snapshot: keep a list of snapshots in .hg/store/snapshotlist

Reviewed By: markbt

Differential Revision: D17226709

fbshipit-source-id: fefa31227f77295793ccaa3448f4488274f70848

edenscm/hgext/snapshot/cmds.py

@@ -20,6 +20,7 @@ from edenscm.mercurial import (
 from edenscm.mercurial.i18n import _
 
 from .metadata import snapshotmetadata
+from .snapshotlist import snapshotlist
 
 
 cmdtable = {}
@@ -81,6 +82,8 @@ def snapshotcreate(ui, repo, *args, **opts):
         if not node:
             ui.status(_("nothing changed\n"))
             return
+        with repo.transaction("update-snapshot-list") as tr:
+            snapshotlist(repo).add([node], tr)
         ui.status(_("snapshot %s created\n") % (repo[node].hex()))
         if visibility.enabled(repo):
             visibility.remove(repo, [node])

edenscm/hgext/snapshot/snapshotlist.py

@@ -0,0 +1,49 @@
+# -*- coding: utf-8 -*-
+
+# snapshotlist.py
+#
+# Copyright 2019 Facebook, 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 edenscm.mercurial import error, node
+
+
+# Supported file format version.
+# Version 1 is:
+#  * A single line containing "v1"
+#  * A list of node hashes for each snapshot, one per line.
+FORMAT_VERSION = "v1"
+
+
+class snapshotlist(object):
+    """list of local snapshots
+    """
+
+    def __init__(self, repo):
+        self.vfs = repo.svfs
+        try:
+            lines = self.vfs("snapshotlist").readlines()
+            if not lines or lines[0].strip() != FORMAT_VERSION:
+                raise error.Abort("invalid snapshots file format")
+            self.snapshots = {node.bin(snapshot.strip()) for snapshot in lines[1:]}
+        except IOError as err:
+            if err.errno != errno.ENOENT:
+                raise
+            self.snapshots = set()
+
+    def _write(self, fp):
+        fp.write("%s\n" % FORMAT_VERSION)
+        for s in sorted(self.snapshots):
+            fp.write("%s\n" % (node.hex(s),))
+
+    def add(self, newnodes, tr):
+        newnodes = self.snapshots.union(newnodes)
+        if self.snapshots != newnodes:
+            self.snapshots = newnodes
+            tr.addfilegenerator("snapshots", ("snapshotlist",), self._write)

tests/test-fb-hgext-snapshot.t

@@ -255,6 +255,13 @@
   $ cat .hg/store/snapshots/objects/"${METADATAID:0:2}"/"${METADATAID:2}"
   {"files": {"deleted": {"foofile": null}, "localvfsfiles": {"merge/fc4ffdcb8ed23cecd44a0e11d23af83b445179b4": {"oid": "0263829989b6fd954f72baaf2fc64bc2e2f01d692d4de72986ea808f6e99813f", "size": "2"}, "merge/state": {"oid": "fdfea51dfeeae94bd846473c7bef891823af465d33f48e92ed2556bde6b346cb", "size": "166"}, "merge/state2": {"oid": "0e421047ebcf7d0cada48ddd801304725de33da3c4048ccb258041946cd0e81d", "size": "361"}}, "unknown": {"mergefile.orig": {"oid": "0263829989b6fd954f72baaf2fc64bc2e2f01d692d4de72986ea808f6e99813f", "size": "2"}, "untrackedfile": {"oid": "b05b74c474c1706953bed876a19f146b371ddf51a36474fe0c094922385cc479", "size": "5"}}}, "version": "1"} (no-eol)
 
+# Check the list of snapshots
+  $ cat .hg/store/snapshotlist
+  v1
+  37c08567761738ed25fa7a8d497dc14de9dfa969
+  aaa7692160b6c5c0e4c13787d9343cf89fc2311a
+  c6f3170138389ab1cc8dd2d43fc275e5add2e1a2
+
 # Move back to BASEREV
   $ hg update -q --clean "$BASEREV" && rm bazfile
   $ rm mergefile.orig