+/*
+ * trace-collection.c
+ *
+ * Babeltrace Library
+ *
+ * Copyright 2012 EfficiOS Inc. and Linux Foundation
+ *
+ * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ */
+#include <babeltrace/babeltrace.h>
+#include <babeltrace/format.h>
+#include <babeltrace/context.h>
+#include <babeltrace/ctf/types.h>
+#include <babeltrace/ctf-text/types.h>
+#include <babeltrace/trace-collection.h>
+#include <babeltrace/ctf-ir/metadata.h> /* for clocks */
+
+#include <inttypes.h>
+
+struct clock_match {
+ GHashTable *clocks;
+ struct ctf_clock *clock_match;
+ struct trace_collection *tc;
+};
+
+static void check_clock_match(gpointer key, gpointer value, gpointer user_data)
+{
+ struct clock_match *match = user_data;
+ struct ctf_clock *clock_a = value, *clock_b;
+
+ if (clock_a->uuid != 0) {
+ /*
+ * Lookup the the trace clocks into the collection
+ * clocks.
+ */
+ clock_b = g_hash_table_lookup(match->clocks,
+ (gpointer) (unsigned long) clock_a->uuid);
+ if (clock_b) {
+ match->clock_match = clock_b;
+ return;
+ }
+ } else if (clock_a->absolute) {
+ /*
+ * Absolute time references, such as NTP, are looked up
+ * by clock name.
+ */
+ clock_b = g_hash_table_lookup(match->clocks,
+ (gpointer) (unsigned long) clock_a->name);
+ if (clock_b) {
+ match->clock_match = clock_b;
+ return;
+ }
+ }
+}
+
+static void clock_add(gpointer key, gpointer value, gpointer user_data)
+{
+ struct clock_match *clock_match = user_data;
+ GHashTable *tc_clocks = clock_match->clocks;
+ struct ctf_clock *t_clock = value;
+ GQuark v;
+
+ if (t_clock->absolute)
+ v = t_clock->name;
+ else
+ v = t_clock->uuid;
+ if (v) {
+ struct ctf_clock *tc_clock;
+
+ tc_clock = g_hash_table_lookup(tc_clocks,
+ (gpointer) (unsigned long) v);
+ if (!tc_clock) {
+ /*
+ * For now, we only support CTF that has one
+ * single clock uuid or name (absolute ref).
+ */
+ if (g_hash_table_size(tc_clocks) > 0) {
+ fprintf(stderr, "[error] Only CTF traces with a single clock description are supported by this babeltrace version.\n");
+ }
+ if (!clock_match->tc->offset_nr) {
+ clock_match->tc->offset_first =
+ (t_clock->offset_s * 1000000000ULL) + t_clock->offset;
+ clock_match->tc->delta_offset_first_sum = 0;
+ clock_match->tc->offset_nr++;
+ clock_match->tc->single_clock_offset_avg =
+ clock_match->tc->offset_first;
+ }
+ g_hash_table_insert(tc_clocks,
+ (gpointer) (unsigned long) v,
+ value);
+ } else {
+ int64_t diff_ns;
+
+ /*
+ * Check that the offsets match. If not, warn
+ * the user that we do an arbitrary choice.
+ */
+ diff_ns = tc_clock->offset_s;
+ diff_ns -= t_clock->offset_s;
+ diff_ns *= 1000000000ULL;
+ diff_ns += tc_clock->offset;
+ diff_ns -= t_clock->offset;
+ printf_debug("Clock \"%s\" offset between traces has a delta of %" PRIu64 " ns.",
+ g_quark_to_string(tc_clock->name),
+ diff_ns < 0 ? -diff_ns : diff_ns);
+ if (diff_ns > 10000) {
+ fprintf(stderr, "[warning] Clock \"%s\" offset differs between traces (delta %" PRIu64 " ns). Using average.\n",
+ g_quark_to_string(tc_clock->name),
+ diff_ns < 0 ? -diff_ns : diff_ns);
+ }
+ /* Compute average */
+ clock_match->tc->delta_offset_first_sum +=
+ (t_clock->offset_s * 1000000000ULL) + t_clock->offset
+ - clock_match->tc->offset_first;
+ clock_match->tc->offset_nr++;
+ clock_match->tc->single_clock_offset_avg =
+ clock_match->tc->offset_first
+ + (clock_match->tc->delta_offset_first_sum / clock_match->tc->offset_nr);
+ }
+ }
+}
+
+/*
+ * Whenever we add a trace to the trace collection, check that we can
+ * correlate this trace with at least one other clock in the trace.
+ */
+int trace_collection_add(struct trace_collection *tc,
+ struct trace_descriptor *td)
+{
+ struct ctf_trace *trace = container_of(td, struct ctf_trace, parent);
+
+ g_ptr_array_add(tc->array, td);
+ trace->collection = tc;
+
+ if (tc->array->len > 1) {
+ struct clock_match clock_match = {
+ .clocks = tc->clocks,
+ .clock_match = NULL,
+ .tc = NULL,
+ };
+
+ /*
+ * With two or more traces, we need correlation info
+ * avalable.
+ */
+ g_hash_table_foreach(trace->clocks,
+ check_clock_match,
+ &clock_match);
+ if (!clock_match.clock_match) {
+ fprintf(stderr, "[error] No clocks can be correlated and multiple traces are added to the collection.\n");
+ goto error;
+ }
+ }
+
+ {
+ struct clock_match clock_match = {
+ .clocks = tc->clocks,
+ .clock_match = NULL,
+ .tc = tc,
+ };
+
+ /*
+ * Add each clock from the trace clocks into the trace
+ * collection clocks.
+ */
+ g_hash_table_foreach(trace->clocks,
+ clock_add,
+ &clock_match);
+ }
+ return 0;
+error:
+ return -EPERM;
+}
+
+int trace_collection_remove(struct trace_collection *tc,
+ struct trace_descriptor *td)
+{
+ if (g_ptr_array_remove(tc->array, td)) {
+ return 0;
+ } else {
+ return -1;
+ }
+
+}
+
+void init_trace_collection(struct trace_collection *tc)
+{
+ tc->array = g_ptr_array_new();
+ tc->clocks = g_hash_table_new(g_direct_hash, g_direct_equal);
+ tc->single_clock_offset_avg = 0;
+ tc->offset_first = 0;
+ tc->delta_offset_first_sum = 0;
+ tc->offset_nr = 0;
+}
+
+/*
+ * finalize_trace_collection() closes the opened traces for read
+ * and free the memory allocated for trace collection
+ */
+void finalize_trace_collection(struct trace_collection *tc)
+{
+ g_ptr_array_free(tc->array, TRUE);
+ g_hash_table_destroy(tc->clocks);
+}