[PATCH 04/28] perf tools: Introduce struct hist_entry_iter

[Namhyung Kim <namhyung@kernel.org>]

There're some duplicate code when adding hist entries.  They are
different in that some have branch info or mem info but generally do
same thing.  So introduce new struct hist_entry_iter and add callbacks
to customize each case in general way.

The new perf_evsel__add_entry() function will look like:

  iter->prepare_entry();
  iter->add_single_entry();

  while (iter->next_entry())
    iter->add_next_entry();

  iter->finish_entry();

This will help further work like the cumulative callchain patchset.

Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-report.c | 362 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 273 insertions(+), 89 deletions(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 6bfcb83db8ff..c11c4e8493da 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -93,29 +93,68 @@ static int hist_entry__append_callchain(struct hist_entry *he, struct perf_sampl
 	return callchain_append(he->callchain, &callchain_cursor, sample->period);
 }
 
-static int report__add_mem_hist_entry(struct perf_tool *tool, struct addr_location *al,
-				      struct perf_sample *sample, struct perf_evsel *evsel,
-				      union perf_event *event)
-{
-	struct report *rep = container_of(tool, struct report, tool);
-	struct symbol *parent = NULL;
-	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
+struct hist_entry_iter {
+	int total;
+	int curr;
+
+	struct report *rep;
+	union perf_event *event;
+	struct perf_evsel *evsel;
+	struct perf_sample *sample;
 	struct hist_entry *he;
-	struct mem_info *mi, *mx;
-	uint64_t cost;
-	int err = report__resolve_callchain(rep, &parent, evsel, al, sample);
+	struct symbol *parent;
+	void *priv;
+
+	int (*prepare_entry)(struct hist_entry_iter *, struct addr_location *);
+	int (*add_single_entry)(struct hist_entry_iter *, struct addr_location *);
+	int (*next_entry)(struct hist_entry_iter *, struct addr_location *);
+	int (*add_next_entry)(struct hist_entry_iter *, struct addr_location *);
+	int (*finish_entry)(struct hist_entry_iter *, struct addr_location *);
+};
 
-	if (err)
-		return err;
+static int
+iter_next_nop_entry(struct hist_entry_iter *iter __maybe_unused,
+		    struct addr_location *al __maybe_unused)
+{
+	return 0;
+}
+
+static int
+iter_add_next_nop_entry(struct hist_entry_iter *iter __maybe_unused,
+			struct addr_location *al __maybe_unused)
+{
+	return 0;
+}
+
+static int
+iter_prepare_mem_entry(struct hist_entry_iter *iter, struct addr_location *al)
+{
+	union perf_event *event = iter->event;
+	struct perf_sample *sample = iter->sample;
+	struct mem_info *mi;
+	u8 cpumode;
+
+	cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
 
 	mi = machine__resolve_mem(al->machine, al->thread, sample, cpumode);
-	if (!mi)
+	if (mi == NULL)
 		return -ENOMEM;
 
-	if (rep->hide_unresolved && !al->sym)
-		return 0;
+	iter->priv = mi;
+	return 0;
+}
+
+static int
+iter_add_single_mem_entry(struct hist_entry_iter *iter, struct addr_location *al)
+{
+	u64 cost;
+	struct mem_info *mi = iter->priv;
+	struct hist_entry *he;
+
+	if (mi == NULL)
+		return -EINVAL;
 
-	cost = sample->weight;
+	cost = iter->sample->weight;
 	if (!cost)
 		cost = 1;
 
@@ -126,11 +165,27 @@ static int report__add_mem_hist_entry(struct perf_tool *tool, struct addr_locati
 	 * and this is indirectly achieved by passing period=weight here
 	 * and the he_stat__add_period() function.
 	 */
-	he = __hists__add_entry(&evsel->hists, al, parent, NULL, mi,
+	he = __hists__add_entry(&iter->evsel->hists, al, iter->parent, NULL, mi,
 				cost, cost, 0);
 	if (!he)
 		return -ENOMEM;
 
+	iter->he = he;
+	return 0;
+}
+
+static int
+iter_finish_mem_entry(struct hist_entry_iter *iter, struct addr_location *al)
+{
+	struct perf_evsel *evsel = iter->evsel;
+	struct hist_entry *he = iter->he;
+	struct mem_info *mx;
+	int err = -EINVAL;
+	u64 cost;
+
+	if (he == NULL)
+		goto out;
+
 	err = hist_entry__inc_addr_samples(he, evsel->idx, al->addr);
 	if (err)
 		goto out;
@@ -140,97 +195,222 @@ static int report__add_mem_hist_entry(struct perf_tool *tool, struct addr_locati
 	if (err)
 		goto out;
 
+	cost = iter->sample->weight;
+	if (!cost)
+		cost = 1;
+
 	evsel->hists.stats.total_period += cost;
 	hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);
-	err = hist_entry__append_callchain(he, sample);
+
+	err = hist_entry__append_callchain(he, iter->sample);
+
 out:
+	/*
+	 * We don't need to free iter->priv (mem_info) here since
+	 * the mem info was either already freed in add_hist_entry() or
+	 * passed to a new hist entry by hist_entry__new().
+	 */
+	iter->priv = NULL;
+
+	iter->he = NULL;
 	return err;
 }
 
-static int report__add_branch_hist_entry(struct perf_tool *tool, struct addr_location *al,
-					 struct perf_sample *sample, struct perf_evsel *evsel)
+static int
+iter_prepare_branch_entry(struct hist_entry_iter *iter, struct addr_location *al)
 {
-	struct report *rep = container_of(tool, struct report, tool);
-	struct symbol *parent = NULL;
-	unsigned i;
-	struct hist_entry *he;
-	struct branch_info *bi, *bx;
-	int err = report__resolve_callchain(rep, &parent, evsel, al, sample);
-
-	if (err)
-		return err;
+	struct branch_info *bi;
+	struct perf_sample *sample = iter->sample;
 
 	bi = machine__resolve_bstack(al->machine, al->thread,
 				     sample->branch_stack);
 	if (!bi)
 		return -ENOMEM;
 
-	for (i = 0; i < sample->branch_stack->nr; i++) {
-		if (rep->hide_unresolved && !(bi[i].from.sym && bi[i].to.sym))
-			continue;
+	iter->curr = 0;
+	iter->total = sample->branch_stack->nr;
 
-		err = -ENOMEM;
+	iter->priv = bi;
+	return 0;
+}
 
-		/* overwrite the 'al' to branch-to info */
-		al->map = bi[i].to.map;
-		al->sym = bi[i].to.sym;
-		al->addr = bi[i].to.addr;
-		/*
-		 * The report shows the percentage of total branches captured
-		 * and not events sampled. Thus we use a pseudo period of 1.
-		 */
-		he = __hists__add_entry(&evsel->hists, al, parent, &bi[i], NULL,
-					1, 1, 0);
-		if (he) {
-			bx = he->branch_info;
-			err = addr_map_symbol__inc_samples(&bx->from, evsel->idx);
-			if (err)
-				goto out;
-
-			err = addr_map_symbol__inc_samples(&bx->to, evsel->idx);
-			if (err)
-				goto out;
-
-			evsel->hists.stats.total_period += 1;
-			hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);
-		} else
-			goto out;
-	}
-	err = 0;
-out:
-	free(bi);
-	return err;
+static int
+iter_add_single_branch_entry(struct hist_entry_iter *iter __maybe_unused,
+			     struct addr_location *al __maybe_unused)
+{
+	return 0;
 }
 
-static int report__add_hist_entry(struct perf_tool *tool, struct perf_evsel *evsel,
-				  struct addr_location *al, struct perf_sample *sample)
+static int
+iter_next_branch_entry(struct hist_entry_iter *iter, struct addr_location *al)
 {
-	struct report *rep = container_of(tool, struct report, tool);
-	struct symbol *parent = NULL;
+	struct branch_info *bi = iter->priv;
+	int i = iter->curr;
+
+	if (bi == NULL)
+		return 0;
+
+	if (iter->curr >= iter->total)
+		return 0;
+
+	al->map = bi[i].to.map;
+	al->sym = bi[i].to.sym;
+	al->addr = bi[i].to.addr;
+	return 1;
+}
+
+static int
+iter_add_next_branch_entry(struct hist_entry_iter *iter, struct addr_location *al)
+{
+	struct branch_info *bi, *bx;
+	struct perf_evsel *evsel = iter->evsel;
 	struct hist_entry *he;
-	int err = report__resolve_callchain(rep, &parent, evsel, al, sample);
+	int i = iter->curr;
+	int err = 0;
+
+	bi = iter->priv;
+
+	if (iter->rep->hide_unresolved && !(bi[i].from.sym && bi[i].to.sym))
+		goto out;
 
+	/*
+	 * The report shows the percentage of total branches captured
+	 * and not events sampled. Thus we use a pseudo period of 1.
+	 */
+	he = __hists__add_entry(&evsel->hists, al, iter->parent, &bi[i], NULL,
+				1, 1, 0);
+	if (he == NULL)
+		return -ENOMEM;
+
+	bx = he->branch_info;
+	err = addr_map_symbol__inc_samples(&bx->from, evsel->idx);
 	if (err)
-		return err;
+		goto out;
+
+	err = addr_map_symbol__inc_samples(&bx->to, evsel->idx);
+	if (err)
+		goto out;
+
+	evsel->hists.stats.total_period += 1;
+	hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);
+
+out:
+	iter->curr++;
+	return err;
+}
+
+static int
+iter_finish_branch_entry(struct hist_entry_iter *iter,
+			 struct addr_location *al __maybe_unused)
+{
+	zfree(&iter->priv);
 
-	he = __hists__add_entry(&evsel->hists, al, parent, NULL, NULL,
+	return iter->curr >= iter->total ? 0 : -1;
+}
+
+static int
+iter_prepare_normal_entry(struct hist_entry_iter *iter __maybe_unused,
+			  struct addr_location *al __maybe_unused)
+{
+	return 0;
+}
+
+static int
+iter_add_single_normal_entry(struct hist_entry_iter *iter, struct addr_location *al)
+{
+	struct perf_evsel *evsel = iter->evsel;
+	struct perf_sample *sample = iter->sample;
+	struct hist_entry *he;
+
+	he = __hists__add_entry(&evsel->hists, al, iter->parent, NULL, NULL,
 				sample->period, sample->weight,
 				sample->transaction);
 	if (he == NULL)
 		return -ENOMEM;
 
-	err = hist_entry__append_callchain(he, sample);
-	if (err)
-		goto out;
+	iter->he = he;
+	return 0;
+}
+
+static int
+iter_finish_normal_entry(struct hist_entry_iter *iter, struct addr_location *al)
+{
+	int err;
+	struct hist_entry *he = iter->he;
+	struct perf_evsel *evsel = iter->evsel;
+	struct perf_sample *sample = iter->sample;
+
+	if (he == NULL)
+		return 0;
+
+	iter->he = NULL;
 
 	err = hist_entry__inc_addr_samples(he, evsel->idx, al->addr);
+	if (err)
+		return err;
+
 	evsel->hists.stats.total_period += sample->period;
 	hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);
+
+	return hist_entry__append_callchain(he, sample);
+}
+
+static struct hist_entry_iter mem_iter = {
+	.prepare_entry 		= iter_prepare_mem_entry,
+	.add_single_entry 	= iter_add_single_mem_entry,
+	.next_entry 		= iter_next_nop_entry,
+	.add_next_entry 	= iter_add_next_nop_entry,
+	.finish_entry 		= iter_finish_mem_entry,
+};
+
+static struct hist_entry_iter branch_iter = {
+	.prepare_entry 		= iter_prepare_branch_entry,
+	.add_single_entry 	= iter_add_single_branch_entry,
+	.next_entry 		= iter_next_branch_entry,
+	.add_next_entry 	= iter_add_next_branch_entry,
+	.finish_entry 		= iter_finish_branch_entry,
+};
+
+static struct hist_entry_iter normal_iter = {
+	.prepare_entry 		= iter_prepare_normal_entry,
+	.add_single_entry 	= iter_add_single_normal_entry,
+	.next_entry 		= iter_next_nop_entry,
+	.add_next_entry 	= iter_add_next_nop_entry,
+	.finish_entry 		= iter_finish_normal_entry,
+};
+
+static int
+iter_add_entry(struct hist_entry_iter *iter, struct addr_location *al)
+{
+	int err, err2;
+
+	err = report__resolve_callchain(iter->rep, &iter->parent, iter->evsel,
+					al, iter->sample);
+	if (err)
+		return err;
+
+	err = iter->prepare_entry(iter, al);
+	if (err)
+		goto out;
+
+	err = iter->add_single_entry(iter, al);
+	if (err)
+		goto out;
+
+	while (iter->next_entry(iter, al)) {
+		err = iter->add_next_entry(iter, al);
+		if (err)
+			break;
+	}
+
 out:
+	err2 = iter->finish_entry(iter, al);
+	if (!err)
+		err = err2;
+
 	return err;
 }
 
-
 static int process_sample_event(struct perf_tool *tool,
 				union perf_event *event,
 				struct perf_sample *sample,
@@ -239,6 +419,7 @@ static int process_sample_event(struct perf_tool *tool,
 {
 	struct report *rep = container_of(tool, struct report, tool);
 	struct addr_location al;
+	struct hist_entry_iter *iter;
 	int ret;
 
 	if (perf_event__preprocess_sample(event, machine, &al, sample) < 0) {
@@ -253,22 +434,25 @@ static int process_sample_event(struct perf_tool *tool,
 	if (rep->cpu_list && !test_bit(sample->cpu, rep->cpu_bitmap))
 		return 0;
 
-	if (sort__mode == SORT_MODE__BRANCH) {
-		ret = report__add_branch_hist_entry(tool, &al, sample, evsel);
-		if (ret < 0)
-			pr_debug("problem adding lbr entry, skipping event\n");
-	} else if (rep->mem_mode == 1) {
-		ret = report__add_mem_hist_entry(tool, &al, sample, evsel, event);
-		if (ret < 0)
-			pr_debug("problem adding mem entry, skipping event\n");
-	} else {
-		if (al.map != NULL)
-			al.map->dso->hit = 1;
-
-		ret = report__add_hist_entry(tool, evsel, &al, sample);
-		if (ret < 0)
-			pr_debug("problem incrementing symbol period, skipping event\n");
-	}
+	if (sort__mode == SORT_MODE__BRANCH)
+		iter = &branch_iter;
+	else if (rep->mem_mode == 1)
+		iter = &mem_iter;
+	else
+		iter = &normal_iter;
+
+	if (al.map != NULL)
+		al.map->dso->hit = 1;
+
+	iter->rep = rep;
+	iter->evsel = evsel;
+	iter->event = event;
+	iter->sample = sample;
+
+	ret = iter_add_entry(iter, &al);
+	if (ret < 0)
+		pr_debug("problem adding hist entry, skipping event\n");
+
 	return ret;
 }
 
-- 
1.7.11.7