Merge pull request #20 from Changaco/links

Better support of links

Author: Changaco

libarchive/entry.py

@@ -61,30 +61,57 @@ def isfifo(self):
 
     @property
     def islnk(self):
+        return bool(ffi.entry_hardlink_w(self._entry_p) or
+                    ffi.entry_hardlink(self._entry_p))
+
+    @property
+    def issym(self):
         return self.filetype & 0o170000 == 0o120000
 
+    def _linkpath(self):
+        return (ffi.entry_symlink_w(self._entry_p) or
+                ffi.entry_hardlink_w(self._entry_p) or
+                ffi.entry_symlink(self._entry_p) or
+                ffi.entry_hardlink(self._entry_p))
+
+    # aliases to get the same api as tarfile
+    linkpath = property(_linkpath)
+    linkname = property(_linkpath)
+
     @property
     def isreg(self):
         return self.filetype & 0o170000 == 0o100000
 
+    @property
+    def isfile(self):
+        return self.isreg
+
     @property
     def issock(self):
         return self.filetype & 0o170000 == 0o140000
 
+    @property
+    def isdev(self):
+        return self.ischr or self.isblk or self.isfifo or self.issock
+
     @property
     def mtime(self):
         return ffi.entry_mtime(self._entry_p)
 
-    @property
-    def pathname(self):
-        return ffi.entry_pathname_w(self._entry_p)
+    def _getpathname(self):
+        return (ffi.entry_pathname_w(self._entry_p) or
+                ffi.entry_pathname(self._entry_p))
 
-    @pathname.setter
-    def pathname(self, value):
+    def _setpathname(self, value):
         if not isinstance(value, bytes):
             value = value.encode('utf8')
         ffi.entry_update_pathname_utf8(self._entry_p, c_char_p(value))
 
+    pathname = property(_getpathname, _setpathname)
+    # aliases to get the same api as tarfile
+    path = property(_getpathname, _setpathname)
+    name = property(_getpathname, _setpathname)
+
     @property
     def size(self):
         if ffi.entry_size_is_set(self._entry_p):
@@ -96,4 +123,6 @@ def mode(self):
 
     @property
     def strmode(self):
-        return ffi.entry_strmode(self._entry_p)
+        # note we strip the mode because archive_entry_strmode
+        # returns a trailing space: strcpy(bp, "?rwxrwxrwx ");
+        return ffi.entry_strmode(self._entry_p).strip()

libarchive/ffi.py

@@ -108,12 +108,17 @@ def ffi(name, argtypes, restype, errcheck=None):
 
 ffi('entry_filetype', [c_archive_entry_p], c_int)
 ffi('entry_mtime', [c_archive_entry_p], c_int)
+ffi('entry_pathname', [c_archive_entry_p], c_char_p)
 ffi('entry_pathname_w', [c_archive_entry_p], c_wchar_p)
 ffi('entry_sourcepath', [c_archive_entry_p], c_char_p)
 ffi('entry_size', [c_archive_entry_p], c_longlong)
 ffi('entry_size_is_set', [c_archive_entry_p], c_int)
 ffi('entry_mode', [c_archive_entry_p], c_int)
 ffi('entry_strmode', [c_archive_entry_p], c_char_p)
+ffi('entry_hardlink', [c_archive_entry_p], c_char_p)
+ffi('entry_hardlink_w', [c_archive_entry_p], c_wchar_p)
+ffi('entry_symlink', [c_archive_entry_p], c_char_p)
+ffi('entry_symlink_w', [c_archive_entry_p], c_wchar_p)
 
 ffi('entry_update_pathname_utf8', [c_archive_entry_p, c_char_p], None)
 

tests/__init__.py

@@ -5,11 +5,20 @@
 
 from __future__ import division, print_function, unicode_literals
 
-from contextlib import contextmanager
+from contextlib import closing, contextmanager
 from copy import copy
 from os import chdir, getcwd, stat, walk
-from os.path import abspath, join
+from os.path import abspath, dirname, join
 from stat import S_ISREG
+import tarfile
+
+from libarchive import file_reader
+
+from . import surrogateescape
+
+
+data_dir = join(dirname(__file__), 'data')
+surrogateescape.register()
 
 
 def check_archive(archive, tree):
@@ -33,6 +42,68 @@ def check_archive(archive, tree):
     assert len(tree2) == 0
 
 
+def get_entries(location):
+    """
+    Using the archive file at `location`, return an iterable of name->value
+    mappings for each libarchive.ArchiveEntry objects essential attributes.
+    Paths are base64-encoded because JSON is UTF-8 and cannot handle
+    arbitrary binary pathdata.
+    """
+    with file_reader(location) as arch:
+        for entry in arch:
+            # libarchive introduces prefixes such as h prefix for
+            # hardlinks: tarfile does not, so we ignore the first char
+            mode = entry.strmode[1:].decode('ascii')
+            yield {
+                'path': surrogate_decode(entry.pathname),
+                'mtime': entry.mtime,
+                'size': entry.size,
+                'mode': mode,
+                'isreg': entry.isreg,
+                'isdir': entry.isdir,
+                'islnk': entry.islnk,
+                'issym': entry.issym,
+                'linkpath': surrogate_decode(entry.linkpath),
+                'isblk': entry.isblk,
+                'ischr': entry.ischr,
+                'isfifo': entry.isfifo,
+                'isdev': entry.isdev,
+            }
+
+
+def get_tarinfos(location):
+    """
+    Using the tar archive file at `location`, return an iterable of
+    name->value mappings for each tarfile.TarInfo objects essential
+    attributes.
+    Paths are base64-encoded because JSON is UTF-8 and cannot handle
+    arbitrary binary pathdata.
+    """
+    with closing(tarfile.open(location)) as tar:
+        for entry in tar:
+            path = surrogate_decode(entry.path or '')
+            if entry.isdir() and not path.endswith('/'):
+                path += '/'
+            # libarchive introduces prefixes such as h prefix for
+            # hardlinks: tarfile does not, so we ignore the first char
+            mode = tarfile.filemode(entry.mode)[1:]
+            yield {
+                'path': path,
+                'mtime': entry.mtime,
+                'size': entry.size,
+                'mode': mode,
+                'isreg': entry.isreg(),
+                'isdir': entry.isdir(),
+                'islnk': entry.islnk(),
+                'issym': entry.issym(),
+                'linkpath': surrogate_decode(entry.linkpath or None),
+                'isblk': entry.isblk(),
+                'ischr': entry.ischr(),
+                'isfifo': entry.isfifo(),
+                'isdev': entry.isdev(),
+            }
+
+
 @contextmanager
 def in_dir(dirpath):
     prev = abspath(getcwd())
@@ -59,3 +130,9 @@ def treestat(d):
             fpath = join(dirpath, fname)
             r[fpath] = stat_dict(fpath)
     return r
+
+
+def surrogate_decode(o):
+    if isinstance(o, bytes):
+        return o.decode('utf8', errors='surrogateescape')
+    return o

tests/data/special.tar

@@ -0,0 +1,3 @@
+This test file is borrowed from Python codebase and test suite.
+This is a trick Tar with several weird and malformed entries:
+https://hg.python.org/cpython/file/bff88c866886/Lib/test/testtar.tar