Added minimal version of watchdog

Sublime/fl0w/watchdog/utils/echo.py

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+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# echo.py: Tracing function calls using Python decorators.
+#
+# Written by Thomas Guest <tag@wordaligned.org>
+# Please see http://wordaligned.org/articles/echo
+#
+# Place into the public domain.
+
+""" Echo calls made to functions and methods in a module.
+
+"Echoing" a function call means printing out the name of the function
+and the values of its arguments before making the call (which is more
+commonly referred to as "tracing", but Python already has a trace module).
+
+Example: to echo calls made to functions in "my_module" do:
+
+  import echo
+  import my_module
+  echo.echo_module(my_module)
+
+Example: to echo calls made to functions in "my_module.my_class" do:
+
+  echo.echo_class(my_module.my_class)
+
+Alternatively, echo.echo can be used to decorate functions. Calls to the
+decorated function will be echoed.
+
+Example:
+
+  @echo.echo
+  def my_function(args):
+      pass
+"""
+import inspect
+import sys
+
+
+def name(item):
+    " Return an item's name. "
+    return item.__name__
+
+
+def is_classmethod(instancemethod):
+    " Determine if an instancemethod is a classmethod. "
+    return instancemethod.__self__ is not None
+
+
+def is_class_private_name(name):
+    " Determine if a name is a class private name. "
+    # Exclude system defined names such as __init__, __add__ etc
+    return name.startswith("__") and not name.endswith("__")
+
+
+def method_name(method):
+    """ Return a method's name.
+
+    This function returns the name the method is accessed by from
+    outside the class (i.e. it prefixes "private" methods appropriately).
+    """
+    mname = name(method)
+    if is_class_private_name(mname):
+        mname = "_%s%s" % (name(method.__self__.__class__), mname)
+    return mname
+
+
+def format_arg_value(arg_val):
+    """ Return a string representing a (name, value) pair.
+
+    >>> format_arg_value(('x', (1, 2, 3)))
+    'x=(1, 2, 3)'
+    """
+    arg, val = arg_val
+    return "%s=%r" % (arg, val)
+
+
+def echo(fn, write=sys.stdout.write):
+    """ Echo calls to a function.
+
+    Returns a decorated version of the input function which "echoes" calls
+    made to it by writing out the function's name and the arguments it was
+    called with.
+    """
+    import functools
+    # Unpack function's arg count, arg names, arg defaults
+    code = fn.__code__
+    argcount = code.co_argcount
+    argnames = code.co_varnames[:argcount]
+    fn_defaults = fn.__defaults__ or list()
+    argdefs = dict(list(zip(argnames[-len(fn_defaults):], fn_defaults)))
+
+    @functools.wraps(fn)
+    def wrapped(*v, **k):
+        # Collect function arguments by chaining together positional,
+        # defaulted, extra positional and keyword arguments.
+        positional = list(map(format_arg_value, list(zip(argnames, v))))
+        defaulted = [format_arg_value((a, argdefs[a]))
+                     for a in argnames[len(v):] if a not in k]
+        nameless = list(map(repr, v[argcount:]))
+        keyword = list(map(format_arg_value, list(k.items())))
+        args = positional + defaulted + nameless + keyword
+        write("%s(%s)\n" % (name(fn), ", ".join(args)))
+        return fn(*v, **k)
+
+    return wrapped
+
+
+def echo_instancemethod(klass, method, write=sys.stdout.write):
+    """ Change an instancemethod so that calls to it are echoed.
+
+    Replacing a classmethod is a little more tricky.
+    See: http://www.python.org/doc/current/ref/types.html
+    """
+    mname = method_name(method)
+    never_echo = "__str__", "__repr__",  # Avoid recursion printing method calls
+    if mname in never_echo:
+        pass
+    elif is_classmethod(method):
+        setattr(klass, mname, classmethod(echo(method.__func__, write)))
+    else:
+        setattr(klass, mname, echo(method, write))
+
+
+def echo_class(klass, write=sys.stdout.write):
+    """ Echo calls to class methods and static functions
+    """
+    for _, method in inspect.getmembers(klass, inspect.ismethod):
+        echo_instancemethod(klass, method, write)
+    for _, fn in inspect.getmembers(klass, inspect.isfunction):
+        setattr(klass, name(fn), staticmethod(echo(fn, write)))
+
+
+def echo_module(mod, write=sys.stdout.write):
+    """ Echo calls to functions and methods in a module.
+    """
+    for fname, fn in inspect.getmembers(mod, inspect.isfunction):
+        setattr(mod, fname, echo(fn, write))
+    for _, klass in inspect.getmembers(mod, inspect.isclass):
+        echo_class(klass, write)
+
+if __name__ == "__main__":
+    import doctest
+
+    optionflags = doctest.ELLIPSIS
+    doctest.testfile('echoexample.txt', optionflags=optionflags)
+    doctest.testmod(optionflags=optionflags)