OPTIM: halog: keep a fast path for the lines-count only

Using "halog -c" is still something quite common to perform on logs,
but unfortunately since the recent added controls, it was sensibly
slowed down due to the parsing of the accept date field.

Now we use a specific loop for the case where nothing is needed from
the input, and this sped up the line counting by 2.5x. A 2.4 GHz Xeon
now counts lines at a rate of 2 GB of logs per second.

diff --git a/contrib/halog/halog.c b/contrib/halog/halog.c
index df224b1b2437e8e8e47c15478f916d8c79183014..40852aec0c3942df04987e98d24c00a528c8a5a2 100644 (file)
--- a/contrib/halog/halog.c
+++ b/contrib/halog/halog.c
@@ -631,6 +631,16 @@ int main(int argc, char **argv)
        else if (filter & FILT_COUNT_ONLY)
                line_filter = NULL;
 
+       if (!line_filter &&
+           !(filter & (FILT_HTTP_ONLY|FILT_TIME_RESP|FILT_ERRORS_ONLY|FILT_HTTP_STATUS|FILT_QUEUE_ONLY|FILT_QUEUE_SRV_ONLY|FILT_TERM_CODE_NAME))) {
+               /* read the whole file at once first */
+               if (!filter_invert)
+                       while (fgets2(stdin) != NULL)
+                               lines_out++;
+
+               goto skip_filters;
+       }
+
        while ((line = fgets2(stdin)) != NULL) {
                linenum++;
                time_field = NULL; accept_field = NULL;
@@ -788,7 +798,7 @@ int main(int argc, char **argv)
                        lines_out++; /* we're just counting lines */
        }
 
-
+ skip_filters:
        /*****************************************************
         * Here we've finished reading all input. Depending on the
         * filters, we may still have some analysis to run on the