X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=src%2Ffilesys%2Fdirectory.c;h=0d265d5da78b7be2ca705a5a9b7eeacfbcd5dfd2;hb=96890516ba515537cae2d4b87df7412f5ad8c73f;hp=5f7dd9ed002ee0bf16582c5a65b80306a8c1832c;hpb=615bf3b3d2a8573ed6fb9ddc0055745e163ac999;p=pintos-anon

diff --git a/src/filesys/directory.c b/src/filesys/directory.c
index 5f7dd9e..0d265d5 100644
--- a/src/filesys/directory.c
+++ b/src/filesys/directory.c
@@ -10,6 +10,7 @@
 struct dir 
   {
     struct inode *inode;                /* Backing store. */
+    off_t pos;                          /* Current position. */
   };
 
 /* A single directory entry. */
@@ -28,37 +29,40 @@ dir_create (disk_sector_t sector, size_t entry_cnt)
   return inode_create (sector, entry_cnt * sizeof (struct dir_entry));
 }
 
-/* Opens the directory in the given INODE, of which it takes
-   ownership, and sets *DIRP to the new directory or a null
-   pointer on failure.  Return true if successful, false on
-   failure. */
-bool
-dir_open (struct inode *inode, struct dir **dirp) 
+/* Opens and returns the directory for the given INODE, of which
+   it takes ownership.  Returns a null pointer on failure. */
+struct dir *
+dir_open (struct inode *inode) 
 {
-  struct dir *dir = NULL;
-  
-  ASSERT (dirp != NULL);
-
-  if (inode != NULL) 
+  struct dir *dir = calloc (1, sizeof *dir);
+  if (inode != NULL && dir != NULL)
     {
-      dir = malloc (sizeof *dir);
-      if (dir != NULL) 
-        dir->inode = inode;
+      dir->inode = inode;
+      dir->pos = 0;
+      return dir;
+    }
+  else
+    {
+      inode_close (inode);
+      free (dir);
+      return NULL; 
     }
-  
-  *dirp = dir;
-  if (dir == NULL)
-    inode_close (inode);
-  return dir != NULL;
 }
 
-/* Opens the root directory and sets *DIRP to it or to a null
-   pointer on failure.  Return true if successful, false on
-   failure. */
-bool
-dir_open_root (struct dir **dirp)
+/* Opens the root directory and returns a directory for it.
+   Return true if successful, false on failure. */
+struct dir *
+dir_open_root (void)
+{
+  return dir_open (inode_open (ROOT_DIR_SECTOR));
+}
+
+/* Opens and returns a new directory for the same inode as DIR.
+   Returns a null pointer on failure. */
+struct dir *
+dir_reopen (struct dir *dir) 
 {
-  return dir_open (inode_open (ROOT_DIR_SECTOR), dirp);
+  return dir_open (inode_reopen (dir->inode));
 }
 
 /* Destroys DIR and frees associated resources. */
@@ -72,6 +76,13 @@ dir_close (struct dir *dir)
     }
 }
 
+/* Returns the inode encapsulated by DIR. */
+struct inode *
+dir_get_inode (struct dir *dir) 
+{
+  return dir->inode;
+}
+
 /* Searches DIR for a file with the given NAME.
    If successful, returns true, sets *EP to the directory entry
    if EP is non-null, and sets *OFSP to the byte offset of the
@@ -204,15 +215,22 @@ dir_remove (struct dir *dir, const char *name)
   return success;
 }
 
-/* Prints the names of the files in DIR to the system console. */
-void
-dir_list (const struct dir *dir)
+/* Reads the next directory entry in DIR and stores the name in
+   NAME.  Returns true if successful, false if the directory
+   contains no more entries. */
+bool
+dir_readdir (struct dir *dir, char name[NAME_MAX + 1])
 {
   struct dir_entry e;
-  size_t ofs;
-  
-  for (ofs = 0; inode_read_at (dir->inode, &e, sizeof e, ofs) == sizeof e;
-       ofs += sizeof e) 
-    if (e.in_use)
-      printf ("%s\n", e.name);
+
+  while (inode_read_at (dir->inode, &e, sizeof e, dir->pos) == sizeof e) 
+    {
+      dir->pos += sizeof e;
+      if (e.in_use)
+        {
+          strlcpy (name, e.name, NAME_MAX + 1);
+          return true;
+        } 
+    }
+  return false;
 }