File hashing (not finished)

src/file_p.c

@@ -1,4 +1,5 @@
 #include "file_p.h"
+#include "libs/murmur3/murmur3.h"
 #include "main.h"
 #include "session.h"
 #include <arpa/inet.h>
@@ -12,6 +13,7 @@
 #include <sys/mman.h>
 #include <sys/select.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
 #include <sys/statvfs.h>
 #include <sys/syslog.h>
 #include <sys/types.h>
@@ -44,7 +46,7 @@ void file_list(session *sess, server_data_t *s_d) {
         full_str[i] = '\a';
       }
     }
-    write(sess->sd, full_str, f_len-1); // -1 : do not include \0
+    write(sess->sd, full_str, f_len - 1); // -1 : do not include \0
     free(full_str);
   } while ((current = current->next) != NULL);
   write(sess->sd, list_end, sizeof(list_end));
@@ -84,6 +86,25 @@ int file_send_prepare(session *sess, char *line, server_data_t *s_d) {
   return 0;
 }
 
+int directory_exists(const char *path) {
+  struct stat info;
+
+  if (stat(path, &info) != 0) {
+    // stat() failed, probably doesn't exist
+    return 0;
+  }
+  return S_ISDIR(info.st_mode); // true if it's a directory
+}
+
+void extract_names_from_hash(uint32_t file_hash, char *dirname, char *fname) {
+  char hashed_full_name[9];
+  sprintf(hashed_full_name, "%08x", file_hash);
+  strncpy(dirname, hashed_full_name, 2);
+  strncpy(fname, hashed_full_name + 2, 6);
+  dirname[2] = 0;
+  fname[6] = 0;
+}
+
 int file_receive_prepare(session *sess, char *line, server_data_t *s_d) {
   int sd = sess->sd;
   char fname[64];
@@ -93,8 +114,6 @@ int file_receive_prepare(session *sess, char *line, server_data_t *s_d) {
   sess->fname = malloc(sizeof(char) * strlen(fname));
   sess->f_perm = (char)perm;
   strncpy(sess->fname, fname, strlen(fname) - 1); // remove the last \"
-  sess->fpath = malloc(strlen(sess->fname) + sizeof(STORAGE_FOLDER) + 2);
-  sprintf(sess->fpath, "%s/%s", STORAGE_FOLDER, sess->fname);
 
   char mes[256];
   char mes_len = 0;
@@ -114,19 +133,43 @@ int file_receive_prepare(session *sess, char *line, server_data_t *s_d) {
     clear_file_from_sess(sess);
     return -1;
   }
-  int file_d = open(sess->fpath, O_WRONLY | O_CREAT | O_EXCL, 0666);
-  if (file_d == -1) {
-    if (errno == EEXIST) {
-      mes_len =
-          sprintf(mes, "File with name \"%s\" is already exist\n", sess->fname);
+
+  char hashed_dir_name[3];
+  char hashed_name[7];
+  int seed = FILE_HASH_SEED;
+  int file_d;
+
+  for (;;) {
+    MurmurHash3_x86_32(sess->fname, strlen(sess->fname), FILE_HASH_SEED,
+                       &(sess->hash));
+
+    extract_names_from_hash(sess->hash, hashed_dir_name, hashed_name);
+
+    sess->fpath = malloc(sizeof(STORAGE_FOLDER) + 2 + 9);
+    sprintf(sess->fpath, "%s/%s/%s", STORAGE_FOLDER, hashed_dir_name,
+            hashed_name);
+
+    if (!directory_exists(hashed_dir_name)) {
+      mkdir(hashed_dir_name, 0700);
+    }
+    chdir(hashed_dir_name);
+
+    file_d = open(sess->fpath, O_WRONLY | O_CREAT | O_EXCL, 0666);
+    if (file_d == -1) {
+      if (errno == EEXIST) {
+        seed++;
+        free(sess->fpath);
+        sess->fpath = NULL;
+        continue;
+      }
+      mes_len = sprintf(mes, "Can't create file with such name: \"%s\"\n",
+                        sess->fname);
       write(sd, mes, mes_len);
+      clear_file_from_sess(sess);
+      return -1;
     }
-    mes_len =
-        sprintf(mes, "Can't create file with such name: \"%s\"\n", sess->fname);
-    write(sd, mes, mes_len);
-    clear_file_from_sess(sess);
-    return -1;
   }
+
   mes_len = sprintf(mes, "accept");
   sess->fd = file_d;
   sess->fsize = fsize;
@@ -257,19 +300,19 @@ void get_files_descriptions(server_data_t *s_d) {
 
       /* file name */
       sscanf(buf_pos, "%s\n", tmp);
-      buf_pos += strlen(tmp)+1;
+      buf_pos += strlen(tmp) + 1;
       fl_item->name = malloc(sizeof(char) * (strlen(tmp) + 1));
-      strcpy(fl_item->name,tmp);
+      strcpy(fl_item->name, tmp);
 
       /* file owner */
       sscanf(buf_pos, "%s\n", tmp);
-      buf_pos += strlen(tmp)+1;
+      buf_pos += strlen(tmp) + 1;
       fl_item->owner = malloc(sizeof(char) * (strlen(tmp) + 1));
       strcpy(fl_item->owner, tmp);
 
       /* file permissions */
       sscanf(buf_pos, "%s\n", tmp);
-      buf_pos += strlen(tmp)+1;
+      buf_pos += strlen(tmp) + 1;
       fl_item->permissions = atoi(tmp);
 
       /* file size */