Initial Commit

lib/logutils/colorize.py

@@ -0,0 +1,194 @@
+#
+# Copyright (C) 2010-2013 Vinay Sajip. All rights reserved.
+#
+import ctypes
+import logging
+import os
+
+try:
+    unicode
+except NameError:
+    unicode = None
+
+class ColorizingStreamHandler(logging.StreamHandler):
+    """
+    A stream handler which supports colorizing of console streams
+    under Windows, Linux and Mac OS X.
+
+    :param strm: The stream to colorize - typically ``sys.stdout``
+                 or ``sys.stderr``.
+    """
+    
+    # color names to indices
+    color_map = {
+        'black': 0,
+        'red': 1,
+        'green': 2,
+        'yellow': 3,
+        'blue': 4,
+        'magenta': 5,
+        'cyan': 6,
+        'white': 7,
+    }
+
+    #levels to (background, foreground, bold/intense)
+    if os.name == 'nt':
+        level_map = {
+            logging.DEBUG: (None, 'blue', True),
+            logging.INFO: (None, 'white', False),
+            logging.WARNING: (None, 'yellow', True),
+            logging.ERROR: (None, 'red', True),
+            logging.CRITICAL: ('red', 'white', True),
+        }
+    else:
+        "Maps levels to colour/intensity settings."
+        level_map = {
+            logging.DEBUG: (None, 'blue', False),
+            logging.INFO: (None, 'black', False),
+            logging.WARNING: (None, 'yellow', False),
+            logging.ERROR: (None, 'red', False),
+            logging.CRITICAL: ('red', 'white', True),
+        }
+
+    csi = '\x1b['
+    reset = '\x1b[0m'
+
+    @property
+    def is_tty(self):
+        "Returns true if the handler's stream is a terminal."
+        isatty = getattr(self.stream, 'isatty', None)
+        return isatty and isatty()
+
+    def emit(self, record):
+        try:
+            message = self.format(record)
+            stream = self.stream
+            if unicode and isinstance(message, unicode):
+                enc = getattr(stream, 'encoding', 'utf-8')
+                message = message.encode(enc, 'replace')
+            if not self.is_tty:
+                stream.write(message)
+            else:
+                self.output_colorized(message)
+            stream.write(getattr(self, 'terminator', '\n'))
+            self.flush()
+        except (KeyboardInterrupt, SystemExit):
+            raise
+        except:
+            self.handleError(record)
+
+    if os.name != 'nt':
+        def output_colorized(self, message):
+            """
+            Output a colorized message.
+
+            On Linux and Mac OS X, this method just writes the
+            already-colorized message to the stream, since on these
+            platforms console streams accept ANSI escape sequences
+            for colorization. On Windows, this handler implements a
+            subset of ANSI escape sequence handling by parsing the
+            message, extracting the sequences and making Win32 API
+            calls to colorize the output.
+
+            :param message: The message to colorize and output.
+            """
+            self.stream.write(message)
+    else:
+        import re
+        ansi_esc = re.compile(r'\x1b\[((?:\d+)(?:;(?:\d+))*)m')
+
+        nt_color_map = {
+            0: 0x00,    # black
+            1: 0x04,    # red
+            2: 0x02,    # green
+            3: 0x06,    # yellow
+            4: 0x01,    # blue
+            5: 0x05,    # magenta
+            6: 0x03,    # cyan
+            7: 0x07,    # white
+        }
+
+        def output_colorized(self, message):
+            """
+            Output a colorized message.
+
+            On Linux and Mac OS X, this method just writes the
+            already-colorized message to the stream, since on these
+            platforms console streams accept ANSI escape sequences
+            for colorization. On Windows, this handler implements a
+            subset of ANSI escape sequence handling by parsing the
+            message, extracting the sequences and making Win32 API
+            calls to colorize the output.
+
+            :param message: The message to colorize and output.
+            """
+            parts = self.ansi_esc.split(message)
+            write = self.stream.write
+            h = None
+            fd = getattr(self.stream, 'fileno', None)
+            if fd is not None:
+                fd = fd()
+                if fd in (1, 2): # stdout or stderr
+                    h = ctypes.windll.kernel32.GetStdHandle(-10 - fd)
+            while parts:
+                text = parts.pop(0)
+                if text:
+                    write(text)
+                if parts:
+                    params = parts.pop(0)
+                    if h is not None:
+                        params = [int(p) for p in params.split(';')]
+                        color = 0
+                        for p in params:
+                            if 40 <= p <= 47:
+                                color |= self.nt_color_map[p - 40] << 4
+                            elif 30 <= p <= 37:
+                                color |= self.nt_color_map[p - 30]
+                            elif p == 1:
+                                color |= 0x08 # foreground intensity on
+                            elif p == 0: # reset to default color
+                                color = 0x07
+                            else:
+                                pass # error condition ignored
+                        ctypes.windll.kernel32.SetConsoleTextAttribute(h, color)
+
+    def colorize(self, message, record):
+        """
+        Colorize a message for a logging event.
+
+        This implementation uses the ``level_map`` class attribute to
+        map the LogRecord's level to a colour/intensity setting, which is
+        then applied to the whole message.
+
+        :param message: The message to colorize.
+        :param record: The ``LogRecord`` for the message.
+        """
+        if record.levelno in self.level_map:
+            bg, fg, bold = self.level_map[record.levelno]
+            params = []
+            if bg in self.color_map:
+                params.append(str(self.color_map[bg] + 40))
+            if fg in self.color_map:
+                params.append(str(self.color_map[fg] + 30))
+            if bold:
+                params.append('1')
+            if params:
+                message = ''.join((self.csi, ';'.join(params),
+                                   'm', message, self.reset))
+        return message
+
+    def format(self, record):
+        """
+        Formats a record for output.
+
+        This implementation colorizes the message line, but leaves
+        any traceback unolorized.
+        """
+        message = logging.StreamHandler.format(self, record)
+        if self.is_tty:
+            # Don't colorize any traceback
+            parts = message.split('\n', 1)
+            parts[0] = self.colorize(parts[0], record)
+            message = '\n'.join(parts)
+        return message
+