Archipelago » qemu

/*

 * Helpers for getting linearized buffers from iov / filling buffers into iovs

 *

 * Copyright IBM, Corp. 2007, 2008

 * Copyright (C) 2010 Red Hat, Inc.

 *

 * Author(s):

 *  Anthony Liguori <aliguori@us.ibm.com>

 *  Amit Shah <amit.shah@redhat.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2.  See

 * the COPYING file in the top-level directory.

 */

#include "iov.h"

size_t iov_from_buf(struct iovec *iov, unsigned int iovcnt,

                    const void *buf, size_t size)

{

    size_t offset;

    unsigned int i;

    offset = 0;

    for (i = 0; offset < size && i < iovcnt; i++) {

        size_t len;

        len = MIN(iov[i].iov_len, size - offset);

        memcpy(iov[i].iov_base, buf + offset, len);

        offset += len;

    }

    return offset;

}

size_t iov_to_buf(const struct iovec *iov, const unsigned int iovcnt,

                  void *buf, size_t offset, size_t size)

{

    uint8_t *ptr;

    size_t iov_off, buf_off;

    unsigned int i;

    ptr = buf;

    iov_off = 0;

    buf_off = 0;

    for (i = 0; i < iovcnt && size; i++) {

        if (offset < (iov_off + iov[i].iov_len)) {

            size_t len = MIN((iov_off + iov[i].iov_len) - offset , size);

            memcpy(ptr + buf_off, iov[i].iov_base + (offset - iov_off), len);

            buf_off += len;

            offset += len;

            size -= len;

        }

        iov_off += iov[i].iov_len;

    }

    return buf_off;

}

size_t iov_size(const struct iovec *iov, const unsigned int iovcnt)

{

    size_t len;

    unsigned int i;

    len = 0;

    for (i = 0; i < iovcnt; i++) {

        len += iov[i].iov_len;

    }

    return len;

}