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A couple of small improvements of the Metadata._repair method

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- Remove the "capturing group" in the regular expression that removes leading "junk" from the raw metadata, since it's not necessary here (it's simply a case of too much copy-pasting in a prior patch).
   According to [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Cheatsheet#Groups_and_ranges) you want to, for performance reasons, avoid "capturing groups" unless actually needed.

 - Add inline comments to document a bunch of magic values in the code.
This commit is contained in:
Jonas Jenwald 2020-02-13 17:20:52 +01:00
parent 993a1d7825
commit 3f1568b51a
1 changed files with 6 additions and 6 deletions
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12
src/display/metadata.js
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@ -37,7 +37,7 @@ class Metadata {
_repair(data) { _repair(data) {
// Start by removing any "junk" before the first tag (see issue 10395). // Start by removing any "junk" before the first tag (see issue 10395).
return data return data
.replace(/^([^<]+)/, "") .replace(/^[^<]+/, "")
.replace(/>\\376\\377([^<]+)/g, function(all, codes) { .replace(/>\\376\\377([^<]+)/g, function(all, codes) {
const bytes = codes const bytes = codes
.replace(/\\([0-3])([0-7])([0-7])/g, function(code, d1, d2, d3) { .replace(/\\([0-3])([0-7])([0-7])/g, function(code, d1, d2, d3) {
@ -63,11 +63,11 @@ class Metadata {
for (let i = 0, ii = bytes.length; i < ii; i += 2) { for (let i = 0, ii = bytes.length; i < ii; i += 2) {
const code = bytes.charCodeAt(i) * 256 + bytes.charCodeAt(i + 1); const code = bytes.charCodeAt(i) * 256 + bytes.charCodeAt(i + 1);
if ( if (
code >= 32 && code >= /* Space = */ 32 &&
code < 127 && code < /* Delete = */ 127 &&
code !== 60 && code !== /* '<' = */ 60 &&
code !== 62 && code !== /* '>' = */ 62 &&
code !== 38 code !== /* '&' = */ 38
) { ) {
chars += String.fromCharCode(code); chars += String.fromCharCode(code);
} else { } else {