[PATCH 3/6] perf session: Introduce decompressor into reader object

[Alexey Bayduraev]

Introduce decompressor into reader object so that decompression
could be executed separately for each data file. Adding active_reader
into perf_session object to select current decompressor.

Acked-by: Namhyung Kim <namhyung@xxxxxxxxx>
Reviewed-by: Riccardo Mancini <rickyman7@xxxxxxxxx>
Tested-by: Riccardo Mancini <rickyman7@xxxxxxxxx>
Signed-off-by: Alexey Bayduraev <alexey.v.bayduraev@xxxxxxxxxxxxxxx>
---
 tools/perf/util/session.c | 48 +++++++++++++++++++++++++++++----------
 tools/perf/util/session.h |  2 ++
 2 files changed, 38 insertions(+), 12 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 262efc18caac..3bea0830b3b8 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -71,6 +71,9 @@ struct reader {
 	u64		 data_offset;
 	reader_cb_t	 process;
 	bool		 in_place_update;
+	struct zstd_data zstd_data;
+	struct decomp	 *decomp;
+	struct decomp	 *decomp_last;
 	struct reader_state state;
 };
 
@@ -82,7 +85,10 @@ static int perf_session__process_compressed_event(struct perf_session *session,
 	size_t decomp_size, src_size;
 	u64 decomp_last_rem = 0;
 	size_t mmap_len, decomp_len = session->header.env.comp_mmap_len;
-	struct decomp *decomp, *decomp_last = session->decomp_last;
+	struct decomp *decomp, *decomp_last = session->active_reader ?
+		session->active_reader->decomp_last : session->decomp_last;
+	struct zstd_data *zstd_data = session->active_reader ?
+		&session->active_reader->zstd_data : &session->zstd_data;
 
 	if (decomp_last) {
 		decomp_last_rem = decomp_last->size - decomp_last->head;
@@ -109,7 +115,7 @@ static int perf_session__process_compressed_event(struct perf_session *session,
 	src = (void *)event + sizeof(struct perf_record_compressed);
 	src_size = event->pack.header.size - sizeof(struct perf_record_compressed);
 
-	decomp_size = zstd_decompress_stream(&(session->zstd_data), src, src_size,
+	decomp_size = zstd_decompress_stream(zstd_data, src, src_size,
 				&(decomp->data[decomp_last_rem]), decomp_len - decomp_last_rem);
 	if (!decomp_size) {
 		munmap(decomp, mmap_len);
@@ -119,12 +125,22 @@ static int perf_session__process_compressed_event(struct perf_session *session,
 
 	decomp->size += decomp_size;
 
-	if (session->decomp == NULL) {
-		session->decomp = decomp;
-		session->decomp_last = decomp;
+	if (session->active_reader) {
+		if (session->active_reader->decomp == NULL) {
+			session->active_reader->decomp = decomp;
+			session->active_reader->decomp_last = decomp;
+		} else {
+			session->active_reader->decomp_last->next = decomp;
+			session->active_reader->decomp_last = decomp;
+		}
 	} else {
-		session->decomp_last->next = decomp;
-		session->decomp_last = decomp;
+		if (session->decomp == NULL) {
+			session->decomp = decomp;
+			session->decomp_last = decomp;
+		} else {
+			session->decomp_last->next = decomp;
+			session->decomp_last = decomp;
+		}
 	}
 
 	pr_debug("decomp (B): %zd to %zd\n", src_size, decomp_size);
@@ -314,11 +330,11 @@ static void perf_session__delete_threads(struct perf_session *session)
 	machine__delete_threads(&session->machines.host);
 }
 
-static void perf_session__release_decomp_events(struct perf_session *session)
+static void perf_decomp__release_events(struct decomp *next)
 {
-	struct decomp *next, *decomp;
+	struct decomp *decomp;
 	size_t mmap_len;
-	next = session->decomp;
+
 	do {
 		decomp = next;
 		if (decomp == NULL)
@@ -337,7 +353,7 @@ void perf_session__delete(struct perf_session *session)
 	auxtrace_index__free(&session->auxtrace_index);
 	perf_session__destroy_kernel_maps(session);
 	perf_session__delete_threads(session);
-	perf_session__release_decomp_events(session);
+	perf_decomp__release_events(session->decomp);
 	perf_env__exit(&session->header.env);
 	machines__exit(&session->machines);
 	if (session->data) {
@@ -2155,7 +2171,8 @@ static int __perf_session__process_decomp_events(struct perf_session *session)
 {
 	s64 skip;
 	u64 size, file_pos = 0;
-	struct decomp *decomp = session->decomp_last;
+	struct decomp *decomp = session->active_reader ?
+		session->active_reader->decomp_last : session->decomp_last;
 
 	if (!decomp)
 		return 0;
@@ -2212,6 +2229,9 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 
 	memset(mmaps, 0, sizeof(st->mmaps));
 
+	if (zstd_init(&rd->zstd_data, 0))
+		return -1;
+
 	mmap_prot  = PROT_READ;
 	mmap_flags = MAP_SHARED;
 
@@ -2255,6 +2275,7 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 		goto remap;
 	}
 
+	session->active_reader = rd;
 	size = event->header.size;
 
 	skip = -EINVAL;
@@ -2287,6 +2308,9 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 		goto more;
 
 out:
+	session->active_reader = NULL;
+	perf_decomp__release_events(rd->decomp);
+	zstd_fini(&rd->zstd_data);
 	return err;
 }
 
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 5d8bd14a0a39..45f9f652a12a 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -19,6 +19,7 @@ struct thread;
 
 struct auxtrace;
 struct itrace_synth_opts;
+struct reader;
 
 struct perf_session {
 	struct perf_header	header;
@@ -41,6 +42,7 @@ struct perf_session {
 	struct zstd_data	zstd_data;
 	struct decomp		*decomp;
 	struct decomp		*decomp_last;
+	struct reader           *active_reader;
 };
 
 struct decomp {
-- 
2.19.0