From d0404dcc2fd266d612be3c48c238a3586379c794 Mon Sep 17 00:00:00 2001
From: Viktor Kreschenski <viktor.kreschenski@altran.com>
Date: Thu, 15 Oct 2020 11:23:13 +0200
Subject: [PATCH 1/2] Replace osi message iteration

Signed-off-by: Viktor Kreschenski <viktor.kreschenski@altran.com>
---
 format/OSITrace.py | 43 +++++++++++++++++++++++--------------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/format/OSITrace.py b/format/OSITrace.py
index f525d102c..90441eaf1 100644
--- a/format/OSITrace.py
+++ b/format/OSITrace.py
@@ -44,6 +44,7 @@ def __init__(self, path=None, type_name="SensorView"):
         self.type_name = type_name
         self.timestep_count = 0
         self.retrieved_scenario_size = 0
+        self._int_length = len(struct.pack("<L", 0))
 
     def from_file(self, path, type_name="SensorView", max_index=-1, format_type=None):
         """Import a scenario from a file"""
@@ -161,19 +162,18 @@ def get_messages_in_index_range(self, begin, end):
         """
         Yield an iterator over messages of indexes between begin and end included.
         """
+        self.scenario_file.seek(self.message_offsets[begin])
+        abs_first_offset = self.message_offsets[begin]
+        abs_last_offset = self.message_offsets[end] \
+            if end < len(self.message_offsets) \
+            else self.retrieved_scenario_size
 
-        if self.format_type == "separated":
-            self.scenario_file.seek(self.message_offsets[begin])
-            abs_first_offset = self.message_offsets[begin]
-            abs_last_offset = self.message_offsets[end] \
-                if end < len(self.message_offsets) \
-                else self.retrieved_scenario_size
-
-            rel_message_offsets = [
-                abs_message_offset - abs_first_offset
-                for abs_message_offset in self.message_offsets[begin:end]
-            ]
+        rel_message_offsets = [
+            abs_message_offset - abs_first_offset
+            for abs_message_offset in self.message_offsets[begin:end]
+        ]
 
+        if self.format_type == "separated":
             message_sequence_len = abs_last_offset - \
                 abs_first_offset - SEPARATOR_LENGTH
             serialized_messages_extract = self.scenario_file.read(
@@ -190,17 +190,20 @@ def get_messages_in_index_range(self, begin, end):
                 yield message
 
         elif self.format_type is None:
-            self.scenario_file.seek(0)
-            serialized_message = self.scenario_file.read()
-            INT_LENGTH = len(struct.pack("<L", 0))
-            message_length = 0
+            message_sequence_len = abs_last_offset - abs_first_offset
+            serialized_messages_extract = self.scenario_file.read(message_sequence_len)
+
+            for rel_index, rel_message_offset in enumerate(rel_message_offsets):
+                rel_begin = rel_message_offset + self._int_length
+                rel_end = (
+                    rel_message_offsets[rel_index + 1] - self._int_length
+                    if rel_index + 1 < len(rel_message_offsets)
+                    else message_sequence_len
+                )
 
-            i = 0
-            while i < len(serialized_message):
                 message = MESSAGES_TYPE[self.type_name]()
-                message_length = struct.unpack("<L", serialized_message[i:INT_LENGTH+i])[0]
-                message.ParseFromString(serialized_message[i+INT_LENGTH:i+INT_LENGTH+message_length])
-                i += message_length + INT_LENGTH
+                serialized_message = serialized_messages_extract[rel_begin:rel_end]
+                message.ParseFromString(serialized_message)
                 yield message
 
         else:

From e8f3317a8bdd00247c67605fb0251a1aba45659e Mon Sep 17 00:00:00 2001
From: Viktor Kreschenski <viktor.kreschenski@altran.com>
Date: Sun, 25 Oct 2020 18:28:38 +0100
Subject: [PATCH 2/2] Fix int subtraction and remove file closing

Signed-off-by: Viktor Kreschenski <viktor.kreschenski@altran.com>
---
 format/OSITrace.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/format/OSITrace.py b/format/OSITrace.py
index 90441eaf1..a63c3ff47 100644
--- a/format/OSITrace.py
+++ b/format/OSITrace.py
@@ -196,7 +196,7 @@ def get_messages_in_index_range(self, begin, end):
             for rel_index, rel_message_offset in enumerate(rel_message_offsets):
                 rel_begin = rel_message_offset + self._int_length
                 rel_end = (
-                    rel_message_offsets[rel_index + 1] - self._int_length
+                    rel_message_offsets[rel_index + 1]
                     if rel_index + 1 < len(rel_message_offsets)
                     else message_sequence_len
                 )
@@ -210,8 +210,6 @@ def get_messages_in_index_range(self, begin, end):
             self.scenario_file.close()
             raise Exception(f"The defined format {self.format_type} does not exist.")
 
-        self.scenario_file.close()
-
     def make_readable(self, name, interval=None, index=None):
         self.scenario_file.seek(0)
         serialized_message = self.scenario_file.read()