utils.py: Make `magic_timestamp` a public variableshashwatdalal/make-magic-timestamp-public

Some plugin elements, such as docker-element and tar-element, require
to set `created` and/or `modified` meta-data fields. It would be nice
to use `magic_timestamp` to ensure these fields are being set in a
consistent and deterministic way.

4 files changed, 10 insertions, 11 deletions

diff --git a/src/buildstream/storage/_casbaseddirectory.py b/src/buildstream/storage/_casbaseddirectory.py
index 29aee7ad3..a93f16d90 100644
--- a/src/buildstream/storage/_casbaseddirectory.py
+++ b/src/buildstream/storage/_casbaseddirectory.py
@@ -32,7 +32,7 @@ import os
 from .._protos.build.bazel.remote.execution.v2 import remote_execution_pb2
 from .directory import Directory, VirtualDirectoryError, _FileType
 from ._filebaseddirectory import FileBasedDirectory
-from ..utils import FileListResult, _magic_timestamp
+from ..utils import FileListResult, BST_ARBITRARY_TIMESTAMP
 
 
 class IndexEntry():
@@ -436,7 +436,7 @@ class CasBasedDirectory(Directory):
 
         self.cas_cache.checkout(to_directory, self._get_digest(), can_link=can_link)
 
-    def export_to_tar(self, tarfile, destination_dir, mtime=_magic_timestamp):
+    def export_to_tar(self, tarfile, destination_dir, mtime=BST_ARBITRARY_TIMESTAMP):
         raise NotImplementedError()
 
     def mark_changed(self):
diff --git a/src/buildstream/storage/_filebaseddirectory.py b/src/buildstream/storage/_filebaseddirectory.py
index 233b56a09..8c55819c9 100644
--- a/src/buildstream/storage/_filebaseddirectory.py
+++ b/src/buildstream/storage/_filebaseddirectory.py
@@ -34,7 +34,7 @@ import time
 
 from .directory import Directory, VirtualDirectoryError, _FileType
 from .. import utils
-from ..utils import link_files, copy_files, list_relative_paths, _get_link_mtime, _magic_timestamp
+from ..utils import link_files, copy_files, list_relative_paths, _get_link_mtime, BST_ARBITRARY_TIMESTAMP
 from ..utils import _set_deterministic_user, _set_deterministic_mtime
 from ..utils import FileListResult
 
@@ -153,7 +153,7 @@ class FileBasedDirectory(Directory):
     # First, it sorts the results of os.listdir() to ensure the ordering of
     # the files in the archive is the same.  Second, it sets a fixed
     # timestamp for each entry. See also https://bugs.python.org/issue24465.
-    def export_to_tar(self, tarfile, destination_dir, mtime=_magic_timestamp):
+    def export_to_tar(self, tarfile, destination_dir, mtime=BST_ARBITRARY_TIMESTAMP):
         # We need directories here, including non-empty ones,
         # so list_relative_paths is not used.
         for filename in sorted(os.listdir(self.external_directory)):
@@ -187,7 +187,7 @@ class FileBasedDirectory(Directory):
         Return value: List(str) - list of modified paths
         """
         return [f for f in list_relative_paths(self.external_directory)
-                if _get_link_mtime(os.path.join(self.external_directory, f)) != _magic_timestamp]
+                if _get_link_mtime(os.path.join(self.external_directory, f)) != BST_ARBITRARY_TIMESTAMP]
 
     def list_relative_paths(self):
         """Provide a list of all relative paths.
diff --git a/src/buildstream/storage/directory.py b/src/buildstream/storage/directory.py
index c40e1bdb9..c9906b058 100644
--- a/src/buildstream/storage/directory.py
+++ b/src/buildstream/storage/directory.py
@@ -34,7 +34,7 @@ See also: :ref:`sandboxing`.
 from enum import Enum
 
 from .._exceptions import BstError, ErrorDomain
-from ..utils import _magic_timestamp
+from ..utils import BST_ARBITRARY_TIMESTAMP
 
 
 class VirtualDirectoryError(BstError):
@@ -122,7 +122,7 @@ class Directory():
 
         raise NotImplementedError()
 
-    def export_to_tar(self, tarfile, destination_dir, mtime=_magic_timestamp):
+    def export_to_tar(self, tarfile, destination_dir, mtime=BST_ARBITRARY_TIMESTAMP):
         """ Exports this directory into the given tar file.
 
         Args:
diff --git a/src/buildstream/utils.py b/src/buildstream/utils.py
index b5b554ee5..0e2cdeb43 100644
--- a/src/buildstream/utils.py
+++ b/src/buildstream/utils.py
@@ -43,8 +43,7 @@ from ._exceptions import BstError, ErrorDomain
 from ._protos.build.bazel.remote.execution.v2 import remote_execution_pb2
 
 # The magic number for timestamps: 2011-11-11 11:11:11
-_magic_timestamp = calendar.timegm([2011, 11, 11, 11, 11, 11])
-
+BST_ARBITRARY_TIMESTAMP = calendar.timegm([2011, 11, 11, 11, 11, 11])
 
 # The separator we use for user specified aliases
 _ALIAS_SEPARATOR = ':'
@@ -952,9 +951,9 @@ def _set_deterministic_mtime(directory):
             # However, nowadays it is possible at least on gnuish systems
             # with with the lutimes glibc function.
             if not os.path.islink(pathname):
-                os.utime(pathname, (_magic_timestamp, _magic_timestamp))
+                os.utime(pathname, (BST_ARBITRARY_TIMESTAMP, BST_ARBITRARY_TIMESTAMP))
 
-        os.utime(dirname, (_magic_timestamp, _magic_timestamp))
+        os.utime(dirname, (BST_ARBITRARY_TIMESTAMP, BST_ARBITRARY_TIMESTAMP))
 
 
 # _tempdir()