# HG changeset patch
# User Patrick Mezard <patrick@mezard.eu>
# Date 1348523063 -7200
# Node ID 34a1217b821886bd636da5118c8364c66454ad1b
# Parent  997de286ba0cc7e18796c68d9f0bed607453dbf0
editor: resolve files copied by directory copy on-demand

Before this change, the data of files brought by directory copies was
resolved immediately and stored for the duration of the run. Now, only
references are stored and are resolved either when opening the files or
when closing the editor. It means RevisionData file data is only set
once per file and only when the file has been handled.

The next step is to turn RevisionData into a data store backed by the
filesystem.

diff --git a/hgsubversion/editor.py b/hgsubversion/editor.py
--- a/hgsubversion/editor.py
+++ b/hgsubversion/editor.py
@@ -104,6 +104,23 @@ class RevisionData(object):
 class EditingError(Exception):
     pass
 
+class CopiedFile(object):
+    def __init__(self, node, path, copypath):
+        self.node = node
+        self.path = path
+        self.copypath = copypath
+
+    def resolve(self, repo, ctx=None):
+        if ctx is None:
+            ctx = repo[self.node]
+        fctx = ctx[self.path]
+        data = fctx.data()
+        flags = fctx.flags()
+        islink = 'l' in flags
+        if islink:
+            data = 'link ' + data
+        return data, 'x' in flags, islink, self.copypath
+
 class HgEditor(svnwrap.Editor):
 
     def __init__(self, meta):
@@ -115,7 +132,7 @@ class HgEditor(svnwrap.Editor):
 
     def _clear(self):
         self._filecounter = 0
-        # A mapping of svn paths to (data, isexec, islink, copypath) tuples
+        # A mapping of svn paths to CopiedFile entries
         self._svncopies = {}
         # A mapping of batons to (path, data, isexec, islink, copypath) tuples
         self._openfiles = {}
@@ -182,7 +199,8 @@ class HgEditor(svnwrap.Editor):
         self.ui.note('M %s\n' % path)
 
         if path in self._svncopies:
-            base, isexec, islink, copypath = self._svncopies.pop(path)
+            copy = self._svncopies.pop(path)
+            base, isexec, islink, copypath = copy.resolve(self.repo)
             return self._openfile(path, base, isexec, islink, copypath)
 
         if not self.meta.is_path_valid(path):
@@ -316,12 +334,7 @@ class HgEditor(svnwrap.Editor):
                 continue
             fctx = fromctx.filectx(f)
             dest = path + '/' + f[len(frompath):]
-            flags = fctx.flags()
-            islink = 'l' in flags
-            data = fctx.data()
-            if islink:
-                data = 'link ' + data
-            svncopies[dest] = (data, 'x' in flags, islink, None)
+            svncopies[dest] = CopiedFile(new_hash, f, None)
             if dest in self.current.deleted:
                 # Remove this once svn copies and edited files are
                 # clearly separated.
@@ -337,8 +350,7 @@ class HgEditor(svnwrap.Editor):
                 parentctx = self.repo.changectx(parentid)
                 for k, v in copies.iteritems():
                     if util.issamefile(parentctx, fromctx, v):
-                        data, isexec, islink = svncopies[k][:-1]
-                        svncopies[k] = (data, isexec, islink, v)
+                        svncopies[k].copypath = v
         self._svncopies.update(svncopies)
 
         # Copy the externals definitions of copied directories
@@ -449,10 +461,16 @@ class HgEditor(svnwrap.Editor):
             raise EditingError('%d edited files were not closed'
                     % len(self._openfiles))
 
-        for c in self._svncopies.iteritems():
-            dest, (data, isexec, islink, copied) = c
-            self.current.set(dest, data, isexec, islink)
-            self.current.copies[dest] = copied
+        # Resolve by changelog entries to avoid extra reads
+        nodes = {}
+        for path, copy in self._svncopies.iteritems():
+            nodes.setdefault(copy.node, []).append((path, copy))
+        for node, copies in nodes.iteritems():
+            ctx = self.repo[node]
+            for path, copy in copies:
+                data, isexec, islink, copied = copy.resolve(self.repo, ctx)
+                self.current.set(path, data, isexec, islink)
+                self.current.copies[path] = copied
         self._svncopies.clear()
 
 _TXDELT_WINDOW_HANDLER_FAILURE_MSG = (