add voteResultCache lookup get add

[bytom/vapor.git] / database / cache.go

diff --git a/database/cache.go b/database/cache.go
index c963f25..ce19044 100644 (file)
--- a/database/cache.go
+++ b/database/cache.go
@@ -2,6 +2,7 @@ package database
 
 import (
        "fmt"
+       "strconv"
        "sync"
 
        "github.com/golang/groupcache/lru"
@@ -9,9 +10,13 @@ import (
 
        "github.com/vapor/protocol/bc"
        "github.com/vapor/protocol/bc/types"
+       "github.com/vapor/protocol/state"
 )
 
-const maxCachedBlocks = 30
+const (
+       maxCachedBlocks      = 30
+       maxCachedVoteResults = 30
+)
 
 func newBlockCache(fillFn func(hash *bc.Hash) (*types.Block, error)) blockCache {
        return blockCache{
@@ -66,3 +71,58 @@ func (c *blockCache) add(block *types.Block) {
        c.lru.Add(block.Hash(), block)
        c.mu.Unlock()
 }
+
+func newVoteResultCache(fillFn func(seq uint64) (*state.VoteResult, error)) voteResultCache {
+       return voteResultCache{
+               lru:    lru.New(maxCachedVoteResults),
+               fillFn: fillFn,
+       }
+}
+
+type voteResultCache struct {
+       mu     sync.Mutex
+       lru    *lru.Cache
+       fillFn func(seq uint64) (*state.VoteResult, error)
+       single singleflight.Group
+}
+
+func (vrc *voteResultCache) lookup(seq uint64) (*state.VoteResult, error) {
+       if voteResult, ok := vrc.get(seq); ok {
+               return voteResult, nil
+       }
+
+       seqStr := strconv.FormatUint(seq, 10)
+       voteResult, err := vrc.single.Do(seqStr, func() (interface{}, error) {
+               v, err := vrc.fillFn(seq)
+               if err != nil {
+                       return nil, err
+               }
+
+               if v == nil {
+                       return nil, fmt.Errorf("There are no vote result with given seq %s", seqStr)
+               }
+
+               vrc.add(v)
+               return v, nil
+       })
+       if err != nil {
+               return nil, err
+       }
+       return voteResult.(*state.VoteResult), nil
+}
+
+func (vrc *voteResultCache) get(seq uint64) (*state.VoteResult, bool) {
+       vrc.mu.Lock()
+       voteResult, ok := vrc.lru.Get(seq)
+       vrc.mu.Unlock()
+       if voteResult == nil {
+               return nil, ok
+       }
+       return voteResult.(*state.VoteResult), ok
+}
+
+func (vrc *voteResultCache) add(voteResult *state.VoteResult) {
+       vrc.mu.Lock()
+       vrc.lru.Add(voteResult.Seq, voteResult)
+       vrc.mu.Unlock()
+}