122851 2013-10-15 12:22:03 -0700 Use unicode-range to prevent unnecessary @font-face donwnloads 2016-05-05 23:36:06 -0700 1 1 1 Unclassified WebKit Text 528+ (Nightly build) Unspecified Unspecified RESOLVED DUPLICATE 42154 BlinkMergeCandidate P2 Normal --- 1 rniwa webkit-unassigned enrica jonlee kling koivisto mmaxfield syoichi oldest_to_newest 940079 0 rniwa 2013-10-15 12:22:03 -0700 Consider merging https://chromium.googlesource.com/chromium/blink/+/342fe16bb002b8ba9cc06a10d8124df6a28c786f This patch delays font loading until creation of GlyphPage whose codepoint range intersects with the @font-face's unicode-range value. GlyphPage is created when glyph data for a character in its codepoint range is requested, so web fonts are not donwloaded if its glyph data is not used. Even if any glyph is not used, font metrics may be used (for example, <input> uses font metrics to calculate its size). These metrics are accessed via SimpleFontData::primarySimpleFontData, so we start loading there too. Caveat: Since GlyphPage has glyph data for contiguous 256 Unicode codepoints, this patch does not 100% prevent unnecessary downloads. Use of codepoint *near* the unicode-range can trigger the font load. To fix this, we need to delay font loading until a codepoint in unicode-range is requested. That may require changing the GlyphPage data structure. 940093 1 rniwa 2013-10-15 12:44:40 -0700 Also see https://chromium.googlesource.com/chromium/blink/+/79ac8708f80986662c7a1458c3a91571db637d92 1190633 2 mmaxfield 2016-05-05 23:36:06 -0700 *** This bug has been marked as a duplicate of bug 42154 ***