Add ovnitop command

src/emu/CMakeLists.txt

@@ -66,6 +66,9 @@ target_link_libraries(ovnidump emu parson-static ovni-static)
 add_executable(ovnisort ovnisort.c)
 target_link_libraries(ovnisort emu parson-static ovni-static)
 
+add_executable(ovnitop ovnitop.c)
+target_link_libraries(ovnitop emu parson-static ovni-static)
+
 set(USE_MPI ON CACHE BOOL "Use MPI (required by ovnisync)")
 if(USE_MPI)
   # Use <PackageName>_ROOT variables if available, commonly used by MPI
@@ -81,4 +84,4 @@ else()
   message(STATUS "Disabling ovnisync as MPI is disabled")
 endif()
 
-install(TARGETS ovniemu ovnidump ovnisort RUNTIME DESTINATION bin)
+install(TARGETS ovniemu ovnidump ovnisort ovnitop RUNTIME DESTINATION bin)

src/emu/ovnitop.c

@@ -0,0 +1,157 @@
+/* Copyright (c) 2023 Barcelona Supercomputing Center (BSC)
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "common.h"
+#include "emu_ev.h"
+#include "emu_stat.h"
+#include "ovni.h"
+#include "player.h"
+#include "trace.h"
+#include "uthash.h"
+
+struct entry {
+	char mcv[4];
+	long count;
+	UT_hash_handle hh;
+};
+
+char *tracedir;
+struct entry *table = NULL;
+
+static void
+accum(struct player *player)
+{
+	struct emu_ev *ev = player_ev(player);
+	struct entry *e = NULL;
+	HASH_FIND_STR(table, ev->mcv, e);
+
+	if (e == NULL) {
+		e = calloc(1, sizeof(struct entry));
+		if (e == NULL)
+			die("calloc failed:");
+
+		strcpy(e->mcv, ev->mcv);
+		e->count = 1;
+		HASH_ADD_STR(table, mcv, e);
+	} else {
+		e->count++;
+	}
+}
+
+static int
+by_count(struct entry *a, struct entry *b)
+{
+	if (a->count < b->count)
+		return +1;
+	if (a->count > b->count)
+		return -1;
+	
+	/* Otherwise they have the same count, sort by mcv */
+	return strcmp(a->mcv, b->mcv);
+}
+
+static void
+report(void)
+{
+	HASH_SORT(table, by_count);
+
+	for (struct entry *e = table; e; e = e->hh.next)
+		printf("%s %10ld\n", e->mcv, e->count);
+}
+
+static void
+usage(void)
+{
+	rerr("Usage: ovnitop DIR\n");
+	rerr("\n");
+	rerr("Show most common events in a trace.\n");
+	rerr("\n");
+	rerr("  DIR      Directory containing ovni traces (%s) or single stream.\n",
+			OVNI_STREAM_EXT);
+	rerr("\n");
+
+	exit(EXIT_FAILURE);
+}
+
+static void
+parse_args(int argc, char *argv[])
+{
+	int opt;
+
+	while ((opt = getopt(argc, argv, "h")) != -1) {
+		switch (opt) {
+			case 'h':
+			default: /* '?' */
+				usage();
+		}
+	}
+
+	if (optind >= argc) {
+		err("bad usage: missing directory");
+		usage();
+	}
+
+	tracedir = argv[optind];
+}
+
+int
+main(int argc, char *argv[])
+{
+	progname_set("ovnitop");
+
+	parse_args(argc, argv);
+
+	struct trace *trace = calloc(1, sizeof(struct trace));
+
+	if (trace == NULL) {
+		err("calloc failed:");
+		return 1;
+	}
+
+	if (trace_load(trace, tracedir) != 0) {
+		err("failed to load trace: %s", tracedir);
+		return 1;
+	}
+
+	struct player *player = calloc(1, sizeof(struct player));
+	if (player == NULL) {
+		err("calloc failed:");
+		return 1;
+	}
+
+	if (player_init(player, trace, 1) != 0) {
+		err("player_init failed");
+		return 1;
+	}
+
+	int ret;
+
+	struct emu_stat stat;
+
+	emu_stat_init(&stat);
+
+	while ((ret = player_step(player)) == 0) {
+		accum(player);
+		emu_stat_update(&stat, player);
+	}
+
+	emu_stat_report(&stat, player, 1);
+
+	/* Report events */
+	report();
+
+	/* Error happened */
+	if (ret < 0) {
+		err("player_step failed");
+		return 1;
+	}
+
+	free(trace);
+	free(player);
+
+	return 0;
+}