Merge pull request #891 from girder/cache-read-tiff

Cache read_tiff calls to speed up restyling

CHANGELOG.md

@@ -11,6 +11,7 @@
 - When converting girder images locally, prefer mount paths ([886](../../pull/886))
 - Store the id of job results for easier post-job work ([887](../../pull/887))
 - Harden style compositing of partial tiles ([889](../../pull/889))
+- Cache read_tiff calls to speed up restyling ([891](../../pull/891))
 
 ### Changes
 - Be more consistent in source class name attribute assignment ([884](../../pull/884))

sources/tiff/large_image_source_tiff/__init__.py

@@ -21,6 +21,7 @@
 import math
 import os
 
+import cachetools
 import numpy
 import PIL.Image
 import tifftools
@@ -48,6 +49,11 @@
     pass
 
 
+@cachetools.cached(cache=cachetools.LRUCache(maxsize=10))
+def _cached_read_tiff(path):
+    return tifftools.read_tiff(path)
+
+
 class TiffFileTileSource(FileTileSource, metaclass=LruCacheMetaclass):
     """
     Provides tile access to TIFF files.
@@ -264,7 +270,7 @@ def _initWithTiffTools(self):  # noqa
         self.levels = max(1, int(math.ceil(math.log(max(
             dir0.imageWidth / dir0.tileWidth,
             dir0.imageHeight / dir0.tileHeight)) / math.log(2))) + 1)
-        info = tifftools.read_tiff(self._largeImagePath)
+        info = _cached_read_tiff(self._largeImagePath)
         frames = []
         associated = []  # for now, a list of directories
         curframe = -1