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/*

 * 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.

 *

 * Contributions after 2012-01-13 are licensed under the terms of the

 * GNU GPL, version 2 or (at your option) any later version.

 */

#include "iov.h"

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

                    const void *buf, size_t iov_off, size_t size)

{

    size_t iovec_off, buf_off;

    unsigned int i;

    iovec_off = 0;

    buf_off = 0;

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

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

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

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

            buf_off += len;

            iov_off += len;

            size -= len;

        }

        iovec_off += iov[i].iov_len;

    }

    return buf_off;

}

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

                  void *buf, size_t iov_off, size_t size)

{

    uint8_t *ptr;

    size_t iovec_off, buf_off;

    unsigned int i;

    ptr = buf;

    iovec_off = 0;

    buf_off = 0;

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

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

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

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

            buf_off += len;

            iov_off += len;

            size -= len;

        }

        iovec_off += iov[i].iov_len;

    }

    return buf_off;

}

size_t iov_clear(const struct iovec *iov, const unsigned int iov_cnt,

                 size_t iov_off, size_t size)

{

    size_t iovec_off, buf_off;

    unsigned int i;

    iovec_off = 0;

    buf_off = 0;

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

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

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

            memset(iov[i].iov_base + (iov_off - iovec_off), 0, len);

            buf_off += len;

            iov_off += len;

            size -= len;

        }

        iovec_off += iov[i].iov_len;

    }

    return buf_off;

}

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

{

    size_t len;

    unsigned int i;

    len = 0;

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

        len += iov[i].iov_len;

    }

    return len;

}

void iov_hexdump(const struct iovec *iov, const unsigned int iov_cnt,

                 FILE *fp, const char *prefix, size_t limit)

{

    unsigned int i, v, b;

    uint8_t *c;

    c = iov[0].iov_base;

    for (i = 0, v = 0, b = 0; b < limit; i++, b++) {

        if (i == iov[v].iov_len) {

            i = 0; v++;

            if (v == iov_cnt) {

                break;

            }

            c = iov[v].iov_base;

        }

        if ((b % 16) == 0) {

            fprintf(fp, "%s: %04x:", prefix, b);

        }

        if ((b % 4) == 0) {

            fprintf(fp, " ");

        }

        fprintf(fp, " %02x", c[i]);

        if ((b % 16) == 15) {

            fprintf(fp, "\n");

        }

    }

    if ((b % 16) != 0) {

        fprintf(fp, "\n");

    }

}