Solução final

common/consistenthash/consistenthash.go

@@ -18,11 +18,7 @@ type Ring struct {
 // search will find the index of the node that is responsible for the range that
 // includes the hashed value of key.
 func (r *Ring) search(key string) int {
-    /////////////////////////
-    // YOUR CODE GOES HERE //
-    /////////////////////////
-
-    return 0
+    return r.Nodes.LowerBound(hashId(key))
 }
 
 // NewRing will create a new Ring object and return a pointer to it.

common/consistenthash/node.go

@@ -30,3 +30,14 @@ type Nodes []*Node
 func (n Nodes) Len() int           { return len(n) }
 func (n Nodes) Swap(i, j int)      { n[i], n[j] = n[j], n[i] }
 func (n Nodes) Less(i, j int) bool { return n[i].HashId < n[j].HashId }
+
+// LowerBound assumes array is sorted
+func (n Nodes) LowerBound(val uint32) int {
+	for index, elem := range n {
+		if elem.HashId >= val {
+			return index
+		}
+	}
+
+	return 0
+}

dynamo/cache.go

@@ -12,6 +12,7 @@ import (
 // Cache is the struct that handle all the data storage for the dynamo server.
 type Cache struct {
     data map[string]string
+    timestamps map[string]int64
     sync.Mutex
 }
 
@@ -20,6 +21,7 @@ func NewCache() *Cache {
     var s Cache
 
     s.data = make(map[string]string)
+    s.timestamps = make(map[string]int64)
 
     return &s
 }
@@ -29,7 +31,7 @@ func NewCache() *Cache {
 func (cache *Cache) Get(key string) (value string, timestamp int64) {
     cache.Lock()
     value = cache.data[key]
-    timestamp = 0
+    timestamp = cache.timestamps[key]
     cache.Unlock()
 
     log.Printf("[CACHE] Getting Key '%v' with Value '%v' @ timestamp '%v'\n", key, value, timestamp)
@@ -43,6 +45,7 @@ func (cache *Cache) Put(key string, value string, timestamp int64) {
 
     cache.Lock()
     cache.data[key] = value
+    cache.timestamps[key] = timestamp
     cache.Unlock()
 
     return
@@ -52,6 +55,6 @@ func (cache *Cache) Put(key string, value string, timestamp int64) {
 // except for testing purposes.
 func (cache *Cache) getAll() (data map[string]string, timestamps map[string]int64) {
     data = cache.data
-    timestamps = make(map[string]int64)
+    timestamps = cache.timestamps
     return data, timestamps
 }

dynamo/coordinator.go

@@ -186,13 +186,15 @@ func (server *Server) Voting(key string, quorum int) (string, error) {
 
 // aggregateVotes will select the right value from the votes received.
 func aggregateVotes(votes []*vote) (result string) {
-	for _, vote := range votes {
+	index := 0
+	for i, vote := range votes {
 		log.Printf("[COORDINATOR] Vote: %v\n", vote.value)
+
+		if votes[i].timestamp > votes[index].timestamp {
+			index = i
+		}
 	}
 
-	/////////////////////////
-	// YOUR CODE GOES HERE //
-	/////////////////////////
-	result = votes[0].value
+	result = votes[index].value
 	return
 }