gomicsv/pagecache/page_cache.go
2024-08-10 14:48:56 +02:00

139 lines
3 KiB
Go

/*
* Copyright (c) 2013-2021 Utkan Güngördü <utkan@freeconsole.org>
* Copyright (c) 2021-2024 Piotr Grabowski
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package pagecache
import (
"sync"
"time"
"github.com/fauu/gomicsv/util"
"github.com/gotk3/gotk3/gdk"
)
type KeepReason uint8
const (
KeepReasonPreload KeepReason = 1 << iota
KeepReasonJumpmark
)
type PageCache struct {
Pages map[int]CachedPage
pagesMutex sync.Mutex
keep map[int]KeepReason
keepMutex sync.Mutex
}
func NewPageCache() PageCache {
return PageCache{
make(map[int]CachedPage),
sync.Mutex{},
make(map[int]KeepReason),
sync.Mutex{},
}
}
type CachedPage struct {
Pixbuf *gdk.Pixbuf
Time time.Time
}
func NewCachedPage(pixbuf *gdk.Pixbuf) CachedPage {
return CachedPage{pixbuf, time.Now()}
}
func (cache *PageCache) Get(i int) (*CachedPage, bool) {
cache.pagesMutex.Lock()
defer cache.pagesMutex.Unlock()
if page, ok := cache.Pages[i]; ok {
return &page, true
} else {
return nil, false
}
}
func (cache *PageCache) Insert(i int, pixbuf *gdk.Pixbuf, keepReason KeepReason) {
cache.set(i, pixbuf)
cache.Keep(i, keepReason)
}
func (cache *PageCache) Keep(i int, reason KeepReason) {
cache.keepMutex.Lock()
defer cache.keepMutex.Unlock()
cache.keep[i] |= reason
}
func (cache *PageCache) DontKeep(i int, reason KeepReason) {
cache.keepMutex.Lock()
defer cache.keepMutex.Unlock()
cache.doDontKeep(i, reason)
}
func (cache *PageCache) DontKeepSlice(indices []int, reason KeepReason) {
cache.keepMutex.Lock()
defer cache.keepMutex.Unlock()
for _, i := range indices {
cache.doDontKeep(i, reason)
}
}
func (cache *PageCache) doDontKeep(i int, reason KeepReason) {
keep, ok := cache.keep[i]
if !ok {
return
}
keep &^= reason
if keep == 0 {
delete(cache.keep, i)
} else {
cache.keep[i] = keep
}
}
func (cache *PageCache) Trim() {
var toRemove []int
for i := range cache.Pages {
if cache.keep[i] == 0 {
toRemove = append(toRemove, i)
}
}
if len(toRemove) > 0 {
cache.remove(toRemove)
}
}
func (cache *PageCache) set(i int, pixbuf *gdk.Pixbuf) {
cache.pagesMutex.Lock()
defer cache.pagesMutex.Unlock()
if pixbuf == nil {
delete(cache.Pages, i)
} else {
cache.Pages[i] = NewCachedPage(pixbuf)
}
}
func (cache *PageCache) remove(indices []int) {
cache.pagesMutex.Lock()
defer cache.pagesMutex.Unlock()
for _, i := range indices {
delete(cache.Pages, i)
}
util.GC()
}