refactor<*>: rewrite all with AvaloniaUI

src/Commands/QueryFileSize.cs

@@ -0,0 +1,29 @@
+using System.Text.RegularExpressions;
+
+namespace SourceGit.Commands {
+    public class QueryFileSize : Command {
+        private static readonly Regex REG_FORMAT = new Regex(@"^\d+\s+\w+\s+[0-9a-f]+\s+(\d+)\s+.*$");
+
+        public QueryFileSize(string repo, string file, string revision) {
+            WorkingDirectory = repo;
+            Context = repo;
+            Args = $"ls-tree {revision} -l -- {file}";
+        }
+
+        public long Result() {
+            if (_result != 0) return _result;
+
+            var rs = ReadToEnd();
+            if (rs.IsSuccess) {
+                var match = REG_FORMAT.Match(rs.StdOut);
+                if (match.Success) {
+                    return long.Parse(match.Groups[1].Value);
+                }
+            }
+
+            return 0;
+        }
+
+        private long _result = 0;
+    }
+}