[meld] dirdiff: Add folder comparison settings and update helper to match

[Kai Willadsen <kaiw src gnome org>]

commit de2d45d6e33e8bda47bb679c54ddaa51eeaaede8
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Fri Nov 15 07:29:05 2013 +1000

    dirdiff: Add folder comparison settings and update helper to match

 data/org.gnome.meld.gschema.xml |   18 ++++++++
 meld/dirdiff.py                 |   82 ++++++++++++++++++++++++++++++--------
 2 files changed, 82 insertions(+), 18 deletions(-)
---
diff --git a/data/org.gnome.meld.gschema.xml b/data/org.gnome.meld.gschema.xml
index 6e86c87..998412e 100644
--- a/data/org.gnome.meld.gschema.xml
+++ b/data/org.gnome.meld.gschema.xml
@@ -45,5 +45,23 @@
           <summary>Highlight current line</summary>
           <description>If true, the line containing the cursor will be highlighted in file 
comparisons.</description>
       </key>
+
+
+      <!-- Folder comparsion properties -->
+      <key name="folder-columns" type="a(sb)">
+          <default>[("size", true), ("modification time", true), ("permissions", false)]</default>
+          <summary>Columns to display</summary>
+          <description>List of column names in folder comparison and whether they should be 
displayed.</description>
+      </key>
+      <key name="folder-shallow-comparison" type="b">
+          <default>false</default>
+          <summary>Use shallow comparison</summary>
+          <description>If true, folder comparisons compare files based solely on size and mtime, considering 
files to be identical if their size and mtime match, and different otherwise.</description>
+      </key>
+      <key name="folder-time-resolution" type="i">
+          <default>100</default>
+          <summary>File timestamp resolution</summary>
+          <description>When comparing based on mtime, this is the minimum difference in nanoseconds between 
two files before they're considered to have different mtimes. This is useful when comparing files between 
filesystems with different timestamp resolution.</description>
+      </key>
   </schema>
 </schemalist>
diff --git a/meld/dirdiff.py b/meld/dirdiff.py
index 4941dfc..255b4a5 100644
--- a/meld/dirdiff.py
+++ b/meld/dirdiff.py
@@ -20,6 +20,7 @@ import collections
 import copy
 import datetime
 import errno
+import functools
 import os
 import re
 import shutil
@@ -46,6 +47,8 @@ from gettext import gettext as _
 from gettext import ngettext
 from .meldapp import app
 
+from meld.settings import settings
+
 
 ################################################################################
 #
@@ -61,7 +64,7 @@ class StatItem(namedtuple('StatItem', 'mode size time')):
         return StatItem(stat.S_IFMT(stat_result.st_mode),
                         stat_result.st_size, stat_result.st_mtime)
 
-    def shallow_equal(self, other, prefs):
+    def shallow_equal(self, other, time_resolution_ns):
         if self.size != other.size:
             return False
 
@@ -72,8 +75,8 @@ class StatItem(namedtuple('StatItem', 'mode size time')):
 
         dectime1 = Decimal(str(self.time)).scaleb(Decimal(9)).quantize(1)
         dectime2 = Decimal(str(other.time)).scaleb(Decimal(9)).quantize(1)
-        mtime1 = dectime1 // prefs.dirdiff_time_resolution_ns
-        mtime2 = dectime2 // prefs.dirdiff_time_resolution_ns
+        mtime1 = dectime1 // time_resolution_ns
+        mtime2 = dectime2 // time_resolution_ns
 
         return mtime1 == mtime2
 
@@ -100,7 +103,7 @@ def remove_blank_lines(text):
     return ''.join(lines)
 
 
-def _files_same(files, regexes, prefs):
+def _files_same(files, regexes, comparison_args):
     """Determine whether a list of files are the same.
 
     Possible results are:
@@ -119,7 +122,11 @@ def _files_same(files, regexes, prefs):
     regexes = tuple(regexes)
     stats = tuple([StatItem._make(os.stat(f)) for f in files])
 
-    need_contents = regexes or prefs.ignore_blank_lines
+    shallow_comparison = comparison_args['shallow-comparison']
+    time_resolution_ns = comparison_args['time-resolution']
+    ignore_blank_lines = comparison_args['ignore_blank_lines']
+
+    need_contents = regexes or ignore_blank_lines
 
     # If all entries are directories, they are considered to be the same
     if all([stat.S_ISDIR(s.mode) for s in stats]):
@@ -130,8 +137,8 @@ def _files_same(files, regexes, prefs):
         return Different
 
     # Compare files superficially if the options tells us to
-    if prefs.dirdiff_shallow_comparison:
-        if all(s.shallow_equal(stats[0], prefs) for s in stats[1:]):
+    if shallow_comparison:
+        if all(s.shallow_equal(stats[0], time_resolution_ns) for s in stats[1:]):
             return DodgySame
         else:
             return Different
@@ -141,7 +148,7 @@ def _files_same(files, regexes, prefs):
         return Different
 
     # Check the cache before doing the expensive comparison
-    cache_key = (files, regexes, prefs.ignore_blank_lines)
+    cache_key = (files, regexes, ignore_blank_lines)
     cache = _cache.get(cache_key)
     if cache and cache.stats == stats:
         return cache.result
@@ -192,7 +199,7 @@ def _files_same(files, regexes, prefs):
         contents = ["".join(c) for c in contents]
         for r in regexes:
             contents = [re.sub(r, "", c) for c in contents]
-        if prefs.ignore_blank_lines:
+        if ignore_blank_lines:
             contents = [remove_blank_lines(c) for c in contents]
         result = SameFiltered if all_same(contents) else Different
 
@@ -242,7 +249,29 @@ class CanonicalListing(object):
 ################################################################################
 
 class DirDiff(melddoc.MeldDoc, gnomeglade.Component):
-    """Two or three way diff of directories"""
+    """Two or three way folder comparison"""
+
+    __gtype_name__ = "DirDiff"
+
+    columns = GObject.property(
+        type=GObject.TYPE_PYOBJECT,
+        nick="Columns to display",
+        blurb="List of columns to display in folder comparison",
+    )
+    shallow_comparison = GObject.property(
+        type=bool,
+        nick="Use shallow comparison",
+        blurb="Whether to compare files based solely on size and mtime",
+        default=False,
+    )
+    time_resolution = GObject.property(
+        type=int,
+        nick="Time resolution",
+        blurb="When comparing based on mtime, the minimum difference in "
+              "nanoseconds between two files before they're considered to "
+              "have different mtimes.",
+        default=100,
+    )
 
     """Dictionary mapping tree states to corresponding difflib-like terms"""
     chunk_type_map = {
@@ -380,6 +409,17 @@ class DirDiff(melddoc.MeldDoc, gnomeglade.Component):
                 action_name = self.state_actions[s][1]
                 self.actiongroup.get_action(action_name).set_active(True)
 
+        settings.bind('folder-shallow-comparison', self, 'shallow-comparison',
+                      Gio.SettingsBindFlags.DEFAULT)
+        settings.bind('folder-time-resolution', self, 'time-resolution',
+                      Gio.SettingsBindFlags.DEFAULT)
+        settings.bind('folder-columns', self, 'columns',
+                      Gio.SettingsBindFlags.DEFAULT)
+
+        self.update_comparator()
+        self.connect("notify::shallow-comparison", self.update_comparator)
+        self.connect("notify::time-resolution", self.update_comparator)
+
     def on_style_set(self, widget, prev_style):
         style = widget.get_style_context()
 
@@ -412,12 +452,18 @@ class DirDiff(melddoc.MeldDoc, gnomeglade.Component):
     def on_preference_changed(self, key, value):
         if key == "dirdiff_columns":
             self.update_treeview_columns(value)
-        elif key == "dirdiff_shallow_comparison":
-            self.refresh()
-        elif key == "dirdiff_time_resolution_ns":
-            self.refresh()
         elif key == "ignore_blank_lines":
-            self.refresh()
+            self.update_comparator()
+
+    def update_comparator(self, *args):
+        comparison_args = {
+            'shallow-comparison': self.props.shallow_comparison,
+            'time-resolution': self.props.time_resolution,
+            'ignore_blank_lines': self.prefs.ignore_blank_lines,
+        }
+        self.file_compare = functools.partial(
+            _files_same, comparison_args=comparison_args)
+        self.refresh()
 
     def update_treeview_columns(self, columns):
         """Update the visibility and order of columns"""
@@ -1162,7 +1208,7 @@ class DirDiff(melddoc.MeldDoc, gnomeglade.Component):
             is_present = [ os.path.exists( f ) for f in curfiles ]
             all_present = 0 not in is_present
             if all_present:
-                if _files_same(curfiles, regexes, self.prefs) in (Same, SameFiltered):
+                if self.file_compare(curfiles, regexes) in (Same, SameFiltered):
                     state = tree.STATE_NORMAL
                 else:
                     state = tree.STATE_MODIFIED
@@ -1194,7 +1240,7 @@ class DirDiff(melddoc.MeldDoc, gnomeglade.Component):
             newest_index = -1 # all same
         all_present = 0 not in mod_times
         if all_present:
-            all_same = _files_same(files, regexes, self.prefs)
+            all_same = self.file_compare(files, regexes)
             all_present_same = all_same
         else:
             lof = []
@@ -1202,7 +1248,7 @@ class DirDiff(melddoc.MeldDoc, gnomeglade.Component):
                 if mod_times[j]:
                     lof.append( files[j] )
             all_same = Different
-            all_present_same = _files_same(lof, regexes, self.prefs)
+            all_present_same = self.file_compare(lof, regexes)
         different = 1
         one_isdir = [None for i in range(self.model.ntree)]
         for j in range(self.model.ntree):