Working filesystem.

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

diff --git a/src/filesys/filehdr.c b/src/filesys/filehdr.c
new file mode 100644 (file)
index 0000000..aad11e5
--- /dev/null
+++ b/src/filesys/filehdr.c
@@ -0,0 +1,94 @@
+#include "filehdr.h"
+#include "bitmap.h"
+#include "debug.h"
+#include "malloc.h"
+#include "filesys.h"
+#include "lib.h"
+
+struct filehdr *
+filehdr_allocate (struct bitmap *b, off_t length) 
+{
+  struct filehdr *h;
+  size_t sector_cnt;
+
+  ASSERT (b != NULL);
+  ASSERT (length >= 0);
+
+  h = calloc (1, sizeof *h);
+  if (h == NULL)
+    return NULL;
+
+  h->length = length;
+  sector_cnt = (length / DISK_SECTOR_SIZE) + (length % DISK_SECTOR_SIZE > 0);
+  while (h->sector_cnt < sector_cnt)
+    {
+      size_t sector = bitmap_find_and_set (b);
+      if (sector == BITMAP_ERROR)
+        {
+          filehdr_deallocate (h, b);
+          return NULL;
+        }
+      h->sectors[h->sector_cnt++] = sector;
+    }
+
+  return h;
+}
+
+void
+filehdr_deallocate (struct filehdr *h, struct bitmap *b) 
+{
+  size_t i;
+  
+  ASSERT (h != NULL);
+  ASSERT (b != NULL);
+
+  for (i = 0; i < h->sector_cnt; i++)
+    bitmap_reset (b, h->sectors[i]);
+}
+
+struct filehdr *
+filehdr_read (disk_sector_no filehdr_sector) 
+{
+  struct filehdr *h = calloc (1, sizeof *h);
+  if (h == NULL)
+    return NULL;
+
+  ASSERT (sizeof *h == DISK_SECTOR_SIZE);
+  disk_read (filesys_disk, filehdr_sector, h);
+
+  return h;
+}
+
+void
+filehdr_write (const struct filehdr *h, disk_sector_no filehdr_sector) 
+{
+  ASSERT (h != NULL);
+  ASSERT (sizeof *h == DISK_SECTOR_SIZE);
+  disk_write (filesys_disk, filehdr_sector, h);
+}
+
+void
+filehdr_destroy (struct filehdr *h) 
+{
+  free (h);
+}
+
+disk_sector_no
+filehdr_byte_to_sector (const struct filehdr *h, off_t pos) 
+{
+  size_t idx;
+
+  ASSERT (h != NULL);
+
+  idx = pos / DISK_SECTOR_SIZE;
+  return idx < h->sector_cnt ? h->sectors[idx] : (disk_sector_no) -1;
+}
+
+off_t
+filehdr_length (const struct filehdr *h)
+{
+  ASSERT (h != NULL);
+  return h->length;
+}
+
+void filehdr_print (const struct filehdr *);