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fzf/src/cache.go
Junegunn Choi 2fe1e28220 Improvements in performance and memory usage
I profiled fzf and it turned out that it was spending significant amount
of time repeatedly converting character arrays into Unicode codepoints.
This commit greatly improves search performance after the initial scan
by memoizing the converted results.

This commit also addresses the problem of unbounded memory usage of fzf.
fzf is a short-lived process that usually processes small input, so it
was implemented to cache the intermediate results very aggressively with
no notion of cache expiration/eviction. I still think a proper
implementation of caching scheme is definitely an overkill. Instead this
commit introduces limits to the maximum size (or minimum selectivity) of
the intermediate results that can be cached.
2015-04-17 22:23:52 +09:00

54 lines
1.1 KiB
Go

package fzf
import "sync"
// queryCache associates strings to lists of items
type queryCache map[string][]*Item
// ChunkCache associates Chunk and query string to lists of items
type ChunkCache struct {
mutex sync.Mutex
cache map[*Chunk]*queryCache
}
// NewChunkCache returns a new ChunkCache
func NewChunkCache() ChunkCache {
return ChunkCache{sync.Mutex{}, make(map[*Chunk]*queryCache)}
}
// Add adds the list to the cache
func (cc *ChunkCache) Add(chunk *Chunk, key string, list []*Item) {
if len(key) == 0 || !chunk.IsFull() || len(list) > queryCacheMax {
return
}
cc.mutex.Lock()
defer cc.mutex.Unlock()
qc, ok := cc.cache[chunk]
if !ok {
cc.cache[chunk] = &queryCache{}
qc = cc.cache[chunk]
}
(*qc)[key] = list
}
// Find is called to lookup ChunkCache
func (cc *ChunkCache) Find(chunk *Chunk, key string) ([]*Item, bool) {
if len(key) == 0 || !chunk.IsFull() {
return nil, false
}
cc.mutex.Lock()
defer cc.mutex.Unlock()
qc, ok := cc.cache[chunk]
if ok {
list, ok := (*qc)[key]
if ok {
return list, true
}
}
return nil, false
}