Add recover middleware for grpc server

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/github.com/hashicorp/golang-lru/lru.go

@@ -86,17 +86,35 @@ func (c *Cache) ContainsOrAdd(key, value interface{}) (ok, evicted bool) {
 }
 
 // Remove removes the provided key from the cache.
-func (c *Cache) Remove(key interface{}) {
+func (c *Cache) Remove(key interface{}) (present bool) {
 	c.lock.Lock()
-	c.lru.Remove(key)
+	present = c.lru.Remove(key)
 	c.lock.Unlock()
+	return
+}
+
+// Resize changes the cache size.
+func (c *Cache) Resize(size int) (evicted int) {
+	c.lock.Lock()
+	evicted = c.lru.Resize(size)
+	c.lock.Unlock()
+	return evicted
 }
 
 // RemoveOldest removes the oldest item from the cache.
-func (c *Cache) RemoveOldest() {
+func (c *Cache) RemoveOldest() (key interface{}, value interface{}, ok bool) {
 	c.lock.Lock()
-	c.lru.RemoveOldest()
+	key, value, ok = c.lru.RemoveOldest()
 	c.lock.Unlock()
+	return
+}
+
+// GetOldest returns the oldest entry
+func (c *Cache) GetOldest() (key interface{}, value interface{}, ok bool) {
+	c.lock.Lock()
+	key, value, ok = c.lru.GetOldest()
+	c.lock.Unlock()
+	return
 }
 
 // Keys returns a slice of the keys in the cache, from oldest to newest.

vendor/github.com/hashicorp/golang-lru/simplelru/lru.go

@@ -73,6 +73,9 @@ func (c *LRU) Add(key, value interface{}) (evicted bool) {
 func (c *LRU) Get(key interface{}) (value interface{}, ok bool) {
 	if ent, ok := c.items[key]; ok {
 		c.evictList.MoveToFront(ent)
+		if ent.Value.(*entry) == nil {
+			return nil, false
+		}
 		return ent.Value.(*entry).value, true
 	}
 	return
@@ -142,6 +145,19 @@ func (c *LRU) Len() int {
 	return c.evictList.Len()
 }
 
+// Resize changes the cache size.
+func (c *LRU) Resize(size int) (evicted int) {
+	diff := c.Len() - size
+	if diff < 0 {
+		diff = 0
+	}
+	for i := 0; i < diff; i++ {
+		c.removeOldest()
+	}
+	c.size = size
+	return diff
+}
+
 // removeOldest removes the oldest item from the cache.
 func (c *LRU) removeOldest() {
 	ent := c.evictList.Back()

vendor/github.com/hashicorp/golang-lru/simplelru/lru_interface.go

@@ -10,7 +10,7 @@ type LRUCache interface {
 	// updates the "recently used"-ness of the key. #value, isFound
 	Get(key interface{}) (value interface{}, ok bool)
 
-	// Check if a key exsists in cache without updating the recent-ness.
+	// Checks if a key exists in cache without updating the recent-ness.
 	Contains(key interface{}) (ok bool)
 
 	// Returns key's value without updating the "recently used"-ness of the key.
@@ -31,6 +31,9 @@ type LRUCache interface {
 	// Returns the number of items in the cache.
 	Len() int
 
-	// Clear all cache entries
+	// Clears all cache entries.
 	Purge()
+
+  // Resizes cache, returning number evicted
+  Resize(int) int
 }