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/*
KSysGuard, the KDE System Guard
Copyright (c) 2000 Chris Schlaeger <cs@kde.org>
This program is free software; you can redistribute it and/or
modify it under the terms of version 2 of the GNU General Public
License as published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <time.h>
#include "ccont.h"
#include "PWUIDCache.h"
/* Cached values become invalid after 5 minutes */
#define TIMEOUT 300
typedef struct {
uid_t uid;
char* uName;
time_t tStamp;
} CachedPWUID;
static CONTAINER UIDCache = 0;
static time_t lastCleanup = 0;
void PWUIDCache_cleanup( void* c );
static int uidCmp( void* p1, void* p2 )
{
return ( ((CachedPWUID*)p1)->uid - ((CachedPWUID*)p2)->uid );
}
void PWUIDCache_cleanup( void* c )
{
if ( c ) {
if ( ((CachedPWUID*)c)->uName )
free ( ((CachedPWUID*)c)->uName );
free ( c );
}
}
void initPWUIDCache()
{
UIDCache = new_ctnr();
}
void exitPWUIDCache()
{
destr_ctnr( UIDCache, PWUIDCache_cleanup );
}
const char* getCachedPWUID( uid_t uid )
{
CachedPWUID key;
CachedPWUID* entry = 0;
long idx;
time_t stamp;
stamp = time( 0 );
if ( stamp - lastCleanup > TIMEOUT ) {
/* Cleanup cache entries every TIMEOUT seconds so that we
* don't pile tons of unused entries, and to make sure that
* our entries are not outdated. */
for ( entry = first_ctnr( UIDCache ); entry; entry = next_ctnr( UIDCache ) ) {
/* If a cache entry has not been updated for TIMEOUT
* seconds the entry is removed. */
if ( stamp - entry->tStamp > TIMEOUT )
PWUIDCache_cleanup( remove_ctnr( UIDCache ) );
}
lastCleanup = stamp;
}
key.uid = uid;
if ( ( idx = search_ctnr( UIDCache, uidCmp, &key ) ) < 0 ) {
struct passwd* pwent;
/* User id is not yet known */
entry = (CachedPWUID*)malloc( sizeof( CachedPWUID ) );
entry->tStamp = stamp;
entry->uid = uid;
pwent = getpwuid( uid );
if ( pwent )
entry->uName = strdup( pwent->pw_name );
else
entry->uName = strdup( "?" );
push_ctnr( UIDCache, entry );
bsort_ctnr( UIDCache, uidCmp );
} else {
/* User is is already known */
entry = get_ctnr( UIDCache, idx );
}
return entry->uName;
}
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