github: add scripts to store size of android release artifact

.github/workflows/postsubmit-main.yml

@@ -6,6 +6,8 @@
       - main
 
 jobs:
+  # Update the renderdiff goldens in filament-assets. This will add or merge the new goldens from
+  # a branch on filament-assets.
   update-renderdiff-goldens:
     name: update-renderdiff-goldens
     runs-on: 'ubuntu-24.04-4core'
@@ -35,6 +37,7 @@
                   --merge-to-main --filament-tag=${COMMIT_HASH} --golden-repo-token=${GH_TOKEN}
           fi
 
+  # Update the /docs (offiicla github-hosted Filament site) if necessary
   update-docs:
     name: update-docs
     runs-on: 'ubuntu-24.04-4core'
@@ -57,3 +60,40 @@
           git config --global user.name "Filament Bot"
           git config --global credential.helper cache
           bash docs_src/build/postsubmit.sh ${COMMIT_HASH} ${GH_TOKEN}
+
+  # Produce a json that describes the android artifact sizes, and will push that json to a folder in
+  # filament-assets
+  update-sizeguard:
+    name: update-sizeguard
+    runs-on: 'ubuntu-24.04-16core'
+    steps:
+      - uses: actions/checkout@v4.1.6
+        with:
+          fetch-depth: 0
+      - uses: ./.github/actions/linux-prereq
+      - uses: actions/setup-java@v3
+        with:
+          distribution: 'temurin'
+          java-version: '17'
+      - id: get_commit_msg
+        uses: ./.github/actions/get-commit-msg
+      - name: Build and generate size report
+        run: |
+          cd build/android && printf "y" | ./build.sh release all
+          cd ../..
+          COMMIT_HASH="${{ steps.get_commit_msg.outputs.hash }}"
+          python3 test/sizeguard/dump_artifact_size.py out/*.tgz out/*.aar > "${COMMIT_HASH}.json"
+      - name: Push to filament-assets
+        env:
+          GH_TOKEN: ${{ secrets.FILAMENTBOT_TOKEN }}
+        run: |
+          COMMIT_HASH="${{ steps.get_commit_msg.outputs.hash }}"
+          git config --global user.email "filament.bot@gmail.com"
+          git config --global user.name "Filament Bot"
+          git clone https://x-access-token:${GH_TOKEN}@github.com/google/filament-assets.git filament-assets
+          mkdir -p filament-assets/sizeguard
+          mv "${COMMIT_HASH}.json" filament-assets/sizeguard/
+          cd filament-assets
+          git add sizeguard/"${COMMIT_HASH}.json"
+          git commit -m "Update sizeguard for filament@${COMMIT_HASH}" || echo "No changes to commit"
+          git push https://x-access-token:${GH_TOKEN}@github.com/google/filament-assets.git main

test/sizeguard/dump_artifact_size.py

@@ -0,0 +1,94 @@
+# Copyright (C) 2026 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#!/usr/bin/env python3
+
+import os
+import sys
+import zipfile
+import tarfile
+import json
+import argparse
+
+# Hardcoded list of library extensions to track
+LIB_EXTENSIONS = ('.a', '.jar', '.so')
+
+def get_archive_content(path):
+    """
+    Extracts metadata for library files within a compressed archive.
+    Returns a list of dicts with 'name' and 'size' (uncompressed).
+    """
+    content = []
+
+    # .aar and .zip are both handled by zipfile
+    if path.endswith(('.zip', '.aar')):
+        with zipfile.ZipFile(path, 'r') as z:
+            for info in z.infolist():
+                # info.is_dir() is available in Python 3.6+
+                if not info.is_dir() and info.filename.endswith(LIB_EXTENSIONS):
+                    content.append({
+                        "name": info.filename,
+                        "size": info.file_size
+                    })
+
+    # .tgz or .tar.gz handled by tarfile
+    elif path.endswith(('.tgz', '.tar.gz')):
+        with tarfile.open(path, 'r:gz') as t:
+            for member in t.getmembers():
+                if member.isfile() and member.name.endswith(LIB_EXTENSIONS):
+                    content.append({
+                        "name": member.name,
+                        "size": member.size
+                    })
+    else:
+        raise ValueError(f"Unsupported archive format: {path}")
+
+    return content
+
+def main():
+    parser = argparse.ArgumentParser(description="Dump sizes of library files inside archives as JSON.")
+    parser.add_argument('archives', nargs='+', help='List of compressed archives (.aar, .tgz, .zip)')
+    args = parser.parse_args()
+
+    results = []
+
+    for archive_path in args.archives:
+        if not os.path.exists(archive_path):
+            print(f"Error: File not found: {archive_path}", file=sys.stderr)
+            sys.exit(1)
+
+        try:
+            archive_full_size = os.path.getsize(archive_path)
+            inner_content = get_archive_content(archive_path)
+
+            # Sort the content list alphabetically by name
+            inner_content.sort(key=lambda x: x['name'])
+
+            results.append({
+                "name": os.path.basename(archive_path),
+                "size": archive_full_size,
+                "content": inner_content
+            })
+        except Exception as e:
+            print(f"Error processing {archive_path}: {e}", file=sys.stderr)
+            sys.exit(1)
+
+    # Sort the top-level results by archive name
+    results.sort(key=lambda x: x['name'])
+
+    # Output JSON to stdout
+    print(json.dumps(results, indent=2))
+
+if __name__ == "__main__":
+    main()