From 8b1d01816b3248f8d702b2b8c8405ed37129e9da Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Wed, 26 May 2021 13:07:00 +0200
Subject: [PATCH] Re-factor the `charsCache` on `Font`-instances
Currently `charsCache` is initialized *lazily*, which considering that it just contains a simple `Object` doesn't seem entirely necessary. This first of all forces us to do repeated exists-checks in the `Font.charsToGlyphs` method, and secondly the similar/related `glyphCache` is already initialized eagerly.
Furthermore, this patch also does a bit of clean-up in the `Font.charsToGlyphs` method since this code is quite old.
---
src/core/fonts.js | 60 ++++++++++++++++++++---------------------------
1 file changed, 25 insertions(+), 35 deletions(-)
diff --git a/src/core/fonts.js b/src/core/fonts.js
index dc569fa2f..ad8efd2b2 100644
--- a/src/core/fonts.js
+++ b/src/core/fonts.js
@@ -802,7 +802,8 @@ class Font {
this.missingFile = false;
this.cssFontInfo = properties.cssFontInfo;
- this.glyphCache = Object.create(null);
+ this._charsCache = Object.create(null);
+ this._glyphCache = Object.create(null);
this.isSerifFont = !!(properties.flags & FontFlags.Serif);
this.isSymbolicFont = !!(properties.flags & FontFlags.Symbolic);
@@ -2946,7 +2947,7 @@ class Font {
}
}
- let glyph = this.glyphCache[charcode];
+ let glyph = this._glyphCache[charcode];
if (
!glyph ||
!glyph.matchesForCache(
@@ -2970,57 +2971,46 @@ class Font {
isSpace,
isInFont
);
- this.glyphCache[charcode] = glyph;
+ this._glyphCache[charcode] = glyph;
}
return glyph;
}
charsToGlyphs(chars) {
- let charsCache = this.charsCache;
- let glyphs, glyph, charcode;
-
- // if we translated this string before, just grab it from the cache
- if (charsCache) {
- glyphs = charsCache[chars];
- if (glyphs) {
- return glyphs;
- }
+ // If we translated this string before, just grab it from the cache.
+ let glyphs = this._charsCache[chars];
+ if (glyphs) {
+ return glyphs;
}
-
- // lazily create the translation cache
- if (!charsCache) {
- charsCache = this.charsCache = Object.create(null);
- }
-
glyphs = [];
- const charsCacheKey = chars;
- let i = 0,
- ii;
if (this.cMap) {
- // composite fonts have multi-byte strings convert the string from
- // single-byte to multi-byte
- const c = Object.create(null);
- while (i < chars.length) {
+ // Composite fonts have multi-byte strings, convert the string from
+ // single-byte to multi-byte.
+ const c = Object.create(null),
+ ii = chars.length;
+ let i = 0;
+ while (i < ii) {
this.cMap.readCharCode(chars, i, c);
- charcode = c.charcode;
- const length = c.length;
+ const { charcode, length } = c;
i += length;
// Space is char with code 0x20 and length 1 in multiple-byte codes.
- const isSpace = length === 1 && chars.charCodeAt(i - 1) === 0x20;
- glyph = this._charToGlyph(charcode, isSpace);
+ const glyph = this._charToGlyph(
+ charcode,
+ length === 1 && chars.charCodeAt(i - 1) === 0x20
+ );
glyphs.push(glyph);
}
} else {
- for (i = 0, ii = chars.length; i < ii; ++i) {
- charcode = chars.charCodeAt(i);
- glyph = this._charToGlyph(charcode, charcode === 0x20);
+ for (let i = 0, ii = chars.length; i < ii; ++i) {
+ const charcode = chars.charCodeAt(i);
+ const glyph = this._charToGlyph(charcode, charcode === 0x20);
glyphs.push(glyph);
}
}
- // Enter the translated string into the cache
- return (charsCache[charsCacheKey] = glyphs);
+ // Enter the translated string into the cache.
+ return (this._charsCache[chars] = glyphs);
}
/**
@@ -3052,7 +3042,7 @@ class Font {
}
get glyphCacheValues() {
- return Object.values(this.glyphCache);
+ return Object.values(this._glyphCache);
}
/**