Ian Cameron C Web Server

src/cache.c

@@ -12,6 +12,24 @@ struct cache_entry *alloc_entry(char *path, char *content_type, void *content, i
     ///////////////////
     // IMPLEMENT ME! //
     ///////////////////
+    //allocate space for the struct were going to return
+    struct cache_entry *ce = malloc(sizeof *ce);  //size of dereference ce if dereffed it is cache_entry
+    //set all fields to values being passed in to initialize
+    //have a pointer to something but have to make sure what you are pointing to persists(make sure it doesnt accidentally get freed)
+    ce->path = malloc(strlen(path) + 1); //so make a copy of path we know will persist. +1 for null terminator
+    strcpy(ce->path, path);  //(dest, args) copy path into allocated memory. this is deep copy.
+
+    ce->content_type = malloc(strlen(content_type) +1);
+    strcpy(ce->content_type, content_type);
+
+    ce->content = malloc(content_length); //content is void pointer so dont know what type so cant use strlen, but know its length so can use that 
+    memcpy(ce->content, content, content_length); //(dest, src, size)
+
+    ce->content_length = content_length;  //int so dont have to malloc 
+
+    ce->prev = ce->next = NULL;
+
+    return ce;
 }
 
 /**
@@ -22,6 +40,12 @@ void free_entry(struct cache_entry *entry)
     ///////////////////
     // IMPLEMENT ME! //
     ///////////////////
+    //have to free the cache entry passed in but have to free everything we malloc'ed space for
+    //free everything in stucture, then free the structure itself so entry last
+    free(entry->path);
+    free(entry->content_type);
+    free(entry->content);
+    free(entry);
 }
 
 /**
@@ -93,7 +117,19 @@ struct cache *cache_create(int max_size, int hashsize)
 {
     ///////////////////
     // IMPLEMENT ME! //
-    ///////////////////
+    ///////////////////  going in opposite order from cache free below. also refer to cache struct in cache.h
+    //allocate cache
+    struct cache *cache = malloc(sizeof *cache);
+    //functions in hashtable.h and c
+    cache->index = hashtable_create(hashsize, NULL); //size and pointer to a function (that takes in certain values and returns int)
+    //initialize head and tail null
+    cache->head = cache->tail = NULL;
+
+    cache->max_size = max_size; //int so dont allocate space
+
+    cache->cur_size = 0;   
+
+    return cache;
 }
 
 void cache_free(struct cache *cache)
@@ -113,6 +149,15 @@ void cache_free(struct cache *cache)
     free(cache);
 }
 
+void clean_lru(struct cache *cache)
+{
+    while (cache->cur_size > cache->max_size) {
+        struct cache_entry *oldtail = dllist_remove_tail(cache);
+
+        hashtable_delete(cache->index, oldtail->path);
+        free_entry(oldtail);
+    }
+}
 /**
  * Store an entry in the cache
  *
@@ -125,6 +170,26 @@ void cache_put(struct cache *cache, char *path, char *content_type, void *conten
     ///////////////////
     // IMPLEMENT ME! //
     ///////////////////
+    //Allocate a new cache entry with the passed parameters
+    struct cache_entry *ce = alloc_entry(path, content_type, content, content_length);
+    //Insert the entry at the head of the doubly-linked list
+    dllist_insert_head(cache, ce);
+    //Store the entry in the hashtable as well, indexed by the entry's path
+    hashtable_put(cache->index, ce->path, ce);
+    //Increment the current size of the cache
+    cache->cur_size++;
+    clean_lru(cache);
+    //If the cache size is greater than the max size
+    // if (cache->cur_size > cache->max_size) {
+    //     //Remove the cache entry at the tail of the linked list
+    //     dllist_remove_tail(ce);
+    //     //Remove that same entry from the hashtable, using the entry's path and the hashtable_delete function
+    //     hashtable_delete(ce->path, ce);
+    //     //Free the cache entry
+    //     cache_free(ce);
+    //     //Ensure the size counter for the number of entries in the cache is correct
+    //     cache->cur_size--;
+    // }
 }
 
 /**
@@ -135,4 +200,14 @@ struct cache_entry *cache_get(struct cache *cache, char *path)
     ///////////////////
     // IMPLEMENT ME! //
     ///////////////////
+    //Attempt to find the cache entry pointer by path in the hash table. If not found, return NULL
+    struct cache_entry *ce = hashtable_get(cache->index, path);
+
+    if (ce == NULL) {
+        return NULL;
+    }
+    //Move the cache entry to the head of the doubly-linked list
+    dllist_move_to_head(cache, ce);
+    //Return the cache entry pointer
+    return ce;
 }

src/cache.h

@@ -8,6 +8,8 @@ struct cache_entry {
     int content_length;
     void *content;
 
+    //time_t timestamp;  //added for comparison implementing cache get/put
+
     struct cache_entry *prev, *next; // Doubly-linked list
 };
 

src/cache_tests/cache_tests.c

@@ -63,7 +63,7 @@ char *test_cache_put()
   mu_assert(check_cache_entries(cache->head, test_entry_1) == 0, "Your cache_put function did not put an entry into the head of the empty cache with the expected form");
   mu_assert(check_cache_entries(cache->tail, test_entry_1) == 0, "Your cache_put function did not put an entry into the tail of the empty cache with the expected form");
   mu_assert(check_cache_entries(hashtable_get(cache->index, "/1"), test_entry_1) == 0, "Your cache_put function did not put the expected entry into the hashtable");
-
+  
   // Add in a second entry to the cache
   cache_put(cache, test_entry_2->path, test_entry_2->content_type, test_entry_2->content, test_entry_2->content_length);
   // Check that the cache is handling both entries as expected
@@ -72,7 +72,7 @@ char *test_cache_put()
   mu_assert(check_cache_entries(cache->tail, test_entry_1) == 0, "Your cache_put function did not move the oldest entry in the cache to the tail of the cache");
   mu_assert(check_cache_entries(cache->head->next, test_entry_1) == 0, "Your cache_put function did not correctly set the head->next pointer of the cache");
   mu_assert(check_cache_entries(hashtable_get(cache->index, "/2"), test_entry_2) == 0, "Your cache_put function did not put the expected entry into the hashtable");
-
+  
   // Add in a third entry to the cache
   cache_put(cache, test_entry_3->path, test_entry_3->content_type, test_entry_3->content, test_entry_3->content_length);
   // Check that the cache is handling all three entries as expected
@@ -83,7 +83,7 @@ char *test_cache_put()
   mu_assert(check_cache_entries(cache->head->next->next, test_entry_1) == 0, "Your cache_put function did not update the head->next->next pointer to point to the tail entry");
   mu_assert(check_cache_entries(cache->tail->prev, test_entry_2) == 0, "Your cache_put function did not update the tail->prev pointer to poin to the second-to-last entry");
   mu_assert(check_cache_entries(cache->tail, test_entry_1) == 0, "Your cache_put function did not correctly update the tail pointer of the cache"); 
-
+  
   // Add in a fourth entry to the cache
   cache_put(cache, test_entry_4->path, test_entry_4->content_type, test_entry_4->content, test_entry_4->content_length);
   // Check that the cache removed the oldest entry and is handling the three most-recent entries correctly
@@ -94,7 +94,7 @@ char *test_cache_put()
   mu_assert(check_cache_entries(cache->head->next->next, test_entry_2) == 0, "Your cache_put function did not update the head->next->next pointer to point to the tail entry");
   mu_assert(check_cache_entries(cache->tail->prev, test_entry_3) == 0, "Your cache_put function did not update the tail->prev pointer to poin to the second-to-last entry");
   mu_assert(check_cache_entries(cache->tail, test_entry_2) == 0, "Your cache_put function did not correctly handle the tail of an already-full cache");
-
+  
   cache_free(cache);
 
   return NULL;

src/server.c

@@ -52,16 +52,38 @@ int send_response(int fd, char *header, char *content_type, void *body, int cont
 {
     const int max_response_size = 262144;
     char response[max_response_size];
-
     // Build HTTP response and store it in response
 
     ///////////////////
     // IMPLEMENT ME! //
     ///////////////////
+    //time
+    time_t rawtime;
+    struct tm *info;
+    time (&rawtime);
+    info = localtime(&rawtime);
+
+    //build header
+    int response_length = snprintf(response, max_response_size,
+        "%s\n"
+        "Date: %s"  //asctime adds its own new line
+        "Content-Type: %s\n"
+        "Content-Length: %d\n"
+        "Connection: close\n"
+        "\n",
+        //"%s\n", //taking body off the response header and creating separate send
+        header, asctime(info), content_type, content_length //,body
+    );
 
     // Send it all!
     int rv = send(fd, response, response_length, 0);
 
+    if (rv < 0) {
+        perror("send");
+    }
+    //refactor this (creating another send) to accommodate png so send body (and its length) separately from the response so still only one request
+    rv = send(fd, body, content_length, 0);
+
     if (rv < 0) {
         perror("send");
     }
@@ -76,16 +98,18 @@ int send_response(int fd, char *header, char *content_type, void *body, int cont
 void get_d20(int fd)
 {
     // Generate a random number between 1 and 20 inclusive
-
     ///////////////////
     // IMPLEMENT ME! //
     ///////////////////
+    char str[4];
+    int random_number = rand() % 21; //num = (rand() % (upper – lower + 1)) + lower
+    sprintf(str, "%d\n", random_number);
 
     // Use send_response() to send it back as text/plain data
-
     ///////////////////
     // IMPLEMENT ME! //
     ///////////////////
+    send_response(fd, "HTTP/1.1 200 OK", "text/plain", str, strlen(str));
 }
 
 /**
@@ -122,6 +146,37 @@ void get_file(int fd, struct cache *cache, char *request_path)
     ///////////////////
     // IMPLEMENT ME! //
     ///////////////////
+    //read file
+    char filepath[4096];
+    struct file_data *filedata; //loads file into memory and returns pointer to data
+    char *mime_type;
+    //fetch file.  
+    //append path user requests (which != filepath) to server root (3490/index.html)
+    snprintf(filepath, sizeof filepath, "%s%s", SERVER_ROOT, request_path);  
+    printf("\"%s\"\n", filepath);
+
+    //time comparison for expiration of cache (implemented with cache put/get)
+    struct cache_entry *ce = cache_get(cache, filepath);
+    //expire then refresh file and delete item out of cache (eg if cur time less that time greater than 1min)
+    if (time(NULL) - ce->timestamp > 60) { //timestamp decl in struct cache_entry in cache.h so know when it was created
+
+    }
+
+    //load that file
+    filedata = file_load(filepath);
+    //if file not found
+    if (filedata == NULL) 
+        {
+            resp_404(fd);
+            return;
+        }
+    //get mimetype
+    mime_type = mime_type_get(filepath);
+    printf("%s\n", mime_type);
+    //send file out
+    send_response(fd, "HTTP/1.1 200 OK", mime_type, filedata->data, filedata->size);
+    //then free data bc loaded these data into memory
+    file_free(filedata);
 }
 
 /**
@@ -130,18 +185,20 @@ void get_file(int fd, struct cache *cache, char *request_path)
  * "Newlines" in HTTP can be \r\n (carriage return followed by newline) or \n
  * (newline) or \r (carriage return).
  */
-char *find_start_of_body(char *header)
-{
-    ///////////////////
-    // IMPLEMENT ME! // (Stretch)
-    ///////////////////
-}
+// char *find_start_of_body(char *header)
+// {
+//     ///////////////////
+//     // IMPLEMENT ME! // (Stretch)
+//     ///////////////////
+//     (void)header;
+// }
 
 /**
  * Handle HTTP request and send response
  */
 void handle_http_request(int fd, struct cache *cache)
 {
+    (void)cache;  //rememember to remove all these voids.  reeeeeeeeemember!
     const int request_buffer_size = 65536; // 64K
     char request[request_buffer_size];
 
@@ -153,20 +210,32 @@ void handle_http_request(int fd, struct cache *cache)
         return;
     }
 
-
     ///////////////////
     // IMPLEMENT ME! //
     ///////////////////
-
     // Read the three components of the first request line
+    char method[512];
+    char path[8192];
+
+    sscanf(request, "%s %s", method, path);
+    printf("method: \"%s\"\n", method);
+    printf("path: \"%s\"\n", path);
 
     // If GET, handle the get endpoints
 
     //    Check if it's /d20 and handle that special case
     //    Otherwise serve the requested file by calling get_file()
-
-
+    if (strcmp(method, "GET") == 0) {
+        if (strcmp(path, "/d20") == 0) {  //strcmp returns 0 if equal
+            get_d20(fd);
+        } else {
+            get_file(fd, NULL, path);
+            //resp_404(fd);  //used 404 before completing get_file
+        }
+    }
+
     // (Stretch) If POST, handle the post request
+    //if (strcmp(method, "POST") == 0)
 }
 
 /**