Magic-Mirror/gecko-dev
1
0
Fork 0
mirror of https://github.com/mozilla/gecko-dev.git synced 2024-11-23 04:41:11 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Bug 1823401: Hash cmap as well as head tables for SFNTData::GetUniqueKey. r=jfkthame

Browse Source 
Differential Revision: https://phabricator.services.mozilla.com/D173252
This commit is contained in:
Bob Owen 2023-03-22 15:31:53 +00:00
parent 94c3f31d97
commit 7403aa001e
2 changed files with 19 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
gfx/2d/SFNTData.cpp
View File

@ -69,6 +69,17 @@ class SFNTData::Font {
return {mFontData + dirEntry->offset, dirEntry->length};
}
Span<const uint8_t> GetCmapTableBytes() const {
const TableDirEntry* dirEntry =
GetDirEntry(TRUETYPE_TAG('c', 'm', 'a', 'p'));
if (!dirEntry) {
gfxWarning() << "Cmap table entry not found.";
return {};
}
return {mFontData + dirEntry->offset, dirEntry->length};
}
private:
const TableDirEntry* GetDirEntry(const uint32_t aTag) const {
const TableDirEntry* foundDirEntry =
@ -141,7 +152,7 @@ uint64_t SFNTData::GetUniqueKey(const uint8_t* aFontData, uint32_t aDataLength,
uint64_t hash = 0;
UniquePtr<SFNTData> sfntData = SFNTData::Create(aFontData, aDataLength);
if (sfntData) {
hash = sfntData->HashHeadTables();
hash = sfntData->HashHeadAndCmapTables();
} else {
gfxWarning() << "Failed to create SFNTData from data, hashing whole font.";
hash = HashBytes(aFontData, aDataLength);
@ -179,14 +190,16 @@ bool SFNTData::AddFont(const uint8_t* aFontData, uint32_t aDataLength,
return mFonts.append(new Font(offsetTable, aFontData, aDataLength));
}
uint32_t SFNTData::HashHeadTables() {
uint32_t headTableHash = std::accumulate(
uint32_t SFNTData::HashHeadAndCmapTables() {
uint32_t tablesHash = std::accumulate(
mFonts.begin(), mFonts.end(), 0U, [](uint32_t hash, Font* font) {
Span<const uint8_t> headBytes = font->GetHeadTableBytes();
return AddToHash(hash, HashBytes(headBytes.data(), headBytes.size()));
hash = AddToHash(hash, HashBytes(headBytes.data(), headBytes.size()));
Span<const uint8_t> cmapBytes = font->GetCmapTableBytes();
return AddToHash(hash, HashBytes(cmapBytes.data(), cmapBytes.size()));
});
return headTableHash;
return tablesHash;
}
} // namespace gfx

2
gfx/2d/SFNTData.h
View File

@ -45,7 +45,7 @@ class SFNTData final {
bool AddFont(const uint8_t* aFontData, uint32_t aDataLength,
uint32_t aOffset);
uint32_t HashHeadTables();
uint32_t HashHeadAndCmapTables();
// Internal representation of single font in font file.
class Font;