hugo/markup/highlight/chromalexers/chromalexers.go
Bjørn Erik Pedersen 7855b47f07 Add a cache for lexers.Get
```
name                            old time/op    new time/op    delta
Codeblocks/Default-10              152ms ±11%      12ms ± 1%  -92.44%  (p=0.029 n=4+4)
Codeblocks/Hook_no_higlight-10     142ms ± 0%       7ms ± 0%  -95.36%  (p=0.029 n=4+4)

name                            old alloc/op   new alloc/op   delta
Codeblocks/Default-10             11.9MB ± 0%    11.7MB ± 0%   -1.59%  (p=0.029 n=4+4)
Codeblocks/Hook_no_higlight-10    4.62MB ± 1%    4.43MB ± 0%   -4.08%  (p=0.029 n=4+4)

name                            old allocs/op  new allocs/op  delta
Codeblocks/Default-10               209k ± 0%      209k ± 0%   -0.03%  (p=0.029 n=4+4)
Codeblocks/Hook_no_higlight-10     68.4k ± 0%     68.3k ± 0%   -0.06%  (p=0.029 n=4+4)

```
2022-11-24 13:18:33 +01:00

50 lines
1.4 KiB
Go

// Copyright 2022 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package chromalexers
import (
"sync"
"github.com/alecthomas/chroma/v2"
"github.com/alecthomas/chroma/v2/lexers"
)
type lexersMap struct {
lexers map[string]chroma.Lexer
mu sync.RWMutex
}
var lexerCache = &lexersMap{lexers: make(map[string]chroma.Lexer)}
// Get returns a lexer for the given language name, nil if not found.
// This is just a wrapper around chromalexers.Get that caches the result.
// Reasoning for this is that chromalexers.Get is slow in the case where the lexer is not found,
// which is a common case in Hugo.
func Get(name string) chroma.Lexer {
lexerCache.mu.RLock()
lexer, found := lexerCache.lexers[name]
lexerCache.mu.RUnlock()
if found {
return lexer
}
lexer = lexers.Get(name)
lexerCache.mu.Lock()
lexerCache.lexers[name] = lexer
lexerCache.mu.Unlock()
return lexer
}