.\" Copyright 1998-2000 The OpenLDAP Foundation All Rights Reserved.
.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
.SH NAME
ldap_enable_cache, ldap_disable_cache, ldap_destroy_cache, ldap_flush_cache, ldap_uncache_entry, ldap_uncache_request, ldap_set_cache_options \- LDAP client caching routines
.SH SYNOPSIS
.nf
.ft B
#include <ldap.h>
.ft
.LP
.ft B
ldap_enable_cache( ld, timeout, maxmem )
.ft
LDAP	*ld;
long	timeout;
long	maxmem;
.LP
.ft B
void ldap_disable_cache( ld )
.ft
LDAP	*ld;
.LP
.ft B
void ldap_destroy_cache( ld )
.ft
LDAP	*ld;
.LP
.ft B
void ldap_flush_cache( ld )
.ft
LDAP	*ld;
.LP
.ft B
void ldap_uncache_entry( ld, dn )
.ft
LDAP	*ld;
char	*dn;
.LP
.ft B
void ldap_uncache_request( ld, msgid )
.ft
LDAP	*ld;
int	msgid;
.LP
.ft B
void ldap_set_cache_options( ld, opts )
.ft
LDAP		*ld;
unsigned long	opts;
.fi
.SH DESCRIPTION
.LP
These routines are used to control the behavior of the
.B experimental
client caching of
.BR ldap_search (3)
and
.BR ldap_compare (3)
operations.  By
default, the cache is disabled and no caching is done.  Enabling the
cache can greatly improve performance and reduce network bandwidth when
a client DUA makes repeated requests.
.LP
.B ldap_enable_cache()
should be called to turn on local caching or to
change cache parameters (lifetime of cached requests and memory used).
The \fIld\fP parameter should be the result of a successful call to
.BR ldap_open (3).
The \fItimeout\fP is specified in seconds, and is used to
decide how long to keep cached requests.  The \fImaxmem\fP value is in
bytes, and is used to set an upper bound on how memory the cache will
use.  You can specify 0 for \fImaxmem\fP to restrict the cache size by
the \fItimeout\fP only.  The first call to ldap_enable_cache creates
the cache; subsequent calls re-enable the cache and set the timeout and
memory values.
.LP
.B ldap_disable_cache()
temporarily disables use of the cache (new
requests are not cached and the cache is not checked when returning
results).  It does not delete the cache contents.
.LP
.B ldap_destroy_cache()
turns off caching and completely removes the cache from memory.
.LP
.B ldap_flush_cache()
deletes the cache contents, but does not effect it in any other way.
.LP
.B ldap_uncache_entry()
removes all requests that make reference to the
distinguished name \fIdn\fP from the cache.  It should be used, for
example, after doing an
.BR ldap_modify (3)
call involving \fIdn\fP.
.LP
.B ldap_uncache_request()
removes the request indicated by the LDAP request
id \fImsgid\fP from the cache.
.LP
.B ldap_set_cache_options()
is used to change caching behavior.  The current supported options are
.B LDAP_CACHE_OPT_CACHENOERRS
to suppress caching of any requests that result in an error, and
.B LDAP_CACHE_OPT_CACHEALLERRS
to enable caching of all requests.  The default behavior is to not
cache requests that result in errors, except that request that result
in the error
.B LDAP_SIZELIMIT_EXCEEDED
are cached.
.SH ERRORS
.B ldap_enable_cache()
returns 0 upon success, and -1 if it is unable to
allocate space for the cache.  All the other calls are declared as
void and return nothing.
.SH SEE ALSO
.BR ldap (3),
.BR ldap_search (3),
.BR ldap_compare (3)
.SH ACKNOWLEDGEMENTS
.B	OpenLDAP
is developed and maintained by The OpenLDAP Project (http://www.openldap.org/).
.B	OpenLDAP
is derived from University of Michigan LDAP 3.3 Release.