Custom Backtrace serializer/deserializer - GSON replacement #162

BartoszLitwiniuk · 2025-02-05T18:12:26Z

Important note: First we need to merge PR #144

Summary
This PR contains all changes needed to replace GSON library which was used for serialization/deserialization data. These modifications are part of the ongoing efforts to optimize the backtrace-android library by reducing external dependencies and enhancing performance.

Key Changes

Introduces new manual serialization and deserialization logic tailored for Backtrace data models.
Eliminates the need for GSON, reducing runtime overhead and potential compatibility issues.
Add unit tests to check the correctness of serialization and deserialization of the main data models

Performance comparison GSON vs custom solution based on included unit-tests

BacktraceData serialization (SerializerBacktraceDataGsonComparisonTest.java)

[GSON] Average execution time: 2.04 milliseconds
[Org.json] Average execution time: 0.942 milliseconds

Different objects serialization (SerializerGsonComparisonTest.java)

Total serialization time of object type BacktraceApiResult [GSON]: 247 milliseconds, [Org.json]: 57 milliseconds
Total serialization time of object type BacktraceResult [GSON]: 11 milliseconds, [Org.json]: 3 milliseconds
Total serialization time of object type BacktraceReport [GSON]: 5 milliseconds, [Org.json]: 8 milliseconds
Total serialization time of object type BacktraceReport [GSON]: 7 milliseconds, [Org.json]: 11 milliseconds
Total serialization time of object type BacktraceStackFrame [GSON]: 1 milliseconds, [Org.json]: 1 milliseconds
Total serialization time of object type SourceCode [GSON]: 2 milliseconds, [Org.json]: 1 milliseconds
Total serialization time of object type ThreadInformation [GSON]: 2 milliseconds, [Org.json]: 2 milliseconds

Different object deserialization (DeserializerGsonComparisonTest.java)

Total deserialization time [GSON] of object BacktraceApiResult: 120 milliseconds, [Org.json]: 42 milliseconds
Total deserialization time [GSON] of object BacktraceApiResult: 1 milliseconds, [Org.json]: 2 milliseconds
Total deserialization time [GSON] of object BacktraceData: 22 milliseconds, [Org.json]: 22 milliseconds
Total deserialization time [GSON] of object BacktraceReport: 3 milliseconds, [Org.json]: 5 milliseconds
Total deserialization time [GSON] of object BacktraceReport: 6 milliseconds, [Org.json]: 4 milliseconds
Total deserialization time [GSON] of object BacktraceResult: 6 milliseconds, [Org.json]: 6 milliseconds
Total deserialization time [GSON] of object BacktraceStackFrame: 2 milliseconds, [Org.json]: 1 milliseconds
Total deserialization time [GSON] of object SourceCode: 1 milliseconds, [Org.json]: 1 milliseconds
Total deserialization time [GSON] of object ThreadInformation: 2 milliseconds, [Org.json]: 2 milliseconds

Potential breaking changes

If you are a client of this library and you were using GSON annotation import com.google.gson.annotations.SerializedName; you need to replace it with import backtraceio.library.common.json.serialization.SerializedName; and verify if your objects are serialized/deserialized correctly before going to production.

Architecture of new serialization/deserialization flow

# Conflicts: # backtrace-library/build.gradle # backtrace-library/src/main/java/backtraceio/library/models/json/BacktraceAttributes.java

# Conflicts: # backtrace-library/src/main/java/backtraceio/library/models/json/BacktraceReport.java

perf2711 · 2025-02-06T08:35:23Z

...roidTest/java/backtraceio/library/common/json/SerializerBacktraceDataGsonComparisonTest.java

+            // GSON
+            long startTime = System.currentTimeMillis();
+            BacktraceSerializeHelper.toJson(data);
+            long endTime = System.currentTimeMillis();
+            timeGson += endTime - startTime;
+
+            // ORG JSON
+            long startTimeOrg = System.currentTimeMillis();
+            BacktraceDataSerializer serializer = new BacktraceDataSerializer(new NamingPolicy());
+            serializer.toJson(data);
+            long endTimeOrg = System.currentTimeMillis();
+            timeOrgJson += endTimeOrg - startTimeOrg;


Maybe it would be nice to test one-time serialization also?
I'm thinking about the FieldNameCache initialization, which may take some more time on the first go.

perf2711 · 2025-02-06T08:36:21Z

...src/main/java/backtraceio/library/common/json/deserialization/BacktraceDataDeserializer.java

+        if (obj == null) {
+            return null;
+        }
+        SourceCodeDeserializer deserializer = new SourceCodeDeserializer();


small nit: maybe keep this (and every other serializer) as class fields, so you won't have to create them each time?

perf2711 · 2025-02-06T08:39:40Z

...src/main/java/backtraceio/library/common/json/deserialization/BacktraceDataDeserializer.java

+            try {
+                if (obj.get(key) instanceof JSONObject) {
+                    result.put(key, deserializer.deserialize((JSONObject) obj.get(key)));
+                }
+            } catch (JSONException e) {
+                BacktraceLogger.e(LOG_TAG, String.format("Exception on deserialization of source code, " +
+                        "key %s, object %s", key, obj), e);
+            }


Shouldn't we try/catch the whole object serialization? Returning a "valid" deserialized object with it's data missing is a code smell.

This applies for every try/catch in this class and other deserializers.

perf2711 · 2025-02-06T08:41:51Z

...src/main/java/backtraceio/library/common/json/deserialization/BacktraceDataDeserializer.java

+        final ThreadInformationDeserializer deserializer = new ThreadInformationDeserializer();
+        Iterator<String> keys = obj.keys();
+
+        while (keys.hasNext()) {


don't you guys have foreach? 😢

perf2711 · 2025-02-06T08:43:54Z

...src/main/java/backtraceio/library/common/json/deserialization/BacktraceDataDeserializer.java

+        if (jsonArray == null) {
+            return null;
+        }


Does this codebase expect ever BacktraceData.classifiers to be null? Maybe return an empty array instead?

perf2711 · 2025-02-06T09:52:26Z