source: mainline/uspace/lib/c/generic/private/stdio.h@ 52acfab

/*
 * Copyright (c) 2011 Martin Decky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libc
 * @{
 */
/** @file
 */

#ifndef _LIBC_PRIVATE_STDIO_H_
#define _LIBC_PRIVATE_STDIO_H_

#include <adt/list.h>
#include <stdio.h>
#include <async.h>
#include <stddef.h>
#include <offset.h>

/** Maximum characters that can be pushed back by ungetc() */
#define UNGETC_MAX 1

/** Stream operations */
typedef struct {
        /** Read from stream */
        size_t (*read)(void *buf, size_t size, size_t nmemb, FILE *stream);
        /** Write to stream */
        size_t (*write)(const void *buf, size_t size, size_t nmemb,
            FILE *stream);
        /** Flush stream */
        int (*flush)(FILE *stream);
} __stream_ops_t;

enum __buffer_state {
        /** Buffer is empty */
        _bs_empty,

        /** Buffer contains data to be written */
        _bs_write,

        /** Buffer contains prefetched data for reading */
        _bs_read
};

struct _IO_FILE {
        /** Linked list pointer. */
        link_t link;

        /** Stream operations */
        __stream_ops_t *ops;

        /** Underlying file descriptor. */
        int fd;

        /** Instance argument */
        void *arg;

        /** File position. */
        aoff64_t pos;

        /** Error indicator. */
        int error;

        /** End-of-file indicator. */
        int eof;

        /** Session to the file provider */
        async_sess_t *sess;

        /**
         * Non-zero if the stream needs sync on fflush(). XXX change
         * console semantics so that sync is not needed.
         */
        int need_sync;

        /** Buffering type */
        enum __buffer_type btype;

        /** Buffer */
        uint8_t *buf;

        /** Buffer size */
        size_t buf_size;

        /** Buffer state */
        enum __buffer_state buf_state;

        /** Buffer I/O pointer */
        uint8_t *buf_head;

        /** Points to end of occupied space when in read mode. */
        uint8_t *buf_tail;

        /** Pushed back characters */
        uint8_t ungetc_buf[UNGETC_MAX];

        /** Number of pushed back characters */
        int ungetc_chars;
};

#endif

/** @}
 */