temp commit for debuggingjmac/cas_backed_vdir

6 files changed, 292 insertions, 3 deletions

diff --git a/buildstream/__init__.py b/buildstream/__init__.py
index 7c4b5e5e6..d367e218f 100644
--- a/buildstream/__init__.py
+++ b/buildstream/__init__.py
@@ -34,3 +34,4 @@ if "_BST_COMPLETION" not in os.environ:
     from .element import Element, ElementError, Scope
     from .buildelement import BuildElement
     from .scriptelement import ScriptElement
+    from .storage import Directory, FileBasedDirectory, VirtualDirectoryError
diff --git a/buildstream/element.py b/buildstream/element.py
index 9158b600e..e30f90295 100644
--- a/buildstream/element.py
+++ b/buildstream/element.py
@@ -97,8 +97,7 @@ from . import _site
 from ._platform import Platform
 from .sandbox._config import SandboxConfig
 
-from .sandbox.Directory import Directory
-from .sandbox._filebaseddirectory import FileBasedDirectory, VirtualDirectoryError
+from . import Directory, FileBasedDirectory, VirtualDirectoryError
 
 
 # _KeyStrength():
diff --git a/buildstream/sandbox/sandbox.py b/buildstream/sandbox/sandbox.py
index 979367b3f..31d56312d 100644
--- a/buildstream/sandbox/sandbox.py
+++ b/buildstream/sandbox/sandbox.py
@@ -32,7 +32,7 @@ See also: :ref:`sandboxing`.
 
 import os
 from .._exceptions import ImplError, BstError
-from ._filebaseddirectory import FileBasedDirectory
+from ..storage._filebaseddirectory import FileBasedDirectory
 
 
 class SandboxFlags():
diff --git a/buildstream/sandbox/Directory.py b/buildstream/storage/Directory.py
index f37fb98ad..27c7d42ef 100644
--- a/buildstream/sandbox/Directory.py
+++ b/buildstream/storage/Directory.py
@@ -132,3 +132,13 @@ class Directory():
         Return value: List(str) - dictionary with all paths
         """
         raise NotImplementedError()
+
+    def get_real_directory(self) -> str:
+        """Return the underlying filesystem directory used by this object, if there is one.
+
+        Return value: str - an absolute path.
+
+        Raises: VirtualDirectoryError - if the implementation does not have an underlying
+                filesystem directory.
+        """
+        raise NotImplementedError()
diff --git a/buildstream/storage/__init__.py b/buildstream/storage/__init__.py
new file mode 100644
index 000000000..ddd514d00
--- /dev/null
+++ b/buildstream/storage/__init__.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+#
+#  Copyright (C) 2018 Codethink Limited
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
+#
+#  Authors:
+#        Jim MacArthur <jim.macarthur@codethink.co.uk>
+
+from .Directory import Directory
+from ._filebaseddirectory import FileBasedDirectory, VirtualDirectoryError
diff --git a/buildstream/storage/_filebaseddirectory.py b/buildstream/storage/_filebaseddirectory.py
new file mode 100644
index 000000000..77a7d068e
--- /dev/null
+++ b/buildstream/storage/_filebaseddirectory.py
@@ -0,0 +1,257 @@
+#!/usr/bin/env python3
+#
+#  Copyright (C) 2018 Codethink Limited
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public
+#  License as published by the Free Software Foundation; either
+#  version 2 of the License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+#  Lesser General Public License for more details.
+#
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library. If not, see <http://www.gnu.org/licenses/>.
+#
+#  Authors:
+#        Jim MacArthur <jim.macarthur@codethink.co.uk>
+
+"""
+FileBasedDirectory
+=========
+
+Implementation of the Directory class which backs onto a normal POSIX filing system.
+
+See also: :ref:`sandboxing`.
+"""
+
+from typing import List
+from collections import OrderedDict
+
+import calendar
+import os
+import time
+from .._exceptions import BstError, ErrorDomain
+from .Directory import Directory
+from ..utils import link_files, copy_files, FileListResult, list_relative_paths
+from ..utils import _set_deterministic_user, _set_deterministic_mtime
+
+
+class VirtualDirectoryError(BstError):
+    """Raised by Directory functions when system calls fail.
+    This will be handled internally by the BuildStream core,
+    if you need to handle this error, then it should be reraised,
+    or either of the :class:`.ElementError` or :class:`.SourceError`
+    exceptions should be raised from this error.
+    """
+    def __init__(self, message, reason=None):
+        super().__init__(message, domain=ErrorDomain.VIRTUAL_FS, reason=reason)
+
+
+# Like os.path.getmtime(), but doesnt explode on symlinks
+# Copy/pasted from compose.py
+def getmtime(path):
+    stat = os.lstat(path)
+    return stat.st_mtime
+
+# FileBasedDirectory intentionally doesn't call its superclass constuctor,
+# which is mean to be unimplemented.
+# pylint: disable=super-init-not-called
+
+
+class _FileObject():
+    """A description of a file in a virtual directory. The contents of
+    this class are never used, but there needs to be something present
+    for files so is_empty() works correctly.
+
+    """
+    def __init__(self, virtual_directory: Directory, filename: str):
+        self.directory = virtual_directory
+        self.filename = filename
+
+
+class FileBasedDirectory(Directory):
+    def __init__(self, external_directory=None):
+        self.external_directory = external_directory
+        self.index = OrderedDict()
+        self._directory_read = False
+
+    def _populate_index(self) -> None:
+        if self._directory_read:
+            return
+        for entry in os.listdir(self.external_directory):
+            if os.path.isdir(os.path.join(self.external_directory, entry)):
+                self.index[entry] = FileBasedDirectory(os.path.join(self.external_directory, entry))
+            else:
+                self.index[entry] = _FileObject(self, entry)
+        self._directory_read = True
+
+    def descend(self, subdirectory_spec: List[str], create: bool = False) -> Directory:
+        """ Descend one or more levels of directory hierarchy and return a new
+        Directory object for that directory.
+
+        Arguments:
+        * subdirectory_spec (list of strings): A list of strings which are all directory
+          names.
+        * create (boolean): If this is true, the directories will be created if
+          they don't already exist.
+        """
+
+        # It's very common to send a directory name instead of a list and this causes
+        # bizarre errors, so check for it here
+        if not isinstance(subdirectory_spec, list):
+            subdirectory_spec = [subdirectory_spec]
+        if not subdirectory_spec:
+            return self
+
+        # Because of the way split works, it's common to get a list which begins with
+        # an empty string. Detect these and remove them, then start again.
+        if subdirectory_spec[0] == "":
+            return self.descend(subdirectory_spec[1:], create)
+
+        self._populate_index()
+        if subdirectory_spec[0] in self.index:
+            entry = self.index[subdirectory_spec[0]]
+            if isinstance(entry, FileBasedDirectory):
+                new_path = os.path.join(self.external_directory, subdirectory_spec[0])
+                return FileBasedDirectory(new_path).descend(subdirectory_spec[1:], create)
+            else:
+                error = "Cannot descend into {}, which is a '{}' in the directory {}"
+                raise VirtualDirectoryError(error.format(subdirectory_spec[0],
+                                                         type(entry).__name__,
+                                                         self.external_directory))
+        else:
+            if create:
+                new_path = os.path.join(self.external_directory, subdirectory_spec[0])
+                os.makedirs(new_path, exist_ok=True)
+                return FileBasedDirectory(new_path).descend(subdirectory_spec[1:], create)
+            else:
+                error = "No entry called '{}' found in the directory rooted at {}"
+                raise VirtualDirectoryError(error.format(subdirectory_spec[0], self.external_directory))
+        return None
+
+    def import_files(self, external_pathspec: any, files: List[str] = None,
+                     report_written: bool = True, update_utimes: bool = False,
+                     can_link: bool = False) -> FileListResult:
+        """Imports some or all files from external_path into this directory.
+
+        Keyword arguments: external_pathspec: Either a string
+        containing a pathname, or a Directory object, to use as the
+        source.
+
+        files (list of strings): A list of all the files relative to
+        the external_pathspec to copy. If 'None' is supplied, all
+        files are copied.
+
+        report_written (bool): Return the full list of files
+        written. Defaults to true. If false, only a list of
+        overwritten files is returned.
+
+        update_utimes (bool): Update the access and modification time
+        of each file copied to the current time.
+
+        can_link (bool): Whether it's OK to create a hard link to the
+        original content, meaning the stored copy will change when the
+        original files change. Setting this doesn't guarantee hard
+        links will be made. can_link will never be used if
+        update_utimes is set.
+        """
+
+        if isinstance(external_pathspec, Directory):
+            source_directory = external_pathspec.external_directory
+        else:
+            source_directory = external_pathspec
+
+        if can_link and not update_utimes:
+            import_result = link_files(source_directory, self.external_directory, files=files,
+                                       ignore_missing=False, report_written=report_written)
+        else:
+            import_result = copy_files(source_directory, self.external_directory, files=files,
+                                       ignore_missing=False, report_written=report_written)
+        if update_utimes:
+            cur_time = time.time()
+
+            for f in import_result.files_written:
+                os.utime(os.path.join(self.external_directory, f), times=(cur_time, cur_time))
+        return import_result
+
+    def set_deterministic_mtime(self) -> None:
+        """ Sets a static modification time for all regular files in this directory.
+        The magic number for timestamps: 2011-11-11 11:11:11
+        """
+        _set_deterministic_mtime(self.external_directory)
+
+    def set_deterministic_user(self) -> None:
+        """ Sets all files in this directory to the current user's euid/egid.
+        """
+        _set_deterministic_user(self.external_directory)
+
+    def export_files(self, to_directory: str, can_link: bool = False, can_destroy: bool = False) -> None:
+        """Copies everything from this into to_directory.
+
+        Arguments:
+
+        to_directory (string): a path outside this directory object
+        where the contents will be copied to.
+
+        can_link (bool): Whether we can create hard links in to_directory
+        instead of copying.
+
+        """
+
+        if can_destroy:
+            # Try a simple rename of the sandbox root; if that
+            # doesnt cut it, then do the regular link files code path
+            try:
+                os.rename(self.external_directory, to_directory)
+                return
+            except OSError:
+                # Proceed using normal link/copy
+                pass
+
+        if can_link:
+            link_files(self.external_directory, to_directory)
+        else:
+            copy_files(self.external_directory, to_directory)
+
+    def is_empty(self) -> bool:
+        """ Return true if this directory has no files, subdirectories or links in it.
+        """
+        self._populate_index()
+        return len(self.index) == 0
+
+    def mark_unmodified(self) -> None:
+        """ Marks all files in this directory (recursively) as unmodified.
+        """
+        _set_deterministic_mtime(self.external_directory)
+
+    def list_modified_paths(self) -> List[str]:
+        """Provide a list of relative paths which have been modified since the
+        last call to mark_unmodified.
+
+        Return value: List(str) - list of modified paths
+        """
+        magic_timestamp = calendar.timegm([2011, 11, 11, 11, 11, 11])
+
+        return [f for f in list_relative_paths(self.external_directory)
+                if getmtime(os.path.join(self.external_directory, f)) != magic_timestamp]
+
+    def list_relative_paths(self) -> List[str]:
+        """Provide a list of all relative paths.
+
+        Return value: List(str) - list of all paths
+        """
+
+        return list_relative_paths(self.external_directory)
+
+    def get_real_directory(self) -> str:
+        return self.external_directory
+
+    def __str__(self) -> str:
+        # This returns the whole path (since we don't know where the directory started)
+        # which exposes the sandbox directory; we will have to assume for the time being
+        # that people will not abuse __str__.
+        return self.external_directory
+