From a6d904d20e0157f2b5ddf364874d0e03abb6ade6 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Fri, 27 Aug 2010 14:44:16 +0200 Subject: [PATCH] s3: Cache results of finding printer names With hundreds of printers or on a slow machine, this can become expensive. Problem reported and patch sponsored by DESY, Hamburg (www.desy.de) --- source3/rpc_server/srv_spoolss_nt.c | 39 +++++++++++++++++++++++++++++++++++ 1 files changed, 39 insertions(+), 0 deletions(-) diff --git a/source3/rpc_server/srv_spoolss_nt.c b/source3/rpc_server/srv_spoolss_nt.c index 4b5385b..2a113e4 100644 --- a/source3/rpc_server/srv_spoolss_nt.c +++ b/source3/rpc_server/srv_spoolss_nt.c @@ -432,6 +432,14 @@ static bool set_printer_hnd_name(Printer_entry *Printer, const char *handlename) NT_PRINTER_INFO_LEVEL *printer = NULL; WERROR result; + /* + * Hopefully nobody names his printers like this. Maybe \ or , + * are illegal in printer names even? + */ + const char printer_not_found[] = "Printer \\, !@#$%^&*( not found"; + char *cache_key; + char *tmp; + DEBUG(4,("Setting printer name=%s (len=%lu)\n", handlename, (unsigned long)strlen(handlename))); @@ -474,6 +482,27 @@ static bool set_printer_hnd_name(Printer_entry *Printer, const char *handlename) found = true; } + /* + * With hundreds of printers, the "for" loop iterating all + * shares can be quite expensive, as it is done on every + * OpenPrinter. The loop maps "aprinter" to "sname", the + * result of which we cache in gencache. + */ + + cache_key = talloc_asprintf(talloc_tos(), "PRINTERNAME/%s", + aprinter); + if ((cache_key != NULL) && gencache_get(cache_key, &tmp, NULL)) { + + found = (strcmp(tmp, printer_not_found) != 0); + if (!found) { + DEBUG(4, ("Printer %s not found\n", aprinter)); + SAFE_FREE(tmp); + return false; + } + fstrcpy(sname, tmp); + SAFE_FREE(tmp); + } + /* Search all sharenames first as this is easier than pulling the printer_info_2 off of disk. Don't use find_service() since that calls out to map_username() */ @@ -539,10 +568,20 @@ static bool set_printer_hnd_name(Printer_entry *Printer, const char *handlename) free_a_printer( &printer, 2); if ( !found ) { + if (cache_key != NULL) { + gencache_set(cache_key, printer_not_found, + time(NULL)+300); + TALLOC_FREE(cache_key); + } DEBUGADD(4,("Printer not found\n")); return false; } + if (cache_key != NULL) { + gencache_set(cache_key, sname, time(NULL)+300); + TALLOC_FREE(cache_key); + } + DEBUGADD(4,("set_printer_hnd_name: Printer found: %s -> %s\n", aprinter, sname)); fstrcpy(Printer->sharename, sname); -- 1.5.6.5