[PATCH v2 05/10] trace-cmd dump: Read extended BUFFER option

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

In trace file version 7 the BUFFER option is extended to hold a trace
metadata, related to the recorded instance. Also, a new BUFFER_TEXT
option is added for latency trace data. Implemented logic for reading
and printing these extended options.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 tracecmd/trace-dump.c | 64 +++++++++++++++++++++++++++++++++++++++----
 1 file changed, 59 insertions(+), 5 deletions(-)

diff --git a/tracecmd/trace-dump.c b/tracecmd/trace-dump.c
index dcc41030..c44870c4 100644
--- a/tracecmd/trace-dump.c
+++ b/tracecmd/trace-dump.c
@@ -446,19 +446,72 @@ static void dump_section_header(int fd, enum dump_items v, unsigned short *flags
 		*flags = fl;
 }
 
-static void dump_option_buffer(int fd, int size)
+static void dump_option_buffer(int fd, unsigned short option, int size)
 {
+	unsigned long long total_size = 0;
+	unsigned long long data_size;
+	unsigned long long current;
 	unsigned long long offset;
+	unsigned short flags;
+	char clock[DUMP_SIZE];
+	char name[DUMP_SIZE];
+	int cpus = 0;
+	int id;
+	int i;
 
 	if (size < 8)
 		die("broken buffer option with size %d", size);
 
 	if (read_file_number(fd, &offset, 8))
 		die("cannot read the offset of the buffer option");
+	if (read_file_string(fd, name, DUMP_SIZE))
+		die("cannot read the name of the buffer option");
+	if (file_version < FILE_VERSION_SECTIONS) {
+		do_print(OPTIONS|FLYRECORD, "\t\t[Option BUFFER, %d bytes]\n", size);
+		do_print(OPTIONS|FLYRECORD, "%lld [offset]\n", offset);
+		do_print(OPTIONS|FLYRECORD, "\"%s\" [name]\n", name);
+		return;
+	}
+
+	current = lseek64(fd, 0, SEEK_CUR);
+	if (lseek64(fd, offset, SEEK_SET) == (off_t)-1)
+		die("cannot goto buffer offset %lld", offset);
+
+	dump_section_header(fd, FLYRECORD, &flags);
+
+	if (lseek64(fd, current, SEEK_SET) == (off_t)-1)
+		die("cannot go back to buffer option");
+
+	do_print(OPTIONS|FLYRECORD, "\t\t[Option BUFFER, %d bytes]\n", size);
+	do_print(OPTIONS|FLYRECORD, "%lld [offset]\n", offset);
+	do_print(OPTIONS|FLYRECORD, "\"%s\" [name]\n", name);
+
+	if (read_file_string(fd, clock, DUMP_SIZE))
+		die("cannot read clock of the buffer option");
+	do_print(OPTIONS|FLYRECORD, "\"%s\" [clock]\n", clock);
+	if (option == TRACECMD_OPTION_BUFFER) {
+		if (read_file_number(fd, &cpus, 4))
+			die("cannot read the cpu count of the buffer option");
+
+		do_print(OPTIONS|FLYRECORD, "%d [CPUs]:\n", cpus);
+		for (i = 0; i < cpus; i++) {
+			if (read_file_number(fd, &id, 4))
+				die("cannot read the id of cpu %d from the buffer option", i);
+			if (read_file_number(fd, &offset, 8))
+				die("cannot read the offset of cpu %d from the buffer option", i);
+			if (read_file_number(fd, &data_size, 8))
+				die("cannot read the data size of cpu %d from the buffer option", i);
+			total_size += data_size;
+			do_print(OPTIONS|FLYRECORD, "   %d %lld\t%lld\t[id, data offset and size]\n",
+				 id, offset, data_size);
+		}
+		do_print(SUMMARY, "\t\[buffer \"%s\", \"%s\" clock, "
+			 "%d cpus, %lld bytes flyrecord data]\n",
+			 name, clock, cpus, total_size);
+	} else {
+		do_print(SUMMARY, "\t\[buffer \"%s\", \"%s\" clock, latency data]\n", name, clock);
+	}
 
-	do_print(OPTIONS, "\t\t[Option BUFFER, %d bytes]\n", size);
-	do_print(OPTIONS, "%lld [offset]\n", offset);
-	read_dump_string(fd, size - 8, OPTIONS);
 }
 
 static void dump_option_int(int fd, int size, char *desc)
@@ -665,7 +718,8 @@ static int dump_options_read(int fd)
 			dump_option_string(fd, size, "CPUSTAT");
 			break;
 		case TRACECMD_OPTION_BUFFER:
-			dump_option_buffer(fd, size);
+		case TRACECMD_OPTION_BUFFER_TEXT:
+			dump_option_buffer(fd, option, size);
 			break;
 		case TRACECMD_OPTION_TRACECLOCK:
 			do_print(OPTIONS, "\t\t[Option TRACECLOCK, %d bytes]\n", size);
-- 
2.31.1