journal: by default do not decompress dat objects larger than 64K

This introduces a new data threshold setting for sd_journal objects
which controls the maximum size of objects to decompress. This is
relieves the library from having to decompress full data objects even
if a client program is only interested in the initial part of them.

This speeds up "systemd-coredumpctl" drastically when invoked without
parameters.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/journal/coredumpctl.c b/src/journal/coredumpctl.c
index 4adc9236f1..f9cebb7a42 100644
--- a/src/journal/coredumpctl.c
+++ b/src/journal/coredumpctl.c
@@ -342,6 +342,11 @@ static int dump_list(sd_journal *j) {
 
         assert(j);
 
+        /* The coredumps are likely to compressed, and for just
+         * listing them we don#t need to decompress them, so let's
+         * pick a fairly low data threshold here */
+        sd_journal_set_data_threshold(j, 4096);
+
         SD_JOURNAL_FOREACH(j) {
                 if (field)
                         print_field(stdout, j);
@@ -381,6 +386,9 @@ static int dump_core(sd_journal* j) {
 
         assert(j);
 
+        /* We want full data, nothing truncated. */
+        sd_journal_set_data_threshold(j, 0);
+
         r = focus(j);
         if (r < 0)
                 return r;
@@ -428,6 +436,8 @@ static int run_gdb(sd_journal *j) {
 
         assert(j);
 
+        sd_journal_set_data_threshold(j, 0);
+
         r = focus(j);
         if (r < 0)
                 return r;