Refresh identitifaction keys in the background

Instead of calling identities refresh everytime.

Signed-off-by: Sergey Matveev <stargrave@stargrave.org>

diff --git a/identify.go b/identify.go
index 8547e6081ef659c022c1f7f113ef222148491915..c6fcc9d1d24c8224e8941d9406f042fd00ee3161 100644 (file)
--- a/identify.go
+++ b/identify.go
@@ -23,12 +23,15 @@ import (
        "encoding/hex"
        "log"
        "os"
+       "sync"
+       "time"
 
        "golang.org/x/crypto/xtea"
 )
 
 const (
-       IDSize = 128 / 8
+       IDSize      = 128 / 8
+       RefreshRate = 60 * time.Second
 )
 
 type PeerId [IDSize]byte
@@ -40,15 +43,21 @@ func (id PeerId) String() string {
 type cipherCache map[PeerId]*xtea.Cipher
 
 var (
-       PeersPath string
-       IDsCache  cipherCache
+       PeersPath       string
+       IDsCache        cipherCache
+       cipherCacheLock sync.RWMutex
 )
 
 // Initialize (pre-cache) available peers info.
 func PeersInit(path string) {
        PeersPath = path
        IDsCache = make(map[PeerId]*xtea.Cipher)
-       IDsCache.refresh()
+       go func() {
+               for {
+                       IDsCache.refresh()
+                       time.Sleep(RefreshRate)
+               }
+       }()
 }
 
 // Refresh IDsCache: remove disappeared keys, add missing ones with
@@ -70,6 +79,8 @@ func (cc cipherCache) refresh() {
                }
                available[*id] = true
        }
+
+       cipherCacheLock.Lock()
        // Cleanup deleted ones from cache
        for k, _ := range cc {
                if _, exists := available[k]; !exists {
@@ -88,20 +99,23 @@ func (cc cipherCache) refresh() {
                        cc[peerId] = cipher
                }
        }
+       cipherCacheLock.Unlock()
 }
 
 // Try to find peer's identity (that equals to an encryption key)
 // by providing cipher and plain texts.
 func (cc cipherCache) Find(plaintext, ciphertext []byte) *PeerId {
-       cc.refresh()
        buf := make([]byte, xtea.BlockSize)
+       cipherCacheLock.RLock()
        for pid, cipher := range cc {
                cipher.Decrypt(buf, ciphertext)
                if subtle.ConstantTimeCompare(buf, plaintext) == 1 {
                        ppid := PeerId(pid)
+                       cipherCacheLock.RUnlock()
                        return &ppid
                }
        }
+       cipherCacheLock.RUnlock()
        return nil
 }