From: Eric Dumazet <eduma...@google.com>
Lets implement a full cache with proper hash table, memory got cheaper
these days.
Before :
$ time ss -t | wc -l
529678
real 0m22.708s
user 0m19.591s
sys 0m2.969s
After :
$ time ss -t | wc -l
528291
real 0m5.078s
user 0m4.099s
sys 0m0.985s
Signed-off-by: Eric Dumazet <eduma...@google.com>
---
misc/ss.c | 71 +++++++++++++++++++++++-----------------------------
1 file changed, 32 insertions(+), 39 deletions(-)
diff --git a/misc/ss.c b/misc/ss.c
index 347e3a1..3f4b7f1 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -858,8 +858,7 @@ static const char *print_ms_timer(int timeout)
return buf;
}
-struct scache
-{
+struct scache {
struct scache *next;
int port;
char *name;
@@ -949,11 +948,15 @@ static const char *__resolve_service(int port)
return NULL;
}
+#define SCACHE_BUCKETS 1024
+static struct scache *cache_htab[SCACHE_BUCKETS];
static const char *resolve_service(int port)
{
static char buf[128];
- static struct scache cache[256];
+ struct scache *c;
+ const char *res;
+ int hash;
if (port == 0) {
buf[0] = '*';
@@ -961,45 +964,35 @@ static const char *resolve_service(int port)
return buf;
}
- if (resolve_services) {
- if (dg_proto == RAW_PROTO) {
- return inet_proto_n2a(port, buf, sizeof(buf));
- } else {
- struct scache *c;
- const char *res;
- int hash = (port^(((unsigned long)dg_proto)>>2))&255;
-
- for (c = &cache[hash]; c; c = c->next) {
- if (c->port == port &&
- c->proto == dg_proto) {
- if (c->name)
- return c->name;
- goto do_numeric;
- }
- }
+ if (!resolve_services)
+ goto do_numeric;
- if ((res = __resolve_service(port)) != NULL) {
- if ((c = malloc(sizeof(*c))) == NULL)
- goto do_numeric;
- } else {
- c = &cache[hash];
- if (c->name)
- free(c->name);
- }
- c->port = port;
- c->name = NULL;
- c->proto = dg_proto;
- if (res) {
- c->name = strdup(res);
- c->next = cache[hash].next;
- cache[hash].next = c;
- }
- if (c->name)
- return c->name;
- }
+ if (dg_proto == RAW_PROTO)
+ return inet_proto_n2a(port, buf, sizeof(buf));
+
+
+ hash = (port^(((unsigned long)dg_proto)>>2)) % SCACHE_BUCKETS;
+
+ for (c = cache_htab[hash]; c; c = c->next) {
+ if (c->port == port && c->proto == dg_proto)
+ goto do_cache;
}
- do_numeric:
+ c = malloc(sizeof(*c));
+ if (!c)
+ goto do_numeric;
+ res = __resolve_service(port);
+ c->port = port;
+ c->name = res ? strdup(res) : NULL;
+ c->proto = dg_proto;
+ c->next = cache_htab[hash];
+ cache_htab[hash] = c;
+
+do_cache:
+ if (c->name)
+ return c->name;
+
+do_numeric:
sprintf(buf, "%u", port);
return buf;
}
--
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