Preview: simplify pyvips timing to single processing ms + req total.

cista/preview.py

@@ -354,10 +354,14 @@ async def preview(req, path):
     except PreviewError:
         return empty(422)
     if preview_resp and preview_resp.backend:
-        load_ms = int(round(preview_resp.load_ms or 0.0))
-        process_ms = int(round(preview_resp.process_ms or 0.0))
-        save_ms = int(round(preview_resp.save_ms or 0.0))
-        req.ctx._log_extra = f"{preview_resp.backend} {load_ms}/{process_ms}/{save_ms} ="
+        if preview_resp.load_ms is not None:
+            load_ms = int(round(preview_resp.load_ms))
+            process_ms = int(round(preview_resp.process_ms or 0.0))
+            save_ms = int(round(preview_resp.save_ms or 0.0))
+            timing_detail = f"{load_ms}/{process_ms}/{save_ms}"
+        else:
+            timing_detail = str(int(round(preview_resp.total_ms or 0.0)))
+        req.ctx._log_extra = f"{preview_resp.backend} {timing_detail} ➛"
     if not img:
         # Preview generation failed, redirect to the file itself
         return redirect(f"/files/{path}", status=303)
@@ -415,16 +419,12 @@ def process_image_with_timing(path, *, maxsize, quality):
 def process_image_pyvips(path, *, maxsize, quality):
     import pyvips
 
-    t_load = perf_counter()
+    t_start = perf_counter()
     img = pyvips.Image.new_from_file(str(path), access="sequential")
-    t_proc = perf_counter()
-
     img = img.autorot()
     scale = min(maxsize / img.width, maxsize / img.height, 1.0)
     if scale < 1.0:
         img = img.resize(scale)
-
-    t_save = perf_counter()
     ret = img.write_to_buffer(
         ".avif",
         Q=quality,
@@ -433,17 +433,11 @@ def process_image_pyvips(path, *, maxsize, quality):
     )
     t_end = perf_counter()
 
-    load_ms = (t_proc - t_load) * 1000
-    proc_ms = (t_save - t_proc) * 1000
-    save_ms = (t_end - t_save) * 1000
     return ret, PreviewResponse(
         ok=True,
         mime="image/avif",
         backend="pyvips",
-        load_ms=round(load_ms, 1),
-        process_ms=round(proc_ms, 1),
-        save_ms=round(save_ms, 1),
-        total_ms=round((t_end - t_load) * 1000, 1),
+        total_ms=round((t_end - t_start) * 1000, 1),
     )
 
 

scripts/preview_images.py

@@ -0,0 +1,102 @@
+import argparse
+import mimetypes
+from pathlib import Path
+
+from cista.preview import process_image_with_timing
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(
+        description="Generate image previews for all files in a folder, one at a time.",
+    )
+    parser.add_argument("folder", type=Path, help="Folder to scan recursively")
+    parser.add_argument(
+        "--px",
+        type=int,
+        default=1024,
+        help="Maximum preview dimension in pixels (default: 1024)",
+    )
+    parser.add_argument(
+        "--quality",
+        type=int,
+        default=60,
+        help="AVIF quality passed to preview generation (default: 60)",
+    )
+    return parser.parse_args()
+
+
+def is_image_file(path: Path) -> bool:
+    mime_type, _ = mimetypes.guess_type(path.name)
+    return bool(mime_type and mime_type.startswith("image/"))
+
+
+def main() -> int:
+    args = parse_args()
+    folder = args.folder.resolve()
+    if not folder.is_dir():
+        raise SystemExit(f"Not a directory: {folder}")
+
+    files = sorted(path for path in folder.rglob("*") if path.is_file() and is_image_file(path))
+    if not files:
+        print(f"No image files found under {folder}")
+        return 0
+
+    total_files = 0
+    total_bytes = 0
+    total_load_ms: float = 0.0
+    total_process_ms: float = 0.0
+    total_save_ms: float = 0.0
+    total_preview_ms: float = 0.0
+    failures = 0
+
+    print(f"Scanning {folder}")
+    print(f"Generating previews for {len(files)} image files")
+
+    for path in files:
+        total_files += 1
+        rel = path.relative_to(folder)
+        try:
+            preview, timing = process_image_with_timing(
+                path,
+                maxsize=args.px,
+                quality=args.quality,
+            )
+        except Exception as exc:
+            failures += 1
+            print(f"FAIL  {rel}  error={exc}")
+            continue
+
+        total_bytes += len(preview)
+        total_load_ms += timing.load_ms or 0.0
+        total_process_ms += timing.process_ms or 0.0
+        total_save_ms += timing.save_ms or 0.0
+        total_preview_ms += timing.total_ms or 0.0
+
+        if timing.load_ms is not None:
+            detail = (
+                f"load={timing.load_ms:.1f}ms  process={timing.process_ms:.1f}ms  "
+                f"save={timing.save_ms:.1f}ms  total={timing.total_ms:.1f}ms"
+            )
+        else:
+            detail = f"total={timing.total_ms:.1f}ms"
+        print(f"OK    {rel}  backend={timing.backend}  bytes={len(preview)}  {detail}")
+
+    completed = total_files - failures
+    print()
+    print("Summary")
+    print(f"  files={total_files}")
+    print(f"  completed={completed}")
+    print(f"  failed={failures}")
+    print(f"  preview_bytes={total_bytes}")
+    if completed:
+        if total_load_ms or total_process_ms or total_save_ms:
+            print(f"  load_total_ms={total_load_ms:.1f}")
+            print(f"  process_total_ms={total_process_ms:.1f}")
+            print(f"  save_total_ms={total_save_ms:.1f}")
+        print(f"  preview_total_ms={total_preview_ms:.1f}")
+        print(f"  preview_avg_ms={total_preview_ms / completed:.1f}")
+    return 0 if failures == 0 else 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())