source: mainline/uspace/lib/libc/generic/io/io.c@ ef8bcc6

/*
 * Copyright (c) 2005 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
 */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <assert.h>
#include <string.h>
#include <errno.h>
#include <bool.h>
#include <malloc.h>
#include <io/klog.h>
#include <vfs/vfs.h>
#include <ipc/devmap.h>
#include <adt/list.h>

static void _fflushbuf(FILE *stream);

static FILE stdin_null = {
        .fd = -1,
        .error = true,
        .eof = true,
        .klog = false,
        .phone = -1,
        .btype = _IONBF,
        .buf = NULL,
        .buf_size = 0,
        .buf_head = NULL
};

static FILE stdout_klog = {
        .fd = -1,
        .error = false,
        .eof = false,
        .klog = true,
        .phone = -1,
        .btype = _IOLBF,
        .buf = NULL,
        .buf_size = BUFSIZ,
        .buf_head = NULL
};

static FILE stderr_klog = {
        .fd = -1,
        .error = false,
        .eof = false,
        .klog = true,
        .phone = -1,
        .btype = _IONBF,
        .buf = NULL,
        .buf_size = 0,
        .buf_head = NULL
};

FILE *stdin = NULL;
FILE *stdout = NULL;
FILE *stderr = NULL;

static LIST_INITIALIZE(files);

void stdio_init(int filc, fdi_node_t *filv[])
{
        if (filc > 0) {
                stdin = fopen_node(filv[0], "r");
        } else {
                stdin = &stdin_null;
                list_append(&stdin->link, &files);
        }
        
        if (filc > 1) {
                stdout = fopen_node(filv[1], "w");
        } else {
                stdout = &stdout_klog;
                list_append(&stdout->link, &files);
        }
        
        if (filc > 2) {
                stderr = fopen_node(filv[2], "w");
        } else {
                stderr = &stderr_klog;
                list_append(&stderr->link, &files);
        }
}

void stdio_done(void)
{
        link_t *link = files.next;
        
        while (link != &files) {
                FILE *file = list_get_instance(link, FILE, link);
                fclose(file);
                link = files.next;
        }
}

static bool parse_mode(const char *mode, int *flags)
{
        /* Parse mode except first character. */
        const char *mp = mode;
        if (*mp++ == 0) {
                errno = EINVAL;
                return false;
        }
        
        if ((*mp == 'b') || (*mp == 't'))
                mp++;
        
        bool plus;
        if (*mp == '+') {
                mp++;
                plus = true;
        } else
                plus = false;
        
        if (*mp != 0) {
                errno = EINVAL;
                return false;
        }
        
        /* Parse first character of mode and determine flags for open(). */
        switch (mode[0]) {
        case 'r':
                *flags = plus ? O_RDWR : O_RDONLY;
                break;
        case 'w':
                *flags = (O_TRUNC | O_CREAT) | (plus ? O_RDWR : O_WRONLY);
                break;
        case 'a':
                /* TODO: a+ must read from beginning, append to the end. */
                if (plus) {
                        errno = ENOTSUP;
                        return false;
                }
                *flags = (O_APPEND | O_CREAT) | (plus ? O_RDWR : O_WRONLY);
        default:
                errno = EINVAL;
                return false;
        }
        
        return true;
}

/** Set stream buffer. */
void setvbuf(FILE *stream, void *buf, int mode, size_t size)
{
        stream->btype = mode;
        stream->buf = buf;
        stream->buf_size = size;
        stream->buf_head = stream->buf;
}

/** Allocate stream buffer. */
static int _fallocbuf(FILE *stream)
{
        assert(stream->buf == NULL);

        stream->buf = malloc(stream->buf_size);
        if (stream->buf == NULL) {
                errno = ENOMEM;
                return -1;
        }

        stream->buf_head = stream->buf;
        return 0;
}

/** Open a stream.
 *
 * @param path Path of the file to open.
 * @param mode Mode string, (r|w|a)[b|t][+].
 *
 */
FILE *fopen(const char *path, const char *mode)
{
        int flags;
        if (!parse_mode(mode, &flags))
                return NULL;
        
        /* Open file. */
        FILE *stream = malloc(sizeof(FILE));
        if (stream == NULL) {
                errno = ENOMEM;
                return NULL;
        }
        
        stream->fd = open(path, flags, 0666);
        if (stream->fd < 0) {
                /* errno was set by open() */
                free(stream);
                return NULL;
        }
        
        stream->error = false;
        stream->eof = false;
        stream->klog = false;
        stream->phone = -1;

        /* FIXME: Should select buffering type based on what was opened. */
        setvbuf(stream, NULL, _IOFBF, BUFSIZ);
        
        list_append(&stream->link, &files);
        
        return stream;
}

FILE *fdopen(int fd, const char *mode)
{
        /* Open file. */
        FILE *stream = malloc(sizeof(FILE));
        if (stream == NULL) {
                errno = ENOMEM;
                return NULL;
        }
        
        stream->fd = fd;
        stream->error = false;
        stream->eof = false;
        stream->klog = false;
        stream->phone = -1;

        /* FIXME: Should select buffering type based on what was opened. */
        setvbuf(stream, NULL, _IOLBF, BUFSIZ);
        
        list_append(&stream->link, &files);
        
        return stream;
}

FILE *fopen_node(fdi_node_t *node, const char *mode)
{
        int flags;
        if (!parse_mode(mode, &flags))
                return NULL;
        
        /* Open file. */
        FILE *stream = malloc(sizeof(FILE));
        if (stream == NULL) {
                errno = ENOMEM;
                return NULL;
        }
        
        stream->fd = open_node(node, flags);
        if (stream->fd < 0) {
                /* errno was set by open_node() */
                free(stream);
                return NULL;
        }
        
        stream->error = false;
        stream->eof = false;
        stream->klog = false;
        stream->phone = -1;

        /* FIXME: Should select buffering type based on what was opened. */
        setvbuf(stream, NULL, _IOLBF, BUFSIZ);
        
        list_append(&stream->link, &files);
        
        return stream;
}

int fclose(FILE *stream)
{
        int rc = 0;
        
        fflush(stream);
        
        if (stream->phone >= 0)
                ipc_hangup(stream->phone);
        
        if (stream->fd >= 0)
                rc = close(stream->fd);
        
        list_remove(&stream->link);
        
        if ((stream != &stdin_null)
            && (stream != &stdout_klog)
            && (stream != &stderr_klog))
                free(stream);
        
        stream = NULL;
        
        if (rc != 0) {
                /* errno was set by close() */
                return EOF;
        }
        
        return 0;
}

/** Read from a stream.
 *
 * @param buf    Destination buffer.
 * @param size   Size of each record.
 * @param nmemb  Number of records to read.
 * @param stream Pointer to the stream.
 *
 */
size_t fread(void *buf, size_t size, size_t nmemb, FILE *stream)
{
        size_t left = size * nmemb;
        size_t done = 0;

        /* Make sure no data is pending write. */
        _fflushbuf(stream);

        while ((left > 0) && (!stream->error) && (!stream->eof)) {
                ssize_t rd = read(stream->fd, buf + done, left);
                
                if (rd < 0)
                        stream->error = true;
                else if (rd == 0)
                        stream->eof = true;
                else {
                        left -= rd;
                        done += rd;
                }
        }
        
        return (done / size);
}

static size_t _fwrite(const void *buf, size_t size, size_t nmemb, FILE *stream)
{
        size_t left = size * nmemb;
        size_t done = 0;
        
        while ((left > 0) && (!stream->error)) {
                ssize_t wr;
                
                if (stream->klog)
                        wr = klog_write(buf + done, left);
                else
                        wr = write(stream->fd, buf + done, left);
                
                if (wr <= 0)
                        stream->error = true;
                else {
                        left -= wr;
                        done += wr;
                }
        }
        
        return (done / size);
}

/** Drain stream buffer, do not sync stream. */
static void _fflushbuf(FILE *stream)
{
        size_t bytes_used;

        if (!stream->buf || stream->btype == _IONBF || stream->error)
                return;

        bytes_used = stream->buf_head - stream->buf;
        if (bytes_used == 0)
                return;

        (void) _fwrite(stream->buf, 1, bytes_used, stream);
        stream->buf_head = stream->buf;
}

/** Write to a stream.
 *
 * @param buf    Source buffer.
 * @param size   Size of each record.
 * @param nmemb  Number of records to write.
 * @param stream Pointer to the stream.
 *
 */
size_t fwrite(const void *buf, size_t size, size_t nmemb, FILE *stream)
{
        uint8_t *data;
        size_t bytes_left;
        size_t now;
        size_t buf_free;
        size_t total_written;
        size_t i;
        uint8_t b;
        bool need_flush;

        /* If not buffered stream, write out directly. */
        if (stream->btype == _IONBF)
                return _fwrite(buf, size, nmemb, stream);

        /* Perform lazy allocation of stream buffer. */
        if (stream->buf == NULL) {
                if (_fallocbuf(stream) != 0)
                        return 0; /* Errno set by _fallocbuf(). */
        }

        data = (uint8_t *) buf;
        bytes_left = size * nmemb;
        total_written = 0;
        need_flush = false;

        while (!stream->error && bytes_left > 0) {

                buf_free = stream->buf_size - (stream->buf_head - stream->buf);
                if (bytes_left > buf_free)
                        now = buf_free;
                else
                        now = bytes_left;

                for (i = 0; i < now; i++) {
                        b = data[i];
                        stream->buf_head[i] = b;

                        if (b == '\n' && stream->btype == _IOLBF)
                                need_flush = true;
                }

                buf += now;
                stream->buf_head += now;
                buf_free -= now;
                bytes_left -= now;
                total_written += now;

                if (buf_free == 0) {
                        /* Only need to drain buffer. */
                        _fflushbuf(stream);
                        need_flush = false;
                }
        }

        if (need_flush)
                fflush(stream);

        return (total_written / size);
}

int fputc(wchar_t c, FILE *stream)
{
        char buf[STR_BOUNDS(1)];
        size_t sz = 0;
        
        if (chr_encode(c, buf, &sz, STR_BOUNDS(1)) == EOK) {
                size_t wr = fwrite(buf, sz, 1, stream);
                
                if (wr < sz)
                        return EOF;
                
                return (int) c;
        }
        
        return EOF;
}

int putchar(wchar_t c)
{
        return fputc(c, stdout);
}

int fputs(const char *str, FILE *stream)
{
        return fwrite(str, str_size(str), 1, stream);
}

int puts(const char *str)
{
        return fputs(str, stdout);
}

int fgetc(FILE *stream)
{
        char c;

        /* This could be made faster by only flushing when needed. */
        if (stdout)
                fflush(stdout);
        if (stderr)
                fflush(stderr);

        if (fread(&c, sizeof(char), 1, stream) < sizeof(char))
                return EOF;
        
        return (int) c;
}

int getchar(void)
{
        return fgetc(stdin);
}

int fseek(FILE *stream, long offset, int origin)
{
        off_t rc = lseek(stream->fd, offset, origin);
        if (rc == (off_t) (-1)) {
                /* errno has been set by lseek. */
                return -1;
        }
        
        stream->eof = false;
        
        return 0;
}

void rewind(FILE *stream)
{
        (void) fseek(stream, 0, SEEK_SET);
}

int fflush(FILE *stream)
{
        _fflushbuf(stream);

        if (stream->klog) {
                klog_update();
                return EOK;
        }
        
        if (stream->fd >= 0)
                return fsync(stream->fd);
        
        return ENOENT;
}

int feof(FILE *stream)
{
        return stream->eof;
}

int ferror(FILE *stream)
{
        return stream->error;
}

int fphone(FILE *stream)
{
        if (stream->fd >= 0) {
                if (stream->phone < 0)
                        stream->phone = fd_phone(stream->fd);
                
                return stream->phone;
        }
        
        return -1;
}

int fnode(FILE *stream, fdi_node_t *node)
{
        if (stream->fd >= 0)
                return fd_node(stream->fd, node);
        
        return ENOENT;
}

/** @}
 */