/*
 * Block driver in RAM
 * 
 * Copyright (c) 2007 Jim Boown
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "vl.h"
#include "block_int.h"
#include <assert.h>

#ifndef QEMU_TOOL
#include "exec-all.h"
#endif

typedef struct BDRVRamState {
    char * ram_data;
} BDRVRamState;

static int ram_probe(const uint8_t *buf, int buf_size, const char *filename)
{
    if (strstart(filename, "ram:", NULL))
	    return 100;
    return 0;
}
static int ram_open(BlockDriverState *bs, const char *filename, int flags)
{
    BDRVRamState *s = bs->opaque;

    if (!strstart(filename, "ram:", NULL))
	    return -1;

    int sectnum = atoi(filename+4);
    if (sectnum == 0) return -2;

    s->ram_data = qemu_mallocz(sectnum*512);
    if (s->ram_data == NULL) return -2;
    memset(s->ram_data, ' ', sectnum*512);

    bs->total_sectors = sectnum;
    return 0;
}

static int ram_read(BlockDriverState *bs, int64_t sector_num, 
                     uint8_t *buf, int nb_sectors)
{
    BDRVRamState *s = bs->opaque;
    if (sector_num+nb_sectors > bs->total_sectors)
	    	return -1;
    memcpy(buf, &(s->ram_data[sector_num*512]), nb_sectors*512);
    return 0;
}

static int ram_write(BlockDriverState *bs, int64_t sector_num, 
                      const uint8_t *buf, int nb_sectors)
{
    BDRVRamState *s = bs->opaque;
    if (sector_num+nb_sectors > bs->total_sectors)
	    	return -1;
    memcpy(&(s->ram_data[sector_num*512]), buf, nb_sectors*512);
    return 0;
}

static void ram_close(BlockDriverState *bs)
{
    BDRVRamState *s = bs->opaque;
    qemu_free(s->ram_data);
}

static int ram_is_allocated(BlockDriverState *bs,
        int64_t sector_num, int nb_sectors, int* n)
{
    *n = bs->total_sectors - sector_num;
    if (*n > nb_sectors)
        *n = nb_sectors;
    else if (*n < 0)
        return 0;
    return 1;
}

BlockDriver bdrv_ram = {
    "ram",
    sizeof(BDRVRamState),
    ram_probe,
    ram_open,
    ram_read,
    ram_write,
    ram_close,
    NULL,
    NULL,
    ram_is_allocated,
   .protocol_name = "ram",
};