Sakurai/pdf.js
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Optimize common cases in hexToStr().

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This avoids the creation of over two million array objects when viewing
http://www.dynacw.co.jp/Portals/3/fontsamplepdf/sample_4942546800828.pdf,
and reduces load time from 76 to 73 ms.
This commit is contained in:
Nicholas Nethercote 2014-07-22 22:09:54 -07:00
parent c7f02d2c8e
commit 501446ccc4
1 changed files with 8 additions and 0 deletions
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8
src/core/cmap.js
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@ -313,6 +313,14 @@ var BinaryCMapReader = (function BinaryCMapReaderClosure() {
} }
function hexToStr(a, size) { function hexToStr(a, size) {
// This code is hot. Special-case some common values to avoid creating an
// object with subarray().
if (size == 1) {
return String.fromCharCode(a[0], a[1]);
}
if (size == 3) {
return String.fromCharCode(a[0], a[1], a[2], a[3]);
}
return String.fromCharCode.apply(null, a.subarray(0, size + 1)); return String.fromCharCode.apply(null, a.subarray(0, size + 1));
} }