Working filesystem.

[pintos-anon] / src / filesys / directory.c

diff --git a/src/filesys/directory.c b/src/filesys/directory.c
new file mode 100644 (file)
index 0000000..43f87f0
--- /dev/null
+++ b/src/filesys/directory.c
@@ -0,0 +1,120 @@
+#include "directory.h"
+#include "file.h"
+#include "lib.h"
+#include "malloc.h"
+
+bool
+dir_init (struct dir *d, size_t entry_cnt) 
+{
+  d->entry_cnt = entry_cnt;
+  d->entries = calloc (1, sizeof *d->entries * entry_cnt);
+  return d->entries != NULL;
+}
+
+void
+dir_destroy (struct dir *d) 
+{
+  free (d->entries);
+}
+
+static off_t
+dir_size (struct dir *d) 
+{
+  return d->entry_cnt * sizeof *d->entries;
+}
+
+void
+dir_read (struct dir *d, struct file *file) 
+{
+  file_read_at (file, d->entries, dir_size (d), 0);
+}
+
+void
+dir_write (struct dir *d, struct file *file) 
+{
+  file_write_at (file, d->entries, dir_size (d), 0);
+}
+
+static struct dir_entry *
+lookup (const struct dir *d, const char *name) 
+{
+  size_t i;
+  
+  ASSERT (d != NULL);
+  ASSERT (name != NULL);
+
+  if (strlen (name) > FILENAME_LEN_MAX)
+    return NULL;
+
+  for (i = 0; i < d->entry_cnt; i++) 
+    {
+      struct dir_entry *e = &d->entries[i];
+      if (e->in_use && !strcmp (name, e->name))
+        return e;
+    }
+  return NULL;
+}
+
+bool
+dir_lookup (const struct dir *d, const char *name,
+            disk_sector_no *filehdr_sector) 
+{
+  const struct dir_entry *e;
+
+  ASSERT (d != NULL);
+  ASSERT (name != NULL);
+  
+  e = lookup (d, name);
+  if (e != NULL) 
+    {
+      if (filehdr_sector != NULL)
+        *filehdr_sector = e->filehdr_sector;
+      return true;
+    }
+  else
+    return false;
+}
+
+bool
+dir_add (struct dir *d, const char *name, disk_sector_no filehdr_sector) 
+{
+  size_t i;
+  
+  ASSERT (d != NULL);
+  ASSERT (name != NULL);
+  ASSERT (lookup (d, name) == NULL);
+
+  for (i = 0; i < d->entry_cnt; i++)
+    {
+      struct dir_entry *e = &d->entries[i];
+      if (!e->in_use) 
+        {
+          e->in_use = true;
+          strlcpy (e->name, name, sizeof e->name);
+          e->filehdr_sector = filehdr_sector;
+          return true;
+        }
+    }
+  return false;
+}
+
+bool
+dir_remove (struct dir *d, const char *name) 
+{
+  struct dir_entry *e;
+
+  ASSERT (d != NULL);
+  ASSERT (name != NULL);
+
+  e = lookup (d, name);
+  if (e != NULL) 
+    {
+      e->in_use = false;
+      return true;
+    }
+  else
+    return false;
+}
+
+void dir_list (const struct dir *);
+void dir_print (const struct dir *);