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authorMichal Schmidt <mschmidt@redhat.com>2014-12-18 14:21:55 +0100
committerMichal Schmidt <mschmidt@redhat.com>2014-12-18 14:29:46 +0100
commit6e693b42dcb0b332364b0414107826826925c49f (patch)
tree9a518765de829bafb6197f3af15ba4b1e6e605a3
parent58439db4cc45a6f84a74ad73f873bd3c113eebf6 (diff)
journal: optimize iteration by skipping exhausted files
If from a previous iteration we know we are at the end of a journal file, don't bother looking into the file again. This is complicated by the fact that the EOF does not have to be permanent (think of "journalctl -f"). So we also check if the number of entries in the journal file changed. This optimization has a similar effect as "journal: optimize iteration: skip whole files behind current location" had.
-rw-r--r--src/journal/journal-file.h1
-rw-r--r--src/journal/sd-journal.c8
2 files changed, 8 insertions, 1 deletions
diff --git a/src/journal/journal-file.h b/src/journal/journal-file.h
index 8084176195..561982fe39 100644
--- a/src/journal/journal-file.h
+++ b/src/journal/journal-file.h
@@ -78,6 +78,7 @@ typedef struct JournalFile {
direction_t last_direction;
LocationType location_type;
+ uint64_t last_n_entries;
char *path;
struct stat last_stat;
diff --git a/src/journal/sd-journal.c b/src/journal/sd-journal.c
index f3aae9b0ed..0aaf2257d4 100644
--- a/src/journal/sd-journal.c
+++ b/src/journal/sd-journal.c
@@ -729,12 +729,18 @@ static int next_with_matches(
static int next_beyond_location(sd_journal *j, JournalFile *f, direction_t direction) {
Object *c;
- uint64_t cp;
+ uint64_t cp, n_entries;
int r;
assert(j);
assert(f);
+ /* If we hit EOF before, recheck if any new entries arrived. */
+ n_entries = le64toh(f->header->n_entries);
+ if (f->location_type == LOCATION_TAIL && n_entries == f->last_n_entries)
+ return 0;
+ f->last_n_entries = n_entries;
+
if (f->last_direction == direction && f->current_offset > 0) {
cp = f->current_offset;