Initial revision

1 files changed, 67 insertions, 0 deletions

diff --git a/devio/open.h b/devio/open.h
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+/* Per-open information for devio.
+
+   Copyright (C) 1995 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#ifndef __OPEN_H__
+#define __OPEN_H__
+
+#include "iostate.h"
+
+/* ---------------------------------------------------------------- */
+
+/* A structure describing a particular i/o stream on this device.  */
+struct open
+{
+  /* Current state of our output stream -- location and the buffer used to do
+     buffered i/o.  */
+  struct io_state io_state;
+
+  /* The memory window we're using to do i/o.  This may be NULL, indicating
+     we're not doing buffered random access i/o.  */
+  struct window *window;
+
+  /* The device that this an open on.  */
+  struct dev *dev;
+};
+
+/* Returns a new per-open structure for the device DEV in OPEN.  If an error
+   occurs, the error-code is returned, otherwise 0.  */
+error_t open_create(struct dev *dev, struct open **open);
+
+/* Free OPEN and any resources it holds.  */
+void open_free(struct open *open);
+
+/* Returns the appropiate io_state object for OPEN (which may be either
+   per-open or a per-device depending on the device).  */
+struct io_state *open_get_io_state(struct open *open);
+
+/* Writes up to LEN bytes from BUF to OPEN's device at device offset OFFS
+   (which may be ignored if the device doesn't support random access),
+   and returns the number of bytes written in AMOUNT.  If no error occurs,
+   zero is returned, otherwise the error code is returned.  */
+error_t open_write(struct open *open, vm_address_t buf, vm_size_t len,
+		   vm_size_t *amount, off_t offs);
+
+/* Reads up to AMOUNT bytes from the device into BUF and BUF_LEN using the
+   standard mach out-array convention.  If no error occurs, zero is returned,
+   otherwise the error code is returned.  */
+error_t open_read(struct open *open, vm_address_t *buf, vm_size_t *buf_len,
+		  vm_size_t amount, off_t offs);
+
+#endif /* !__OPEN_H__ */