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arc_cache.go
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arc_cache.go
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package blockstore
import (
"github.com/ipfs/go-ipfs/blocks"
key "github.com/ipfs/go-ipfs/blocks/key"
ds "gx/ipfs/QmTxLSvdhwg68WJimdS6icLPhZi28aTp6b7uihC2Yb47Xk/go-datastore"
lru "gx/ipfs/QmVYxfoJQiZijTgPNHCHgHELvQpbsJNTg6Crmc3dQkj3yy/golang-lru"
context "gx/ipfs/QmZy2y8t9zQH2a1b8q2ZSLKp17ATuJoCNxxyMFG5qFExpt/go-net/context"
)
type arccache struct {
arc *lru.ARCCache
blockstore Blockstore
}
func arcCached(bs Blockstore, lruSize int) (*arccache, error) {
arc, err := lru.NewARC(lruSize)
if err != nil {
return nil, err
}
return &arccache{arc: arc, blockstore: bs}, nil
}
func (b *arccache) DeleteBlock(k key.Key) error {
if has, ok := b.hasCached(k); ok && !has {
return ErrNotFound
}
b.arc.Remove(k) // Invalidate cache before deleting.
err := b.blockstore.DeleteBlock(k)
switch err {
case nil, ds.ErrNotFound, ErrNotFound:
b.arc.Add(k, false)
return nil
default:
return err
}
}
// if ok == false has is inconclusive
// if ok == true then has respons to question: is it contained
func (b *arccache) hasCached(k key.Key) (has bool, ok bool) {
if k == "" {
// Return cache invalid so the call to blockstore happens
// in case of invalid key and correct error is created.
return false, false
}
h, ok := b.arc.Get(k)
if ok {
return h.(bool), true
}
return false, false
}
func (b *arccache) Has(k key.Key) (bool, error) {
if has, ok := b.hasCached(k); ok {
return has, nil
}
res, err := b.blockstore.Has(k)
if err == nil {
b.arc.Add(k, res)
}
return res, err
}
func (b *arccache) Get(k key.Key) (blocks.Block, error) {
if has, ok := b.hasCached(k); ok && !has {
return nil, ErrNotFound
}
bl, err := b.blockstore.Get(k)
if bl == nil && err == ErrNotFound {
b.arc.Add(k, false)
} else if bl != nil {
b.arc.Add(k, true)
}
return bl, err
}
func (b *arccache) Put(bl blocks.Block) error {
if has, ok := b.hasCached(bl.Key()); ok && has {
return nil
}
err := b.blockstore.Put(bl)
if err == nil {
b.arc.Add(bl.Key(), true)
}
return err
}
func (b *arccache) PutMany(bs []blocks.Block) error {
var good []blocks.Block
for _, block := range bs {
if has, ok := b.hasCached(block.Key()); !ok || (ok && !has) {
good = append(good, block)
}
}
err := b.blockstore.PutMany(bs)
if err != nil {
return err
}
for _, block := range bs {
b.arc.Add(block.Key(), true)
}
return nil
}
func (b *arccache) AllKeysChan(ctx context.Context) (<-chan key.Key, error) {
return b.blockstore.AllKeysChan(ctx)
}
func (b *arccache) GCLock() Unlocker {
return b.blockstore.(GCBlockstore).GCLock()
}
func (b *arccache) PinLock() Unlocker {
return b.blockstore.(GCBlockstore).PinLock()
}
func (b *arccache) GCRequested() bool {
return b.blockstore.(GCBlockstore).GCRequested()
}