1 files changed, 241 insertions, 100 deletions

diff --git a/P3/server.c b/P3/server.c
index 1e7a6c3..6d76df5 100644
--- a/P3/server.c
+++ b/P3/server.c
@@ -21,7 +21,7 @@
 #define BUFF_SIZE 1024
 
 int port, workers, dispatchers, dynFlag, qLen, cSiz = 0;
-char* path;
+char *path;
 pthread_mutex_t Qlock, logLock;
 
 /*
@@ -29,26 +29,30 @@ pthread_mutex_t Qlock, logLock;
 */
 
 // structs:
-typedef struct request_queue {
-   int fd;
-   char *request;
-   struct request_queue* next;
+typedef struct request_queue
+{
+  int fd;
+  char *request;
+  struct request_queue *next;
 } request_t;
 request_t *Q = NULL; // The request queue
 
-typedef struct cache_entry {
-    int len;
-    char *request;
-    char *content;
-    struct cache_entry* next;
+typedef struct cache_entry
+{
+  int len;
+  char *request;
+  char *content;
+  struct cache_entry *next;
 } cache_entry_t;
 cache_entry_t *dynQ = NULL; //The cache queue
 
 /* ******************** Dynamic Pool Code  [Extra Credit A] **********************/
 // Extra Credit: This function implements the policy to change the worker thread pool dynamically
 // depending on the number of requests
-void * dynamic_pool_size_update(void *arg) {
-  while(1) {
+void *dynamic_pool_size_update(void *arg)
+{
+  while (1)
+  {
     // Run at regular intervals
     // Increase / decrease dynamically based on your policy
   }
@@ -58,12 +62,19 @@ void * dynamic_pool_size_update(void *arg) {
 /* ************************ Cache Code [Extra Credit B] **************************/
 
 // Function to check whether the given request is present in cache
-int getCacheIndex(char *request){
+int isInCache(char *request)
+{
   /// return the index if the request is present in the cache
   cache_entry_t *traverse = dynQ;
+  if (dynQ == NULL)
+    return -2;
   int index = 0;
-  while (traverse != NULL) {
-    if (!strcmp(request, traverse->request)) {
+  while (traverse != NULL)
+  {
+    if (traverse->request == NULL)
+      break;
+    if (!strcmp(request, traverse->request))
+    {
       return index;
     }
     index++;
@@ -71,17 +82,66 @@ int getCacheIndex(char *request){
   return -1;
 }
 
+// Function to traverse cache queue to find cache
+int readFromCache(int index, char *buffer)
+{
+  // Open and read the contents of file given the request
+  cache_entry_t *traverse = dynQ;
+  for (int i = 0; i < index; i++)
+  {
+    if (traverse == NULL)
+      return -1;
+    traverse = traverse->next;
+  }
+  buffer = traverse->content;
+  return 0;
+}
+
 // Function to add the request and its file content into the cache
-void addIntoCache(char *mybuf, char *memory , int memory_size){
+void addIntoCache(char *mybuf, char *memory, int memory_size)
+{
   // It should add the request at an index according to the cache replacement policy
   // Make sure to allocate/free memory when adding or replacing cache entries
+  cache_entry_t *traverse = dynQ;
+  if (dynQ == NULL)
+    return;
+  int cacheIndex = 0;
+  bool fullCache = false;
+  while (traverse->next != NULL)
+  {
+    if (++cacheIndex > cSiz)
+    {
+      fullCache = true;
+      break;
+    }
+    traverse = traverse->next;
+  }
+  if (fullCache)
+  {
+    cache_entry_t *temp = dynQ;
+    dynQ = dynQ->next;
+    free(temp);
+    free(temp->content);
+    free(temp->request);
+    cacheIndex--;
+    addIntoCache(mybuf, memory, memory_size);
+  }
+  else
+  {
+    cache_entry_t *temp = calloc(1, sizeof(cache_entry_t));
+    temp->request = mybuf;
+    temp->content = memory;
+    temp->len = memory_size;
+    cacheIndex++;
+  }
 }
 
 // clear the memory allocated to the cache
-void deleteCache(){
-  
+void deleteCache()
+{
   request_t *tempReq = NULL;
-  while (Q != NULL) {
+  while (Q != NULL)
+  {
     tempReq = Q;
     Q = Q->next;
     free(tempReq->request);
@@ -93,47 +153,64 @@ void deleteCache(){
   {
     tempCache = dynQ;
     dynQ = dynQ->next;
+    free(tempCache->content);
+    free(tempCache->request);
     free(tempCache);
   }
 }
 
 // Function to initialize the cache
-void initCache(){
+int cacheLength;
+void initCache()
+{
   // Allocating memory and initializing the cache array
-  
+  dynQ = calloc(1, sizeof(cache_entry_t));
+  cacheLength = 0;
+  // cache_entry_t *tempTrav = dynQ;
+  // for (int i=0; i<cSiz; i++) {
+  //   tempTrav->next = calloc(1, sizeof(cache_entry_t));
+  //   tempTrav = tempTrav->next;
+  // }
 }
 
 /**********************************************************************************/
 
 /* ************************************ Utilities ********************************/
 // Function to get the content type from the request
-char* getContentType(char * mybuf) {
+char *getContentType(char *mybuf)
+{
   // Should return the content type based on the file type in the request
   // (See Section 5 in Project description for more details)
-  char* ext = strrchr(mybuf, '.');
+  char *ext = strrchr(mybuf, '.');
 
-  if (ext == NULL) {
-      printf("Filetype not found. Exiting\n");
-      exit(-1);
+  if (ext == NULL)
+  {
+    printf("Filetype not found. Exiting\n");
+    exit(-1);
   }
-  else if ((strcmp((ext + 1), "htm") == 0) || (strcmp((ext + 1), "html") == 0)) {
+  else if ((strcmp((ext + 1), "htm") == 0) || (strcmp((ext + 1), "html") == 0))
+  {
     return "text/html";
   }
-  else if (strcmp((ext + 1), "jpg") == 0) {
+  else if (strcmp((ext + 1), "jpg") == 0)
+  {
     return "image/jpeg";
   }
-  else if (strcmp((ext + 1), "gif") == 0) {
+  else if (strcmp((ext + 1), "gif") == 0)
+  {
     return "image/gif";
   }
-  else {
+  else
+  {
     return "text/plain";
   }
 }
 
 // Function to get the size of the file in the queue
 // (Thanks Matt from stackOverflow)
-unsigned long getFileSize(char *file) {
-  char* temp = malloc(BUFF_SIZE);
+unsigned long getFileSize(char *file)
+{
+  char *temp = malloc(BUFF_SIZE);
   sprintf(temp, ".%s", file);
   FILE *f = fopen(temp, "r");
   free(temp);
@@ -147,114 +224,163 @@ unsigned long getFileSize(char *file) {
 
 // Function to open and read the file from the disk into the memory
 // Add necessary arguments as needed
-int readFromDisk(char* fileName, char* buffer, long fileSize) {
-    char* temp = malloc(BUFF_SIZE);
-    sprintf(temp, ".%s", fileName);
-    // Open and read the contents of file given the request
-    int requestFile = open(temp, O_RDONLY);
-    free(temp);
-    if (requestFile == -1) {
-      return -1; // Error handle
-    }
-    read(requestFile, buffer, fileSize);
-    close(requestFile);
-    return 0;
+int readFromDisk(char *fileName, char *buffer, long fileSize)
+{
+  char *temp = malloc(BUFF_SIZE);
+  sprintf(temp, ".%s", fileName);
+  // Open and read the contents of file given the request
+  int requestFile = open(temp, O_RDONLY);
+  free(temp);
+  if (requestFile == -1)
+  {
+    return -1; // Error handle
+  }
+  read(requestFile, buffer, fileSize);
+  close(requestFile);
+  return 0;
 }
 
 /**********************************************************************************/
 
 // Function to receive the request from the client and add to the queue
-void * dispatch(void *arg) {
+void *dispatch(void *arg)
+{
 
-  while (1) {
+  while (1)
+  {
     // Accept client connection and get the fd
     int newReq = accept_connection();
-    if (newReq > INVALID) {
+    if (newReq > INVALID)
+    {
       pthread_mutex_lock(&Qlock);
-      request_t* traverse = Q;
-      
+      request_t *traverse = Q;
+
       // Get request from the client
       // Add the request into the queue
-      for(int i = 0; i < qLen; i++) {
-        if (traverse == NULL || traverse->next == NULL) {
+      for (int i = 0; i < qLen; i++)
+      {
+        if (traverse == NULL || traverse->next == NULL)
+        {
           //Add things to queue. Lock & unlock to prevent a deadlock
-          
+
           request_t *tempNode = (request_t *)calloc(1, sizeof(request_t));
-          char* dispatchBuf = (char *) malloc(BUFF_SIZE); // Buffer to store the requested filename 
-          if (get_request(newReq, dispatchBuf) != 0) {
+          char *dispatchBuf = (char *)malloc(BUFF_SIZE); // Buffer to store the requested filename
+          if (get_request(newReq, dispatchBuf) != 0)
+          {
             pthread_mutex_unlock(&Qlock);
             free(tempNode);
             free(dispatchBuf);
             continue; // If get_request fails, try again
-          } 
+          }
           tempNode->fd = newReq;
           tempNode->request = dispatchBuf;
           tempNode->next = NULL;
-          if (traverse == NULL) {
+          if (traverse == NULL)
+          {
             Q = tempNode;
-          } else {
+          }
+          else
+          {
             traverse->next = tempNode;
           }
-          
+
           pthread_mutex_unlock(&Qlock);
           break;
-        } else {
-          traverse = traverse -> next;
+        }
+        else
+        {
+          traverse = traverse->next;
         }
       }
     }
-   }
-   return NULL;
+  }
+  return NULL;
 }
 
 /**********************************************************************************/
 
 // Function to retrieve the request from the queue, process it and then return a result to the client
-void * worker(void *arg) {
-  int id = *(int*) arg;
+void *worker(void *arg)
+{
+  int id = *(int *)arg;
   unsigned long numbytes;
   unsigned long long numReqs = 0;
-  while (1) {
+  while (1)
+  {
     // Get the request from the queue
     pthread_mutex_lock(&Qlock);
-    if (Q == NULL) {
+    if (Q == NULL)
+    {
       pthread_mutex_unlock(&Qlock);
       continue;
     }
     //Make copy of request and get rid of old one.
     request_t *request = NULL;
-    request = (request_t*) malloc(sizeof(request_t));
+    request = (request_t *)malloc(sizeof(request_t));
     request->fd = Q->fd;
     request->request = Q->request;
     Q = Q->next;
     pthread_mutex_unlock(&Qlock);
 
-    // TODO! Get the data from the disk or the cache (extra credit B)
+    //Get the data from the disk or the cache (extra credit B)
     numbytes = getFileSize(request->request);
-    char *workerBuf = (char *) malloc(numbytes*sizeof(char));
-    char *bytesError = malloc(BUFF_SIZE); 
-    if (numbytes != 0) {
+    char *workerBuf = (char *)malloc(numbytes * sizeof(char));
+    char *bytesError = malloc(BUFF_SIZE);
+    bool fail = false;
+    if (numbytes != 0)
+    {
       //SUCC
       sprintf(bytesError, "%ld", numbytes);
-    } else {
+    }
+    else
+    {
       //ERR
+      fail = true;
       sprintf(bytesError, "%s", strerror(errno));
     }
+    char *cacheTest; //HIT/MISS only
+    if (!fail)
+    {
+      int test = isInCache(request->request);
+      if (test != -1)
+      {
+        //In cache, file exists
+        cacheTest = "HIT";
+        readFromCache(test, workerBuf);
+      }
+      else
+      {
+        cacheTest = "MISS";
+        if (readFromDisk(request->request, workerBuf, numbytes) == -1)
+        {
+          //Not in cache, disk read failed
+          fail = true;
+        }
+        else
+        {
+          //Not in cache, disk read succeeds
+          addIntoCache(request->request, workerBuf, (int)numbytes);
+        }
+      }
+    }
 
     // Log the request into the file and terminal
     pthread_mutex_lock(&logLock);
-    FILE* log = fopen("../webserver_log", "a");
-    fprintf(log, "[%d][%lld][%d][%s][%s][%s]\n", id, ++numReqs, request->fd, request->request, bytesError, "CACHE");
-    printf("[%d][%lld][%d][%s][%s][%s]\n", id, numReqs, request->fd, request->request, bytesError, "CACHE");
+    FILE *log = fopen("../webserver_log", "a");
+    fprintf(log, "[%d][%lld][%d][%s][%s][%s]\n", id, ++numReqs, request->fd, request->request, bytesError, cacheTest);
+    printf("[%d][%lld][%d][%s][%s][%s]\n", id, numReqs, request->fd, request->request, bytesError, cacheTest);
     fclose(log);
     pthread_mutex_unlock(&logLock);
     free(bytesError);
 
     // Return the result
-    if (readFromDisk(request->request, workerBuf, numbytes) != 0) {
+    if (fail)
+    {
       //ERR
       return_error(request->fd, request->request);
-    } else {
+    }
+    else
+    {
       //SUCC
       return_result(request->fd, getContentType(request->request), workerBuf, numbytes);
     }
@@ -271,12 +397,15 @@ void * worker(void *arg) {
 static volatile sig_atomic_t exitFlag = 0;
 
 //Sets exit flag so process can die happily and not sad.
-static void eggs(int signo) {
+static void eggs(int signo)
+{
   exitFlag |= 1;
 }
-int main(int argc, char **argv) {
+int main(int argc, char **argv)
+{
   // Error check on number of arguments
-  if(argc != 8){
+  if (argc != 8)
+  {
     printf("usage: %s port path num_dispatcher num_workers dynamic_flag queue_length cache_size\n", argv[0]);
     return -1;
   }
@@ -297,19 +426,23 @@ int main(int argc, char **argv) {
   cSiz = atoi(argv[7]);
 
   /* -- ERROR CHECKING -- */
-  if (port < 1025 || port > 65535) {
+  if (port < 1025 || port > 65535)
+  {
     printf("Invalid port. Port must be greater than 1025 or less than 65535 (inclusive).\n");
     return -1;
   }
-  if (dispatchers > MAX_THREADS || dispatchers < 1) {
+  if (dispatchers > MAX_THREADS || dispatchers < 1)
+  {
     printf("Number of dispatchers is invalid. It must be greater than 1 or less than %d (inclusive).\n", MAX_THREADS);
     return -1;
   }
-  if (workers > MAX_THREADS || workers < 1) {
+  if (workers > MAX_THREADS || workers < 1)
+  {
     printf("Number of dispatchers is invalid. It must be greater than 1 or less than %d (inclusive).\n", MAX_THREADS);
     return -1;
   }
-  if (qLen > MAX_queue_len || qLen < 1) {
+  if (qLen > MAX_queue_len || qLen < 1)
+  {
     printf("Queue length is invalid It must be greater than 1 or less than %d (inclusive).\n", MAX_queue_len);
     return -1;
   }
@@ -320,16 +453,18 @@ int main(int argc, char **argv) {
   act.sa_handler = eggs;
   act.sa_flags = 0;
   if (sigemptyset(&act.sa_mask) == -1 ||
-      sigaction(SIGINT, &act, NULL) == -1) {
-        perror("SIGINT Handler Error");
-        return -2;
+      sigaction(SIGINT, &act, NULL) == -1)
+  {
+    perror("SIGINT Handler Error");
+    return -2;
   }
   // Create instance of logfil
-  FILE* logfile = fopen("webserver_log", "w");
+  FILE *logfile = fopen("webserver_log", "w");
   fclose(logfile);
 
   // Change the current working directory to server root directory
-  if (chdir(path) == -1) {
+  if (chdir(path) == -1)
+  {
     perror("Directory Change error");
     return -2;
   }
@@ -345,37 +480,43 @@ int main(int argc, char **argv) {
   char threadName[16];
   // Create dispatcher threads (make detachable????)
   pthread_t dThreads[dispatchers];
-  for (int i=0; i<dispatchers; i++) {
+  for (int i = 0; i < dispatchers; i++)
+  {
     pthread_create(&dThreads[i], &attr, dispatch, NULL); // DEBUG! figure out last arg
     sprintf(threadName, "Dispatch %d", i);
     pthread_setname_np(dThreads[i], threadName);
   }
   //Create workers (make detachable?????)
   pthread_t wThreads[workers];
-  int* Wargs = malloc(sizeof(int)*workers);
-  for (int i = 0; i < workers; i++) {
-    Wargs[i]=i;
-    pthread_create(&wThreads[i], &attr, worker, (void *) &Wargs[i]); //TODO: Worker arguments
+  int *Wargs = malloc(sizeof(int) * workers);
+  for (int i = 0; i < workers; i++)
+  {
+    Wargs[i] = i;
+    pthread_create(&wThreads[i], &attr, worker, (void *)&Wargs[i]); //TODO: Worker arguments
     sprintf(threadName, "Worker %d", i);
     pthread_setname_np(wThreads[i], threadName);
-    }
+  }
   free(Wargs);
   // Create dynamic pool manager thread (extra credit A)
-  if (dynFlag) {
+  if (dynFlag)
+  {
     pthread_t pThread;
     pthread_create(&pThread, &attr, dynamic_pool_size_update, NULL); //TODO: possible arguments
     pthread_setname_np(pThread, "Pool Manager");
   }
- 
+
   //Server loop (RUNS FOREVER)
-  while (1) {
+  while (1)
+  {
     //TODO: Add something else?
     // Terminate server gracefully
-    if (exitFlag){
+    if (exitFlag)
+    {
       printf("\nSIGINT caught, exiting now.\n");
       // Print the number of pending requests in the request queue
       int pendReqs;
-      for (pendReqs = 0; pendReqs < qLen; pendReqs++) {
+      for (pendReqs = 0; pendReqs < qLen; pendReqs++)
+      {
         if (Q == NULL || Q->next == NULL)
           break;
       }