Faster emojify() by avoiding str.replace() entirely (#4049)

pull/3908/merge
Nolan Lawson 8 years ago committed by Eugen Rochko
parent 331f0953e9
commit e282580101

@ -1,60 +1,55 @@
import emojione from 'emojione';
import Trie from 'substring-trie';
const toImage = str => shortnameToImage(unicodeToImage(str));
const mappedUnicode = emojione.mapUnicodeToShort();
const trie = new Trie(Object.keys(emojione.jsEscapeMap));
const unicodeToImage = str => {
const mappedUnicode = emojione.mapUnicodeToShort();
return str.replace(emojione.regUnicode, unicodeChar => {
if (typeof unicodeChar === 'undefined' || unicodeChar === '' || !(unicodeChar in emojione.jsEscapeMap)) {
return unicodeChar;
}
const unicode = emojione.jsEscapeMap[unicodeChar];
const short = mappedUnicode[unicode];
const filename = emojione.emojioneList[short].fname;
const alt = emojione.convert(unicode.toUpperCase());
return `<img draggable="false" class="emojione" alt="${alt}" title="${short}" src="/emoji/${filename}.svg" />`;
});
};
const shortnameToImage = str => {
// This walks through the string from end to start, ignoring any tags (<p>, <br>, etc.)
// and replacing valid shortnames like :smile: and :wink: that _aren't_ within
// tags with an <img> version.
// The goal is to be the same as an emojione.regShortNames replacement, but faster.
// The reason we go backwards is because then we can replace substrings as we go.
let i = str.length;
function emojify(str) {
// This walks through the string from start to end, ignoring any tags (<p>, <br>, etc.)
// and replacing valid shortnames like :smile: and :wink: as well as unicode strings
// that _aren't_ within tags with an <img> version.
// The goal is to be the same as an emojione.regShortNames/regUnicode replacement, but faster.
let i = -1;
let insideTag = false;
let insideShortname = false;
let shortnameEndIndex = -1;
while (i--) {
let shortnameStartIndex = -1;
let match;
while (++i < str.length) {
const char = str.charAt(i);
if (insideShortname && char === ':') {
const shortname = str.substring(i, shortnameEndIndex + 1);
const shortname = str.substring(shortnameStartIndex, i + 1);
if (shortname in emojione.emojioneList) {
const unicode = emojione.emojioneList[shortname].unicode[emojione.emojioneList[shortname].unicode.length - 1];
const alt = emojione.convert(unicode.toUpperCase());
const replacement = `<img draggable="false" class="emojione" alt="${alt}" title="${shortname}" src="/emoji/${unicode}.svg" />`;
str = str.substring(0, i) + replacement + str.substring(shortnameEndIndex + 1);
str = str.substring(0, shortnameStartIndex) + replacement + str.substring(i + 1);
i += (replacement.length - shortname.length - 1); // jump ahead the length we've added to the string
} else {
i++; // stray colon, try again
i--; // stray colon, try again
}
insideShortname = false;
} else if (insideTag && char === '<') {
} else if (insideTag && char === '>') {
insideTag = false;
} else if (char === '>') {
} else if (char === '<') {
insideTag = true;
insideShortname = false;
} else if (!insideTag && char === ':') {
insideShortname = true;
shortnameEndIndex = i;
shortnameStartIndex = i;
} else if (!insideTag && (match = trie.search(str.substring(i)))) {
const unicodeStr = match;
if (unicodeStr in emojione.jsEscapeMap) {
const unicode = emojione.jsEscapeMap[unicodeStr];
const short = mappedUnicode[unicode];
const filename = emojione.emojioneList[short].fname;
const alt = emojione.convert(unicode.toUpperCase());
const replacement = `<img draggable="false" class="emojione" alt="${alt}" title="${short}" src="/emoji/${filename}.svg" />`;
str = str.substring(0, i) + replacement + str.substring(i + unicodeStr.length);
i += (replacement.length - unicodeStr.length); // jump ahead the length we've added to the string
}
}
}
return str;
};
}
export default function emojify(text) {
return toImage(text);
};
export default emojify;

@ -102,6 +102,7 @@
"sass-loader": "^6.0.6",
"stringz": "^0.2.2",
"style-loader": "^0.18.2",
"substring-trie": "^1.0.0",
"throng": "^4.0.0",
"tiny-queue": "^0.2.1",
"uuid": "^3.1.0",

@ -46,4 +46,38 @@ describe('emojify', () => {
expect(emojify(':smile')).to.equal(':smile');
});
it('does two emoji next to each other', () => {
expect(emojify(':smile::wink:')).to.equal(
'<img draggable="false" class="emojione" alt="😄" title=":smile:" src="/emoji/1f604.svg" /><img draggable="false" class="emojione" alt="😉" title=":wink:" src="/emoji/1f609.svg" />');
});
it('does unicode', () => {
expect(emojify('\uD83D\uDC69\u200D\uD83D\uDC69\u200D\uD83D\uDC66\u200D\uD83D\uDC66')).to.equal(
'<img draggable="false" class="emojione" alt="👩‍👩‍👦‍👦" title=":family_wwbb:" src="/emoji/1f469-1f469-1f466-1f466.svg" />');
expect(emojify('\uD83D\uDC68\uD83D\uDC69\uD83D\uDC67\uD83D\uDC67')).to.equal(
'<img draggable="false" class="emojione" alt="👨👩👧👧" title=":family_mwgg:" src="/emoji/1f468-1f469-1f467-1f467.svg" />');
expect(emojify('\uD83D\uDC69\uD83D\uDC69\uD83D\uDC66')).to.equal('<img draggable="false" class="emojione" alt="👩👩👦" title=":family_wwb:" src="/emoji/1f469-1f469-1f466.svg" />');
expect(emojify('\u2757')).to.equal(
'<img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" />');
});
it('does multiple unicode', () => {
expect(emojify('\u2757 #\uFE0F\u20E3')).to.equal(
'<img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" /> <img draggable="false" class="emojione" alt="#️⃣" title=":hash:" src="/emoji/0023-20e3.svg" />');
expect(emojify('\u2757#\uFE0F\u20E3')).to.equal(
'<img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" /><img draggable="false" class="emojione" alt="#️⃣" title=":hash:" src="/emoji/0023-20e3.svg" />');
expect(emojify('\u2757 #\uFE0F\u20E3 \u2757')).to.equal(
'<img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" /> <img draggable="false" class="emojione" alt="#️⃣" title=":hash:" src="/emoji/0023-20e3.svg" /> <img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" />');
expect(emojify('foo \u2757 #\uFE0F\u20E3 bar')).to.equal(
'foo <img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" /> <img draggable="false" class="emojione" alt="#️⃣" title=":hash:" src="/emoji/0023-20e3.svg" /> bar');
});
it('does mixed unicode and shortnames', () => {
expect(emojify(':smile:#\uFE0F\u20E3:wink:\u2757')).to.equal('<img draggable="false" class="emojione" alt="😄" title=":smile:" src="/emoji/1f604.svg" /><img draggable="false" class="emojione" alt="#️⃣" title=":hash:" src="/emoji/0023-20e3.svg" /><img draggable="false" class="emojione" alt="😉" title=":wink:" src="/emoji/1f609.svg" /><img draggable="false" class="emojione" alt="❗" title=":exclamation:" src="/emoji/2757.svg" />');
});
it('ignores unicode inside of tags', () => {
expect(emojify('<p data-foo="\uD83D\uDC69\uD83D\uDC69\uD83D\uDC66"></p>')).to.equal('<p data-foo="\uD83D\uDC69\uD83D\uDC69\uD83D\uDC66"></p>');
});
});

@ -6819,6 +6819,10 @@ style-loader@^0.18.2:
loader-utils "^1.0.2"
schema-utils "^0.3.0"
substring-trie@^1.0.0:
version "1.0.0"
resolved "https://registry.yarnpkg.com/substring-trie/-/substring-trie-1.0.0.tgz#5a7ecb83aefcca7b3720f7897cf69e97023be143"
sugarss@^1.0.0:
version "1.0.0"
resolved "https://registry.yarnpkg.com/sugarss/-/sugarss-1.0.0.tgz#65e51b3958432fb70d5451a68bb33e32d0cf1ef7"

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