/*
 * Copyright 2007-2008, Ingo Weinhold, bonefish@cs.tu-berlin.de.
 * Distributed under the terms of the MIT License.
 */

#include "compatibility.h"

#include "fssh_uio.h"

#if defined(HAIKU_HOST_PLATFORM_FREEBSD)
#include <unistd.h>
#endif

#include <new>

#include <errno.h>
#include <sys/uio.h>

#include "partition_support.h"

#if (!defined(__BEOS__) && !defined(__HAIKU__))
        // Defined in libroot_build.so.
#       define _kern_readv      _kernbuild_readv
#       define _kern_writev     _kernbuild_writev
        extern "C" ssize_t _kern_readv(int fd, off_t pos, const struct iovec *vecs, size_t count);
        extern "C" ssize_t _kern_writev(int fd, off_t pos, const struct iovec *vecs, size_t count);
#endif


static const int kMaxIOVecs = 1024;


bool
prepare_iovecs(const struct fssh_iovec *vecs, int count,
        struct iovec* systemVecs)
{
        if (count < 0 || count > kMaxIOVecs) {
                errno = B_BAD_VALUE;
                return false;
        }

        for (int i = 0; i < count; i++) {
                systemVecs[i].iov_base = vecs[i].iov_base;
                systemVecs[i].iov_len = vecs[i].iov_len;
        }

        return true;
}


fssh_ssize_t
fssh_readv(int fd, const struct fssh_iovec *vector, int count)
{
        struct iovec systemVecs[kMaxIOVecs];
        if (!prepare_iovecs(vector, count, systemVecs))
                return -1;

        fssh_off_t pos = -1;
        fssh_size_t length = 0;
        if (FSShell::restricted_file_restrict_io(fd, pos, length) < 0)
                return -1;

        #if !defined(HAIKU_HOST_PLATFORM_FREEBSD)
                return readv(fd, systemVecs, count);
        #else
                return _kern_readv(fd, lseek(fd, 0, SEEK_CUR), systemVecs, count);
        #endif
}


fssh_ssize_t
fssh_readv_pos(int fd, fssh_off_t pos, const struct fssh_iovec *vec, int count)
{
        struct iovec systemVecs[kMaxIOVecs];
        if (!prepare_iovecs(vec, count, systemVecs))
                return -1;

        fssh_size_t length = 0;
        if (FSShell::restricted_file_restrict_io(fd, pos, length) < 0)
                return -1;

#if defined(__HAIKU__)
        return readv_pos(fd, pos, systemVecs, count);
#else
        return _kern_readv(fd, pos, systemVecs, count);
#endif
}


fssh_ssize_t
fssh_writev(int fd, const struct fssh_iovec *vector, int count)
{
        struct iovec systemVecs[kMaxIOVecs];
        if (!prepare_iovecs(vector, count, systemVecs))
                return -1;

        fssh_off_t pos = -1;
        fssh_size_t length = 0;
        if (FSShell::restricted_file_restrict_io(fd, pos, length) < 0)
                return -1;

        #if !defined(HAIKU_HOST_PLATFORM_FREEBSD)
                return writev(fd, systemVecs, count);
        #else
                return _kern_writev(fd, lseek(fd, 0, SEEK_CUR), systemVecs, count);
        #endif
}


fssh_ssize_t
fssh_writev_pos(int fd, fssh_off_t pos, const struct fssh_iovec *vec, int count)
{
        struct iovec systemVecs[kMaxIOVecs];
        if (!prepare_iovecs(vec, count, systemVecs))
                return -1;

        fssh_size_t length = 0;
        if (FSShell::restricted_file_restrict_io(fd, pos, length) < 0)
                return -1;

#if defined(__HAIKU__)
        return writev_pos(fd, pos, systemVecs, count);
#else
        return _kern_writev(fd, pos, systemVecs, count);
#endif
}