Convert watch page to flask framework

1 files changed, 334 insertions, 0 deletions

diff --git a/python/werkzeug/_reloader.py b/python/werkzeug/_reloader.py
new file mode 100644
index 0000000..f06a63d
--- /dev/null
+++ b/python/werkzeug/_reloader.py
@@ -0,0 +1,334 @@
+import os
+import subprocess
+import sys
+import threading
+import time
+from itertools import chain
+
+from ._compat import iteritems
+from ._compat import PY2
+from ._compat import text_type
+from ._internal import _log
+
+
+def _iter_module_files():
+    """This iterates over all relevant Python files.  It goes through all
+    loaded files from modules, all files in folders of already loaded modules
+    as well as all files reachable through a package.
+    """
+    # The list call is necessary on Python 3 in case the module
+    # dictionary modifies during iteration.
+    for module in list(sys.modules.values()):
+        if module is None:
+            continue
+        filename = getattr(module, "__file__", None)
+        if filename:
+            if os.path.isdir(filename) and os.path.exists(
+                os.path.join(filename, "__init__.py")
+            ):
+                filename = os.path.join(filename, "__init__.py")
+
+            old = None
+            while not os.path.isfile(filename):
+                old = filename
+                filename = os.path.dirname(filename)
+                if filename == old:
+                    break
+            else:
+                if filename[-4:] in (".pyc", ".pyo"):
+                    filename = filename[:-1]
+                yield filename
+
+
+def _find_observable_paths(extra_files=None):
+    """Finds all paths that should be observed."""
+    rv = set(
+        os.path.dirname(os.path.abspath(x)) if os.path.isfile(x) else os.path.abspath(x)
+        for x in sys.path
+    )
+
+    for filename in extra_files or ():
+        rv.add(os.path.dirname(os.path.abspath(filename)))
+
+    for module in list(sys.modules.values()):
+        fn = getattr(module, "__file__", None)
+        if fn is None:
+            continue
+        fn = os.path.abspath(fn)
+        rv.add(os.path.dirname(fn))
+
+    return _find_common_roots(rv)
+
+
+def _get_args_for_reloading():
+    """Returns the executable. This contains a workaround for windows
+    if the executable is incorrectly reported to not have the .exe
+    extension which can cause bugs on reloading.  This also contains
+    a workaround for linux where the file is executable (possibly with
+    a program other than python)
+    """
+    rv = [sys.executable]
+    py_script = os.path.abspath(sys.argv[0])
+    args = sys.argv[1:]
+    # Need to look at main module to determine how it was executed.
+    __main__ = sys.modules["__main__"]
+
+    if __main__.__package__ is None:
+        # Executed a file, like "python app.py".
+        if os.name == "nt":
+            # Windows entry points have ".exe" extension and should be
+            # called directly.
+            if not os.path.exists(py_script) and os.path.exists(py_script + ".exe"):
+                py_script += ".exe"
+
+            if (
+                os.path.splitext(rv[0])[1] == ".exe"
+                and os.path.splitext(py_script)[1] == ".exe"
+            ):
+                rv.pop(0)
+
+        elif os.path.isfile(py_script) and os.access(py_script, os.X_OK):
+            # The file is marked as executable. Nix adds a wrapper that
+            # shouldn't be called with the Python executable.
+            rv.pop(0)
+
+        rv.append(py_script)
+    else:
+        # Executed a module, like "python -m werkzeug.serving".
+        if sys.argv[0] == "-m":
+            # Flask works around previous behavior by putting
+            # "-m flask" in sys.argv.
+            # TODO remove this once Flask no longer misbehaves
+            args = sys.argv
+        else:
+            py_module = __main__.__package__
+            name = os.path.splitext(os.path.basename(py_script))[0]
+
+            if name != "__main__":
+                py_module += "." + name
+
+            rv.extend(("-m", py_module.lstrip(".")))
+
+    rv.extend(args)
+    return rv
+
+
+def _find_common_roots(paths):
+    """Out of some paths it finds the common roots that need monitoring."""
+    paths = [x.split(os.path.sep) for x in paths]
+    root = {}
+    for chunks in sorted(paths, key=len, reverse=True):
+        node = root
+        for chunk in chunks:
+            node = node.setdefault(chunk, {})
+        node.clear()
+
+    rv = set()
+
+    def _walk(node, path):
+        for prefix, child in iteritems(node):
+            _walk(child, path + (prefix,))
+        if not node:
+            rv.add("/".join(path))
+
+    _walk(root, ())
+    return rv
+
+
+class ReloaderLoop(object):
+    name = None
+
+    # monkeypatched by testsuite. wrapping with `staticmethod` is required in
+    # case time.sleep has been replaced by a non-c function (e.g. by
+    # `eventlet.monkey_patch`) before we get here
+    _sleep = staticmethod(time.sleep)
+
+    def __init__(self, extra_files=None, interval=1):
+        self.extra_files = set(os.path.abspath(x) for x in extra_files or ())
+        self.interval = interval
+
+    def run(self):
+        pass
+
+    def restart_with_reloader(self):
+        """Spawn a new Python interpreter with the same arguments as this one,
+        but running the reloader thread.
+        """
+        while 1:
+            _log("info", " * Restarting with %s" % self.name)
+            args = _get_args_for_reloading()
+
+            # a weird bug on windows. sometimes unicode strings end up in the
+            # environment and subprocess.call does not like this, encode them
+            # to latin1 and continue.
+            if os.name == "nt" and PY2:
+                new_environ = {}
+                for key, value in iteritems(os.environ):
+                    if isinstance(key, text_type):
+                        key = key.encode("iso-8859-1")
+                    if isinstance(value, text_type):
+                        value = value.encode("iso-8859-1")
+                    new_environ[key] = value
+            else:
+                new_environ = os.environ.copy()
+
+            new_environ["WERKZEUG_RUN_MAIN"] = "true"
+            exit_code = subprocess.call(args, env=new_environ, close_fds=False)
+            if exit_code != 3:
+                return exit_code
+
+    def trigger_reload(self, filename):
+        self.log_reload(filename)
+        sys.exit(3)
+
+    def log_reload(self, filename):
+        filename = os.path.abspath(filename)
+        _log("info", " * Detected change in %r, reloading" % filename)
+
+
+class StatReloaderLoop(ReloaderLoop):
+    name = "stat"
+
+    def run(self):
+        mtimes = {}
+        while 1:
+            for filename in chain(_iter_module_files(), self.extra_files):
+                try:
+                    mtime = os.stat(filename).st_mtime
+                except OSError:
+                    continue
+
+                old_time = mtimes.get(filename)
+                if old_time is None:
+                    mtimes[filename] = mtime
+                    continue
+                elif mtime > old_time:
+                    self.trigger_reload(filename)
+            self._sleep(self.interval)
+
+
+class WatchdogReloaderLoop(ReloaderLoop):
+    def __init__(self, *args, **kwargs):
+        ReloaderLoop.__init__(self, *args, **kwargs)
+        from watchdog.observers import Observer
+        from watchdog.events import FileSystemEventHandler
+
+        self.observable_paths = set()
+
+        def _check_modification(filename):
+            if filename in self.extra_files:
+                self.trigger_reload(filename)
+            dirname = os.path.dirname(filename)
+            if dirname.startswith(tuple(self.observable_paths)):
+                if filename.endswith((".pyc", ".pyo", ".py")):
+                    self.trigger_reload(filename)
+
+        class _CustomHandler(FileSystemEventHandler):
+            def on_created(self, event):
+                _check_modification(event.src_path)
+
+            def on_modified(self, event):
+                _check_modification(event.src_path)
+
+            def on_moved(self, event):
+                _check_modification(event.src_path)
+                _check_modification(event.dest_path)
+
+            def on_deleted(self, event):
+                _check_modification(event.src_path)
+
+        reloader_name = Observer.__name__.lower()
+        if reloader_name.endswith("observer"):
+            reloader_name = reloader_name[:-8]
+        reloader_name += " reloader"
+
+        self.name = reloader_name
+
+        self.observer_class = Observer
+        self.event_handler = _CustomHandler()
+        self.should_reload = False
+
+    def trigger_reload(self, filename):
+        # This is called inside an event handler, which means throwing
+        # SystemExit has no effect.
+        # https://github.com/gorakhargosh/watchdog/issues/294
+        self.should_reload = True
+        self.log_reload(filename)
+
+    def run(self):
+        watches = {}
+        observer = self.observer_class()
+        observer.start()
+
+        try:
+            while not self.should_reload:
+                to_delete = set(watches)
+                paths = _find_observable_paths(self.extra_files)
+                for path in paths:
+                    if path not in watches:
+                        try:
+                            watches[path] = observer.schedule(
+                                self.event_handler, path, recursive=True
+                            )
+                        except OSError:
+                            # Clear this path from list of watches We don't want
+                            # the same error message showing again in the next
+                            # iteration.
+                            watches[path] = None
+                    to_delete.discard(path)
+                for path in to_delete:
+                    watch = watches.pop(path, None)
+                    if watch is not None:
+                        observer.unschedule(watch)
+                self.observable_paths = paths
+                self._sleep(self.interval)
+        finally:
+            observer.stop()
+            observer.join()
+
+        sys.exit(3)
+
+
+reloader_loops = {"stat": StatReloaderLoop, "watchdog": WatchdogReloaderLoop}
+
+try:
+    __import__("watchdog.observers")
+except ImportError:
+    reloader_loops["auto"] = reloader_loops["stat"]
+else:
+    reloader_loops["auto"] = reloader_loops["watchdog"]
+
+
+def ensure_echo_on():
+    """Ensure that echo mode is enabled. Some tools such as PDB disable
+    it which causes usability issues after reload."""
+    # tcgetattr will fail if stdin isn't a tty
+    if not sys.stdin.isatty():
+        return
+    try:
+        import termios
+    except ImportError:
+        return
+    attributes = termios.tcgetattr(sys.stdin)
+    if not attributes[3] & termios.ECHO:
+        attributes[3] |= termios.ECHO
+        termios.tcsetattr(sys.stdin, termios.TCSANOW, attributes)
+
+
+def run_with_reloader(main_func, extra_files=None, interval=1, reloader_type="auto"):
+    """Run the given function in an independent python interpreter."""
+    import signal
+
+    reloader = reloader_loops[reloader_type](extra_files, interval)
+    signal.signal(signal.SIGTERM, lambda *args: sys.exit(0))
+    try:
+        if os.environ.get("WERKZEUG_RUN_MAIN") == "true":
+            ensure_echo_on()
+            t = threading.Thread(target=main_func, args=())
+            t.setDaemon(True)
+            t.start()
+            reloader.run()
+        else:
+            sys.exit(reloader.restart_with_reloader())
+    except KeyboardInterrupt:
+        pass