-#include "file.h"
-#include "debug.h"
-#include "lib.h"
-#include "malloc.h"
-#include "directory.h"
-#include "filehdr.h"
-#include "filesys.h"
-
-bool
-file_open (struct file *file, disk_sector_no hdr_sector)
+#include "filesys/file.h"
+#include <debug.h>
+#include <string.h>
+#include "filesys/directory.h"
+#include "filesys/inode.h"
+#include "filesys/filesys.h"
+#include "threads/malloc.h"
+
+/* An open file. */
+struct file
+ {
+ struct inode *inode; /* File's inode. */
+ uint8_t *bounce; /* Bounce buffer for reads and writes. */
+ off_t pos; /* Current position. */
+ };
+
+/* Opens and returns the file whose inode is in sector
+ INODE_SECTOR. Returns a null pointer if unsuccessful. */
+struct file *
+file_open (disk_sector_t inode_sector)
{
- file->hdr = filehdr_read (hdr_sector);
+ struct file *file = calloc (1, sizeof *file);
+ if (file == NULL)
+ return NULL;
+
+ file->inode = inode_open (inode_sector);
file->bounce = malloc (DISK_SECTOR_SIZE);
file->pos = 0;
- if (file->hdr != NULL && file->bounce != NULL)
- return true;
- else
+ if (file->inode == NULL || file->bounce == NULL)
{
- filehdr_destroy (file->hdr);
+ inode_close (file->inode);
free (file->bounce);
- return false;
+ return NULL;
}
+
+ return file;
}
+/* Closes FILE. */
void
file_close (struct file *file)
{
- filehdr_destroy (file->hdr);
+ if (file == NULL)
+ return;
+
+ inode_close (file->inode);
+ free (file->bounce);
}
+/* Reads SIZE bytes from FILE into BUFFER,
+ starting at the file's current position,
+ and advances the current position.
+ Returns the number of bytes actually read,
+ which may be less than SIZE if end of file is reached. */
off_t
file_read (struct file *file, void *buffer, off_t size)
{
return bytes_read;
}
+/* Reads SIZE bytes from FILE into BUFFER,
+ starting at offset FILE_OFS in the file.
+ The file's current position is unaffected
+ Returns the number of bytes actually read,
+ which may be less than SIZE if end of file is reached. */
off_t
file_read_at (struct file *file, void *buffer_, off_t size,
off_t file_ofs)
while (size > 0)
{
/* Disk sector to read, starting byte offset within sector. */
- off_t sector_idx = filehdr_byte_to_sector (file->hdr, file_ofs);
+ disk_sector_t sector_idx;
int sector_ofs = file_ofs % DISK_SECTOR_SIZE;
/* Bytes left in file, bytes left in sector, lesser of the two. */
- off_t file_left = filehdr_length (file->hdr) - file_ofs;
+ off_t file_left = inode_length (file->inode) - file_ofs;
int sector_left = DISK_SECTOR_SIZE - sector_ofs;
int min_left = file_left < sector_left ? file_left : sector_left;
/* Number of bytes to actually copy out of this sector. */
int chunk_size = size < min_left ? size : min_left;
- if (chunk_size == 0)
+ if (chunk_size <= 0)
break;
/* Read sector into bounce buffer, then copy into caller's
buffer. */
+ sector_idx = inode_byte_to_sector (file->inode, file_ofs);
disk_read (filesys_disk, sector_idx, file->bounce);
memcpy (buffer + bytes_read, file->bounce + sector_ofs, chunk_size);
return bytes_read;
}
+/* Writes SIZE bytes from BUFFER into FILE,
+ starting at the file's current position,
+ and advances the current position.
+ Returns the number of bytes actually written,
+ which may be less than SIZE if end of file is reached.
+ (Normally we'd grow the file in that case, but file growth is
+ not yet implemented.) */
off_t
file_write (struct file *file, const void *buffer, off_t size)
{
return bytes_written;
}
+/* Writes SIZE bytes from BUFFER into FILE,
+ starting at offset FILE_OFS in the file.
+ The file's current position is unaffected
+ Returns the number of bytes actually written,
+ which may be less than SIZE if end of file is reached.
+ (Normally we'd grow the file in that case, but file growth is
+ not yet implemented.) */
off_t
file_write_at (struct file *file, const void *buffer_, off_t size,
off_t file_ofs)
while (size > 0)
{
- /* Starting byte offset within sector to read. */
- off_t sector_idx = filehdr_byte_to_sector (file->hdr, file_ofs);
+ /* Sector to write, starting byte offset within sector. */
+ off_t sector_idx;
int sector_ofs = file_ofs % DISK_SECTOR_SIZE;
/* Bytes left in file, bytes left in sector, lesser of the two. */
- off_t file_left = filehdr_length (file->hdr) - file_ofs;
+ off_t file_left = inode_length (file->inode) - file_ofs;
int sector_left = DISK_SECTOR_SIZE - sector_ofs;
int min_left = file_left < sector_left ? file_left : sector_left;
- /* Number of bytes to actually writen into this sector. */
+ /* Number of bytes to actually write into this sector. */
int chunk_size = size < min_left ? size : min_left;
- if (chunk_size == 0)
+ if (chunk_size <= 0)
break;
/* If the sector contains data before or after the chunk
we're writing, then we need to read in the sector
first. Otherwise we start with a sector of all zeros. */
- if (sector_ofs > 0 || chunk_size < sector_ofs)
+ sector_idx = inode_byte_to_sector (file->inode, file_ofs);
+ if (sector_ofs > 0 || chunk_size < sector_left)
disk_read (filesys_disk, sector_idx, file->bounce);
else
memset (file->bounce, 0, DISK_SECTOR_SIZE);
file_ofs += chunk_size;
bytes_written += chunk_size;
}
- free (file->bounce);
return bytes_written;
}
+/* Returns the size of FILE in bytes. */
off_t
file_length (struct file *file)
{
ASSERT (file != NULL);
- return filehdr_length (file->hdr);
+ return inode_length (file->inode);
}
+/* Sets the current position in FILE to an offset of FILE_OFS
+ bytes from the start of the file. */
void
file_seek (struct file *file, off_t file_ofs)
{
file->pos = file_ofs;
}
+/* Returns the current position in FILE as a byte offset from the
+ start of the file. */
off_t
file_tell (struct file *file)
{
projects / pintos-anon / blobdiff