Infrastructure for current directory handling

[stgit] / stgit / commands / common.py

diff --git a/stgit/commands/common.py b/stgit/commands/common.py
index 8ed47ca..27ef465 100644 (file)
--- a/stgit/commands/common.py
+++ b/stgit/commands/common.py
@@ -21,8 +21,10 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 import sys, os, os.path, re
 from optparse import OptionParser, make_option
 
+from stgit.exception import *
 from stgit.utils import *
 from stgit.out import *
+from stgit.run import *
 from stgit import stack, git, basedir
 from stgit.config import config, file_extensions
 
@@ -30,12 +32,11 @@ crt_series = None
 
 
 # Command exception class
-class CmdException(Exception):
+class CmdException(StgException):
     pass
 
-
 # Utility functions
-class RevParseException(Exception):
+class RevParseException(StgException):
     """Revision spec parse error."""
     pass
 
@@ -114,9 +115,9 @@ def check_local_changes():
 def check_head_top_equal():
     if not crt_series.head_top_equal():
         raise CmdException(
-            'HEAD and top are not the same. You probably committed\n'
-            '  changes to the tree outside of StGIT. To bring them\n'
-            '  into StGIT, use the "assimilate" command')
+"""HEAD and top are not the same. This can happen if you
+   modify a branch with git. The "assimilate" command can
+   fix this situation.""")
 
 def check_conflicts():
     if os.path.exists(os.path.join(basedir.get(), 'conflicts')):
@@ -318,14 +319,7 @@ def address_or_alias(addr_str):
                  for addr in addr_str.split(',')]
     return ', '.join([addr for addr in addr_list if addr])
 
-def prepare_rebase(force=None):
-    if not force:
-        # Be sure we won't loose results of stg-(un)commit by error.
-        # Do not require an existing orig-base for compatibility with 0.12 and earlier.
-        origbase = crt_series._get_field('orig-base')
-        if origbase and crt_series.get_base() != origbase:
-            raise CmdException, 'Rebasing would possibly lose data'
-
+def prepare_rebase():
     # pop all patches
     applied = crt_series.get_applied()
     if len(applied) > 0:
@@ -335,11 +329,20 @@ def prepare_rebase(force=None):
     return applied
 
 def rebase(target):
-    if target == git.get_head():
+    try:
+        tree_id = git_id(target)
+    except:
+        # it might be that we use a custom rebase command with its own
+        # target type
+        tree_id = target
+    if tree_id == git.get_head():
         out.info('Already at "%s", no need for rebasing.' % target)
         return
-    out.start('Rebasing to "%s"' % target)
-    git.reset(tree_id = git_id(target))
+    if target:
+        out.start('Rebasing to "%s"' % target)
+    else:
+        out.start('Rebasing to the default target')
+    git.rebase(tree_id = tree_id)
     out.done()
 
 def post_rebase(applied, nopush, merged):
@@ -478,3 +481,70 @@ def parse_patch(fobj):
     # we don't yet have an agreed place for the creation date.
     # Just return None
     return (descr, authname, authemail, authdate, diff)
+
+def readonly_constant_property(f):
+    """Decorator that converts a function that computes a value to an
+    attribute that returns the value. The value is computed only once,
+    the first time it is accessed."""
+    def new_f(self):
+        n = '__' + f.__name__
+        if not hasattr(self, n):
+            setattr(self, n, f(self))
+        return getattr(self, n)
+    return property(new_f)
+
+class DirectoryException(StgException):
+    pass
+
+class _Directory(object):
+    @readonly_constant_property
+    def git_dir(self):
+        try:
+            return Run('git-rev-parse', '--git-dir'
+                       ).discard_stderr().output_one_line()
+        except RunException:
+            raise DirectoryException('No git repository found')
+    @readonly_constant_property
+    def __topdir_path(self):
+        try:
+            lines = Run('git-rev-parse', '--show-cdup'
+                        ).discard_stderr().output_lines()
+            if len(lines) == 0:
+                return '.'
+            elif len(lines) == 1:
+                return lines[0]
+            else:
+                raise RunException('Too much output')
+        except RunException:
+            raise DirectoryException('No git repository found')
+    @readonly_constant_property
+    def is_inside_git_dir(self):
+        return { 'true': True, 'false': False
+                 }[Run('git-rev-parse', '--is-inside-git-dir'
+                       ).output_one_line()]
+    @readonly_constant_property
+    def is_inside_worktree(self):
+        return { 'true': True, 'false': False
+                 }[Run('git-rev-parse', '--is-inside-work-tree'
+                       ).output_one_line()]
+    def cd_to_topdir(self):
+        os.chdir(self.__topdir_path)
+
+class DirectoryAnywhere(_Directory):
+    def setup(self):
+        pass
+
+class DirectoryHasRepository(_Directory):
+    def setup(self):
+        self.git_dir # might throw an exception
+
+class DirectoryInWorktree(DirectoryHasRepository):
+    def setup(self):
+        DirectoryHasRepository.setup(self)
+        if not self.is_inside_worktree:
+            raise DirectoryException('Not inside a git worktree')
+
+class DirectoryGotoToplevel(DirectoryInWorktree):
+    def setup(self):
+        DirectoryInWorktree.setup(self)
+        self.cd_to_topdir()