narrow: extract helper for parsing narrowspec file

This will be used for parsing a file that's stored in a different
location.

Differential Revision: https://phab.mercurial-scm.org/D5277

mercurial/narrowspec.py

@@ -1,225 +1,228
 # narrowspec.py - methods for working with a narrow view of a repository
 #
 # Copyright 2017 Google, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import errno
 
 from .i18n import _
 from . import (
     error,
     match as matchmod,
     repository,
     sparse,
     util,
 )
 
 FILENAME = 'narrowspec'
 
 # Pattern prefixes that are allowed in narrow patterns. This list MUST
 # only contain patterns that are fast and safe to evaluate. Keep in mind
 # that patterns are supplied by clients and executed on remote servers
 # as part of wire protocol commands. That means that changes to this
 # data structure influence the wire protocol and should not be taken
 # lightly - especially removals.
 VALID_PREFIXES = (
     b'path:',
     b'rootfilesin:',
 )
 
 def normalizesplitpattern(kind, pat):
     """Returns the normalized version of a pattern and kind.
 
     Returns a tuple with the normalized kind and normalized pattern.
     """
     pat = pat.rstrip('/')
     _validatepattern(pat)
     return kind, pat
 
 def _numlines(s):
     """Returns the number of lines in s, including ending empty lines."""
     # We use splitlines because it is Unicode-friendly and thus Python 3
     # compatible. However, it does not count empty lines at the end, so trick
     # it by adding a character at the end.
     return len((s + 'x').splitlines())
 
 def _validatepattern(pat):
     """Validates the pattern and aborts if it is invalid.
 
     Patterns are stored in the narrowspec as newline-separated
     POSIX-style bytestring paths. There's no escaping.
     """
 
     # We use newlines as separators in the narrowspec file, so don't allow them
     # in patterns.
     if _numlines(pat) > 1:
         raise error.Abort(_('newlines are not allowed in narrowspec paths'))
 
     components = pat.split('/')
     if '.' in components or '..' in components:
         raise error.Abort(_('"." and ".." are not allowed in narrowspec paths'))
 
 def normalizepattern(pattern, defaultkind='path'):
     """Returns the normalized version of a text-format pattern.
 
     If the pattern has no kind, the default will be added.
     """
     kind, pat = matchmod._patsplit(pattern, defaultkind)
     return '%s:%s' % normalizesplitpattern(kind, pat)
 
 def parsepatterns(pats):
     """Parses an iterable of patterns into a typed pattern set.
 
     Patterns are assumed to be ``path:`` if no prefix is present.
     For safety and performance reasons, only some prefixes are allowed.
     See ``validatepatterns()``.
 
     This function should be used on patterns that come from the user to
     normalize and validate them to the internal data structure used for
     representing patterns.
     """
     res = {normalizepattern(orig) for orig in pats}
     validatepatterns(res)
     return res
 
 def validatepatterns(pats):
     """Validate that patterns are in the expected data structure and format.
 
     And that is a set of normalized patterns beginning with ``path:`` or
     ``rootfilesin:``.
 
     This function should be used to validate internal data structures
     and patterns that are loaded from sources that use the internal,
     prefixed pattern representation (but can't necessarily be fully trusted).
     """
     if not isinstance(pats, set):
         raise error.ProgrammingError('narrow patterns should be a set; '
                                      'got %r' % pats)
 
     for pat in pats:
         if not pat.startswith(VALID_PREFIXES):
             # Use a Mercurial exception because this can happen due to user
             # bugs (e.g. manually updating spec file).
             raise error.Abort(_('invalid prefix on narrow pattern: %s') % pat,
                               hint=_('narrow patterns must begin with one of '
                                      'the following: %s') %
                                    ', '.join(VALID_PREFIXES))
 
 def format(includes, excludes):
     output = '[include]\n'
     for i in sorted(includes - excludes):
         output += i + '\n'
     output += '[exclude]\n'
     for e in sorted(excludes):
         output += e + '\n'
     return output
 
 def match(root, include=None, exclude=None):
     if not include:
         # Passing empty include and empty exclude to matchmod.match()
         # gives a matcher that matches everything, so explicitly use
         # the nevermatcher.
         return matchmod.never(root, '')
     return matchmod.match(root, '', [], include=include or [],
                           exclude=exclude or [])
 
+def parseconfig(ui, spec):
+    # maybe we should care about the profiles returned too
+    includepats, excludepats, profiles = sparse.parseconfig(ui, spec, 'narrow')
+    if profiles:
+        raise error.Abort(_("including other spec files using '%include' is not"
+                            " supported in narrowspec"))
+
+    validatepatterns(includepats)
+    validatepatterns(excludepats)
+
+    return includepats, excludepats
+
 def load(repo):
     try:
         spec = repo.svfs.read(FILENAME)
     except IOError as e:
         # Treat "narrowspec does not exist" the same as "narrowspec file exists
         # and is empty".
         if e.errno == errno.ENOENT:
             return set(), set()
         raise
-    # maybe we should care about the profiles returned too
-    includepats, excludepats, profiles = sparse.parseconfig(repo.ui, spec,
-                                                            'narrow')
-    if profiles:
-        raise error.Abort(_("including other spec files using '%include' is not"
-                            " supported in narrowspec"))
 
-    validatepatterns(includepats)
-    validatepatterns(excludepats)
-
-    return includepats, excludepats
+    return parseconfig(repo.ui, spec)
 
 def save(repo, includepats, excludepats):
     validatepatterns(includepats)
     validatepatterns(excludepats)
     spec = format(includepats, excludepats)
     repo.svfs.write(FILENAME, spec)
 
 def savebackup(repo, backupname):
     if repository.NARROW_REQUIREMENT not in repo.requirements:
         return
     vfs = repo.vfs
     vfs.tryunlink(backupname)
     util.copyfile(repo.svfs.join(FILENAME), vfs.join(backupname), hardlink=True)
 
 def restorebackup(repo, backupname):
     if repository.NARROW_REQUIREMENT not in repo.requirements:
         return
     util.rename(repo.vfs.join(backupname), repo.svfs.join(FILENAME))
 
 def clearbackup(repo, backupname):
     if repository.NARROW_REQUIREMENT not in repo.requirements:
         return
     repo.vfs.unlink(backupname)
 
 def restrictpatterns(req_includes, req_excludes, repo_includes, repo_excludes):
     r""" Restricts the patterns according to repo settings,
     results in a logical AND operation
 
     :param req_includes: requested includes
     :param req_excludes: requested excludes
     :param repo_includes: repo includes
     :param repo_excludes: repo excludes
     :return: include patterns, exclude patterns, and invalid include patterns.
 
     >>> restrictpatterns({'f1','f2'}, {}, ['f1'], [])
     (set(['f1']), {}, [])
     >>> restrictpatterns({'f1'}, {}, ['f1','f2'], [])
     (set(['f1']), {}, [])
     >>> restrictpatterns({'f1/fc1', 'f3/fc3'}, {}, ['f1','f2'], [])
     (set(['f1/fc1']), {}, [])
     >>> restrictpatterns({'f1_fc1'}, {}, ['f1','f2'], [])
     ([], set(['path:.']), [])
     >>> restrictpatterns({'f1/../f2/fc2'}, {}, ['f1','f2'], [])
     (set(['f2/fc2']), {}, [])
     >>> restrictpatterns({'f1/../f3/fc3'}, {}, ['f1','f2'], [])
     ([], set(['path:.']), [])
     >>> restrictpatterns({'f1/$non_exitent_var'}, {}, ['f1','f2'], [])
     (set(['f1/$non_exitent_var']), {}, [])
     """
     res_excludes = set(req_excludes)
     res_excludes.update(repo_excludes)
     invalid_includes = []
     if not req_includes:
         res_includes = set(repo_includes)
     elif 'path:.' not in repo_includes:
         res_includes = []
         for req_include in req_includes:
             req_include = util.expandpath(util.normpath(req_include))
             if req_include in repo_includes:
                 res_includes.append(req_include)
                 continue
             valid = False
             for repo_include in repo_includes:
                 if req_include.startswith(repo_include + '/'):
                     valid = True
                     res_includes.append(req_include)
                     break
             if not valid:
                 invalid_includes.append(req_include)
         if len(res_includes) == 0:
             res_excludes = {'path:.'}
         else:
             res_includes = set(res_includes)
     else:
         res_includes = set(req_includes)
     return res_includes, res_excludes, invalid_includes