aboutsummaryrefslogtreecommitdiffstats
path: root/meta/lib/oe/path.py
blob: 804ecd5fea96e5709d967bb5a7e9085d1508b6f1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
import errno
import glob
import shutil
import subprocess
import os.path

def join(*paths):
    """Like os.path.join but doesn't treat absolute RHS specially"""
    return os.path.normpath("/".join(paths))

def relative(src, dest):
    """ Return a relative path from src to dest.

    >>> relative("/usr/bin", "/tmp/foo/bar")
    ../../tmp/foo/bar

    >>> relative("/usr/bin", "/usr/lib")
    ../lib

    >>> relative("/tmp", "/tmp/foo/bar")
    foo/bar
    """

    return os.path.relpath(dest, src)

def make_relative_symlink(path):
    """ Convert an absolute symlink to a relative one """
    if not os.path.islink(path):
        return
    link = os.readlink(path)
    if not os.path.isabs(link):
        return

    # find the common ancestor directory
    ancestor = path
    depth = 0
    while ancestor and not link.startswith(ancestor):
        ancestor = ancestor.rpartition('/')[0]
        depth += 1

    if not ancestor:
        print("make_relative_symlink() Error: unable to find the common ancestor of %s and its target" % path)
        return

    base = link.partition(ancestor)[2].strip('/')
    while depth > 1:
        base = "../" + base
        depth -= 1

    os.remove(path)
    os.symlink(base, path)

def format_display(path, metadata):
    """ Prepare a path for display to the user. """
    rel = relative(metadata.getVar("TOPDIR"), path)
    if len(rel) > len(path):
        return path
    else:
        return rel

def copytree(src, dst):
    # We could use something like shutil.copytree here but it turns out to
    # to be slow. It takes twice as long copying to an empty directory. 
    # If dst already has contents performance can be 15 time slower
    # This way we also preserve hardlinks between files in the tree.

    bb.utils.mkdirhier(dst)
    cmd = "tar --xattrs --xattrs-include='*' -cf - -C %s -p . | tar --xattrs --xattrs-include='*' -xf - -C %s" % (src, dst)
    subprocess.check_output(cmd, shell=True, stderr=subprocess.STDOUT)

def copyhardlinktree(src, dst):
    """ Make the hard link when possible, otherwise copy. """
    bb.utils.mkdirhier(dst)
    if os.path.isdir(src) and not len(os.listdir(src)):
        return

    if (os.stat(src).st_dev ==  os.stat(dst).st_dev):
        # Need to copy directories only with tar first since cp will error if two 
        # writers try and create a directory at the same time
        cmd = "cd %s; find . -type d -print | tar --xattrs --xattrs-include='*' -cf - -C %s -p --no-recursion --files-from - | tar --xattrs --xattrs-include='*' -xf - -C %s" % (src, src, dst)
        subprocess.check_output(cmd, shell=True, stderr=subprocess.STDOUT)
        source = ''
        if os.path.isdir(src):
            if len(glob.glob('%s/.??*' % src)) > 0:
                source = '%s/.??* ' % src
            source = source + '%s/*' % src
        else:
            source = src
        cmd = 'cp -afl --preserve=xattr %s %s' % (source, dst)
        subprocess.check_output(cmd, shell=True, stderr=subprocess.STDOUT)
    else:
        copytree(src, dst)

def remove(path, recurse=True):
    """Equivalent to rm -f or rm -rf"""
    for name in glob.glob(path):
        try:
            os.unlink(name)
        except OSError as exc:
            if recurse and exc.errno == errno.EISDIR:
                shutil.rmtree(name)
            elif exc.errno != errno.ENOENT:
                raise

def symlink(source, destination, force=False):
    """Create a symbolic link"""
    try:
        if force:
            remove(destination)
        os.symlink(source, destination)
    except OSError as e:
        if e.errno != errno.EEXIST or os.readlink(destination) != source:
            raise

def find(dir, **walkoptions):
    """ Given a directory, recurses into that directory,
    returning all files as absolute paths. """

    for root, dirs, files in os.walk(dir, **walkoptions):
        for file in files:
            yield os.path.join(root, file)


## realpath() related functions
def __is_path_below(file, root):
    return (file + os.path.sep).startswith(root)

def __realpath_rel(start, rel_path, root, loop_cnt, assume_dir):
    """Calculates real path of symlink 'start' + 'rel_path' below
    'root'; no part of 'start' below 'root' must contain symlinks. """
    have_dir = True

    for d in rel_path.split(os.path.sep):
        if not have_dir and not assume_dir:
            raise OSError(errno.ENOENT, "no such directory %s" % start)

        if d == os.path.pardir: # '..'
            if len(start) >= len(root):
                # do not follow '..' before root
                start = os.path.dirname(start)
            else:
                # emit warning?
                pass
        else:
            (start, have_dir) = __realpath(os.path.join(start, d),
                                           root, loop_cnt, assume_dir)

        assert(__is_path_below(start, root))

    return start

def __realpath(file, root, loop_cnt, assume_dir):
    while os.path.islink(file) and len(file) >= len(root):
        if loop_cnt == 0:
            raise OSError(errno.ELOOP, file)

        loop_cnt -= 1
        target = os.path.normpath(os.readlink(file))

        if not os.path.isabs(target):
            tdir = os.path.dirname(file)
            assert(__is_path_below(tdir, root))
        else:
            tdir = root

        file = __realpath_rel(tdir, target, root, loop_cnt, assume_dir)

    try:
        is_dir = os.path.isdir(file)
    except:
        is_dir = false

    return (file, is_dir)

def realpath(file, root, use_physdir = True, loop_cnt = 100, assume_dir = False):
    """ Returns the canonical path of 'file' with assuming a
    toplevel 'root' directory. When 'use_physdir' is set, all
    preceding path components of 'file' will be resolved first;
    this flag should be set unless it is guaranteed that there is
    no symlink in the path. When 'assume_dir' is not set, missing
    path components will raise an ENOENT error"""

    root = os.path.normpath(root)
    file = os.path.normpath(file)

    if not root.endswith(os.path.sep):
        # letting root end with '/' makes some things easier
        root = root + os.path.sep

    if not __is_path_below(file, root):
        raise OSError(errno.EINVAL, "file '%s' is not below root" % file)

    try:
        if use_physdir:
            file = __realpath_rel(root, file[(len(root) - 1):], root, loop_cnt, assume_dir)
        else:
            file = __realpath(file, root, loop_cnt, assume_dir)[0]
    except OSError as e:
        if e.errno == errno.ELOOP:
            # make ELOOP more readable; without catching it, there will
            # be printed a backtrace with 100s of OSError exceptions
            # else
            raise OSError(errno.ELOOP,
                          "too much recursions while resolving '%s'; loop in '%s'" %
                          (file, e.strerror))

        raise

    return file