source: mainline/uspace/lib/http/receive-buffer.c@ 3ce68b7

/*
 * Copyright (c) 2012 Jiri Svoboda
 * Copyright (c) 2013 Martin Sucha
 * 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 http
 * @{
 */
/**
 * @file
 */

#include <stdlib.h>
#include <str.h>
#include <errno.h>
#include <macros.h>
#include <adt/list.h>

#include "receive-buffer.h"

int recv_buffer_init(receive_buffer_t *rb, size_t buffer_size,
    receive_func_t receive, void *client_data)
{
        rb->receive = receive;
        rb->client_data = client_data;
        
        rb->in = 0;
        rb->out = 0;
        rb->size = buffer_size;
        
        list_initialize(&rb->marks);
        
        rb->buffer = malloc(buffer_size);
        if (rb->buffer == NULL)
                return ENOMEM;
        return EOK;
}

static ssize_t dummy_receive(void *unused, void *buf, size_t buf_size)
{
        return 0;
}

int recv_buffer_init_const(receive_buffer_t *rb, void *buf, size_t size)
{
        int rc = recv_buffer_init(rb, size, dummy_receive, NULL);
        if (rc != EOK)
                return rc;
        
        memcpy(rb->buffer, buf, size);
        rb->in = size;
        return EOK;
}

void recv_buffer_fini(receive_buffer_t *rb)
{
        free(rb->buffer);
}

void recv_reset(receive_buffer_t *rb)
{
        rb->in = 0;
        rb->out = 0;
}

void recv_mark(receive_buffer_t *rb, receive_buffer_mark_t *mark)
{
        link_initialize(&mark->link);
        list_append(&mark->link, &rb->marks);
        recv_mark_update(rb, mark);
}

void recv_unmark(receive_buffer_t *rb, receive_buffer_mark_t *mark)
{
        list_remove(&mark->link);
}

void recv_mark_update(receive_buffer_t *rb, receive_buffer_mark_t *mark)
{
        mark->offset = rb->out;
}

int recv_cut(receive_buffer_t *rb, receive_buffer_mark_t *a, receive_buffer_mark_t *b, void **out_buf, size_t *out_size)
{
        if (a->offset > b->offset)
                return EINVAL;
        
        size_t size = b->offset - a->offset;
        void *buf = malloc(size);
        if (buf == NULL)
                return ENOMEM;
        
        memcpy(buf, rb->buffer + a->offset, size);
        *out_buf = buf;
        *out_size = size;
        return EOK;
}

int recv_cut_str(receive_buffer_t *rb, receive_buffer_mark_t *a, receive_buffer_mark_t *b, char **out_buf)
{
        if (a->offset > b->offset)
                return EINVAL;
        
        size_t size = b->offset - a->offset;
        char *buf = malloc(size + 1);
        if (buf == NULL)
                return ENOMEM;
        
        memcpy(buf, rb->buffer + a->offset, size);
        buf[size] = 0;
        for (size_t i = 0; i < size; i++) {
                if (buf[i] == 0) {
                        free(buf);
                        return EIO;
                }
        }
        *out_buf = buf;
        return EOK;
}


/** Receive one character (with buffering) */
int recv_char(receive_buffer_t *rb, char *c, bool consume)
{
        if (rb->out == rb->in) {
                size_t free = rb->size - rb->in;
                if (free == 0) {
                        size_t min_mark = rb->size;
                        list_foreach(rb->marks, link, receive_buffer_mark_t, mark) {
                                min_mark = min(min_mark, mark->offset);
                        }
                        
                        if (min_mark == 0)
                                return ELIMIT;
                        
                        size_t new_in = rb->in - min_mark;
                        memmove(rb->buffer, rb->buffer + min_mark, new_in);
                        rb->out = rb->in = new_in;
                        free = rb->size - rb->in;
                        list_foreach(rb->marks, link, receive_buffer_mark_t, mark) {
                                mark->offset -= min_mark;
                        }
                }
                
                ssize_t rc = rb->receive(rb->client_data, rb->buffer + rb->in, free);
                if (rc <= 0)
                        return rc;
                
                rb->in = rc;
        }
        
        *c = rb->buffer[rb->out];
        if (consume)
                rb->out++;
        return EOK;
}

ssize_t recv_buffer(receive_buffer_t *rb, char *buf, size_t buf_size)
{
        /* Flush any buffered data*/
        if (rb->out != rb->in) {
                size_t size = min(rb->in - rb->out, buf_size);
                memcpy(buf, rb->buffer + rb->out, size);
                rb->out += size;
                return size;
        }
        
        return rb->receive(rb->client_data, buf, buf_size);
}

/** Receive a character and if it is c, discard it from input buffer
 * @return number of characters discarded (0 or 1) or negative error code
 */
ssize_t recv_discard(receive_buffer_t *rb, char discard)
{
        char c = 0;
        int rc = recv_char(rb, &c, false);
        if (rc != EOK)
                return rc;
        if (c != discard)
                return 0;
        rc = recv_char(rb, &c, true);
        if (rc != EOK)
                return rc;
        return 1;
}

/** Receive an end of line, either CR, LF, CRLF or LFCR
 *
 * @return number of bytes read (0 if no newline is present in the stream)
 *         or negative error code
 */
ssize_t recv_eol(receive_buffer_t *rb)
{
        char c = 0;
        int rc = recv_char(rb, &c, false);
        if (rc != EOK)
                return rc;
        
        if (c != '\r' && c != '\n')
                return 0;
        
        rc = recv_char(rb, &c, true);
        if (rc != EOK)
                return rc;
        
        ssize_t rc2 = recv_discard(rb, (c == '\r' ? '\n' : '\r'));
        if (rc2 < 0)
                return rc2;
        
        return 1 + rc2;
}

/* Receive a single line */
ssize_t recv_line(receive_buffer_t *rb, char *line, size_t size)
{
        size_t written = 0;
        
        while (written < size) {
                char c = 0;
                int rc = recv_char(rb, &c, true);
                if (rc != EOK)
                        return rc;
                if (c == '\n') {
                        recv_discard(rb, '\r');
                        line[written++] = 0;
                        return written;
                }
                else if (c == '\r') {
                        recv_discard(rb, '\n');
                        line[written++] = 0;
                        return written;
                }
                line[written++] = c;
        }
        
        return ELIMIT;
}

/** @}
 */