mergeresult: introduce action -> (filename, data, msg) mapping and related API

Good number of places in code, we iterate over the actions dict which has
filename as keys and filter based on the action.

This patch introduced another mapping which has action as key. This will help in
refactoring the code much more in upcoming patch.

Differential Revision: https://phab.mercurial-scm.org/D8830

mercurial/merge.py

@@ -7,6 +7,7 b''
 
 from __future__ import absolute_import
 
+import collections
 import errno
 import stat
 import struct
@@ -564,11 +565,14 b' class mergeresult(object):'
                       deleted on one side and renamed on other.
         commitinfo: dict containing data which should be used on commit
                     contains a filename -> info mapping
+        actionmapping: dict of action names as keys and list of files and
+                       related data as values
         """
         self._filemapping = {}
         self._diverge = {}
         self._renamedelete = {}
         self._commitinfo = {}
+        self._actionmapping = collections.defaultdict(list)
 
     def updatevalues(self, diverge, renamedelete, commitinfo):
         self._diverge = diverge
@@ -583,12 +587,33 b' class mergeresult(object):'
         data: a tuple of information like fctx and ctx related to this merge
         message: a message about the merge
         """
+        # if the file already existed, we need to delete it's old
+        # entry form _actionmapping too
+        if filename in self._filemapping:
+            # TODO: this is inefficient
+            a, d, m = self._filemapping[filename]
+            self._actionmapping[a].remove((filename, d, m))
+
         self._filemapping[filename] = (action, data, message)
+        self._actionmapping[action].append((filename, data, message))
 
     def removefile(self, filename):
         """ removes a file from the mergeresult object as the file might
         not merging anymore """
+        action, data, message = self._filemapping[filename]
         del self._filemapping[filename]
+        # TODO: this is inefficient
+        self._actionmapping[action].remove((filename, data, message))
+
+    def getactions(self, actions):
+        """ get list of files which are marked with these actions
+
+        Returns a list of tuple of form (filename, data, message)
+        """
+        res = []
+        for a in actions:
+            res.extend(self._actionmapping[a])
+        return res
 
     @property
     def actions(self):
@@ -610,20 +635,17 b' class mergeresult(object):'
     def actionsdict(self):
         """ returns a dictionary of actions to be perfomed with action as key
         and a list of files and related arguments as values """
-        # Convert to dictionary-of-lists format
-        actions = emptyactions()
-        for f, (m, args, msg) in pycompat.iteritems(self._filemapping):
-            if m not in actions:
-                actions[m] = []
-            actions[m].append((f, args, msg))
-
-        return actions
+        return self._actionmapping
 
     def setactions(self, actions):
         self._filemapping = actions
+        self._actionmapping = collections.defaultdict(list)
+        for f, (act, data, msg) in pycompat.iteritems(self._filemapping):
+            self._actionmapping[act].append((f, data, msg))
 
     def updateactions(self, updates):
-        self._filemapping.update(updates)
+        for f, (a, data, msg) in pycompat.iteritems(updates):
+            self.addfile(f, a, data, msg)
 
     def hasconflicts(self):
         """ tells whether this merge resulted in some actions which can