test(benchmark): add batch size benchmark

tests/benchmark_tagger.py

@@ -0,0 +1,32 @@
+import os
+
+import pytest
+from PIL import Image
+
+from wdtagger import Tagger
+
+tagger = Tagger()
+image_dir = "./tests/images/"
+image_paths = [os.path.join(image_dir, image) for image in os.listdir(image_dir)] * 16
+images = [Image.open(image_path) for image_path in image_paths]
+
+
+def tag_in_batch(images, batch=1):
+    for i in range(0, len(images), batch):
+        tagger.tag(images[i : i + batch])
+
+
+@pytest.mark.benchmark(
+    group="tagger",
+    min_rounds=10,
+    warmup=False,
+    disable_gc=True,
+)
+@pytest.mark.parametrize("batch", [1, 2, 4, 8, 16])
+def test_tagger_benchmark(benchmark, batch):
+    # warmup
+    tag_in_batch(images[:1])
+    benchmark.pedantic(tag_in_batch, args=(images, batch), iterations=1, rounds=10)
+
+
+# cmd: pytest tests/benchmark_tagger.py -v