Cache font key instead of whole font content

Fix Kozea#2130.
okkays · May 1, 2024 · 4693087 · 4693087
1 parent 365960c
commit 4693087
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Showing 2 changed files with 17 additions and 11 deletions.
diff --git a/weasyprint/pdf/stream.py b/weasyprint/pdf/stream.py
@@ -1,7 +1,6 @@
 """PDF stream."""
 
 import io
-from functools import lru_cache
 from hashlib import md5
 
 import pydyf
@@ -13,7 +12,7 @@
 from ..matrix import Matrix
 from ..text.constants import PANGO_STRETCH_PERCENT
 from ..text.ffi import ffi, harfbuzz, pango, units_to_double
-from ..text.fonts import get_hb_face_data, get_pango_font_hb_face
+from ..text.fonts import get_hb_face_data, get_pango_font_hb_face, get_pango_font_key
 
 
 class Font:
@@ -323,15 +322,8 @@ def set_blend_mode(self, mode):
             'BM': f'/{mode}',
         }))
 
-    @lru_cache()
     def add_font(self, pango_font):
-        description = pango.pango_font_describe(pango_font)
-        mask = (
-            pango.PANGO_FONT_MASK_SIZE +
-            pango.PANGO_FONT_MASK_GRAVITY)
-        pango.pango_font_description_unset_fields(description, mask)
-        key = pango.pango_font_description_hash(description)
-        pango.pango_font_description_free(description)
+        key = get_pango_font_key(pango_font)
         if key not in self._fonts:
             self._fonts[key] = Font(pango_font)
         return self._fonts[key]

diff --git a/weasyprint/text/fonts.py b/weasyprint/text/fonts.py
@@ -1,5 +1,6 @@
 """Interface with external libraries managing fonts installed on the system."""
 
+from functools import lru_cache
 from hashlib import md5
 from io import BytesIO
 from pathlib import Path
@@ -364,7 +365,7 @@ def get_pango_font_hb_face(pango_font):
     return pangoft2.pango_fc_font_map_get_hb_face(fontmap, fc_font)
 
 
-def get_hb_face_blob_data(hb_face, ot_color=None):
+def get_hb_face_data(hb_face, ot_color=None):
     """Get binary data out of given Harfbuzz face.
 
     If ``ot_color`` is 'svg', return the SVG color glyph reference. If it’s 'png',
@@ -382,3 +383,16 @@ def get_hb_face_blob_data(hb_face, ot_color=None):
         hb_data = harfbuzz.hb_blob_get_data(hb_blob, length)
         if hb_data != ffi.NULL:
             return ffi.unpack(hb_data, int(length[0]))
+
+
+@lru_cache()
+def get_pango_font_key(pango_font):
+    """Get key corresponding to given Pango font."""
+    description = ffi.gc(
+        pango.pango_font_describe(pango_font),
+        pango.pango_font_description_free)
+    mask = (
+        pango.PANGO_FONT_MASK_SIZE +
+        pango.PANGO_FONT_MASK_GRAVITY)
+    pango.pango_font_description_unset_fields(description, mask)
+    return pango.pango_font_description_hash(description)