consul/vendor/github.com/gocql/gocql/prepared_cache.go

65 lines
1.2 KiB
Go

package gocql
import (
"github.com/gocql/gocql/internal/lru"
"sync"
)
const defaultMaxPreparedStmts = 1000
// preparedLRU is the prepared statement cache
type preparedLRU struct {
mu sync.Mutex
lru *lru.Cache
}
// Max adjusts the maximum size of the cache and cleans up the oldest records if
// the new max is lower than the previous value. Not concurrency safe.
func (p *preparedLRU) max(max int) {
p.mu.Lock()
defer p.mu.Unlock()
for p.lru.Len() > max {
p.lru.RemoveOldest()
}
p.lru.MaxEntries = max
}
func (p *preparedLRU) clear() {
p.mu.Lock()
defer p.mu.Unlock()
for p.lru.Len() > 0 {
p.lru.RemoveOldest()
}
}
func (p *preparedLRU) add(key string, val *inflightPrepare) {
p.mu.Lock()
defer p.mu.Unlock()
p.lru.Add(key, val)
}
func (p *preparedLRU) remove(key string) bool {
p.mu.Lock()
defer p.mu.Unlock()
return p.lru.Remove(key)
}
func (p *preparedLRU) execIfMissing(key string, fn func(lru *lru.Cache) *inflightPrepare) (*inflightPrepare, bool) {
p.mu.Lock()
defer p.mu.Unlock()
val, ok := p.lru.Get(key)
if ok {
return val.(*inflightPrepare), true
}
return fn(p.lru), false
}
func (p *preparedLRU) keyFor(addr, keyspace, statement string) string {
// TODO: maybe use []byte for keys?
return addr + keyspace + statement
}