gencache: Add gencache values to memcache

gencache_parse calling tdb shows up in profiles when we do a lot of open/close
traffic with large ACLs. For every file we convert unix ids to sids, and in the
domain member case this goes through gencache.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Tue Mar 11 19:56:47 CET 2014 on sn-devel-104

diff --git a/source3/include/memcache.h b/source3/include/memcache.h
index 9362483cea4a9bebd4dfa7965c6323dc7d8045d1..d5a03763bd1b277b65705e6256cfeacd276ad30e 100644 (file)
--- a/source3/include/memcache.h
+++ b/source3/include/memcache.h
@@ -35,6 +35,7 @@ struct memcache;
 
 enum memcache_number {
        STAT_CACHE,
+       GENCACHE_RAM,
        GETWD_CACHE,
        GETPWNAM_CACHE,         /* talloc */
        MANGLE_HASH2_CACHE,

diff --git a/source3/lib/gencache.c b/source3/lib/gencache.c
index 168b51191e5a8f5a81d3b166b3e3c43cb8b0dcec..0fb1fd8280ef52db47c72aa165161b6d57f6623f 100644 (file)
--- a/source3/lib/gencache.c
+++ b/source3/lib/gencache.c
@@ -25,6 +25,7 @@
 #include "system/filesys.h"
 #include "system/glob.h"
 #include "util_tdb.h"
+#include "memcache.h"
 
 #undef  DBGC_CLASS
 #define DBGC_CLASS DBGC_TDB
@@ -37,6 +38,7 @@
 
 static struct tdb_context *cache;
 static struct tdb_context *cache_notrans;
+static int cache_notrans_seqnum;
 
 /**
  * @file gencache.c
@@ -112,6 +114,7 @@ static bool gencache_init(void)
        cache_notrans = tdb_open_log(cache_fname, 0,
                                     TDB_CLEAR_IF_FIRST|
                                     TDB_INCOMPATIBLE_HASH|
+                                    TDB_SEQNUM|
                                     TDB_NOSYNC,
                                     open_flags, 0644);
        if (cache_notrans == NULL) {
@@ -413,6 +416,7 @@ static bool gencache_pull_timeout(char *val, time_t *pres, char **pendptr)
 struct gencache_parse_state {
        void (*parser)(time_t timeout, DATA_BLOB blob, void *private_data);
        void *private_data;
+       bool is_memcache;
 };
 
 static int gencache_parse_fn(TDB_DATA key, TDB_DATA data, void *private_data)
@@ -434,6 +438,13 @@ static int gencache_parse_fn(TDB_DATA key, TDB_DATA data, void *private_data)
        blob = data_blob_const(
                endptr+1, data.dsize - PTR_DIFF(endptr+1, data.dptr));
        state->parser(t, blob, state->private_data);
+
+       if (!state->is_memcache) {
+               memcache_add(NULL, GENCACHE_RAM,
+                            data_blob_const(key.dptr, key.dsize),
+                            data_blob_const(data.dptr, data.dsize));
+       }
+
        return 0;
 }
 
@@ -444,6 +455,7 @@ bool gencache_parse(const char *keystr,
 {
        struct gencache_parse_state state;
        TDB_DATA key = string_term_tdb_data(keystr);
+       DATA_BLOB memcache_val;
        int ret;
 
        if (keystr == NULL) {
@@ -459,6 +471,31 @@ bool gencache_parse(const char *keystr,
        state.parser = parser;
        state.private_data = private_data;
 
+       if (memcache_lookup(NULL, GENCACHE_RAM,
+                           data_blob_const(key.dptr, key.dsize),
+                           &memcache_val)) {
+               /*
+                * Make sure that nobody has changed the gencache behind our
+                * back.
+                */
+               int current_seqnum = tdb_get_seqnum(cache_notrans);
+               if (current_seqnum == cache_notrans_seqnum) {
+                       /*
+                        * Ok, our memcache is still current, use it without
+                        * going to the tdb files.
+                        */
+                       state.is_memcache = true;
+                       gencache_parse_fn(key, make_tdb_data(memcache_val.data,
+                                                            memcache_val.length),
+                                         &state);
+                       return true;
+               }
+               memcache_flush(NULL, GENCACHE_RAM);
+               cache_notrans_seqnum = current_seqnum;
+       }
+
+       state.is_memcache = false;
+
        ret = tdb_parse_record(cache_notrans, key, gencache_parse_fn, &state);
        if (ret == 0) {
                return true;