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Rework some code to enhance performance (CIIM6/CIIM9 are rejected by the sanitizer now)

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This commit is contained in:
Vivien Nicolas 2011-06-17 06:02:29 +02:00
parent 675b2f0471
commit eb6f7499dc
2 changed files with 142 additions and 199 deletions
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338
PDFFont.js
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@ -546,7 +546,14 @@ Font.prototype = {
* to fonts in particular and needs to be share between them.
*/
var FontsUtils = {
_bytesArray: new Uint8Array(4),
integerToBytes: function fu_integerToBytes(aValue, aBytesCount) {
// If we want only one byte, take a fast path
if (aBytesCount == 1) {
this._bytesArray.set([aValue]);
return this._bytesArray[0];
}
var bytes = [];
for (var i = 0; i < aBytesCount; i++)
bytes[i] = 0x00;
@ -1087,61 +1094,6 @@ var Type1Parser = function() {
return charString;
};
/*
* The operand stack holds arbitrary PostScript objects that are the operands
* and results of PostScript operators being executed. The interpreter pushes
* objects on the operand stack when it encounters them as literal data in a
* program being executed. When an operator requires one or more operands, it
* obtains them by popping them off the top of the operand stack. When an
* operator returns one or more results, it does so by pushing them on the
* operand stack.
*/
var operandStack = new Stack(40);
// Flag indicating if the topmost operand of the operandStack is an array
var operandIsArray = 0;
/*
* The dictionary stack holds only dictionary objects. The current set of
* dictionaries on the dictionary stack defines the environment for all
* implicit name searches, such as those that occur when the interpreter
* encounters an executable name. The role of the dictionary stack is
* introduced in Section 3.3, “Data Types and Objects,” and is further
* explained in Section 3.5, “Execution.” of the PostScript Language
* Reference.
*/
var systemDict = new Dict(),
globalDict = new Dict(),
userDict = new Dict();
var dictionaryStack = new Stack();
dictionaryStack.push(systemDict);
dictionaryStack.push(globalDict);
dictionaryStack.push(userDict);
/*
* The execution stack holds executable objects (mainly procedures and files)
* that are in intermediate stages of execution. At any point in the
* execution of a PostScript program, this stack represents the program’s
* call stack. Whenever the interpreter suspends execution of an object to
* execute some other object, it pushes the new object on the execution
* stack. When the interpreter finishes executing an object, it pops that
* object off the execution stack and resumes executing the suspended object
* beneath it.
*/
var executionStack = new Stack();
/*
* Return the next token in the execution stack
*/
function nextInStack() {
var currentProcedure = executionStack.peek();
var command = currentProcedure.shift();
if (!currentProcedure.length)
executionStack.pop();
return command;
};
/**
* Returns an object containing a Subrs array and a CharStrings array
* extracted from and eexec encrypted block of data
@ -1205,79 +1157,6 @@ var Type1Parser = function() {
subrs: subrs,
charstrings: glyphs
}
};
/*
* Flatten the commands by interpreting the postscript code and replacing
* every 'callsubr', 'callothersubr' by the real commands.
* At the moment OtherSubrs are not fully supported and only otherSubrs 0-4
* as described in 'Using Subroutines' of 'Adobe Type 1 Font Format',
* chapter 8.
*/
this.flattenCharstring = function(aCharstring, aSubrs) {
operandStack.clear();
executionStack.clear();
executionStack.push(aCharstring.slice());
var leftSidebearing = 0;
var lastPoint = 0;
while (true) {
var obj = nextInStack();
if (IsInt(obj) || IsBool(obj)) {
operandStack.push(obj);
} else {
switch (obj) {
case "callsubr":
var index = operandStack.pop();
executionStack.push(aSubrs[index].slice());
break;
case "callothersubr":
var index = operandStack.pop();
var count = operandStack.pop();
var data = operandStack.pop();
// XXX The callothersubr needs to support at least the 3 defaults
// otherSubrs of the spec
if (index != 3)
error("callothersubr for index: " + index);
operandStack.push(3);
operandStack.push("callothersubr");
break;
case "div":
var num2 = operandStack.pop();
var num1 = operandStack.pop();
operandStack.push(num2 / num1);
break;
case "pop":
operandStack.pop();
break;
case "return":
break;
case "hsbw":
var charWidthVector = operandStack.pop();
var leftSidebearing = operandStack.pop();
operandStack.push(charWidthVector);
if (leftSidebearing) {
operandStack.push(leftSidebearing);
operandStack.push("hmoveto");
}
break;
case "endchar":
operandStack.push("endchar");
return operandStack.clone();
default:
operandStack.push(obj);
break;
}
}
}
}
};
@ -1339,10 +1218,11 @@ CFF.prototype = {
return data;
},
encodeNumber: function(aValue) {
encodeNumber: function(aValue, aIsCharstring) {
var x = 0;
// XXX we don't really care about Type2 optimization here...
if (aValue >= -32768 && aValue <= 32767) {
if (aIsCharstring && aValue >= -107 && aValue <= 107) {
return [aValue + 139];
} else if (aValue >= -32768 && aValue <= 32767) {
return [
28,
FontsUtils.integerToBytes(aValue >> 8, 1),
@ -1389,6 +1269,128 @@ CFF.prototype = {
return charstrings;
},
/*
* Flatten the commands by interpreting the postscript code and replacing
* every 'callsubr', 'callothersubr' by the real commands.
*
* TODO This function also do a string to command number transformation
* that can probably be avoided if the Type1 decodeCharstring code is smarter
*/
commandsMap: {
"hstem": 1,
"vstem": 3,
"vmoveto": 4,
"rlineto": 5,
"hlineto": 6,
"vlineto": 7,
"rrcurveto": 8,
"endchar": 14,
"rmoveto": 21,
"hmoveto": 22,
"vhcurveto": 30,
"hvcurveto": 31,
},
flattenCharstring: function(aCharstring, aSubrs) {
var i = 0;
while (true) {
var obj = aCharstring[i];
if (IsString(obj)) {
switch (obj) {
case "callsubr":
var subr = aSubrs[aCharstring[i- 1]].slice();
if (subr.length > 1) {
subr = this.flattenCharstring(subr, aSubrs);
subr.pop();
aCharstring.splice(i - 1, 2, subr);
}
else
aCharstring.splice(i - 1, 2);
i -= 1;
break;
case "callothersubr":
var index = aCharstring[i - 1];
var count = aCharstring[i - 2];
var data = aCharstring[i - 3];
// XXX The callothersubr needs to support at least the 3 defaults
// otherSubrs of the spec
if (index != 3)
error("callothersubr for index: " + index + " (" + aCharstring + ")");
if (!data) {
aCharstring.splice(i - 2, 3, "pop", 3);
i -= 2;
} else {
// 5 to remove the arguments, the callothersubr call and the pop command
aCharstring.splice(i - 3, 5, 3);
i -= 3;
}
break;
case "div":
var num2 = aCharstring[i - 1];
var num1 = aCharstring[i - 2];
aCharstring.splice(i - 2, 3, num2 / num1);
i -= 2;
break;
case "pop":
aCharstring.splice(i - 2, 2);
i -= 1;
break;
case "hsbw":
var charWidthVector = aCharstring[i - 1];
var leftSidebearing = aCharstring[i - 2];
aCharstring.splice(i - 2, 3, charWidthVector, leftSidebearing, "hmoveto");
break;
case "endchar":
case "return":
// CharString is ready to be re-encode to commands number at this point
for (var j = 0; j < aCharstring.length; j++) {
var command = aCharstring[j];
if (IsNum(command)) {
var number = this.encodeNumber(command, true);
aCharstring.splice(j, 1);
for (var k = 0; k < number.length; k++)
aCharstring.splice(j + k, 0, number[k]);
j+= number.length - 1;
} else if (IsString(command)) {
var command = this.commandsMap[command];
if (IsArray(command)) {
aCharstring.splice(j - 1, 1, command[0], command[1]);
j += 1;
} else {
aCharstring[j] = command;
}
} else if (IsArray(command)) {
aCharstring.splice(j, 1);
// command has already been translated, just add them to the
// charstring directly
for (var k = 0; k < command.length; k++)
aCharstring.splice(j + k, 0, command[k]);
j+= command.length - 1;
} else { // what else?
error("Error while flattening the Type1 charstring: " + aCharstring);
}
}
return aCharstring;
default:
break;
}
}
i++;
}
error("failing with i = " + i + " in charstring:" + aCharstring + "(" + aCharstring.length + ")");
},
convertToCFF: function(aFontInfo) {
var debug = false;
function dump(aMsg) {
@ -1398,39 +1400,24 @@ CFF.prototype = {
var charstrings = this.getOrderedCharStrings(aFontInfo.charstrings);
// Starts the conversion of the Type1 charstrings to Type2
var start = Date.now();
var charstringsCount = 0;
var charstringsDataLength = 0;
var glyphs = [];
var glyphsChecker = {};
var subrs = aFontInfo.subrs;
// FIXME This code is actually the only reason the dummy PS Interpreter
// called Type1Parser continue to lives, basically the goal here is
// to embed the OtherSubrs/Subrs into the charstring directly.
// But since Type2 charstrings use a bias to index Subrs and can
// theorically store twice the number of Type1 we could directly
// save the OtherSubrs and Subrs in the Type2 table for Subrs
// and avoid this 'flattening' slow method.
//
// The other thinds done by this method is splitting the initial
// 'width lsb hswb' command of Type1 to something similar in Type2
// that is: 'width dx moveto' but this can be done in the
// decodeCharstring method directly (maybe one day it will be called
// translateCharstring?)
var parser = new Type1Parser();
for (var i = 0; i < charstrings.length; i++) {
var charstring = charstrings[i].charstring.slice();
var glyph = charstrings[i].glyph;
if (glyphsChecker[glyph])
error("glyphs already exists!");
glyphsChecker[glyph] = true;
var flattened = parser.flattenCharstring(charstring, subrs);
var flattened = this.flattenCharstring(charstring, aFontInfo.subrs);
glyphs.push(flattened);
charstringsCount++;
charstringsDataLength += flattened.length;
}
var end = Date.now();
dump("There is " + charstringsCount + " glyphs (size: " + charstringsDataLength + ")");
dump("Time to flatten the strings is : " + (end -start));
// Create a CFF font data
var cff = new Uint8Array(kMaxFontFileSize);
@ -1473,52 +1460,7 @@ CFF.prototype = {
charset.push(bytes[1]);
}
// Convert charstrings
var getNumFor = {
"hstem": 1,
"vstem": 3,
"vmoveto": 4,
"rlineto": 5,
"hlineto": 6,
"vlineto": 7,
"rrcurveto": 8,
"endchar": 14,
"rmoveto": 21,
"hmoveto": 22,
"vhcurveto": 30,
"hvcurveto": 31,
};
// FIXME Concatenating array with this algorithm (O²) is expensive and
// can be avoided if the voodoo's dance of charstrings decoding
// encoding is left for dead. Actually charstrings command number
// are converted to a string and then back to a number with the
// next few lines of code...
var r = [[0x40, 0x0E]];
for (var i = 0; i < glyphs.length; i++) {
var data = glyphs[i].slice();
var charstring = [];
for (var j = 0; j < data.length; j++) {
var c = data[j];
if (!IsNum(c)) {
var token = getNumFor[c];
if (!token)
error("Token " + c + " is not recognized in charstring " + data);
charstring.push(token);
} else {
try {
var bytes = this.encodeNumber(c);
} catch(e) {
log("Glyph " + i + " has a wrong value: " + c + " in charstring: " + data);
log("the default value is glyph " + charstrings[i].glyph + " and is supposed to be: " + charstrings[i].charstring);
}
charstring = charstring.concat(bytes);
}
}
r.push(charstring);
}
var charstringsIndex = this.createCFFIndexHeader(r, true);
var charstringsIndex = this.createCFFIndexHeader([[0x40, 0x0E]].concat(glyphs), true);
charstringsIndex = charstringsIndex.join(" ").split(" "); // XXX why?
//Top Dict Index

3
PDFFontUtils.js
View File

@ -310,7 +310,8 @@ var Type2Parser = function(aFilePath) {
// Read the Global Subr Index that comes just after the Strings Index
// (cf. "The Compact Font Format Specification" Chapter 16)
dump("Reading Global Subr Index");
var subrs = readFontIndexData(aStream);
var subrs = readFontIndexData(aStream, true);
dump(subrs);
// Reading Private Dict
var private = font.get("Private");