The Tor Browser: gfx/thebes/gfxFontUtils.h@97036ab72558 (annotated)

gfx/thebes/gfxFontUtils.h@97036ab72558 (annotated)

gfx/thebes/gfxFontUtils.h

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * 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_FONT_UTILS_H
 #define GFX_FONT_UTILS_H
 #include "gfxPlatform.h"
 #include "nsComponentManagerUtils.h"
 #include "nsTArray.h"
 #include "nsAutoPtr.h"
 #include "mozilla/Likely.h"
 #include "mozilla/Endian.h"
 #include "mozilla/MemoryReporting.h"
 #include "zlib.h"
 #include <algorithm>
 /* Bug 341128 - w32api defines min/max which causes problems with <bitset> */
 #ifdef __MINGW32__
 #undef min
 #undef max
 #endif
 typedef struct hb_blob_t hb_blob_t;
 class gfxSparseBitSet {
 private:
     enum { BLOCK_SIZE = 32 };   // ==> 256 codepoints per block
     enum { BLOCK_SIZE_BITS = BLOCK_SIZE * 8 };
     enum { BLOCK_INDEX_SHIFT = 8 };
     struct Block {
         Block(const Block& aBlock) { memcpy(mBits, aBlock.mBits, sizeof(mBits)); }
         Block(unsigned char memsetValue = 0) { memset(mBits, memsetValue, BLOCK_SIZE); }
         uint8_t mBits[BLOCK_SIZE];
     };
 public:
     gfxSparseBitSet() { }
     gfxSparseBitSet(const gfxSparseBitSet& aBitset) {
         uint32_t len = aBitset.mBlocks.Length();
         mBlocks.AppendElements(len);
         for (uint32_t i = 0; i < len; ++i) {
             Block *block = aBitset.mBlocks[i];
             if (block)
                 mBlocks[i] = new Block(*block);
         }
     }
     bool Equals(const gfxSparseBitSet *aOther) const {
         if (mBlocks.Length() != aOther->mBlocks.Length()) {
             return false;
         }
         size_t n = mBlocks.Length();
         for (size_t i = 0; i < n; ++i) {
             const Block *b1 = mBlocks[i];
             const Block *b2 = aOther->mBlocks[i];
             if (!b1 != !b2) {
                 return false;
             }
             if (!b1) {
                 continue;
             }
             if (memcmp(&b1->mBits, &b2->mBits, BLOCK_SIZE) != 0) {
                 return false;
             }
         }
         return true;
     }
     bool test(uint32_t aIndex) const {
         NS_ASSERTION(mBlocks.DebugGetHeader(), "mHdr is null, this is bad");
         uint32_t blockIndex = aIndex/BLOCK_SIZE_BITS;
         if (blockIndex >= mBlocks.Length())
             return false;
         Block *block = mBlocks[blockIndex];
         if (!block)
             return false;
         return ((block->mBits[(aIndex>>3) & (BLOCK_SIZE - 1)]) & (1 << (aIndex & 0x7))) != 0;
     }
 #if PR_LOGGING
     // dump out contents of bitmap
     void Dump(const char* aPrefix, eGfxLog aWhichLog) const;
 #endif
     bool TestRange(uint32_t aStart, uint32_t aEnd) {
         uint32_t startBlock, endBlock, blockLen;
         // start point is beyond the end of the block array? return false immediately
         startBlock = aStart >> BLOCK_INDEX_SHIFT;
         blockLen = mBlocks.Length();
         if (startBlock >= blockLen) return false;
         // check for blocks in range, if none, return false
         uint32_t blockIndex;
         bool hasBlocksInRange = false;
         endBlock = aEnd >> BLOCK_INDEX_SHIFT;
         blockIndex = startBlock;
         for (blockIndex = startBlock; blockIndex <= endBlock; blockIndex++) {
             if (blockIndex < blockLen && mBlocks[blockIndex])
                 hasBlocksInRange = true;
         }
         if (!hasBlocksInRange) return false;
         Block *block;
         uint32_t i, start, end;
         // first block, check bits
         if ((block = mBlocks[startBlock])) {
             start = aStart;
             end = std::min(aEnd, ((startBlock+1) << BLOCK_INDEX_SHIFT) - 1);
             for (i = start; i <= end; i++) {
                 if ((block->mBits[(i>>3) & (BLOCK_SIZE - 1)]) & (1 << (i & 0x7)))
                     return true;
             }
         }
         if (endBlock == startBlock) return false;
         // [2..n-1] blocks check bytes
         for (blockIndex = startBlock + 1; blockIndex < endBlock; blockIndex++) {
             uint32_t index;
             if (blockIndex >= blockLen || !(block = mBlocks[blockIndex])) continue;
             for (index = 0; index < BLOCK_SIZE; index++) {
                 if (block->mBits[index])
                     return true;
             }
         }
         // last block, check bits
         if (endBlock < blockLen && (block = mBlocks[endBlock])) {
             start = endBlock << BLOCK_INDEX_SHIFT;
             end = aEnd;
             for (i = start; i <= end; i++) {
                 if ((block->mBits[(i>>3) & (BLOCK_SIZE - 1)]) & (1 << (i & 0x7)))
                     return true;
             }
         }
         return false;
     }
     void set(uint32_t aIndex) {
         uint32_t blockIndex = aIndex/BLOCK_SIZE_BITS;
         if (blockIndex >= mBlocks.Length()) {
             nsAutoPtr<Block> *blocks = mBlocks.AppendElements(blockIndex + 1 - mBlocks.Length());
             if (MOZ_UNLIKELY(!blocks)) // OOM
                 return;
         }
         Block *block = mBlocks[blockIndex];
         if (!block) {
             block = new Block;
             mBlocks[blockIndex] = block;
         }
         block->mBits[(aIndex>>3) & (BLOCK_SIZE - 1)] |= 1 << (aIndex & 0x7);
     }
     void set(uint32_t aIndex, bool aValue) {
         if (aValue)
             set(aIndex);
         else
             clear(aIndex);
     }
     void SetRange(uint32_t aStart, uint32_t aEnd) {
         const uint32_t startIndex = aStart/BLOCK_SIZE_BITS;
         const uint32_t endIndex = aEnd/BLOCK_SIZE_BITS;
         if (endIndex >= mBlocks.Length()) {
             uint32_t numNewBlocks = endIndex + 1 - mBlocks.Length();
             nsAutoPtr<Block> *blocks = mBlocks.AppendElements(numNewBlocks);
             if (MOZ_UNLIKELY(!blocks)) // OOM
                 return;
         }
         for (uint32_t i = startIndex; i <= endIndex; ++i) {
             const uint32_t blockFirstBit = i * BLOCK_SIZE_BITS;
             const uint32_t blockLastBit = blockFirstBit + BLOCK_SIZE_BITS - 1;
             Block *block = mBlocks[i];
             if (!block) {
                 bool fullBlock = false;
                 if (aStart <= blockFirstBit && aEnd >= blockLastBit)
                     fullBlock = true;
                 block = new Block(fullBlock ? 0xFF : 0);
                 mBlocks[i] = block;
                 if (fullBlock)
                     continue;
             }
             const uint32_t start = aStart > blockFirstBit ? aStart - blockFirstBit : 0;
             const uint32_t end = std::min<uint32_t>(aEnd - blockFirstBit, BLOCK_SIZE_BITS - 1);
             for (uint32_t bit = start; bit <= end; ++bit) {
                 block->mBits[bit>>3] |= 1 << (bit & 0x7);
             }
         }
     }
     void clear(uint32_t aIndex) {
         uint32_t blockIndex = aIndex/BLOCK_SIZE_BITS;
         if (blockIndex >= mBlocks.Length()) {
             nsAutoPtr<Block> *blocks = mBlocks.AppendElements(blockIndex + 1 - mBlocks.Length());
             if (MOZ_UNLIKELY(!blocks)) // OOM
                 return;
         }
         Block *block = mBlocks[blockIndex];
         if (!block) {
             return;
         }
         block->mBits[(aIndex>>3) & (BLOCK_SIZE - 1)] &= ~(1 << (aIndex & 0x7));
     }
     void ClearRange(uint32_t aStart, uint32_t aEnd) {
         const uint32_t startIndex = aStart/BLOCK_SIZE_BITS;
         const uint32_t endIndex = aEnd/BLOCK_SIZE_BITS;
         if (endIndex >= mBlocks.Length()) {
             uint32_t numNewBlocks = endIndex + 1 - mBlocks.Length();
             nsAutoPtr<Block> *blocks = mBlocks.AppendElements(numNewBlocks);
             if (MOZ_UNLIKELY(!blocks)) // OOM
                 return;
         }
         for (uint32_t i = startIndex; i <= endIndex; ++i) {
             const uint32_t blockFirstBit = i * BLOCK_SIZE_BITS;
             Block *block = mBlocks[i];
             if (!block) {
                 // any nonexistent block is implicitly all clear,
                 // so there's no need to even create it
                 continue;
             }
             const uint32_t start = aStart > blockFirstBit ? aStart - blockFirstBit : 0;
             const uint32_t end = std::min<uint32_t>(aEnd - blockFirstBit, BLOCK_SIZE_BITS - 1);
             for (uint32_t bit = start; bit <= end; ++bit) {
                 block->mBits[bit>>3] &= ~(1 << (bit & 0x7));
             }
         }
     }
     size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
         size_t total = mBlocks.SizeOfExcludingThis(aMallocSizeOf);
         for (uint32_t i = 0; i < mBlocks.Length(); i++) {
             if (mBlocks[i]) {
                 total += aMallocSizeOf(mBlocks[i]);
             }
         }
         return total;
     }
     size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
         return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
     }
     // clear out all blocks in the array
     void reset() {
         uint32_t i;
         for (i = 0; i < mBlocks.Length(); i++)
             mBlocks[i] = nullptr;
     }
     // set this bitset to the union of its current contents and another
     void Union(const gfxSparseBitSet& aBitset) {
         // ensure mBlocks is large enough
         uint32_t blockCount = aBitset.mBlocks.Length();
         if (blockCount > mBlocks.Length()) {
             uint32_t needed = blockCount - mBlocks.Length();
             nsAutoPtr<Block> *blocks = mBlocks.AppendElements(needed);
             if (MOZ_UNLIKELY(!blocks)) { // OOM
                 return;
             }
         }
         // for each block that may be present in aBitset...
         for (uint32_t i = 0; i < blockCount; ++i) {
             // if it is missing (implicitly empty), just skip
             if (!aBitset.mBlocks[i]) {
                 continue;
             }
             // if the block is missing in this set, just copy the other
             if (!mBlocks[i]) {
                 mBlocks[i] = new Block(*aBitset.mBlocks[i]);
                 continue;
             }
             // else set existing block to the union of both
             uint32_t *dst = reinterpret_cast<uint32_t*>(mBlocks[i]->mBits);
             const uint32_t *src =
                 reinterpret_cast<const uint32_t*>(aBitset.mBlocks[i]->mBits);
             for (uint32_t j = 0; j < BLOCK_SIZE / 4; ++j) {
                 dst[j] |= src[j];
             }
         }
     }
     void Compact() {
         mBlocks.Compact();
     }
     uint32_t GetChecksum() const {
         uint32_t check = adler32(0, Z_NULL, 0);
         for (uint32_t i = 0; i < mBlocks.Length(); i++) {
             if (mBlocks[i]) {
                 const Block *block = mBlocks[i];
                 check = adler32(check, (uint8_t*) (&i), 4);
                 check = adler32(check, (uint8_t*) block, sizeof(Block));
             }
         }
         return check;
     }
 private:
     nsTArray< nsAutoPtr<Block> > mBlocks;
 };
 #define TRUETYPE_TAG(a, b, c, d) ((a) << 24 | (b) << 16 | (c) << 8 | (d))
 namespace mozilla {
 // Byte-swapping types and name table structure definitions moved from
 // gfxFontUtils.cpp to .h file so that gfxFont.cpp can also refer to them
 #pragma pack(1)
 struct AutoSwap_PRUint16 {
 #ifdef __SUNPRO_CC
     AutoSwap_PRUint16& operator = (const uint16_t aValue)
     {
         this->value = mozilla::NativeEndian::swapToBigEndian(aValue);
         return *this;
     }
 #else
     AutoSwap_PRUint16(uint16_t aValue)
     {
         value = mozilla::NativeEndian::swapToBigEndian(aValue);
     }
 #endif
     operator uint16_t() const
     {
         return mozilla::NativeEndian::swapFromBigEndian(value);
     }
     operator uint32_t() const
     {
         return mozilla::NativeEndian::swapFromBigEndian(value);
     }
     operator uint64_t() const
     {
         return mozilla::NativeEndian::swapFromBigEndian(value);
     }
 private:
     uint16_t value;
 };
 struct AutoSwap_PRInt16 {
 #ifdef __SUNPRO_CC
     AutoSwap_PRInt16& operator = (const int16_t aValue)
     {
         this->value = mozilla::NativeEndian::swapToBigEndian(aValue);
         return *this;
     }
 #else
     AutoSwap_PRInt16(int16_t aValue)
     {
         value = mozilla::NativeEndian::swapToBigEndian(aValue);
     }
 #endif
     operator int16_t() const
     {
         return mozilla::NativeEndian::swapFromBigEndian(value);
     }
     operator uint32_t() const
     {
         return mozilla::NativeEndian::swapFromBigEndian(value);
     }
 private:
     int16_t  value;
 };
 struct AutoSwap_PRUint32 {
 #ifdef __SUNPRO_CC
     AutoSwap_PRUint32& operator = (const uint32_t aValue)
     {
         this->value = mozilla::NativeEndian::swapToBigEndian(aValue);
         return *this;
     }
 #else
     AutoSwap_PRUint32(uint32_t aValue)
     {
         value = mozilla::NativeEndian::swapToBigEndian(aValue);
     }
 #endif
     operator uint32_t() const
     {
         return mozilla::NativeEndian::swapFromBigEndian(value);
     }
 private:
     uint32_t  value;
 };
 struct AutoSwap_PRInt32 {
 #ifdef __SUNPRO_CC
     AutoSwap_PRInt32& operator = (const int32_t aValue)
     {
         this->value = mozilla::NativeEndian::swapToBigEndian(aValue);
         return *this;
     }
 #else
     AutoSwap_PRInt32(int32_t aValue)
     {
         value = mozilla::NativeEndian::swapToBigEndian(aValue);
     }
 #endif
     operator int32_t() const
     {
         return mozilla::NativeEndian::swapFromBigEndian(value);
     }
 private:
     int32_t  value;
 };
 struct AutoSwap_PRUint64 {
 #ifdef __SUNPRO_CC
     AutoSwap_PRUint64& operator = (const uint64_t aValue)
     {
         this->value = mozilla::NativeEndian::swapToBigEndian(aValue);
         return *this;
     }
 #else
     AutoSwap_PRUint64(uint64_t aValue)
     {
         value = mozilla::NativeEndian::swapToBigEndian(aValue);
     }
 #endif
     operator uint64_t() const
     {
         return mozilla::NativeEndian::swapFromBigEndian(value);
     }
 private:
     uint64_t  value;
 };
 struct AutoSwap_PRUint24 {
     operator uint32_t() const { return value[0] << 16 | value[1] << 8 | value[2]; }
 private:
     AutoSwap_PRUint24() { }
     uint8_t  value[3];
 };
 struct SFNTHeader {
     AutoSwap_PRUint32    sfntVersion;            // Fixed, 0x00010000 for version 1.0.
     AutoSwap_PRUint16    numTables;              // Number of tables.
     AutoSwap_PRUint16    searchRange;            // (Maximum power of 2 <= numTables) x 16.
     AutoSwap_PRUint16    entrySelector;          // Log2(maximum power of 2 <= numTables).
     AutoSwap_PRUint16    rangeShift;             // NumTables x 16-searchRange.
 };
 struct TableDirEntry {
     AutoSwap_PRUint32    tag;                    // 4 -byte identifier.
     AutoSwap_PRUint32    checkSum;               // CheckSum for this table.
     AutoSwap_PRUint32    offset;                 // Offset from beginning of TrueType font file.
     AutoSwap_PRUint32    length;                 // Length of this table.
 };
 struct HeadTable {
     enum {
         HEAD_VERSION = 0x00010000,
         HEAD_MAGIC_NUMBER = 0x5F0F3CF5,
         HEAD_CHECKSUM_CALC_CONST = 0xB1B0AFBA
     };
     AutoSwap_PRUint32    tableVersionNumber;    // Fixed, 0x00010000 for version 1.0.
     AutoSwap_PRUint32    fontRevision;          // Set by font manufacturer.
     AutoSwap_PRUint32    checkSumAdjustment;    // To compute: set it to 0, sum the entire font as ULONG, then store 0xB1B0AFBA - sum.
     AutoSwap_PRUint32    magicNumber;           // Set to 0x5F0F3CF5.
     AutoSwap_PRUint16    flags;
     AutoSwap_PRUint16    unitsPerEm;            // Valid range is from 16 to 16384. This value should be a power of 2 for fonts that have TrueType outlines.
     AutoSwap_PRUint64    created;               // Number of seconds since 12:00 midnight, January 1, 1904. 64-bit integer
     AutoSwap_PRUint64    modified;              // Number of seconds since 12:00 midnight, January 1, 1904. 64-bit integer
     AutoSwap_PRInt16     xMin;                  // For all glyph bounding boxes.
     AutoSwap_PRInt16     yMin;                  // For all glyph bounding boxes.
     AutoSwap_PRInt16     xMax;                  // For all glyph bounding boxes.
     AutoSwap_PRInt16     yMax;                  // For all glyph bounding boxes.
     AutoSwap_PRUint16    macStyle;              // Bit 0: Bold (if set to 1);
     AutoSwap_PRUint16    lowestRecPPEM;         // Smallest readable size in pixels.
     AutoSwap_PRInt16     fontDirectionHint;
     AutoSwap_PRInt16     indexToLocFormat;
     AutoSwap_PRInt16     glyphDataFormat;
 };
 struct OS2Table {
     AutoSwap_PRUint16    version;                // 0004 = OpenType 1.5
     AutoSwap_PRInt16     xAvgCharWidth;
     AutoSwap_PRUint16    usWeightClass;
     AutoSwap_PRUint16    usWidthClass;
     AutoSwap_PRUint16    fsType;
     AutoSwap_PRInt16     ySubscriptXSize;
     AutoSwap_PRInt16     ySubscriptYSize;
     AutoSwap_PRInt16     ySubscriptXOffset;
     AutoSwap_PRInt16     ySubscriptYOffset;
     AutoSwap_PRInt16     ySuperscriptXSize;
     AutoSwap_PRInt16     ySuperscriptYSize;
     AutoSwap_PRInt16     ySuperscriptXOffset;
     AutoSwap_PRInt16     ySuperscriptYOffset;
     AutoSwap_PRInt16     yStrikeoutSize;
     AutoSwap_PRInt16     yStrikeoutPosition;
     AutoSwap_PRInt16     sFamilyClass;
     uint8_t              panose[10];
     AutoSwap_PRUint32    unicodeRange1;
     AutoSwap_PRUint32    unicodeRange2;
     AutoSwap_PRUint32    unicodeRange3;
     AutoSwap_PRUint32    unicodeRange4;
     uint8_t              achVendID[4];
     AutoSwap_PRUint16    fsSelection;
     AutoSwap_PRUint16    usFirstCharIndex;
     AutoSwap_PRUint16    usLastCharIndex;
     AutoSwap_PRInt16     sTypoAscender;
     AutoSwap_PRInt16     sTypoDescender;
     AutoSwap_PRInt16     sTypoLineGap;
     AutoSwap_PRUint16    usWinAscent;
     AutoSwap_PRUint16    usWinDescent;
     AutoSwap_PRUint32    codePageRange1;
     AutoSwap_PRUint32    codePageRange2;
     AutoSwap_PRInt16     sxHeight;
     AutoSwap_PRInt16     sCapHeight;
     AutoSwap_PRUint16    usDefaultChar;
     AutoSwap_PRUint16    usBreakChar;
     AutoSwap_PRUint16    usMaxContext;
 };
 struct PostTable {
     AutoSwap_PRUint32    version;
     AutoSwap_PRInt32     italicAngle;
     AutoSwap_PRInt16     underlinePosition;
     AutoSwap_PRUint16    underlineThickness;
     AutoSwap_PRUint32    isFixedPitch;
     AutoSwap_PRUint32    minMemType42;
     AutoSwap_PRUint32    maxMemType42;
     AutoSwap_PRUint32    minMemType1;
     AutoSwap_PRUint32    maxMemType1;
 };
 struct HheaTable {
     AutoSwap_PRUint32    version;
     AutoSwap_PRInt16     ascender;
     AutoSwap_PRInt16     descender;
     AutoSwap_PRInt16     lineGap;
     AutoSwap_PRUint16    advanceWidthMax;
     AutoSwap_PRInt16     minLeftSideBearing;
     AutoSwap_PRInt16     minRightSideBearing;
     AutoSwap_PRInt16     xMaxExtent;
     AutoSwap_PRInt16     caretSlopeRise;
     AutoSwap_PRInt16     caretSlopeRun;
     AutoSwap_PRInt16     caretOffset;
     AutoSwap_PRInt16     reserved1;
     AutoSwap_PRInt16     reserved2;
     AutoSwap_PRInt16     reserved3;
     AutoSwap_PRInt16     reserved4;
     AutoSwap_PRInt16     metricDataFormat;
     AutoSwap_PRUint16    numOfLongHorMetrics;
 };
 struct MaxpTableHeader {
     AutoSwap_PRUint32    version; // CFF: 0x00005000; TrueType: 0x00010000
     AutoSwap_PRUint16    numGlyphs;
 // truetype version has additional fields that we don't currently use
 };
 // old 'kern' table, supported on Windows
 // see http://www.microsoft.com/typography/otspec/kern.htm
 struct KernTableVersion0 {
     AutoSwap_PRUint16    version; // 0x0000
     AutoSwap_PRUint16    nTables;
 };
 struct KernTableSubtableHeaderVersion0 {
     AutoSwap_PRUint16    version;
     AutoSwap_PRUint16    length;
     AutoSwap_PRUint16    coverage;
 };
 // newer Mac-only 'kern' table, ignored by Windows
 // see http://developer.apple.com/textfonts/TTRefMan/RM06/Chap6kern.html
 struct KernTableVersion1 {
     AutoSwap_PRUint32    version; // 0x00010000
     AutoSwap_PRUint32    nTables;
 };
 struct KernTableSubtableHeaderVersion1 {
     AutoSwap_PRUint32    length;
     AutoSwap_PRUint16    coverage;
     AutoSwap_PRUint16    tupleIndex;
 };
 #pragma pack()
 // Return just the highest bit of the given value, i.e., the highest
 // power of 2 that is <= value, or zero if the input value is zero.
 inline uint32_t
 FindHighestBit(uint32_t value)
 {
     // propagate highest bit into all lower bits of the value
     value |= (value >> 1);
     value |= (value >> 2);
     value |= (value >> 4);
     value |= (value >> 8);
     value |= (value >> 16);
     // isolate the leftmost bit
     return (value & ~(value >> 1));
 }
 } // namespace mozilla
 // used for overlaying name changes without touching original font data
 struct FontDataOverlay {
     // overlaySrc != 0 ==> use overlay
     uint32_t  overlaySrc;    // src offset from start of font data
     uint32_t  overlaySrcLen; // src length
     uint32_t  overlayDest;   // dest offset from start of font data
 };
 enum gfxUserFontType {
     GFX_USERFONT_UNKNOWN = 0,
     GFX_USERFONT_OPENTYPE = 1,
     GFX_USERFONT_SVG = 2,
     GFX_USERFONT_WOFF = 3
 };
 extern const uint8_t sCJKCompatSVSTable[];
 class gfxFontUtils {
 public:
     // these are public because gfxFont.cpp also looks into the name table
     enum {
         NAME_ID_FAMILY = 1,
         NAME_ID_STYLE = 2,
         NAME_ID_UNIQUE = 3,
         NAME_ID_FULL = 4,
         NAME_ID_VERSION = 5,
         NAME_ID_POSTSCRIPT = 6,
         NAME_ID_PREFERRED_FAMILY = 16,
         NAME_ID_PREFERRED_STYLE = 17,
         PLATFORM_ALL = -1,
         PLATFORM_ID_UNICODE = 0,           // Mac OS uses this typically
         PLATFORM_ID_MAC = 1,
         PLATFORM_ID_ISO = 2,
         PLATFORM_ID_MICROSOFT = 3,
         ENCODING_ID_MAC_ROMAN = 0,         // traditional Mac OS script manager encodings
         ENCODING_ID_MAC_JAPANESE = 1,      // (there are others defined, but some were never
         ENCODING_ID_MAC_TRAD_CHINESE = 2,  // implemented by Apple, and I have never seen them
         ENCODING_ID_MAC_KOREAN = 3,        // used in font names)
         ENCODING_ID_MAC_ARABIC = 4,
         ENCODING_ID_MAC_HEBREW = 5,
         ENCODING_ID_MAC_GREEK = 6,
         ENCODING_ID_MAC_CYRILLIC = 7,
         ENCODING_ID_MAC_DEVANAGARI = 9,
         ENCODING_ID_MAC_GURMUKHI = 10,
         ENCODING_ID_MAC_GUJARATI = 11,
         ENCODING_ID_MAC_SIMP_CHINESE = 25,
         ENCODING_ID_MICROSOFT_SYMBOL = 0,  // Microsoft platform encoding IDs
         ENCODING_ID_MICROSOFT_UNICODEBMP = 1,
         ENCODING_ID_MICROSOFT_SHIFTJIS = 2,
         ENCODING_ID_MICROSOFT_PRC = 3,
         ENCODING_ID_MICROSOFT_BIG5 = 4,
         ENCODING_ID_MICROSOFT_WANSUNG = 5,
         ENCODING_ID_MICROSOFT_JOHAB  = 6,
         ENCODING_ID_MICROSOFT_UNICODEFULL = 10,
         LANG_ALL = -1,
         LANG_ID_MAC_ENGLISH = 0,      // many others are defined, but most don't affect
         LANG_ID_MAC_HEBREW = 10,      // the charset; should check all the central/eastern
         LANG_ID_MAC_JAPANESE = 11,    // european codes, though
         LANG_ID_MAC_ARABIC = 12,
         LANG_ID_MAC_ICELANDIC = 15,
         LANG_ID_MAC_TURKISH = 17,
         LANG_ID_MAC_TRAD_CHINESE = 19,
         LANG_ID_MAC_URDU = 20,
         LANG_ID_MAC_KOREAN = 23,
         LANG_ID_MAC_POLISH = 25,
         LANG_ID_MAC_FARSI = 31,
         LANG_ID_MAC_SIMP_CHINESE = 33,
         LANG_ID_MAC_ROMANIAN = 37,
         LANG_ID_MAC_CZECH = 38,
         LANG_ID_MAC_SLOVAK = 39,
         LANG_ID_MICROSOFT_EN_US = 0x0409,        // with Microsoft platformID, EN US lang code
         CMAP_MAX_CODEPOINT = 0x10ffff     // maximum possible Unicode codepoint
                                           // contained in a cmap
     };
     // name table has a header, followed by name records, followed by string data
     struct NameHeader {
         mozilla::AutoSwap_PRUint16    format;       // Format selector (=0).
         mozilla::AutoSwap_PRUint16    count;        // Number of name records.
         mozilla::AutoSwap_PRUint16    stringOffset; // Offset to start of string storage
                                                     // (from start of table)
     };
     struct NameRecord {
         mozilla::AutoSwap_PRUint16    platformID;   // Platform ID
         mozilla::AutoSwap_PRUint16    encodingID;   // Platform-specific encoding ID
         mozilla::AutoSwap_PRUint16    languageID;   // Language ID
         mozilla::AutoSwap_PRUint16    nameID;       // Name ID.
         mozilla::AutoSwap_PRUint16    length;       // String length (in bytes).
         mozilla::AutoSwap_PRUint16    offset;       // String offset from start of storage
                                                     // (in bytes).
     };
     // for reading big-endian font data on either big or little-endian platforms
     static inline uint16_t
     ReadShortAt(const uint8_t *aBuf, uint32_t aIndex)
     {
         return (aBuf[aIndex] << 8) | aBuf[aIndex + 1];
     }
     static inline uint16_t
     ReadShortAt16(const uint16_t *aBuf, uint32_t aIndex)
     {
         const uint8_t *buf = reinterpret_cast<const uint8_t*>(aBuf);
         uint32_t index = aIndex << 1;
         return (buf[index] << 8) | buf[index+1];
     }
     static inline uint32_t
     ReadUint24At(const uint8_t *aBuf, uint32_t aIndex)
     {
         return ((aBuf[aIndex] << 16) | (aBuf[aIndex + 1] << 8) |
                 (aBuf[aIndex + 2]));
     }
     static inline uint32_t
     ReadLongAt(const uint8_t *aBuf, uint32_t aIndex)
     {
         return ((aBuf[aIndex] << 24) | (aBuf[aIndex + 1] << 16) |
                 (aBuf[aIndex + 2] << 8) | (aBuf[aIndex + 3]));
     }
     static nsresult
     ReadCMAPTableFormat12(const uint8_t *aBuf, uint32_t aLength,
                           gfxSparseBitSet& aCharacterMap);
     static nsresult
     ReadCMAPTableFormat4(const uint8_t *aBuf, uint32_t aLength,
                          gfxSparseBitSet& aCharacterMap);
     static nsresult
     ReadCMAPTableFormat14(const uint8_t *aBuf, uint32_t aLength,
                           uint8_t*& aTable);
     static uint32_t
     FindPreferredSubtable(const uint8_t *aBuf, uint32_t aBufLength,
                           uint32_t *aTableOffset, uint32_t *aUVSTableOffset,
                           bool *aSymbolEncoding);
     static nsresult
     ReadCMAP(const uint8_t *aBuf, uint32_t aBufLength,
              gfxSparseBitSet& aCharacterMap,
              uint32_t& aUVSOffset,
              bool& aUnicodeFont, bool& aSymbolFont);
     static uint32_t
     MapCharToGlyphFormat4(const uint8_t *aBuf, char16_t aCh);
     static uint32_t
     MapCharToGlyphFormat12(const uint8_t *aBuf, uint32_t aCh);
     static uint16_t
     MapUVSToGlyphFormat14(const uint8_t *aBuf, uint32_t aCh, uint32_t aVS);
     // sCJKCompatSVSTable is a 'cmap' format 14 subtable that maps
     // <char + var-selector> pairs to the corresponding Unicode
     // compatibility ideograph codepoints.
     static MOZ_ALWAYS_INLINE uint32_t
     GetUVSFallback(uint32_t aCh, uint32_t aVS) {
         aCh = MapUVSToGlyphFormat14(sCJKCompatSVSTable, aCh, aVS);
         return aCh >= 0xFB00 ? aCh + (0x2F800 - 0xFB00) : aCh;
     }
     static uint32_t
     MapCharToGlyph(const uint8_t *aCmapBuf, uint32_t aBufLength,
                    uint32_t aUnicode, uint32_t aVarSelector = 0);
 #ifdef XP_WIN
     // determine whether a font (which has already been sanitized, so is known
     // to be a valid sfnt) is CFF format rather than TrueType
     static bool
     IsCffFont(const uint8_t* aFontData);
 #endif
     // determine the format of font data
     static gfxUserFontType
     DetermineFontDataType(const uint8_t *aFontData, uint32_t aFontDataLength);
     // Read the fullname from the sfnt data (used to save the original name
     // prior to renaming the font for installation).
     // This is called with sfnt data that has already been validated,
     // so it should always succeed in finding the name table.
     static nsresult
     GetFullNameFromSFNT(const uint8_t* aFontData, uint32_t aLength,
                         nsAString& aFullName);
     // helper to get fullname from name table, constructing from family+style
     // if no explicit fullname is present
     static nsresult
     GetFullNameFromTable(hb_blob_t *aNameTable,
                          nsAString& aFullName);
     // helper to get family name from name table
     static nsresult
     GetFamilyNameFromTable(hb_blob_t *aNameTable,
                            nsAString& aFamilyName);
     // create a new name table and build a new font with that name table
     // appended on the end, returns true on success
     static nsresult
     RenameFont(const nsAString& aName, const uint8_t *aFontData,
                uint32_t aFontDataLength, FallibleTArray<uint8_t> *aNewFont);
     // read all names matching aNameID, returning in aNames array
     static nsresult
     ReadNames(const char *aNameData, uint32_t aDataLen, uint32_t aNameID,
               int32_t aPlatformID, nsTArray<nsString>& aNames);
     // reads English or first name matching aNameID, returning in aName
     // platform based on OS
     static nsresult
     ReadCanonicalName(hb_blob_t *aNameTable, uint32_t aNameID,
                       nsString& aName);
     static nsresult
     ReadCanonicalName(const char *aNameData, uint32_t aDataLen,
                       uint32_t aNameID, nsString& aName);
     // convert a name from the raw name table data into an nsString,
     // provided we know how; return true if successful, or false
     // if we can't handle the encoding
     static bool
     DecodeFontName(const char *aBuf, int32_t aLength,
                    uint32_t aPlatformCode, uint32_t aScriptCode,
                    uint32_t aLangCode, nsAString& dest);
     static inline bool IsJoinCauser(uint32_t ch) {
         return (ch == 0x200D);
     }
     static inline bool IsJoinControl(uint32_t ch) {
         return (ch == 0x200C || ch == 0x200D);
     }
     enum {
         kUnicodeVS1 = 0xFE00,
         kUnicodeVS16 = 0xFE0F,
         kUnicodeVS17 = 0xE0100,
         kUnicodeVS256 = 0xE01EF
     };
     static inline bool IsVarSelector(uint32_t ch) {
         return (ch >= kUnicodeVS1 && ch <= kUnicodeVS16) ||
                (ch >= kUnicodeVS17 && ch <= kUnicodeVS256);
     }
     static inline bool IsInvalid(uint32_t ch) {
         return (ch == 0xFFFD);
     }
     // Font code may want to know if there is the potential for bidi behavior
     // to be triggered by any of the characters in a text run; this can be
     // used to test that possibility.
     enum {
         kUnicodeBidiScriptsStart = 0x0590,
         kUnicodeBidiScriptsEnd = 0x08FF,
         kUnicodeBidiPresentationStart = 0xFB1D,
         kUnicodeBidiPresentationEnd = 0xFEFC,
         kUnicodeFirstHighSurrogateBlock = 0xD800,
         kUnicodeRLM = 0x200F,
         kUnicodeRLE = 0x202B,
         kUnicodeRLO = 0x202E
     };
     static inline bool PotentialRTLChar(char16_t aCh) {
         if (aCh >= kUnicodeBidiScriptsStart && aCh <= kUnicodeBidiScriptsEnd)
             // bidi scripts Hebrew, Arabic, Syriac, Thaana, N'Ko are all encoded together
             return true;
         if (aCh == kUnicodeRLM || aCh == kUnicodeRLE || aCh == kUnicodeRLO)
             // directional controls that trigger bidi layout
             return true;
         if (aCh >= kUnicodeBidiPresentationStart &&
             aCh <= kUnicodeBidiPresentationEnd)
             // presentation forms of Arabic and Hebrew letters
             return true;
         if ((aCh & 0xFF00) == kUnicodeFirstHighSurrogateBlock)
             // surrogate that could be part of a bidi supplementary char
             // (Cypriot, Aramaic, Phoenecian, etc)
             return true;
         // otherwise we know this char cannot trigger bidi reordering
         return false;
     }
     // for a given font list pref name, set up a list of font names
     static void GetPrefsFontList(const char *aPrefName,
                                  nsTArray<nsString>& aFontList);
     // generate a unique font name
     static nsresult MakeUniqueUserFontName(nsAString& aName);
 protected:
     static nsresult
     ReadNames(const char *aNameData, uint32_t aDataLen, uint32_t aNameID,
               int32_t aLangID, int32_t aPlatformID, nsTArray<nsString>& aNames);
     // convert opentype name-table platform/encoding/language values to a charset name
     // we can use to convert the name data to unicode, or "" if data is UTF16BE
     static const char*
     GetCharsetForFontName(uint16_t aPlatform, uint16_t aScript, uint16_t aLanguage);
     struct MacFontNameCharsetMapping {
         uint16_t    mEncoding;
         uint16_t    mLanguage;
         const char *mCharsetName;
         bool operator<(const MacFontNameCharsetMapping& rhs) const {
             return (mEncoding < rhs.mEncoding) ||
                    ((mEncoding == rhs.mEncoding) && (mLanguage < rhs.mLanguage));
         }
     };
     static const MacFontNameCharsetMapping gMacFontNameCharsets[];
     static const char* gISOFontNameCharsets[];
     static const char* gMSFontNameCharsets[];
 };
 #endif /* GFX_FONT_UTILS_H */

The Tor Browser / annotate

gfx/thebes/gfxFontUtils.h@97036ab72558 (annotated)

gfx/thebes/gfxFontUtils.h