Initial checkin

1 files changed, 68 insertions, 0 deletions

diff --git a/storeio/open.h b/storeio/open.h
new file mode 100644
index 00000000..efb2128d
--- /dev/null
+++ b/storeio/open.h
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+/* Per-open information for storeio
+
+   Copyright (C) 1995, 1996 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 "dev.h"
+
+/* ---------------------------------------------------------------- */
+
+/* A structure describing a particular i/o stream on this device.  */
+struct open
+{
+  /* The device that this an open on.  */
+  struct dev *dev;
+
+  /* The per-open offset used for I/O operations that don't specify an
+     explicit offset.  */
+  off_t offs;
+
+  /* A lock used to control write access to OFFS.  */
+  struct mutex lock;
+};
+
+/* 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);
+
+/* 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, off_t offs, char *buf, size_t len,
+		    size_t *amount);
+
+/* 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, off_t offs, size_t amount,
+		   char **buf, size_t *buf_len);
+
+/* Set OPEN's location to OFFS, interpreted according to WHENCE as by seek.
+   The new absolute location is returned in NEW_OFFS (and may not be the same
+   as OFFS).  If no error occurs, zero is returned, otherwise the error code
+   is returned.  */
+error_t open_seek (struct open *open, off_t offs, int whence, off_t *new_offs);
+
+#endif /* !__OPEN_H__ */