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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 14:29:10 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 14:29:10 +0000
commit2aa4a82499d4becd2284cdb482213d541b8804dd (patch)
treeb80bf8bf13c3766139fbacc530efd0dd9d54394c /gfx/thebes/gfxOTSUtils.h
parentInitial commit. (diff)
downloadfirefox-2aa4a82499d4becd2284cdb482213d541b8804dd.tar.xz
firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.zip
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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1 files changed, 164 insertions, 0 deletions
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+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef GFX_OTS_UTILS_H
+#define GFX_OTS_UTILS_H
+
+#include "gfxFontUtils.h"
+
+#include "opentype-sanitiser.h"
+
+struct gfxOTSMozAlloc {
+ void* Grow(void* aPtr, size_t aLength) { return moz_xrealloc(aPtr, aLength); }
+ void* ShrinkToFit(void* aPtr, size_t aLength) {
+ return moz_xrealloc(aPtr, aLength);
+ }
+ void Free(void* aPtr) { free(aPtr); }
+};
+
+// Based on ots::ExpandingMemoryStream from ots-memory-stream.h,
+// adapted to use Mozilla allocators and to allow the final
+// memory buffer to be adopted by the client.
+template <typename AllocT = gfxOTSMozAlloc>
+class gfxOTSExpandingMemoryStream : public ots::OTSStream {
+ public:
+ // limit output/expansion to 256MB by default
+ enum { DEFAULT_LIMIT = 256 * 1024 * 1024 };
+
+ explicit gfxOTSExpandingMemoryStream(size_t initial,
+ size_t limit = DEFAULT_LIMIT)
+ : mLength(initial), mLimit(limit), mOff(0) {
+ mPtr = mAlloc.Grow(nullptr, mLength);
+ }
+
+ ~gfxOTSExpandingMemoryStream() { mAlloc.Free(mPtr); }
+
+ // Return the buffer, resized to fit its contents (as it may have been
+ // over-allocated during growth), and give up ownership of it so the
+ // caller becomes responsible to call free() when finished with it.
+ auto forget() {
+ auto p = mAlloc.ShrinkToFit(mPtr, mOff);
+ mPtr = nullptr;
+ return p;
+ }
+
+ bool WriteRaw(const void* data, size_t length) override {
+ if ((mOff + length > mLength) ||
+ (mLength > std::numeric_limits<size_t>::max() - mOff)) {
+ if (mLength == mLimit) {
+ return false;
+ }
+ size_t newLength = (mLength + 1) * 2;
+ if (newLength < mLength) {
+ return false;
+ }
+ if (newLength > mLimit) {
+ newLength = mLimit;
+ }
+ mPtr = mAlloc.Grow(mPtr, newLength);
+ mLength = newLength;
+ return WriteRaw(data, length);
+ }
+ std::memcpy(static_cast<char*>(mPtr) + mOff, data, length);
+ mOff += length;
+ return true;
+ }
+
+ bool Seek(off_t position) override {
+ if (position < 0) {
+ return false;
+ }
+ if (static_cast<size_t>(position) > mLength) {
+ return false;
+ }
+ mOff = position;
+ return true;
+ }
+
+ off_t Tell() const override { return mOff; }
+
+ private:
+ AllocT mAlloc;
+ void* mPtr;
+ size_t mLength;
+ const size_t mLimit;
+ off_t mOff;
+};
+
+class MOZ_STACK_CLASS gfxOTSContext : public ots::OTSContext {
+ public:
+ gfxOTSContext() {
+ using namespace mozilla;
+
+ // Whether to apply OTS validation to OpenType Layout tables
+ mCheckOTLTables = StaticPrefs::gfx_downloadable_fonts_otl_validation();
+ // Whether to preserve Variation tables in downloaded fonts
+ mCheckVariationTables =
+ StaticPrefs::gfx_downloadable_fonts_validate_variation_tables();
+ // Whether to preserve color bitmap glyphs
+ mKeepColorBitmaps =
+ StaticPrefs::gfx_downloadable_fonts_keep_color_bitmaps();
+ }
+
+ virtual ots::TableAction GetTableAction(uint32_t aTag) override {
+ // Preserve Graphite, color glyph and SVG tables,
+ // and possibly OTL and Variation tables (depending on prefs)
+ if ((!mCheckOTLTables && (aTag == TRUETYPE_TAG('G', 'D', 'E', 'F') ||
+ aTag == TRUETYPE_TAG('G', 'P', 'O', 'S') ||
+ aTag == TRUETYPE_TAG('G', 'S', 'U', 'B'))) ||
+ (!mCheckVariationTables &&
+ (aTag == TRUETYPE_TAG('a', 'v', 'a', 'r') ||
+ aTag == TRUETYPE_TAG('c', 'v', 'a', 'r') ||
+ aTag == TRUETYPE_TAG('f', 'v', 'a', 'r') ||
+ aTag == TRUETYPE_TAG('g', 'v', 'a', 'r') ||
+ aTag == TRUETYPE_TAG('H', 'V', 'A', 'R') ||
+ aTag == TRUETYPE_TAG('M', 'V', 'A', 'R') ||
+ aTag == TRUETYPE_TAG('S', 'T', 'A', 'T') ||
+ aTag == TRUETYPE_TAG('V', 'V', 'A', 'R'))) ||
+ aTag == TRUETYPE_TAG('S', 'V', 'G', ' ') ||
+ aTag == TRUETYPE_TAG('C', 'O', 'L', 'R') ||
+ aTag == TRUETYPE_TAG('C', 'P', 'A', 'L') ||
+ (mKeepColorBitmaps && (aTag == TRUETYPE_TAG('C', 'B', 'D', 'T') ||
+ aTag == TRUETYPE_TAG('C', 'B', 'L', 'C'))) ||
+ false) {
+ return ots::TABLE_ACTION_PASSTHRU;
+ }
+ return ots::TABLE_ACTION_DEFAULT;
+ }
+
+ static size_t GuessSanitizedFontSize(size_t aLength,
+ gfxUserFontType aFontType,
+ bool aStrict = true) {
+ switch (aFontType) {
+ case GFX_USERFONT_UNKNOWN:
+ // If being permissive of unknown types, make a reasonable guess
+ // at how much room the sanitized font may take, if it passes. Just
+ // enough extra space to accomodate some growth without excessive
+ // bloat in case of large fonts. 1.5x is a reasonable compromise
+ // for growable vectors in general.
+ return aStrict || !aLength ? 0 : (aLength * 3) / 2;
+ case GFX_USERFONT_WOFF:
+ return aLength * 2;
+ case GFX_USERFONT_WOFF2:
+ return aLength * 3;
+ default:
+ return aLength;
+ }
+ }
+
+ static size_t GuessSanitizedFontSize(const uint8_t* aData, size_t aLength,
+ bool aStrict = true) {
+ gfxUserFontType fontType =
+ gfxFontUtils::DetermineFontDataType(aData, aLength);
+ return GuessSanitizedFontSize(aLength, fontType, aStrict);
+ }
+
+ private:
+ bool mCheckOTLTables;
+ bool mCheckVariationTables;
+ bool mKeepColorBitmaps;
+};
+
+#endif /* GFX_OTS_UTILS_H */