~ubuntu-branches/ubuntu/trusty/landscape-client/trusty-proposed

from __future__ import division

import os

import statvfs

def get_mount_info(mounts_file, statvfs_, filesystems_whitelist=None):

    """

    Given a mounts file (e.g., /proc/mounts), generate dicts with the following

    keys:

    @param filesystems_whitelist: if provided, the list of file systems which

        we're allowed to stat.

     - device: The device file which is mounted.

     - mount-point: The path at which the filesystem is mounted.

     - filesystem: The filesystem type.

     - total-space: The capacity of the filesystem in megabytes.

     - free-space: The amount of space available in megabytes.

    """

    for line in open(mounts_file):

        try:

            device, mount_point, filesystem = line.split()[:3]

            mount_point = mount_point.decode("string-escape")

        except ValueError:

            continue

        if (filesystems_whitelist is not None and

            filesystem not in filesystems_whitelist):

            continue

        megabytes = 1024 * 1024

        stats = statvfs_(mount_point)

        block_size = stats[statvfs.F_BSIZE]

        total_space = (stats[statvfs.F_BLOCKS] * block_size) // megabytes

        free_space = (stats[statvfs.F_BFREE] * block_size) // megabytes

        yield {"device": device, "mount-point": mount_point,

               "filesystem": filesystem, "total-space": total_space,

               "free-space": free_space}

def get_filesystem_for_path(path, mounts_file, statvfs_,

                            filesystems_whitelist=None):

    candidate = None

    path = os.path.realpath(path)

    path_segments = path.split("/")

    for info in get_mount_info(mounts_file, statvfs_, filesystems_whitelist):

        mount_segments = info["mount-point"].split("/")

        if path.startswith(info["mount-point"]):

            if ((not candidate)

                or path_segments[:len(mount_segments)] == mount_segments):

                candidate = info

    return candidate