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Reduce unnecessary usage of Array.prototype.concat()

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There are obviously cases where using `concat` makes perfect sense, since that method doesn't change any of the existing Arrays; see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/concat

However, in a few cases throughout the code-base that's not an issue and using `concat` only leads to unnecessary intermediate allocations. With modern JavaScript we can thus replace those with a combination of `push` and spread-syntax, which wasn't originally possible when the code was written.
This commit is contained in:
Jonas Jenwald 2022-06-19 12:26:48 +02:00
parent f516bb2174
commit c21f4faaf8
4 changed files with 21 additions and 23 deletions
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14
src/core/cff_parser.js
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@ -1387,7 +1387,7 @@ class CFFCompiler {
const output = {
data: [],
length: 0,
add: function CFFCompiler_add(data) {
add(data) {
this.data = this.data.concat(data);
this.length = this.data.length;
},
@ -1680,7 +1680,7 @@ class CFFCompiler {
}
compileDict(dict, offsetTracker) {
let out = [];
const out = [];
// The dictionary keys must be in a certain order.
const order = dict.order;
for (let i = 0; i < order.length; ++i) {
@ -1708,7 +1708,7 @@ class CFFCompiler {
switch (type) {
case "num":
case "sid":
out = out.concat(this.encodeNumber(value));
out.push(...this.encodeNumber(value));
break;
case "offset":
// For offsets we just insert a 32bit integer so we don't have to
@ -1720,20 +1720,20 @@ class CFFCompiler {
if (!offsetTracker.isTracking(name)) {
offsetTracker.track(name, out.length);
}
out = out.concat([0x1d, 0, 0, 0, 0]);
out.push(0x1d, 0, 0, 0, 0);
break;
case "array":
case "delta":
out = out.concat(this.encodeNumber(value));
out.push(...this.encodeNumber(value));
for (let k = 1, kk = values.length; k < kk; ++k) {
out = out.concat(this.encodeNumber(values[k]));
out.push(...this.encodeNumber(values[k]));
}
break;
default:
throw new FormatError(`Unknown data type of ${type}`);
}
}
out = out.concat(dict.opcodes[key]);
out.push(...dict.opcodes[key]);
}
return out;
}