changeset 40923:3ed77780f4a6

wireprotov2: send linknodes to emitfilerevisions()

Previously, linknodes were calculated within emitfilerevisions() by
using filectx.introrev(), which would always use the linkrev/linknode
as recorded by storage. This is wrong for cases where the receiver
doesn't have the changeset the linknode refers to.

This commit changes the logic for linknode emission so the mapping
of filenode to linknode is computed by the caller and passed into
emitfilerevisions().

As part of the change, linknodes for "filesdata" in the
haveparents=False case are now correct: the existing code performed a
manifest walk and it was trivial to plug in the correct linknode.

However, behavior for the haveparents=True case is still wrong
because it relies on filtering linkrevs against the outgoing set in
order to determine what to send. This will be fixed in a subsequent
commit.

The change test test-wireproto-exchangev2-shallow.t is a bit wonky.
The test repo has 6 revisions. The changed test is performing a shallow
clone with depth=1. So, only file data for revision 5 is present
locally. So, the new behavior of associating the linknode with
revision 5 for every file revision seems correct. Of course, when
backfilling old revisions, we'll want to update the linknode. But
this problem requires wire protocol support and we'll cross that
bridge later.

Differential Revision: https://phab.mercurial-scm.org/D5405

--- a/mercurial/wireprotov2server.py	Mon Dec 10 17:26:12 2018 +0000
+++ b/mercurial/wireprotov2server.py	Mon Dec 10 18:04:12 2018 +0000
@@ -984,9 +984,7 @@
 
     return fl
 
-def emitfilerevisions(repo, path, revisions, fields):
-    clnode = repo.changelog.node
-
+def emitfilerevisions(repo, path, revisions, linknodes, fields):
     for revision in revisions:
         d = {
             b'node': revision.node,
@@ -996,13 +994,7 @@
             d[b'parents'] = [revision.p1node, revision.p2node]
 
         if b'linknode' in fields:
-            # TODO by creating the filectx against a specific file revision
-            # instead of changeset, linkrev() is always used. This is wrong for
-            # cases where linkrev() may refer to a hidden changeset. We need an
-            # API for performing linkrev adjustment that takes this into
-            # account.
-            fctx = repo.filectx(path, fileid=revision.node)
-            d[b'linknode'] = clnode(fctx.introrev())
+            d[b'linknode'] = linknodes[revision.node]
 
         followingmeta = []
         followingdata = []
@@ -1086,6 +1078,9 @@
     except FileAccessError as e:
         raise error.WireprotoCommandError(e.msg, e.args)
 
+    clnode = repo.changelog.node
+    linknodes = {}
+
     # Validate requested nodes.
     for node in nodes:
         try:
@@ -1094,6 +1089,14 @@
             raise error.WireprotoCommandError('unknown file node: %s',
                                               (hex(node),))
 
+        # TODO by creating the filectx against a specific file revision
+        # instead of changeset, linkrev() is always used. This is wrong for
+        # cases where linkrev() may refer to a hidden changeset. But since this
+        # API doesn't know anything about changesets, we're not sure how to
+        # disambiguate the linknode. Perhaps we should delete this API?
+        fctx = repo.filectx(path, fileid=node)
+        linknodes[node] = clnode(fctx.introrev())
+
     revisions = store.emitrevisions(nodes,
                                     revisiondata=b'revision' in fields,
                                     assumehaveparentrevisions=haveparents)
@@ -1102,7 +1105,7 @@
         b'totalitems': len(nodes),
     }
 
-    for o in emitfilerevisions(repo, path, revisions, fields):
+    for o in emitfilerevisions(repo, path, revisions, linknodes, fields):
         yield o
 
 def filesdatacapabilities(repo, proto):
@@ -1154,12 +1157,14 @@
     # changeset.
 
     cl = repo.changelog
+    clnode = cl.node
     outgoing = resolvenodes(repo, revisions)
     filematcher = makefilematcher(repo, pathfilter)
 
     # Figure out what needs to be emitted.
     changedpaths = set()
-    fnodes = collections.defaultdict(set)
+    # path -> {fnode: linknode}
+    fnodes = collections.defaultdict(dict)
 
     for node in outgoing:
         ctx = repo[node]
@@ -1182,7 +1187,7 @@
                 linkrev = store.linkrev(rev)
 
                 if linkrev in outgoingclrevs:
-                    fnodes[path].add(store.node(rev))
+                    fnodes[path].setdefault(store.node(rev), clnode(linkrev))
 
     # If ancestors aren't known, we walk the manifests and send all
     # encountered file revisions.
@@ -1192,7 +1197,7 @@
 
             for path, fnode in mctx.read().items():
                 if filematcher(path):
-                    fnodes[path].add(fnode)
+                    fnodes[path].setdefault(fnode, node)
 
     yield {
         b'totalpaths': len(fnodes),
@@ -1210,11 +1215,11 @@
             b'totalitems': len(filenodes),
         }
 
-        revisions = store.emitrevisions(filenodes,
+        revisions = store.emitrevisions(filenodes.keys(),
                                         revisiondata=b'revision' in fields,
                                         assumehaveparentrevisions=haveparents)
 
-        for o in emitfilerevisions(repo, path, revisions, fields):
+        for o in emitfilerevisions(repo, path, revisions, filenodes, fields):
             yield o
 
 @wireprotocommand(

--- a/tests/test-wireproto-command-filesdata.t	Mon Dec 10 17:26:12 2018 +0000
+++ b/tests/test-wireproto-command-filesdata.t	Mon Dec 10 18:04:12 2018 +0000
@@ -1239,7 +1239,6 @@
 
 Request for changeset where recorded linknode isn't in DAG ancestry will get
 rewritten accordingly
-TODO this is buggy
 
   $ sendhttpv2peer << EOF
   > command filesdata
@@ -1263,7 +1262,7 @@
       b'totalitems': 1
     },
     {
-      b'linknode': b'\xb1l\xce)g\xc1t\x9e\xf4\xf4\xe3\x08j\x80l\xfb\xad\x8a:\xf7',
+      b'linknode': b'G\xfc0X\t\x11#,\xb2dg[@(\x19\xde\xdd\xf6\xc6\xf0',
       b'node': b'.\xd2\xa3\x91*\x0b$P C\xea\xe8N\xe4\xb2y\xc1\x8b\x90\xdd'
     }
   ]

--- a/tests/test-wireproto-exchangev2-shallow.t	Mon Dec 10 17:26:12 2018 +0000
+++ b/tests/test-wireproto-exchangev2-shallow.t	Mon Dec 10 18:04:12 2018 +0000
@@ -196,7 +196,7 @@
      node = I\x1d\xa1\xbb\x89\xeax\xc0\xc0\xa2s[\x16\xce}\x93\x1d\xc8\xe2\r (esc)
     p1rev = -1
     p2rev = -1
-  linkrev = 4
+  linkrev = 5
     flags = 2
   
        id = 4
@@ -205,7 +205,7 @@
      node = S\x82\x06\xdc\x97\x1eR\x15@\xd6\x84:\xbf\xe6\xd1`2\xf6\xd4& (esc)
     p1rev = -1
     p2rev = -1
-  linkrev = 1
+  linkrev = 5
     flags = 0
   
        id = 5
@@ -214,7 +214,7 @@
      node = ]\xf3\xac\xd8\xd0\xc7\xfaP\x98\xd0'\x9a\x044\xc3\x02\x9e+x\xe1 (esc)
     p1rev = -1
     p2rev = -1
-  linkrev = 4
+  linkrev = 5
     flags = 2
   
        id = 6
@@ -223,7 +223,7 @@
      node = (\xc7v\xae\x08\xd0\xd5^\xb4\x06H\xb4\x01\xb9\x0f\xf5DH4\x8e (esc)
     p1rev = -1
     p2rev = -1
-  linkrev = 4
+  linkrev = 5
     flags = 2
 
 Test a shallow clone with only some files
@@ -342,7 +342,7 @@
      node = I\x1d\xa1\xbb\x89\xeax\xc0\xc0\xa2s[\x16\xce}\x93\x1d\xc8\xe2\r (esc)
     p1rev = -1
     p2rev = -1
-  linkrev = 4
+  linkrev = 5
     flags = 2
   
        id = 2
@@ -351,7 +351,7 @@
      node = S\x82\x06\xdc\x97\x1eR\x15@\xd6\x84:\xbf\xe6\xd1`2\xf6\xd4& (esc)
     p1rev = -1
     p2rev = -1
-  linkrev = 1
+  linkrev = 5
     flags = 0
 
 Cloning an old revision with depth=1 works