modified persistent cache

cache.cpp

@@ -35,8 +35,18 @@ using namespace std;
 
 list<cacheNode> cache;
 unordered_map<string, list <cacheNode> :: iterator> hashTable;
+// pthread_mutex_t cLock, pLock;
 pthread_mutex_t cLock;
 
+
+void initializeCache()
+{
+    pthread_mutex_init(&cLock, NULL);
+    // pthread_mutex_init(&pLock, NULL);
+    initializeStorageVariables();
+}
+
+
 /* 
  * Returns 1 if key-value pair is present in cache and 0 otherwise
  * If key is present, brings correspoding node to front of the cache(To identify recently used element)
@@ -93,34 +103,29 @@ void insert(string key, string value) {
 }
 
 string GET(string key) {
-    // printf("GET function\n");
+    printf("GET function\n");
     pthread_mutex_lock(&cLock);
     string ans = search(key);
     pthread_mutex_unlock(&cLock);
-    /*need to add ravi code*/
     if(ans=="")
     {
-        // char * new_key = new char[key.size() + 1];
-        // copy(key.begin(), key.end(), new_key);
-        // new_key[key.size()] = '\0';
-        // string value = GETT(new_key);
-        // if(value[0] != (char)240) {
-        //     // cLock
-        //     pthread_mutex_lock(&cLock);
-        //     insert(key, value);
-        //     pthread_mutex_unlock(&cLock);
-        //     //uncLock
-        // }
-        // return value;
-        return "ERROR";
-    }
-   
+        char * new_key = new char[key.size() + 1];
+        copy(key.begin(), key.end(), new_key);
+        new_key[key.size()] = '\0';
+        string value = GETT(new_key);
+        if(value[0] != (char)240) {
+            pthread_mutex_lock(&cLock);
+            insert(key, value);
+            pthread_mutex_unlock(&cLock);
+        }
+        return value;
+    }   
     return ans;
     
 }
 
+
 string PUT(string key, string value) {
-    // cout << "PUT started" << endl;
     pthread_mutex_lock(&cLock);
     string ans = search(key);
     if(ans == "") {
@@ -131,14 +136,13 @@ string PUT(string key, string value) {
         it->second->value = value;
     }
     pthread_mutex_unlock(&cLock);
-    // uncLock
     char * new_key = new char[key.size() + 1];
     copy(key.begin(), key.end(), new_key);
     new_key[key.size()] = '\0';
     char * new_value = new char[value.size() + 1];
     copy(value.begin(), value.end(), new_value);
     new_value[value.size()] = '\0';
-    // PUTT(new_key, new_value);
+    PUTT(new_key, new_value);
     string s(1, (char)200);
     string response = s + "Put Completed Successfully";
     return response;
@@ -148,8 +152,6 @@ string PUT(string key, string value) {
  * Delete from cache
  */ 
 string DEL(string key) {
-    /*Need to add ravi code*/
-    //cLock
     pthread_mutex_lock(&cLock);
     string ans = search(key);
     if(ans != "") {
@@ -157,16 +159,12 @@ string DEL(string key) {
         list<cacheNode> :: iterator cnode_it = it->second;
         cache.erase(cnode_it);
         hashTable.erase(key);
-        pthread_mutex_unlock(&cLock);
-        return "SUCCESS";
     }
-    //uncLock
     pthread_mutex_unlock(&cLock);
     char * new_key = new char[key.size() + 1];
     copy(key.begin(), key.end(), new_key);
     new_key[key.size()] = '\0';
-    // string response=DELL(new_key);
-    string response = "ERROR";
+    string response=DELL(new_key);
     return response;
 }
 

persistentStorage.cpp

@@ -40,19 +40,34 @@ struct n2
 struct n1 *h1=NULL;
 struct n2 *h2=NULL;
 unsigned int nooffiles=0;
+
+
+
+void initializeStorageVariables()
+{
+	pthread_mutex_init(&m, NULL);
+	sem_init(&w, 0,1);
+}
+
+
 struct n2 * check(struct n2 *h2){
 	while (1)
 	{
-		if(h2==NULL){
-		return NULL;
-	}
-	else{
-		if((h2->nooffreeline)>0){
-		return h2;}
-		else{
-			h2=h2->pointer;
+		if(h2==NULL)
+		{
+			return NULL;
+		}
+		else
+		{
+			if((h2->nooffreeline)>0)
+			{
+				return h2;
+			}
+			else
+			{
+				h2=h2->pointer;
+			}
 		}
-	}
 	}
 	
 	
@@ -642,7 +657,7 @@ string GETT(char * key){
 
 void PUTT(char *key,char *value){
 	sem_wait(&w);
-	printf("key = %s\nvalue=%s",key, value);
+	// printf("key = %s\nvalue=%s",key, value);
 	h1=insert(h1,key);
 	char filename2[10];
 	strcpy(filename2,add->filename);
@@ -800,16 +815,6 @@ void pp2(struct n1*r){
 
 
 
-// int main()
-// {
-// 	printf("Saikumar\n");
-// 	return 0;
-// }
-
-
-
-
-