diff mercurial/dirstatemap.py @ 48223:b4f83c9e7905

dirstate-v2: Add support when Rust is not enabled

This wires into `dirstatemap` the parser and serializer added in previous
changesets. The memory representation is still the same, with a flat `dict`
for `DirstateItem`s and another one for copy sources. Serialization always
creates a new dirstate-v2 data file and does not support (when Rust is not
enabled) appending to an existing one, since we don’t keep track of which
tree nodes are new or modified. Instead the tree is reconstructed during
serialization.

Differential Revision: https://phab.mercurial-scm.org/D11520

--- a/mercurial/dirstatemap.py	Thu Jul 22 17:31:37 2021 +0200
+++ b/mercurial/dirstatemap.py	Fri Jul 16 18:42:20 2021 +0200
@@ -332,15 +332,6 @@
       denormalized form that they appear as in the dirstate.
     """
 
-    def __init__(self, ui, opener, root, nodeconstants, use_dirstate_v2):
-        super(dirstatemap, self).__init__(
-            ui, opener, root, nodeconstants, use_dirstate_v2
-        )
-        if self._use_dirstate_v2:
-            msg = "Dirstate V2 not supportedi"
-            msg += "(should have detected unsupported requirement)"
-            raise error.ProgrammingError(msg)
-
     ### Core data storage and access
 
     @propertycache
@@ -406,19 +397,17 @@
             self._opener.join(self._filename)
         )
 
-        try:
-            fp = self._opendirstatefile()
-            try:
-                st = fp.read()
-            finally:
-                fp.close()
-        except IOError as err:
-            if err.errno != errno.ENOENT:
-                raise
-            return
+        if self._use_dirstate_v2:
+            if not self.docket.uuid:
+                return
+            st = self._opener.read(self.docket.data_filename())
+        else:
+            st = self._readdirstatefile()
+
         if not st:
             return
 
+        # TODO: adjust this estimate for dirstate-v2
         if util.safehasattr(parsers, b'dict_new_presized'):
             # Make an estimate of the number of files in the dirstate based on
             # its size. This trades wasting some memory for avoiding costly
@@ -440,8 +429,14 @@
         # parsing the dirstate.
         #
         # (we cannot decorate the function directly since it is in a C module)
-        parse_dirstate = util.nogc(parsers.parse_dirstate)
-        p = parse_dirstate(self._map, self.copymap, st)
+        if self._use_dirstate_v2:
+            p = self.docket.parents
+            meta = self.docket.tree_metadata
+            parse_dirstate = util.nogc(v2.parse_dirstate)
+            parse_dirstate(self._map, self.copymap, st, meta)
+        else:
+            parse_dirstate = util.nogc(parsers.parse_dirstate)
+            p = parse_dirstate(self._map, self.copymap, st)
         if not self._dirtyparents:
             self.setparents(*p)
 
@@ -450,10 +445,16 @@
         self.__getitem__ = self._map.__getitem__
         self.get = self._map.get
 
-    def write(self, _tr, st, now):
-        d = parsers.pack_dirstate(self._map, self.copymap, self.parents(), now)
-        st.write(d)
-        st.close()
+    def write(self, tr, st, now):
+        if self._use_dirstate_v2:
+            packed, meta = v2.pack_dirstate(self._map, self.copymap, now)
+            self.write_v2_no_append(tr, st, meta, packed)
+        else:
+            packed = parsers.pack_dirstate(
+                self._map, self.copymap, self.parents(), now
+            )
+            st.write(packed)
+            st.close()
         self._dirtyparents = False
 
     @propertycache