+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2011 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd 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
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <string.h>
-#include <errno.h>
-
-#include "journald-rate-limit.h"
-#include "list.h"
-#include "util.h"
-#include "hashmap.h"
-
-#define POOLS_MAX 5
-#define BUCKETS_MAX 127
-#define GROUPS_MAX 2047
-
-static const int priority_map[] = {
- [LOG_EMERG] = 0,
- [LOG_ALERT] = 0,
- [LOG_CRIT] = 0,
- [LOG_ERR] = 1,
- [LOG_WARNING] = 2,
- [LOG_NOTICE] = 3,
- [LOG_INFO] = 3,
- [LOG_DEBUG] = 4
-};
-
-typedef struct JournalRateLimitPool JournalRateLimitPool;
-typedef struct JournalRateLimitGroup JournalRateLimitGroup;
-
-struct JournalRateLimitPool {
- usec_t begin;
- unsigned num;
- unsigned suppressed;
-};
-
-struct JournalRateLimitGroup {
- JournalRateLimit *parent;
-
- char *id;
- JournalRateLimitPool pools[POOLS_MAX];
- unsigned long hash;
-
- LIST_FIELDS(JournalRateLimitGroup, bucket);
- LIST_FIELDS(JournalRateLimitGroup, lru);
-};
-
-struct JournalRateLimit {
- usec_t interval;
- unsigned burst;
-
- JournalRateLimitGroup* buckets[BUCKETS_MAX];
- JournalRateLimitGroup *lru, *lru_tail;
-
- unsigned n_groups;
-
- uint8_t hash_key[16];
-};
-
-JournalRateLimit *journal_rate_limit_new(usec_t interval, unsigned burst) {
- JournalRateLimit *r;
-
- assert(interval > 0 || burst == 0);
-
- r = new0(JournalRateLimit, 1);
- if (!r)
- return NULL;
-
- r->interval = interval;
- r->burst = burst;
-
- random_bytes(r->hash_key, sizeof(r->hash_key));
-
- return r;
-}
-
-static void journal_rate_limit_group_free(JournalRateLimitGroup *g) {
- assert(g);
-
- if (g->parent) {
- assert(g->parent->n_groups > 0);
-
- if (g->parent->lru_tail == g)
- g->parent->lru_tail = g->lru_prev;
-
- LIST_REMOVE(lru, g->parent->lru, g);
- LIST_REMOVE(bucket, g->parent->buckets[g->hash % BUCKETS_MAX], g);
-
- g->parent->n_groups --;
- }
-
- free(g->id);
- free(g);
-}
-
-void journal_rate_limit_free(JournalRateLimit *r) {
- assert(r);
-
- while (r->lru)
- journal_rate_limit_group_free(r->lru);
-
- free(r);
-}
-
-_pure_ static bool journal_rate_limit_group_expired(JournalRateLimitGroup *g, usec_t ts) {
- unsigned i;
-
- assert(g);
-
- for (i = 0; i < POOLS_MAX; i++)
- if (g->pools[i].begin + g->parent->interval >= ts)
- return false;
-
- return true;
-}
-
-static void journal_rate_limit_vacuum(JournalRateLimit *r, usec_t ts) {
- assert(r);
-
- /* Makes room for at least one new item, but drop all
- * expored items too. */
-
- while (r->n_groups >= GROUPS_MAX ||
- (r->lru_tail && journal_rate_limit_group_expired(r->lru_tail, ts)))
- journal_rate_limit_group_free(r->lru_tail);
-}
-
-static JournalRateLimitGroup* journal_rate_limit_group_new(JournalRateLimit *r, const char *id, usec_t ts) {
- JournalRateLimitGroup *g;
-
- assert(r);
- assert(id);
-
- g = new0(JournalRateLimitGroup, 1);
- if (!g)
- return NULL;
-
- g->id = strdup(id);
- if (!g->id)
- goto fail;
-
- g->hash = string_hash_func(g->id, r->hash_key);
-
- journal_rate_limit_vacuum(r, ts);
-
- LIST_PREPEND(bucket, r->buckets[g->hash % BUCKETS_MAX], g);
- LIST_PREPEND(lru, r->lru, g);
- if (!g->lru_next)
- r->lru_tail = g;
- r->n_groups ++;
-
- g->parent = r;
- return g;
-
-fail:
- journal_rate_limit_group_free(g);
- return NULL;
-}
-
-static unsigned burst_modulate(unsigned burst, uint64_t available) {
- unsigned k;
-
- /* Modulates the burst rate a bit with the amount of available
- * disk space */
-
- k = u64log2(available);
-
- /* 1MB */
- if (k <= 20)
- return burst;
-
- burst = (burst * (k-20)) / 4;
-
- /*
- * Example:
- *
- * <= 1MB = rate * 1
- * 16MB = rate * 2
- * 256MB = rate * 3
- * 4GB = rate * 4
- * 64GB = rate * 5
- * 1TB = rate * 6
- */
-
- return burst;
-}
-
-int journal_rate_limit_test(JournalRateLimit *r, const char *id, int priority, uint64_t available) {
- unsigned long h;
- JournalRateLimitGroup *g;
- JournalRateLimitPool *p;
- unsigned burst;
- usec_t ts;
-
- assert(id);
-
- if (!r)
- return 1;
-
- if (r->interval == 0 || r->burst == 0)
- return 1;
-
- burst = burst_modulate(r->burst, available);
-
- ts = now(CLOCK_MONOTONIC);
-
- h = string_hash_func(id, r->hash_key);
- g = r->buckets[h % BUCKETS_MAX];
-
- LIST_FOREACH(bucket, g, g)
- if (streq(g->id, id))
- break;
-
- if (!g) {
- g = journal_rate_limit_group_new(r, id, ts);
- if (!g)
- return -ENOMEM;
- }
-
- p = &g->pools[priority_map[priority]];
-
- if (p->begin <= 0) {
- p->suppressed = 0;
- p->num = 1;
- p->begin = ts;
- return 1;
- }
-
- if (p->begin + r->interval < ts) {
- unsigned s;
-
- s = p->suppressed;
- p->suppressed = 0;
- p->num = 1;
- p->begin = ts;
-
- return 1 + s;
- }
-
- if (p->num <= burst) {
- p->num++;
- return 1;
- }
-
- p->suppressed++;
- return 0;
-}
~ianmdlvl / elogind.git / blobdiff