flectra/addons/web/static/lib/pdfjs/external/cmapscompress/compress.js

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/* Copyright 2014 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var fs = require('fs');
var path = require('path');
var parseAdobeCMap = require('./parse.js').parseAdobeCMap;
var optimizeCMap = require('./optimize.js').optimizeCMap;
function compressCmap(srcPath, destPath, verify) {
var content = fs.readFileSync(srcPath).toString();
var inputData = parseAdobeCMap(content);
optimizeCMap(inputData);
var out = writeByte((inputData.type << 1) | inputData.wmode);
if (inputData.comment) {
out += writeByte(0xE0) + writeString(inputData.comment);
}
if (inputData.usecmap) {
out += writeByte(0xE1) + writeString(inputData.usecmap);
}
var i = 0;
while (i < inputData.body.length) {
var item = inputData.body[i++], subitems = item.items;
var first = item.items[0];
var sequence = item.sequence === true;
var flags = (item.type << 5) | (sequence ? 0x10 : 0);
var nextStart, nextCode;
switch (item.type) {
case 0:
out += writeByte(flags | getHexSize(first.start)) + writeNumber(subitems.length);
out += first.start + writeNumber(subHex(first.end, first.start));
nextStart = incHex(first.end);
for (var j = 1; j < subitems.length; j++) {
out += writeNumber(subHex(subitems[j].start, nextStart)) +
writeNumber(subHex(subitems[j].end, subitems[j].start));
nextStart = incHex(subitems[j].end);
}
break;
case 1:
out += writeByte(flags | getHexSize(first.start)) + writeNumber(subitems.length);
out += first.start + writeNumber(subHex(first.end, first.start)) + writeNumber(first.code);
nextStart = incHex(first.end);
for (var j = 1; j < subitems.length; j++) {
out += writeNumber(subHex(subitems[j].start, nextStart)) +
writeNumber(subHex(subitems[j].end, subitems[j].start)) +
writeNumber(subitems[j].code);
nextStart = incHex(subitems[j].end);
}
break;
case 2:
out += writeByte(flags | getHexSize(first.char)) + writeNumber(subitems.length);
out += first.char + writeNumber(first.code);
nextStart = incHex(first.char);
nextCode = first.code + 1;
for (var j = 1; j < subitems.length; j++) {
out += (sequence ? '' : writeNumber(subHex(subitems[j].char, nextStart))) +
writeSigned(subitems[j].code - nextCode);
nextStart = incHex(subitems[j].char);
nextCode = item.items[j].code + 1;
}
break;
case 3:
out += writeByte(flags | getHexSize(first.start)) + writeNumber(subitems.length);
out += first.start + writeNumber(subHex(first.end, first.start)) + writeNumber(first.code);
nextStart = incHex(first.end);
for (var j = 1; j < subitems.length; j++) {
out += (sequence ? '' : writeNumber(subHex(subitems[j].start, nextStart))) +
writeNumber(subHex(subitems[j].end, subitems[j].start)) +
writeNumber(subitems[j].code);
nextStart = incHex(subitems[j].end);
}
break;
case 4:
out += writeByte(flags | getHexSize(first.code)) + writeNumber(subitems.length);
out += first.char + first.code;
nextStart = incHex(first.char);
nextCode = incHex(first.code);
for (var j = 1; j < subitems.length; j++) {
out += (sequence ? '' : writeNumber(subHex(subitems[j].char, nextStart))) +
writeSigned(subHex(subitems[j].code, nextCode));
nextStart = incHex(subitems[j].char);
nextCode = incHex(subitems[j].code);
}
break;
case 5:
out += writeByte(flags | getHexSize(first.code)) + writeNumber(subitems.length);
out += first.start + writeNumber(subHex(first.end, first.start)) + first.code;
nextStart = incHex(first.end);
for (var j = 1; j < subitems.length; j++) {
out += (sequence ? '' : writeNumber(subHex(subitems[j].start, nextStart))) +
writeNumber(subHex(subitems[j].end, subitems[j].start)) +
subitems[j].code;
nextStart = incHex(subitems[j].end);
}
break;
}
}
fs.writeFileSync(destPath, new Buffer(out, 'hex'));
if (verify) {
var result2 = parseCMap(out);
var isGood = JSON.stringify(inputData) == JSON.stringify(result2);
if (!isGood) {
throw new Error('Extracted data does not match the expected result');
}
}
return {
orig: fs.statSync(srcPath).size,
packed: out.length >> 1
};
}
function parseCMap(binaryData) {
var reader = {
buffer: binaryData,
pos: 0,
end: binaryData.length,
readByte: function () {
if (this.pos >= this.end) {
return -1;
}
var d1 = fromHexDigit(this.buffer[this.pos]);
var d2 = fromHexDigit(this.buffer[this.pos + 1]);
this.pos += 2;
return (d1 << 4) | d2;
},
readNumber: function () {
var n = 0;
var last;
do {
var b = this.readByte();
last = !(b & 0x80);
n = (n << 7) | (b & 0x7F);
} while (!last);
return n;
},
readSigned: function () {
var n = this.readNumber();
return (n & 1) ? -(n >>> 1) - 1 : n >>> 1;
},
readHex: function (size) {
var lengthInChars = (size + 1) << 1;
var s = this.buffer.substr(this.pos, lengthInChars);
this.pos += lengthInChars;
return s;
},
readHexNumber: function (size) {
var lengthInChars = (size + 1) << 1;
var stack = [];
do {
var b = this.readByte();
last = !(b & 0x80);
stack.push(b & 0x7F);
} while (!last);
var s = '', buffer = 0, bufferSize = 0;
while (s.length < lengthInChars) {
while (bufferSize < 4 && stack.length > 0) {
buffer = (stack.pop() << bufferSize) | buffer;
bufferSize += 7;
}
s = toHexDigit(buffer & 15) + s;
buffer >>= 4;
bufferSize -= 4;
}
return s;
},
readHexSigned: function (size) {
var num = this.readHexNumber(size);
var sign = fromHexDigit(num[num.length - 1]) & 1 ? 15 : 0;
var c = 0;
var result = '';
for (var i = 0; i < num.length; i++) {
c = (c << 4) | fromHexDigit(num[i]);
result += toHexDigit(sign ? (c >> 1) ^ sign : (c >> 1));
c &= 1;
}
return result;
},
readString: function () {
var len = this.readNumber();
var s = '';
for (var i = 0; i < len; i++) {
s += String.fromCharCode(this.readNumber());
}
return s;
}
};
var header = reader.readByte();
var result = {
type: header >> 1,
wmode: header & 1,
comment: null,
usecmap: null,
body: []
};
var b;
while ((b = reader.readByte()) >= 0) {
var type = b >> 5;
if (type === 7) {
switch (b & 0x1F) {
case 0:
result.comment = reader.readString();
break;
case 1:
result.usecmap = reader.readString();
break;
}
continue;
}
var sequence = !!(b & 0x10);
var dataSize = b & 15;
var subitems = [];
var item = {
type: type,
items: subitems
};
if (sequence) {
item.sequence = true;
}
var ucs2DataSize = 1;
var subitemsCount = reader.readNumber();
var start, end, code, char;
switch (type) {
case 0:
start = reader.readHex(dataSize);
end = addHex(reader.readHexNumber(dataSize), start);
subitems.push({start: start, end: end});
for (var i = 1; i < subitemsCount; i++) {
start = addHex(reader.readHexNumber(dataSize), incHex(end));
end = addHex(reader.readHexNumber(dataSize), start);
subitems.push({start: start, end: end});
}
break;
case 1:
start = reader.readHex(dataSize);
end = addHex(reader.readHexNumber(dataSize), start);
code = reader.readNumber();
subitems.push({start: start, end: end, code: code});
for (var i = 1; i < subitemsCount; i++) {
start = addHex(reader.readHexNumber(dataSize), incHex(end));
end = addHex(reader.readHexNumber(dataSize), start);
code = reader.readNumber();
subitems.push({start: start, end: end, code: code});
}
break;
case 2:
char = reader.readHex(dataSize);
code = reader.readNumber();
subitems.push({char: char, code: code});
for (var i = 1; i < subitemsCount; i++) {
char = sequence ? incHex(char) : addHex(reader.readHexNumber(dataSize), incHex(char));
code = reader.readSigned() + (code + 1);
subitems.push({char: char, code: code});
}
break;
case 3:
start = reader.readHex(dataSize);
end = addHex(reader.readHexNumber(dataSize), start);
code = reader.readNumber();
subitems.push({start: start, end: end, code: code});
for (var i = 1; i < subitemsCount; i++) {
start = sequence ? incHex(end) : addHex(reader.readHexNumber(dataSize), incHex(end));
end = addHex(reader.readHexNumber(dataSize), start);
code = reader.readNumber();
subitems.push({start: start, end: end, code: code});
}
break;
case 4:
char = reader.readHex(ucs2DataSize);
code = reader.readHex(dataSize);
subitems.push({char: char, code: code});
for (var i = 1; i < subitemsCount; i++) {
char = sequence ? incHex(char) : addHex(reader.readHexNumber(ucs2DataSize), incHex(char));
code = addHex(reader.readHexSigned(dataSize), incHex(code));
subitems.push({char: char, code: code});
}
break;
case 5:
start = reader.readHex(ucs2DataSize);
end = addHex(reader.readHexNumber(ucs2DataSize), start);
code = reader.readHex(dataSize);
subitems.push({start: start, end: end, code: code});
for (var i = 1; i < subitemsCount; i++) {
start = sequence ? incHex(end) : addHex(reader.readHexNumber(ucs2DataSize), incHex(end));
end = addHex(reader.readHexNumber(ucs2DataSize), start);
code = reader.readHex(dataSize);
subitems.push({start: start, end: end, code: code});
}
break;
default:
throw new Error('Unknown type: ' + type)
}
result.body.push(item);
}
return result;
}
function toHexDigit(n) {
return n.toString(16);
}
function fromHexDigit(s) {
return parseInt(s, 16);
}
function getHexSize(s) {
return (s.length >> 1) - 1;
}
function writeByte(b) {
return toHexDigit((b >> 4) & 15) + toHexDigit(b & 15);
}
function writeNumber(n) {
if (typeof n === 'string') {
var s = '', buffer = 0, bufferSize = 0;
var i = n.length;
while (i > 0) {
--i;
buffer = (fromHexDigit(n[i]) << bufferSize) | buffer;
bufferSize += 4;
if (bufferSize >= 7) {
s = writeByte((buffer & 0x7f) | (s.length > 0 ? 0x80 : 0)) + s;
buffer >>>= 7;
bufferSize -= 7;
}
}
if (buffer > 0) {
s = writeByte((buffer & 0x7f) | (s.length > 0 ? 0x80 : 0)) + s;
}
while (s.indexOf('80') === 0) {
s = s.substr(2);
}
return s;
} else {
var s = writeByte(n & 0x7F);
n >>>= 7;
while (n > 0) {
s = writeByte((n & 0x7F) | 0x80) + s;
n >>>= 7;
}
return s;
}
}
function writeSigned(n) {
if (typeof n === 'string') {
var t = '';
var c = fromHexDigit(n[0]);
var neg = c >= 8;
c = neg ? (c ^ 15) : c;
for (var i = 1; i < n.length; i++) {
var d = fromHexDigit(n[i]);
c = (c << 4) | (neg ? (d ^ 15) : d);
t += toHexDigit(c >> 3);
c = c & 7;
}
t += toHexDigit((c << 1) | (neg ? 1 : 0));
return writeNumber(t);
}
return n < 0 ? writeNumber(-2 * n - 1) : writeNumber(2 * n);
}
function writeString(s) {
var t = writeNumber(s.length);
for (var i = 0; i < s.length; i++) {
t += writeNumber(s.charCodeAt(i));
}
return t;
}
function addHex(a, b) {
var c = 0, s = '';
for (var i = a.length - 1; i >= 0; i--) {
c += fromHexDigit(a[i]) + fromHexDigit(b[i]);
if (c >= 16) {
s = toHexDigit(c - 16) + s;
c = 1;
} else {
s = toHexDigit(c) + s;
c = 0;
}
}
return s;
}
function subHex(a, b) {
var c = 0, s = '';
for (var i = a.length - 1; i >= 0; i--) {
c += fromHexDigit(a[i]) - fromHexDigit(b[i]);
if (c < 0) {
s = toHexDigit(c + 16) + s;
c = -1;
} else {
s = toHexDigit(c) + s;
c = 0;
}
}
return s;
}
function incHex(a) {
var c = 1, s = '';
for (var i = a.length - 1; i >= 0; i--) {
c += fromHexDigit(a[i]);
if (c >= 16) {
s = toHexDigit(c - 16) + s;
c = 1;
} else {
s = toHexDigit(c) + s;
c = 0;
}
}
return s;
}
exports.compressCmaps = function (src, dest, verify) {
var files = fs.readdirSync(src).filter(function (fn) {
return fn.indexOf('.') < 0; // skipping files with the extension
});
files.forEach(function (fn) {
var srcPath = path.join(src, fn);
var destPath = path.join(dest, fn + '.bcmap');
var stats = compressCmap(srcPath, destPath, verify);
console.log('Compressing ' + fn + ': ' + stats.orig + ' vs ' + stats.packed +
' ' + (stats.packed / stats.orig * 100).toFixed(1) + '%');
});
};