osi2read: add json output option

osi3trace/osi2read.py

@@ -1,20 +1,27 @@
 """
-This program converts serialized osi trace files into a human readable txth file. 
+This program converts serialized osi trace files into a human readable output.
+
+Supported output formats:
+    txth - Human readable text (default)
+    json - JSON format (machine parsable, protobuf compatible)
 
 Example usage:
     python3 osi2read.py -d trace.osi -o myreadableosifile
+    python3 osi2read.py -d trace.osi --format json
 """
 
 from osi3trace.osi_trace import OSITrace
+from google.protobuf.json_format import MessageToJson
 import argparse
+import json
 import pathlib
 
 
 def command_line_arguments():
     """Define and handle command line interface"""
 
     parser = argparse.ArgumentParser(
-        description="Convert a serialized osi trace file to a readable txth output.",
+        description="Convert a serialized osi trace file to a readable txth or json output.",
         prog="osi2read",
     )
     parser.add_argument(
@@ -40,6 +47,15 @@ def command_line_arguments():
         type=str,
         required=False,
     )
+    parser.add_argument(
+        "--format",
+        "-f",
+        help="Output format.",
+        choices=["txth", "json"],
+        default="txth",
+        type=str,
+        required=False,
+    )
 
     return parser.parse_args()
 
@@ -52,12 +68,23 @@ def main():
     trace = OSITrace(args.data, args.type)
 
     if not args.output:
-        path = pathlib.Path(args.data).with_suffix(".txth")
+        suffix = ".json" if args.format == "json" else ".txth"
+        path = pathlib.Path(args.data).with_suffix(suffix)
         args.output = str(path)
 
     with open(args.output, "wt") as f:
-        for message in trace:
-            f.write(str(message))
+        if args.format == "json":
+            f.write("[\n")
+            first = True
+            for message in trace:
+                if not first:
+                    f.write(",\n")
+                first = False
+                f.write(MessageToJson(message))
+            f.write("\n]\n")
+        else:
+            for message in trace:
+                f.write(str(message))
 
     trace.close()