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Cache Packer.prepareText/Js() results during the optimization.
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they are surprisingly slow and take more than 10% of time
in a typical call to Packer.makeDecoder, so we try to reuse
their results as much as possible.
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@lifthrasiir
lifthrasiir committed Sep 12, 2021
1 parent c6a88ee commit 02d09a3
Showing 1 changed file with 48 additions and 39 deletions.
87 changes: 48 additions & 39 deletions index.mjs
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Original file line number Diff line number Diff line change
Expand Up @@ -876,9 +876,7 @@ export class Packer {
return { abbrs: commonIdents, code: replacements + output, maxAbbreviations };
}

static pack(inputsByType, options) {
const preparedText = Packer.prepareText(inputsByType['text'] || [], options);
const preparedJs = Packer.prepareJs(inputsByType['js'] || [], options);
static doPack(preparedText, preparedJs, mainInputAction, options) {
// TODO if we are to have multiple inputs they have to be splitted
const combinedInput = [...preparedText.text, ...preparedJs.code].map(c => c.charCodeAt(0));

Expand Down Expand Up @@ -1156,33 +1154,28 @@ export class Packer {
// so that the GC can free the memory as soon as possible.
let outputVar = 'κ'; // can be replaced with assignment statements if possible

const [input] = inputsByType['text'] || inputsByType['js'];
switch (input.type) {
case 'text':
outputVar = stringifiedInput(preparedText.utf8);
break;

case 'js':
if (preparedJs.abbrs.length === 0) {
outputVar = (options.allowFreeVars ? 'κ=π=' : '') + stringifiedInput();
} else if (preparedJs.abbrs.length < 3) {
secondLine += `κ=${options.allowFreeVars ? 'π=' : ''}${stringifiedInput()};`;
for (const [, abbr] of preparedJs.abbrs) {
secondLine += `with(κ.split(\`${escapeCharInTemplate(abbr)}\`))` +
`κ=join(shift());`;
}
} else {
// character class is probably uncompressible so the shorter one is preferred
const abbrCharSet = new Set(preparedJs.abbrs.map(([, abbr]) => abbr.charCodeAt(0)));
const abbrCharClass1 = makeCharClass(abbrCharSet, true);
const abbrCharClass2 = makeCharClass(abbrCharSet, false);
const abbrCharClass = (abbrCharClass2.length < abbrCharClass1.length ? abbrCharClass2 : abbrCharClass1);
secondLine +=
`for(κ=${stringifiedInput()};π=/[${abbrCharClass}]/.exec(κ);)` +
`with(κ.split(π))` +
`κ=join(shift());`;
if (!preparedJs.code) {
outputVar = stringifiedInput(preparedText.utf8);
} else {
if (preparedJs.abbrs.length === 0) {
outputVar = (options.allowFreeVars ? 'κ=π=' : '') + stringifiedInput();
} else if (preparedJs.abbrs.length < 3) {
secondLine += `κ=${options.allowFreeVars ? 'π=' : ''}${stringifiedInput()};`;
for (const [, abbr] of preparedJs.abbrs) {
secondLine += `with(κ.split(\`${escapeCharInTemplate(abbr)}\`))` +
`κ=join(shift());`;
}
break;
} else {
// character class is probably uncompressible so the shorter one is preferred
const abbrCharSet = new Set(preparedJs.abbrs.map(([, abbr]) => abbr.charCodeAt(0)));
const abbrCharClass1 = makeCharClass(abbrCharSet, true);
const abbrCharClass2 = makeCharClass(abbrCharSet, false);
const abbrCharClass = (abbrCharClass2.length < abbrCharClass1.length ? abbrCharClass2 : abbrCharClass1);
secondLine +=
`for(κ=${stringifiedInput()};π=/[${abbrCharClass}]/.exec(κ);)` +
`with(κ.split(π))` +
`κ=join(shift());`;
}
}

const [scopeSensitive, prefix, suffix] = {
Expand All @@ -1194,7 +1187,7 @@ export class Packer {
// undocumented, mainly used for debugging
'console': [false, `console.log(`, `)`],
'return': [true, ``, ``],
}[input.action];
}[mainInputAction];

const placeholderNames =
'ι' +
Expand Down Expand Up @@ -1253,7 +1246,11 @@ export class Packer {
}

makeDecoder() {
const result = Packer.pack(this.inputsByType, this.options);
const preparedText = Packer.prepareText(this.inputsByType['text'] || [], this.options);
const preparedJs = Packer.prepareJs(this.inputsByType['js'] || [], this.options);
const [input] = this.inputsByType['text'] || this.inputsByType['js'];

const result = Packer.doPack(preparedText, preparedJs, input.action, this.options);

// so that optimizer doesn't need to try numAbbreviations larger than maxAbbreviations
if (this.options.numAbbreviations > result.maxAbbreviations) {
Expand All @@ -1273,17 +1270,29 @@ export class Packer {
const performance = await getPerformanceObject();
const copy = v => JSON.parse(JSON.stringify(v));

const cache = new Map(); // `${preferTextOverJS | 0},${numAbbreviations}` -> { preparedText, preparedJs }
const mainInputAction = (this.inputsByType['text'] || this.inputsByType['js'])[0].action;

let maxAbbreviations = -1;
const calculateSize = current => {
const inputsByType = { ...this.inputsByType };
if (current.preferTextOverJS && (inputsByType['text'] || inputsByType['js'])) {
inputsByType['text'] = [
...inputsByType['text'] || [],
...(inputsByType['js'] || []).map(input => ({ ...input, type: 'text' })),
];
delete inputsByType['js'];
const options = { ...this.options, ...current };

const key = `${options.preferTextOverJS},${options.numAbbreviations}`;
if (!cache.has(key)) {
let textInputs = this.inputsByType['text'] || [];
let jsInputs = this.inputsByType['js'] || [];
if (current.preferTextOverJS) {
textInputs = [...textInputs, ...jsInputs.map(input => ({ ...input, type: 'text' }))];
jsInputs = [];
}

const preparedText = Packer.prepareText(textInputs, options);
const preparedJs = Packer.prepareJs(jsInputs, options);
cache.set(key, { preparedText, preparedJs });
}
const result = Packer.pack(inputsByType, { ...this.options, ...current });

const { preparedText, preparedJs } = cache.get(key);
const result = Packer.doPack(preparedText, preparedJs, mainInputAction, options);
if (maxAbbreviations < 0) maxAbbreviations = result.maxAbbreviations;
return new Packed(result).estimateLength();
};
Expand Down

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