More work on the diff kitten

kittens/diff/render.py

@@ -0,0 +1,103 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+# License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
+
+import re
+from gettext import gettext as _
+from functools import partial
+
+from kitty.fast_data_types import wcswidth
+
+from .collect import data_for_path, path_name_map
+from .config import formats
+
+sanitize_pat = re.compile('[\x00-\x1f\x7f\x80-\x9f]')
+
+
+def human_readable(size, sep=' '):
+    """ Convert a size in bytes into a human readable form """
+    divisor, suffix = 1, "B"
+    for i, candidate in enumerate(('B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB')):
+        if size < (1 << ((i + 1) * 10)):
+            divisor, suffix = (1 << (i * 10)), candidate
+            break
+    size = str(float(size)/divisor)
+    if size.find(".") > -1:
+        size = size[:size.find(".")+2]
+    if size.endswith('.0'):
+        size = size[:-2]
+    return size + sep + suffix
+
+
+def sanitize_sub(m):
+    return '<{:x}>'.format(ord(m.group()[0]))
+
+
+def sanitize(text):
+    return sanitize_pat.sub(sanitize_sub, text)
+
+
+def fit_in(text, count):
+    w = wcswidth(text)
+    if w <= count:
+        return text
+    text = text[:count-1]
+    while wcswidth(text) > count - 1:
+        text = text[:-1]
+    return text + '…'
+
+
+def formatted(fmt, text):
+    return '\x1b[' + fmt + 'm' + text + '\x1b[0m'
+
+
+title_format = partial(formatted, formats['title'])
+margin_format = partial(formatted, formats['margin'])
+text_format = partial(formatted, formats['text'])
+del formatted
+
+
+def place_in(text, sz):
+    return fit_in(text, sz).ljust(sz)
+
+
+def title_lines(left_path, right_path, args, columns, margin_size):
+    name = fit_in(sanitize(path_name_map[left_path]), columns - 2 * margin_size)
+    yield title_format((' ' + name).ljust(columns))
+    yield title_format('━' * columns)
+    yield title_format(' ' * columns)
+
+
+def binary_lines(path, other_path, columns, margin_size):
+    template = _('Binary file: {}')
+
+    def fl(path):
+        text = template.format(human_readable(len(data_for_path(path))))
+        text = place_in(text, columns // 2 - margin_size)
+        return margin_format(' ' * margin_size) + text_format(text)
+
+    return fl(path) + fl(other_path)
+
+
+def lines_for_diff(left_path, right_path, hunks, args, columns, margin_size):
+    return iter(())
+
+
+def render_diff(collection, diff_map, args, columns):
+    largest_line_number = 0
+    for path, item_type, other_path in collection:
+        if item_type == 'diff':
+            patch = diff_map.get(path)
+            if patch is not None:
+                largest_line_number = max(largest_line_number, patch.largest_line_number)
+
+    margin_size = max(3, len(str(largest_line_number)) + 1)
+
+    for path, item_type, other_path in collection:
+        if item_type == 'diff':
+            yield from title_lines(path, other_path, args, columns, margin_size)
+            is_binary = isinstance(data_for_path(path), bytes)
+            if is_binary:
+                yield from binary_lines(path, other_path, columns, margin_size)
+            else:
+                yield from lines_for_diff(path, other_path, diff_map[path], args, columns, margin_size)