Junk table dispatch for execute

projects/vfs/src/python/vfs/impl.py

@@ -16,64 +16,75 @@ class Vfs(object):
     def __init__(self, log=None):
         self._log = log or []
 
+    def _execute_exec(self, e):
+        _, dir, cmd = e
+        run(cmd, cwd=str(dir))
+
+    def _execute_link(self, e):
+        _, src, dest = e
+        if dest.is_file() or dest.is_symlink():
+            if dest.is_symlink() and dest.readlink() == src:
+                return
+            else:
+                _log.warn(f"Replacing {dest}")
+                dest.unlink()
+        elif dest.is_dir():
+            _log.warn(f"Replacing {dest}")
+            rmtree(dest)
+
+        assert not dest.exists(), f"{dest} should not exist"
+        dest.symlink_to(src)
+
+    def _execute_chmod(self, e):
+        _, dest, mode = e
+        dest.chmod(mode)
+
+    def _execute_mkdir(self, e):
+        _, dest = e
+        if dest.is_dir():
+            return
+        elif dest.exists() or dest.is_symlink():
+            dest.unlink()
+
+        dest.mkdir(exist_ok=True)
+
+    def _execute_unlink(self, e):
+        _, dest = e
+        # Note that a path which is a dangling symlink will NOT exist but WILL be a symlink
+        if not dest.exists() and not dest.is_symlink():
+            return
+        # Files and dirs just unlink
+        if dest.is_symlink() or dest.is_file():
+            dest.unlink()
+            # Dirs require recursion
+        elif dest.is_dir():
+            rmtree(dest)
+            # Don't succeed silently
+        else:
+            raise Exception(f"Couldn't unlink {dest}")
+
+    def _execute_unimplemented(self, e):
+        raise NotImplementedError()
+
+    def _entry_to_command(self, e):
+        return e
+
     def execute(self, /, callback=None):
         for e in self._log:
-            _log.debug(e)
+            cmd = self._entry_to_command(e)
+            _log.debug(f"Executing %r as %r", e, cmd)
+
             if callback:
-                callback(e)
+                callback(cmd)
 
-            if e[0] == "exec":
+            # Using self as a dispatch table lol
-                _, dir, cmd = e
+            getattr(self, f"_execute_{cmd[0]}", self._execute_unimplemented)(cmd)
-                run(cmd, cwd=str(dir))
 
-            elif e[0] == "link":
+    def _command_to_entry(self, cmd):
-                _, src, dest = e
+        return cmd
-                if dest.is_file() or dest.is_symlink():
-                    if dest.is_symlink() and dest.readlink() == src:
-                        continue
-                    else:
-                        _log.warn(f"Replacing {dest}")
-                        dest.unlink()
-                elif dest.is_dir():
-                    _log.warn(f"Replacing {dest}")
-                    rmtree(dest)
 
-                assert not dest.exists(), f"{dest} should not exist"
+    def _append(self, cmd):
-                dest.symlink_to(src)
+        self._log.append(self._command_to_entry(cmd))
-
-            elif e[0] == "copy":
-                raise NotImplementedError()
-
-            elif e[0] == "chmod":
-                _, dest, mode = e
-                dest.chmod(mode)
-
-            elif e[0] == "mkdir":
-                _, dest = e
-                if dest.is_dir():
-                    continue
-                elif dest.exists() or dest.is_symlink():
-                    dest.unlink()
-
-                dest.mkdir(exist_ok=True)
-
-            elif e[0] == "unlink":
-                _, dest = e
-                # Note that a path which is a dangling symlink will NOT exist but WILL be a symlink
-                if not dest.exists() and not dest.is_symlink():
-                    continue
-                # Files and dirs just unlink
-                if dest.is_symlink() or dest.is_file():
-                    dest.unlink()
-                # Dirs require recursion
-                elif dest.is_dir():
-                    rmtree(dest)
-                # Don't succeed silently
-                else:
-                    raise Exception(f"Couldn't unlink {dest}")
-
-    def _append(self, msg):
-        self._log.append(msg)
 
     def link(self, src, dest):
         self._append(("link", src, dest))