[Notes] [Git][BuildStream/buildstream][jmac/cas_to_cas_v2] 2 commits:

Jim MacArthur pushed to branch jmac/cas_to_cas_v2 at BuildStream / buildstream

Commits:

2f612826

by Jim MacArthur at 2018-10-31T14:34:32Z

_casbaseddirectory.py: Enable direct CAS-to-CAS import.

e63bd60a
by Jim MacArthur at 2018-10-31T14:34:32Z
```
virtual_directory_import.py: New test
```

2 changed files:

buildstream/storage/_casbaseddirectory.py
+ tests/storage/virtual_directory_import.py

Changes:

buildstream/storage/_casbaseddirectory.py

@@ -38,6 +38,8 @@ from .._exceptions import BstError
  from .directory import Directory, VirtualDirectoryError
  from ._filebaseddirectory import FileBasedDirectory
  from ..utils import FileListResult, safe_copy, list_relative_paths
 +from ..utils import FileListResult, safe_copy, list_relative_paths, _relative_symlink_target
 +from .._artifactcache.cascache import CASCache
  class IndexEntry():
@@ -51,6 +53,20 @@ class IndexEntry():
          self.modified = modified
 +class ResolutionException(Exception):
 +    """ Superclass of all exceptions that can be raised by CasBasedDirectory._resolve. Should not be exposed externally."""
 +    pass
++
 +class InfiniteSymlinkException(ResolutionException):
 +    """ Raised when an infinite symlink loop is found. """
 +    pass
++
 +class AbsoluteSymlinkException(ResolutionException):
 +    """Raised if we try to follow an absolute symlink (i.e. one whose
 +    target starts with the path separator) and we have disallowed
 +    following such symlinks. """
 +    pass
++
  # CasBasedDirectory intentionally doesn't call its superclass constuctor,
  # which is meant to be unimplemented.
  # pylint: disable=super-init-not-called
@@ -176,21 +192,26 @@ class CasBasedDirectory(Directory):
          filenode.is_executable = is_executable
          self.index[filename] = IndexEntry(filenode, modified=(filename in self.index))
 -    def _add_new_link(self, basename, filename):
 -        existing_link = self._find_pb2_entry(filename)
 +    def _copy_link_from_filesystem(self, basename, filename):
 +        self._add_new_link_direct(filename, os.readlink(os.path.join(basename, filename)))
++
 +    def _add_new_link_direct(self, name, target):
 +        existing_link = self._find_pb2_entry(name)
          if existing_link:
              symlinknode = existing_link
          else:
              symlinknode = self.pb2_directory.symlinks.add()
 -        symlinknode.name = filename
 +        assert(isinstance(symlinknode, remote_execution_pb2.SymlinkNode))
 +        symlinknode.name = name
          # A symlink node has no digest.
 -        symlinknode.target = os.readlink(os.path.join(basename, filename))
 -        self.index[filename] = IndexEntry(symlinknode, modified=(existing_link is not None))
 +        symlinknode.target = target
 +        self.index[name] = IndexEntry(symlinknode, modified=(existing_link is not None))
      def delete_entry(self, name):
          for collection in [self.pb2_directory.files, self.pb2_directory.symlinks, self.pb2_directory.directories]:
 -            if name in collection:
 -                collection.remove(name)
 +            for thing in collection:
 +                if thing.name == name:
 +                    collection.remove(thing)
          if name in self.index:
              del self.index[name]
@@ -231,9 +252,13 @@ class CasBasedDirectory(Directory):
              if isinstance(entry, CasBasedDirectory):
                  return entry.descend(subdirectory_spec[1:], create)
              else:
 +                # May be a symlink
 +                target = self._resolve(subdirectory_spec[0], force_create=create)
 +                if isinstance(target, CasBasedDirectory):
 +                    return target
                  error = "Cannot descend into {}, which is a '{}' in the directory {}"
                  raise VirtualDirectoryError(error.format(subdirectory_spec[0],
 -                                                         type(entry).__name__,
 +                                                         type(self.index[subdirectory_spec[0]].pb_object).__name__,
                                                           self))
          else:
              if create:
@@ -254,7 +279,7 @@ class CasBasedDirectory(Directory):
          else:
              return self
 -    def _resolve_symlink_or_directory(self, name):
 +    def _force_resolve(self, name):
          """Used only by _import_files_from_directory. Tries to resolve a
          directory name or symlink name. 'name' must be an entry in this
          directory. It must be a single symlink or directory name, not a path
@@ -267,23 +292,128 @@ class CasBasedDirectory(Directory):
          as a directory as long as it's within this directory tree.
          """
 +        return self._resolve(name, force_create=True)
++
 +    def _is_followable(self, name):
 +        """ Returns true if this is a directory or symlink to a valid directory. """
 +        if name not in self.index:
 +            return False
          if isinstance(self.index[name].buildstream_object, Directory):
 -            return self.index[name].buildstream_object
 -        # OK then, it's a symlink
 -        symlink = self._find_pb2_entry(name)
 +            return True
 +        try:
 +            target = self._resolve(name)
 +        except InfiniteSymlinkException:
 +            return False
 +        return isinstance(target, CasBasedDirectory) or target is None
 +        # TODO: But why return True if it's None (broken link/circular loop)? Surely that is against the docstring.
++
 +    def _resolve(self, name, absolute_symlinks_resolve=True, force_create=False, seen_objects=None):
 +        """Resolves any name to an object. If the name points to a symlink in
 +        this directory, it returns the thing it points to,
 +        recursively.
++
 +        Returns a CasBasedDirectory, FileNode or None. None indicates
 +        either that 'none' does not exist in this directory, or is a
 +        symlink chain which points to a nonexistent name (broken
 +        symlink).
++
++
 +        Raises:
 +        - InfiniteSymlinkException if 'name' points to an infinite symlink loop.
 +        - AbsoluteSymlinkException if 'name' points to an absolute symlink and absolute_symlinks_resolve is False.
++
 +        If force_create is on, this will attempt to create directories to make symlinks and directories resolve.
 +        If force_create is off, this will never alter this directory.
++
 +        """
++
 +        if name not in self.index:
 +            return None
++
 +        # First check if it's a normal object and return that
 +        index_entry = self.index[name]
 +        if isinstance(index_entry.buildstream_object, Directory):
 +            return index_entry.buildstream_object
 +        elif isinstance(index_entry.pb_object, remote_execution_pb2.FileNode):
 +            return index_entry.pb_object
++
 +        assert isinstance(index_entry.pb_object, remote_execution_pb2.SymlinkNode)
++
 +        if seen_objects is None:
 +            seen_objects = [index_entry.pb_object]
 +        else:
 +            if index_entry.pb_object in seen_objects:
 +                # Infinite symlink loop detected
 +                raise InfiniteSymlinkException()
++
 +        symlink = index_entry.pb_object
 +        components = symlink.target.split(CasBasedDirectory._pb2_path_sep)
++
          absolute = symlink.target.startswith(CasBasedDirectory._pb2_absolute_path_prefix)
          if absolute:
 -            root = self.find_root()
 +            if absolute_symlinks_resolve:
 +                start_directory = self.find_root()
 +                # Discard the first empty element
 +                components.pop(0)
 +            else:
 +                # Unresolvable absolute symlink
 +                raise AbsoluteSymlinkException()
          else:
 -            root = self
 -        directory = root
 -        components = symlink.target.split(CasBasedDirectory._pb2_path_sep)
 -        for c in components:
 -            if c == "..":
 -                directory = directory.parent
 +            start_directory = self
++
 +        directory = start_directory
 +        while True:
 +            if not components:
 +                # We ran out of path elements and ended up in a directory
 +                return directory
 +            c = components.pop(0)
 +            if c == ".":
 +                pass
 +            elif c == "..":
 +                if directory.parent is not None:
 +                    directory = directory.parent
 +                # If directory.parent *is* None, this is an attempt to access
 +                # '..' from the root, which is valid under POSIX; it just
 +                # returns the root.
 +            elif c in directory.index:
 +                # Recursive resolve and continue
 +                try:
 +                    f = directory._resolve(c, absolute_symlinks_resolve, seen_objects=seen_objects)
 +                except ResolutionException:
 +                    f = None
 +                if isinstance(f, CasBasedDirectory):
 +                    directory = f
 +                elif isinstance(f, remote_execution_pb2.FileNode):
 +                    if components:
 +                        # We have components still to resolve, but one of the path components
 +                        # is a file.
 +                        if force_create:
 +                            self.delete_entry(c)
 +                            directory = directory.descend(c, create=True)
 +                        else:
 +                            return f
 +                            # TODO: Why return f? We've got
 +                            # components left and hit a file; this
 +                            # should be an error.
++
 +                            # errormsg = "Reached a file called {} while trying to resolve a symlink; cannot proceed"
 +                            # raise VirtualDirectoryError(errormsg.format(c))
 +                    else:
 +                        # It's a file, and there's no path components left, so just return that.
 +                        return f
 +                else:
 +                    # f was not found
 +                    if force_create:
 +                        directory = directory.descend(c, create=True)
 +                    else:
 +                        return None
              else:
 -                directory = directory.descend(c, create=True)
 -        return directory
 +                # c is not in our index
 +                if force_create:
 +                    directory = directory.descend(c, create=True)
 +                else:
 +                    return None
 +        # You can only exit the while loop with a return, or exception, so you shouldn't be here.
      def _check_replacement(self, name, path_prefix, fileListResult):
          """ Checks whether 'name' exists, and if so, whether we can overwrite it.
@@ -297,6 +427,7 @@ class CasBasedDirectory(Directory):
              return True
          if (isinstance(existing_entry,
                         (remote_execution_pb2.FileNode, remote_execution_pb2.SymlinkNode))):
 +            self.delete_entry(name)
              fileListResult.overwritten.append(relative_pathname)
              return True
          elif isinstance(existing_entry, remote_execution_pb2.DirectoryNode):
@@ -314,23 +445,29 @@ class CasBasedDirectory(Directory):
                         .format(name, type(existing_entry)))
          return False  # In case asserts are disabled
 -    def _import_directory_recursively(self, directory_name, source_directory, remaining_path, path_prefix):
 -        """ _import_directory_recursively and _import_files_from_directory will be called alternately
 -        as a directory tree is descended. """
 -        if directory_name in self.index:
 -            subdir = self._resolve_symlink_or_directory(directory_name)
 -        else:
 -            subdir = self._add_directory(directory_name)
 -        new_path_prefix = os.path.join(path_prefix, directory_name)
 -        subdir_result = subdir._import_files_from_directory(os.path.join(source_directory, directory_name),
 -                                                            [os.path.sep.join(remaining_path)],
 -                                                            path_prefix=new_path_prefix)
 -        return subdir_result
+-
      def _import_files_from_directory(self, source_directory, files, path_prefix=""):
 -        """ Imports files from a traditional directory """
 +        """ Imports files from a traditional directory. """
++
 +        def _import_directory_recursively(directory_name, source_directory, remaining_path, path_prefix):
 +            """ _import_directory_recursively and _import_files_from_directory will be called alternately
 +            as a directory tree is descended. """
 +            if directory_name in self.index:
 +                if self._is_followable(directory_name):
 +                    subdir = self._force_resolve(directory_name)
 +                else:
 +                    self.delete_entry(directory_name)
 +                    subdir = self._add_directory(directory_name)
 +                    result.overwritten.append(relative_pathname)
 +            else:
 +                subdir = self._add_directory(directory_name)
 +            new_path_prefix = os.path.join(path_prefix, directory_name)
 +            subdir_result = subdir._import_files_from_directory(os.path.join(source_directory, directory_name),
 +                                                                [os.path.sep.join(remaining_path)],
 +                                                                path_prefix=new_path_prefix)
 +            return subdir_result
++
          result = FileListResult()
 -        for entry in sorted(files):
 +        for entry in files:
              split_path = entry.split(os.path.sep)
              # The actual file on the FS we're importing
              import_file = os.path.join(source_directory, entry)
@@ -338,14 +475,18 @@ class CasBasedDirectory(Directory):
              relative_pathname = os.path.join(path_prefix, entry)
              if len(split_path) > 1:
                  directory_name = split_path[0]
 -                # Hand this off to the importer for that subdir. This will only do one file -
 -                # a better way would be to hand off all the files in this subdir at once.
 -                subdir_result = self._import_directory_recursively(directory_name, source_directory,
 -                                                                   split_path[1:], path_prefix)
 +                # Hand this off to the importer for that subdir.
++
 +                # It would be advantageous to batch these together by
 +                # directory_name. However, we can't do it out of
 +                # order, since importing symlinks affects the results
 +                # of other imports.
 +                subdir_result = _import_directory_recursively(directory_name, source_directory,
 +                                                              split_path[1:], path_prefix)
                  result.combine(subdir_result)
              elif os.path.islink(import_file):
                  if self._check_replacement(entry, path_prefix, result):
 -                    self._add_new_link(source_directory, entry)
 +                    self._copy_link_from_filesystem(source_directory, entry)
                      result.files_written.append(relative_pathname)
              elif os.path.isdir(import_file):
                  # A plain directory which already exists isn't a problem; just ignore it.
@@ -357,6 +498,93 @@ class CasBasedDirectory(Directory):
                      result.files_written.append(relative_pathname)
          return result
 +    def _files_in_subdir(sorted_files, dirname):
 +        """Filters sorted_files and returns only the ones which have
 +           'dirname' as a prefix, with that prefix removed.
++
 +        """
 +        if not dirname.endswith(os.path.sep):
 +            dirname += os.path.sep
 +        return [f[len(dirname):] for f in sorted_files if f.startswith(dirname)]
++
 +    def _partial_import_cas_into_cas(self, source_directory, files, path_prefix="", file_list_required=True):
 +        """ Import only the files and symlinks listed in 'files' from source_directory to this one.
 +        Args:
 +           source_directory (:class:`.CasBasedDirectory`): The directory to import from
 +           files ([str]): List of pathnames to import.
 +           path_prefix (str): Prefix used to add entries to the file list result.
 +           file_list_required: Whether to update the file list while processing.
 +        """
 +        result = FileListResult()
 +        processed_directories = set()
 +        for f in files:
 +            fullname = os.path.join(path_prefix, f)
 +            components = f.split(os.path.sep)
 +            if len(components) > 1:
 +                # We are importing a thing which is in a subdirectory. We may have already seen this dirname
 +                # for a previous file.
 +                dirname = components[0]
 +                if dirname not in processed_directories:
 +                    # Now strip off the first directory name and import files recursively.
 +                    subcomponents = CasBasedDirectory._files_in_subdir(files, dirname)
 +                    # We will fail at this point if there is a file or symlink to file called 'dirname'.
 +                    if dirname in self.index:
 +                        resolved_component = self._resolve(dirname, force_create=True)
 +                        if isinstance(resolved_component, remote_execution_pb2.FileNode):
 +                            self.delete_entry(dirname)
 +                            result.overwritten.append(f)
 +                            dest_subdir = self.descend(dirname, create=True)
 +                        else:
 +                            dest_subdir = resolved_component
 +                    else:
 +                        dest_subdir = self.descend(dirname, create=True)
 +                    src_subdir = source_directory.descend(dirname)
 +                    import_result = dest_subdir._partial_import_cas_into_cas(src_subdir, subcomponents,
 +                                                                             path_prefix=fullname,
 +                                                                             file_list_required=file_list_required)
 +                    result.combine(import_result)
 +                processed_directories.add(dirname)
 +            elif isinstance(source_directory.index[f].buildstream_object, CasBasedDirectory):
 +                # The thing in the input file list is a directory on
 +                # its own. In which case, replace any existing file,
 +                # or symlink to file with the new, blank directory -
 +                # if it's neither of those things, or doesn't exist,
 +                # then just create the dir.
 +                if f in self.index:
 +                    x = self._resolve(f)
 +                    if x is None:
 +                        # If we're importing a blank directory, and the target has a broken symlink, then do nothing.
 +                        pass
 +                    elif isinstance(x, remote_execution_pb2.FileNode):
 +                        # Files with the same name, or symlinks to files, get removed.
 +                        pass
 +                    else:
 +                        # There's either a symlink (valid or not) or existing directory with this name, so do nothing.
 +                        pass
 +                else:
 +                    self.descend(f, create=True)
 +            else:
 +                # We're importing a file or symlink - replace anything with the same name.
 +                importable = self._check_replacement(f, path_prefix, result)
 +                if importable:
 +                    item = source_directory.index[f].pb_object
 +                    if isinstance(item, remote_execution_pb2.FileNode):
 +                        filenode = self.pb2_directory.files.add(digest=item.digest, name=f,
 +                                                                is_executable=item.is_executable)
 +                        self.index[f] = IndexEntry(filenode, modified=(fullname in result.overwritten))
 +                    else:
 +                        assert(isinstance(item, remote_execution_pb2.SymlinkNode))
 +                        self._add_new_link_direct(name=f, target=item.target)
 +        return result
++
 +    def _import_cas_into_cas(self, source_directory, files=None):
 +        """ A full import is significantly quicker than a partial import, because we can just
 +        replace one directory with another's hash, without doing any recursion.
 +        """
++
 +        # You must pass a list into _partial_import (not a generator)
 +        return self._partial_import_cas_into_cas(source_directory, list(files))
++
      def import_files(self, external_pathspec, *, files=None,
                       report_written=True, update_utimes=False,
                       can_link=False):
@@ -378,28 +606,27 @@ class CasBasedDirectory(Directory):
          can_link (bool): Ignored, since hard links do not have any meaning within CAS.
          """
 -        if isinstance(external_pathspec, FileBasedDirectory):
 -            source_directory = external_pathspec._get_underlying_directory()
 -        elif isinstance(external_pathspec, CasBasedDirectory):
 -            # TODO: This transfers from one CAS to another via the
 -            # filesystem, which is very inefficient. Alter this so it
 -            # transfers refs across directly.
 -            with tempfile.TemporaryDirectory(prefix="roundtrip") as tmpdir:
 -                external_pathspec.export_files(tmpdir)
 -                if files is None:
 -                    files = list_relative_paths(tmpdir)
 -                result = self._import_files_from_directory(tmpdir, files=files)
 -            return result
 -        else:
 -            source_directory = external_pathspec
          if files is None:
 -            files = list_relative_paths(source_directory)
 +            if isinstance(external_pathspec, str):
 +                files = list_relative_paths(external_pathspec)
 +            else:
 +                assert isinstance(external_pathspec, Directory)
 +                files = external_pathspec.list_relative_paths()
++
 +        if isinstance(external_pathspec, FileBasedDirectory):
 +            source_directory = external_pathspec.get_underlying_directory()
 +            result = self._import_files_from_directory(source_directory, files=files)
 +        elif isinstance(external_pathspec, str):
 +            source_directory = external_pathspec
 +            result = self._import_files_from_directory(source_directory, files=files)
 +        else:
 +            assert isinstance(external_pathspec, CasBasedDirectory)
 +            result = self._import_cas_into_cas(external_pathspec, files=files)
          # TODO: No notice is taken of report_written, update_utimes or can_link.
          # Current behaviour is to fully populate the report, which is inefficient,
          # but still correct.
 -        result = self._import_files_from_directory(source_directory, files=files)
          # We need to recalculate and store the hashes of all directories both
          # up and down the tree; we have changed our directory by importing files
@@ -526,7 +753,7 @@ class CasBasedDirectory(Directory):
                  filelist.append(k)
          return filelist
 -    def list_relative_paths(self):
 +    def list_relative_paths(self, relpath=""):
          """Provide a list of all relative paths.
          NOTE: This list is not in the same order as utils.list_relative_paths.
@@ -534,13 +761,32 @@ class CasBasedDirectory(Directory):
          Return value: List(str) - list of all paths
          """
 -        filelist = []
 -        for (k, v) in self.index.items():
 -            if isinstance(v.buildstream_object, CasBasedDirectory):
 -                filelist.extend([k + os.path.sep + x for x in v.buildstream_object.list_relative_paths()])
 -            elif isinstance(v.pb_object, remote_execution_pb2.FileNode):
 -                filelist.append(k)
 -        return filelist
 +        symlink_list = filter(lambda i: isinstance(i[1].pb_object, remote_execution_pb2.SymlinkNode),
 +                              self.index.items())
 +        file_list = list(filter(lambda i: isinstance(i[1].pb_object, remote_execution_pb2.FileNode),
 +                           self.index.items()))
 +        directory_list = filter(lambda i: isinstance(i[1].buildstream_object, CasBasedDirectory),
 +                                self.index.items())
++
 +        # We need to mimic the behaviour of os.walk, in which symlinks
 +        # to directories count as directories and symlinks to file or
 +        # broken symlinks count as files. os.walk doesn't follow
 +        # symlinks, so we don't recurse.
 +        for (k, v) in sorted(symlink_list):
 +            target = self._resolve(k, absolute_symlinks_resolve=True)
 +            if isinstance(target, CasBasedDirectory):
 +                yield os.path.join(relpath, k)
 +            else:
 +                file_list.append((k, v))
++
 +        if file_list == [] and relpath != "":
 +            yield relpath
 +        else:
 +            for (k, v) in sorted(file_list):
 +                yield os.path.join(relpath, k)
++
 +        for (k, v) in sorted(directory_list):
 +            yield from v.buildstream_object.list_relative_paths(relpath=os.path.join(relpath, k))
      def recalculate_hash(self):
          """ Recalcuates the hash for this directory and store the results in

tests/storage/virtual_directory_import.py

 +import os
 +import pytest
 +import random
 +import copy
 +import tempfile
 +from tests.testutils import cli
++
++
 +from buildstream.storage._casbaseddirectory import CasBasedDirectory
 +from buildstream.storage._filebaseddirectory import FileBasedDirectory
 +from buildstream._artifactcache import ArtifactCache
 +from buildstream._artifactcache.cascache import CASCache
 +from buildstream import utils
++
++
 +class FakeContext():
 +    def __init__(self):
 +        self.config_cache_quota = "65536"
++
 +    def get_projects(self):
 +        return []
++
 +# This is a set of example file system contents. The test attempts to import
 +# each on top of each other to test importing works consistently.
 +# Each tuple is defined as (<filename>, <type>, <content>). Type can be
 +# 'F' (file), 'S' (symlink) or 'D' (directory) with content being the contents
 +# for a file or the destination for a symlink.
 +root_filesets = [
 +    # Arbitrary test sets
 +    [('a/b/c/textfile1', 'F', 'This is textfile 1\n')],
 +    [('a/b/c/textfile1', 'F', 'This is the replacement textfile 1\n')],
 +    [('a/b/d', 'D', '')],
 +    [('a/b/c', 'S', '/a/b/d')],
 +    [('a/b/d', 'S', '/a/b/c')],
 +    [('a/b/d', 'D', ''), ('a/b/c', 'S', '/a/b/d')],
 +    [('a/b/c', 'D', ''), ('a/b/d', 'S', '/a/b/c')],
 +    [('a/b', 'F', 'This is textfile 1\n')],
 +    [('a/b/c', 'F', 'This is textfile 1\n')],
 +    [('a/b/c', 'D', '')]
 +]
++
 +empty_hash_ref = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
 +RANDOM_SEED = 69105
++
++
 +def generate_import_roots(rootno, directory):
 +    rootname = "root{}".format(rootno)
 +    rootdir = os.path.join(directory, "content", rootname)
++
 +    for (path, typesymbol, content) in root_filesets[rootno - 1]:
 +        if typesymbol == 'F':
 +            (dirnames, filename) = os.path.split(path)
 +            os.makedirs(os.path.join(rootdir, dirnames), exist_ok=True)
 +            with open(os.path.join(rootdir, dirnames, filename), "wt") as f:
 +                f.write(content)
 +        elif typesymbol == 'D':
 +            os.makedirs(os.path.join(rootdir, path), exist_ok=True)
 +        elif typesymbol == 'S':
 +            (dirnames, filename) = os.path.split(path)
 +            os.makedirs(os.path.join(rootdir, dirnames), exist_ok=True)
 +            os.symlink(content, os.path.join(rootdir, path))
++
++
 +def generate_random_root(rootno, directory):
 +    random.seed(RANDOM_SEED + rootno)
 +    rootname = "root{}".format(rootno)
 +    rootdir = os.path.join(directory, "content", rootname)
 +    things = []
 +    locations = ['.']
 +    os.makedirs(rootdir)
 +    for i in range(0, 100):
 +        location = random.choice(locations)
 +        thingname = "node{}".format(i)
 +        thing = random.choice(['dir', 'link', 'file'])
 +        target = os.path.join(rootdir, location, thingname)
 +        description = thing
 +        if thing == 'dir':
 +            os.makedirs(target)
 +            locations.append(os.path.join(location, thingname))
 +        elif thing == 'file':
 +            with open(target, "wt") as f:
 +                f.write("This is node {}\n".format(i))
 +        elif thing == 'link':
 +            # TODO: Make some relative symlinks
 +            if random.randint(1, 3) == 1 or len(things) == 0:
 +                os.symlink("/broken", target)
 +                description = "symlink pointing to /broken"
 +            else:
 +                symlink_destination = random.choice(things)
 +                os.symlink(symlink_destination, target)
 +                description = "symlink pointing to {}".format(symlink_destination)
 +        things.append(os.path.join(location, thingname))
++
++
 +def file_contents(path):
 +    with open(path, "r") as f:
 +        result = f.read()
 +    return result
++
++
 +def file_contents_are(path, contents):
 +    return file_contents(path) == contents
++
++
 +def create_new_casdir(root_number, fake_context, tmpdir):
 +    d = CasBasedDirectory(fake_context)
 +    d.import_files(os.path.join(tmpdir, "content", "root{}".format(root_number)))
 +    assert d.ref.hash != empty_hash_ref
 +    return d
++
++
 +def create_new_filedir(root_number, tmpdir):
 +    root = os.path.join(tmpdir, "vdir")
 +    os.makedirs(root)
 +    d = FileBasedDirectory(root)
 +    d.import_files(os.path.join(tmpdir, "content", "root{}".format(root_number)))
 +    return d
++
++
 +def combinations(integer_range):
 +    for x in integer_range:
 +        for y in integer_range:
 +            yield (x, y)
++
++
 +def resolve_symlinks(path, root):
 +    """ A function to resolve symlinks inside 'path' components apart from the last one.
 +        For example, resolve_symlinks('/a/b/c/d', '/a/b')
 +        will return '/a/b/f/d' if /a/b/c is a symlink to /a/b/f. The final component of
 +        'path' is not resolved, because we typically want to inspect the symlink found
 +        at that path, not its target.
++
 +    """
 +    components = path.split(os.path.sep)
 +    location = root
 +    for i in range(0, len(components) - 1):
 +        location = os.path.join(location, components[i])
 +        if os.path.islink(location):
 +            # Resolve the link, add on all the remaining components
 +            target = os.path.join(os.readlink(location))
 +            tail = os.path.sep.join(components[i + 1:])
++
 +            if target.startswith(os.path.sep):
 +                # Absolute link - relative to root
 +                location = os.path.join(root, target, tail)
 +            else:
 +                # Relative link - relative to symlink location
 +                location = os.path.join(location, target)
 +            return resolve_symlinks(location, root)
 +    # If we got here, no symlinks were found. Add on the final component and return.
 +    location = os.path.join(location, components[-1])
 +    return location
++
++
 +def directory_not_empty(path):
 +    return os.listdir(path)
++
++
 +def _import_test(tmpdir, original, overlay, generator_function, verify_contents=False):
 +    fake_context = FakeContext()
 +    fake_context.artifactdir = tmpdir
 +    print("Creating CAS Cache with artifact dir {}".format(tmpdir))
 +    fake_context.artifactcache = CASCache(fake_context)
 +    # Create some fake content
 +    generator_function(original, tmpdir)
 +    if original != overlay:
 +        generator_function(overlay, tmpdir)
++
 +    d = create_new_casdir(original, fake_context, tmpdir)
++
 +    duplicate_cas = create_new_casdir(original, fake_context, tmpdir)
++
 +    assert duplicate_cas.ref.hash == d.ref.hash
++
 +    d2 = create_new_casdir(overlay, fake_context, tmpdir)
 +    print("Importing dir {} into {}".format(overlay, original))
 +    d.import_files(d2)
 +    export_dir = os.path.join(tmpdir, "output")
 +    roundtrip_dir = os.path.join(tmpdir, "roundtrip")
 +    d2.export_files(roundtrip_dir)
 +    d.export_files(export_dir)
++
 +    if verify_contents:
 +        for item in root_filesets[overlay - 1]:
 +            (path, typename, content) = item
 +            realpath = resolve_symlinks(path, export_dir)
 +            if typename == 'F':
 +                if os.path.isdir(realpath) and directory_not_empty(realpath):
 +                    # The file should not have overwritten the directory in this case.
 +                    pass
 +                else:
 +                    assert os.path.isfile(realpath), "{} did not exist in the combined virtual directory".format(path)
 +                    assert file_contents_are(realpath, content)
 +            elif typename == 'S':
 +                if os.path.isdir(realpath) and directory_not_empty(realpath):
 +                    # The symlink should not have overwritten the directory in this case.
 +                    pass
 +                else:
 +                    assert os.path.islink(realpath)
 +                    assert os.readlink(realpath) == content
 +            elif typename == 'D':
 +                # We can't do any more tests than this because it
 +                # depends on things present in the original. Blank
 +                # directories here will be ignored and the original
 +                # left in place.
 +                assert os.path.lexists(realpath)
++
 +    # Now do the same thing with filebaseddirectories and check the contents match
++
 +    files = list(utils.list_relative_paths(roundtrip_dir))
 +    print("Importing from filesystem: filelist is: {}".format(files))
 +    duplicate_cas._import_files_from_directory(roundtrip_dir, files=files)
 +    duplicate_cas._recalculate_recursing_down()
 +    if duplicate_cas.parent:
 +        duplicate_cas.parent._recalculate_recursing_up(duplicate_cas)
 +        print("Result of direct import: {}".format(duplicate_cas.show_files_recursive()))
++
 +    assert duplicate_cas.ref.hash == d.ref.hash
++
++
 +@pytest.mark.parametrize("original,overlay", combinations(range(1, len(root_filesets) + 1)))
 +def test_fixed_cas_import(cli, tmpdir, original, overlay):
 +    _import_test(tmpdir, original, overlay, generate_import_roots, verify_contents=True)
++
++
 +@pytest.mark.parametrize("original,overlay", combinations(range(1, 11)))
 +def test_random_cas_import_fast(cli, tmpdir, original, overlay):
 +    _import_test(tmpdir, original, overlay, generate_random_root, verify_contents=False)
++
++
 +def _listing_test(tmpdir, root, generator_function):
 +    fake_context = FakeContext()
 +    fake_context.artifactdir = tmpdir
 +    print("Creating CAS Cache with artifact dir {}".format(tmpdir))
 +    fake_context.artifactcache = CASCache(fake_context)
 +    # Create some fake content
 +    generator_function(root, tmpdir)
++
 +    d = create_new_filedir(root, tmpdir)
 +    filelist = list(d.list_relative_paths())
++
 +    d2 = create_new_casdir(root, fake_context, tmpdir)
 +    filelist2 = list(d2.list_relative_paths())
++
 +    print("filelist for root {} via FileBasedDirectory:".format(root))
 +    print("{}".format(filelist))
 +    print("filelist for root {} via CasBasedDirectory:".format(root))
 +    print("{}".format(filelist2))
 +    assert filelist == filelist2
++
++
 +@pytest.mark.parametrize("root", range(1, 11))
 +def test_random_directory_listing(cli, tmpdir, root):
 +    _listing_test(tmpdir, root, generate_random_root)
++
++
 +@pytest.mark.parametrize("root", [1, 2, 3, 4, 5])
 +def test_fixed_directory_listing(cli, tmpdir, root):
 +    _listing_test(tmpdir, root, generate_import_roots)
++
++
 +def main():
 +    for i in range(1, 6):
 +        with tempfile.TemporaryDirectory(prefix="/home/jimmacarthur/.cache/buildstream/cas") as tmpdirname:
 +            test_fixed_directory_listing(None, tmpdirname, i)
++
 +    for i in range(1, 11):
 +        with tempfile.TemporaryDirectory(prefix="/home/jimmacarthur/.cache/buildstream/cas") as tmpdirname:
 +            test_random_directory_listing(None, tmpdirname, i)
++
 +    for i in range(1, 21):
 +        for j in range(1, 21):
 +            with tempfile.TemporaryDirectory(prefix="/home/jimmacarthur/.cache/buildstream/cas") as tmpdirname:
 +                test_random_cas_import_fast(None, tmpdirname, i, j)
++
 +    for i in range(1, len(root_filesets) + 1):
 +        for j in range(1, len(root_filesets) + 1):
 +            with tempfile.TemporaryDirectory(prefix="/home/jimmacarthur/.cache/buildstream/cas") as tmpdirname:
 +                test_fixed_cas_import(None, tmpdirname, i, j)
++
++
 +if __name__ == "__main__":
 +    main()

[Notes] [Git][BuildStream/buildstream][jmac/cas_to_cas_v2] 2 commits: _casbaseddirectory.py: Enable direct CAS-to-CAS import.

Jim MacArthur pushed to branch jmac/cas_to_cas_v2 at BuildStream / buildstream

Commits:

2 changed files:

Changes: