add --latency-marker-skip <N> to ignore the first occurrences of a ma…

…rker
satori-com · May 15, 2015 · fda7d72 · fda7d72
1 parent f83b218
commit fda7d72
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Showing 4 changed files with 38 additions and 1 deletion.
diff --git a/ChangeLog b/ChangeLog
@@ -1,4 +1,7 @@
 
+0.?:    ?
+    * --latency-marker-skip <N> to ignore the first occurrences of a marker.
+
 0.6:    2015-May-13
     * Parse \{connection.uid} type expressions in
       --first-message, --message, --latency-marker parameters,

diff --git a/src/tcpkali.c b/src/tcpkali.c
@@ -74,6 +74,7 @@ static struct option cli_long_options[] = {
     { "first-message-file", 1, 0, 'F' },
     { "help", 0, 0, 'h' },
     { "latency-marker", 1, 0, 'L' },
+    { "latency-marker-skip", 1, 0, 'S' },
     { "listen-port", 1, 0, 'l' },
     { "message", 1, 0, 'm' },
     { "message-file", 1, 0, 'f' },
@@ -415,6 +416,18 @@ int main(int argc, char **argv) {
             }
             }
             break;
+        case 'S': { /* --latency-marker-skip */
+            engine_params.latency_marker_skip =
+                            parse_with_multipliers(option, optarg,
+                            km_multiplier,
+                            sizeof(km_multiplier)/sizeof(km_multiplier[0]));
+            if(engine_params.latency_marker_skip < 0) {
+                fprintf(stderr, "--latency-marker-skip: "
+                            "Failed to parse or out of range expression\n");
+                exit(EX_USAGE);
+            }
+            }
+            break;
         default:
             fprintf(stderr, "%s: unknown option\n", option);
             usage(argv[0], &default_config);
@@ -949,6 +962,7 @@ usage(char *argv0, struct tcpkali_config *conf) {
     "  -r, --message-rate <R>      Messages per second to send in a connection\n"
     "\n"
     "  --latency-marker <string>   Measure latency using a per-message marker\n"
+    "  --latency-marker-skip <N>   Ignore the first N occurrences of a marker\n"
     "\n"
     "  --statsd                    Enable StatsD output (default %s)\n"
     "  --statsd-host <host>        StatsD host to send data (default is localhost)\n"

diff --git a/src/tcpkali_engine.c b/src/tcpkali_engine.c
@@ -104,6 +104,7 @@ struct connection {
         struct ring_buffer *sent_timestamps;
         struct hdr_histogram *histogram;
         unsigned message_bytes_credit;  /* See (EXPL:1) below. */
+        unsigned lm_occurrences_skip;   /* See --latency-marker-skip */
         /* Boyer-Moore-Horspool substring search algorithm data */
         struct StreamBMH     *sbmh_ctx;
         /* The following fields might be shared across connections. */
@@ -1007,6 +1008,11 @@ static void start_new_connection(TK_P) {
     if(largs->params.latency_marker && conn->data.single_message_size) {
         conn->latency.message_bytes_credit  /* See (EXPL:1) below. */
             = conn->data.single_message_size - 1;
+        /*
+         * Figure out how many latency markers to skip
+         * before starting to measure latency with them.
+         */
+        conn->latency.lm_occurrences_skip = largs->params.latency_marker_skip;
 
         /*
          * Initialize the Boyer-Moore-Horspool context for substring search.
@@ -1415,7 +1421,7 @@ static void latency_record_incoming_ts(TK_P_ struct connection *conn, char *buf,
 
     const uint8_t *lm = conn->latency.sbmh_data;
     size_t   lm_size  = conn->latency.sbmh_size;
-    int num_markers_found = 0;
+    unsigned num_markers_found = 0;
 
     for(; size > 0; ) {
         size_t analyzed = sbmh_feed(conn->latency.sbmh_ctx,
@@ -1431,6 +1437,19 @@ static void latency_record_incoming_ts(TK_P_ struct connection *conn, char *buf,
         }
     }
 
+    /*
+     * Skip the necessary numbers of markers.
+     */
+    if(conn->latency.lm_occurrences_skip) {
+        if(num_markers_found <= conn->latency.lm_occurrences_skip) {
+            conn->latency.lm_occurrences_skip -= num_markers_found;
+            return;
+        } else {
+            num_markers_found -= conn->latency.lm_occurrences_skip;
+            conn->latency.lm_occurrences_skip = 0;
+        }
+    }
+
     /*
      * Now, for all found markers extract and use the corresponding
      * end-to-end message latency.

diff --git a/src/tcpkali_engine.h b/src/tcpkali_engine.h
@@ -68,6 +68,7 @@ struct engine_params {
     struct message_collection    message_collection; /* A descr. what to send */
     struct transport_data_spec  *data_template;
     tk_expr_t *latency_marker;      /* --latency-marker */
+    int        latency_marker_skip;    /* --latency-marker-skip <N> */
     struct StreamBMH_Occ sbmh_shared_occ;  /* Streaming Boyer-Moore-Horspool */
 };