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-rw-r--r--src/journal/journal-file.c109
-rw-r--r--src/journal/journal-file.h3
-rw-r--r--src/journal/test-journal-enum.c53
3 files changed, 157 insertions, 8 deletions
diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
index edf8e7dd5e..6c9deacf2c 100644
--- a/src/journal/journal-file.c
+++ b/src/journal/journal-file.c
@@ -65,6 +65,9 @@
/* n_data was the first entry we added after the initial file format design */
#define HEADER_SIZE_MIN ALIGN64(offsetof(Header, n_data))
+/* How many entries to keep in the entry array chain cache at max */
+#define CHAIN_CACHE_MAX 20
+
void journal_file_close(JournalFile *f) {
assert(f);
@@ -97,6 +100,8 @@ void journal_file_close(JournalFile *f) {
if (f->mmap)
mmap_cache_unref(f->mmap);
+ hashmap_free_free(f->chain_cache);
+
#ifdef HAVE_XZ
free(f->compress_buffer);
#endif
@@ -1307,37 +1312,89 @@ int journal_file_append_entry(JournalFile *f, const dual_timestamp *ts, const st
return r;
}
+typedef struct ChainCacheItem {
+ uint64_t first; /* the array at the begin of the chain */
+ uint64_t array; /* the cached array */
+ uint64_t begin; /* the first item in the cached array */
+ uint64_t total; /* the total number of items in all arrays before this one in the chain */
+} ChainCacheItem;
+
+static void chain_cache_put(
+ Hashmap *h,
+ ChainCacheItem *ci,
+ uint64_t first,
+ uint64_t array,
+ uint64_t begin,
+ uint64_t total) {
+
+ if (!ci) {
+ if (hashmap_size(h) >= CHAIN_CACHE_MAX)
+ ci = hashmap_steal_first(h);
+ else {
+ ci = new(ChainCacheItem, 1);
+ if (!ci)
+ return;
+ }
+
+ ci->first = first;
+
+ if (hashmap_put(h, &ci->first, ci) < 0) {
+ free(ci);
+ return;
+ }
+ } else
+ assert(ci->first == first);
+
+ ci->array = array;
+ ci->begin = begin;
+ ci->total = total;
+}
+
static int generic_array_get(JournalFile *f,
uint64_t first,
uint64_t i,
Object **ret, uint64_t *offset) {
Object *o;
- uint64_t p = 0, a;
+ uint64_t p = 0, a, t = 0;
int r;
+ ChainCacheItem *ci;
assert(f);
a = first;
+
+ /* Try the chain cache first */
+ ci = hashmap_get(f->chain_cache, &first);
+ if (ci && i > ci->total) {
+ a = ci->array;
+ i -= ci->total;
+ t = ci->total;
+ }
+
while (a > 0) {
- uint64_t n;
+ uint64_t k;
r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &o);
if (r < 0)
return r;
- n = journal_file_entry_array_n_items(o);
- if (i < n) {
+ k = journal_file_entry_array_n_items(o);
+ if (i < k) {
p = le64toh(o->entry_array.items[i]);
- break;
+ goto found;
}
- i -= n;
+ i -= k;
+ t += k;
a = le64toh(o->entry_array.next_entry_array_offset);
}
- if (a <= 0 || p <= 0)
- return 0;
+ return 0;
+
+found:
+ /* Let's cache this item for the next invocation */
+ chain_cache_put(f->chain_cache, ci, first, a, o->entry_array.items[0], t);
r = journal_file_move_to_object(f, OBJECT_ENTRY, p, &o);
if (r < 0)
@@ -1401,11 +1458,38 @@ static int generic_array_bisect(JournalFile *f,
bool subtract_one = false;
Object *o, *array = NULL;
int r;
+ ChainCacheItem *ci;
assert(f);
assert(test_object);
+ /* Start with the first array in the chain */
a = first;
+
+ ci = hashmap_get(f->chain_cache, &first);
+ if (ci && n > ci->total) {
+ /* Ah, we have iterated this bisection array chain
+ * previously! Let's see if we can skip ahead in the
+ * chain, as far as the last time. But we can't jump
+ * backwards in the chain, so let's check that
+ * first. */
+
+ r = test_object(f, ci->begin, needle);
+ if (r < 0)
+ return r;
+
+ if (r == TEST_LEFT) {
+ /* OK, what we are looking for is right of th
+ * begin of this EntryArray, so let's jump
+ * straight to previously cached array in the
+ * chain */
+
+ a = ci->array;
+ n -= ci->total;
+ t = ci->total;
+ }
+ }
+
while (a > 0) {
uint64_t left, right, k, lp;
@@ -1486,6 +1570,9 @@ found:
if (subtract_one && t == 0 && i == 0)
return 0;
+ /* Let's cache this item for the next invocation */
+ chain_cache_put(f->chain_cache, ci, first, a, array->entry_array.items[0], t);
+
if (subtract_one && i == 0)
p = last_p;
else if (subtract_one)
@@ -2265,6 +2352,12 @@ int journal_file_open(
goto fail;
}
+ f->chain_cache = hashmap_new(uint64_hash_func, uint64_compare_func);
+ if (!f->chain_cache) {
+ r = -ENOMEM;
+ goto fail;
+ }
+
f->fd = open(f->path, f->flags|O_CLOEXEC, f->mode);
if (f->fd < 0) {
r = -errno;
diff --git a/src/journal/journal-file.h b/src/journal/journal-file.h
index d87cbe4876..cdbc8e41f6 100644
--- a/src/journal/journal-file.h
+++ b/src/journal/journal-file.h
@@ -33,6 +33,7 @@
#include "journal-def.h"
#include "util.h"
#include "mmap-cache.h"
+#include "hashmap.h"
typedef struct JournalMetrics {
uint64_t max_use;
@@ -64,6 +65,8 @@ typedef struct JournalFile {
JournalMetrics metrics;
MMapCache *mmap;
+ Hashmap *chain_cache;
+
#ifdef HAVE_XZ
void *compress_buffer;
uint64_t compress_buffer_size;
diff --git a/src/journal/test-journal-enum.c b/src/journal/test-journal-enum.c
new file mode 100644
index 0000000000..8a843ecdda
--- /dev/null
+++ b/src/journal/test-journal-enum.c
@@ -0,0 +1,53 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2012 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 <stdio.h>
+
+#include "log.h"
+#include "sd-journal.h"
+
+int main(int argc, char *argv[]) {
+ unsigned n = 0;
+ sd_journal *j;
+
+ log_set_max_level(LOG_DEBUG);
+
+ assert_se(sd_journal_open(&j, SD_JOURNAL_LOCAL_ONLY) >= 0);
+
+ assert_se(sd_journal_add_match(j, "_TRANSPORT=syslog", 0) >= 0);
+ assert_se(sd_journal_add_match(j, "_UID=0", 0) >= 0);
+
+ SD_JOURNAL_FOREACH_BACKWARDS(j) {
+ const void *d;
+ size_t l;
+
+ assert_se(sd_journal_get_data(j, "MESSAGE", &d, &l) >= 0);
+
+ printf("%.*s\n", (int) l, (char*) d);
+
+ n ++;
+ if (n >= 10)
+ break;
+ }
+
+ sd_journal_close(j);
+ return 0;
+}
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