configfile: Move config file code from klippy.py to new file

Add a klippy/configfile.py file with the code needed to read the main
printer config file.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/configfile.py

@@ -0,0 +1,116 @@
+# Code for reading the Klipper config file
+#
+# Copyright (C) 2016-2018  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import ConfigParser
+
+error = ConfigParser.Error
+
+class sentinel:
+    pass
+
+class ConfigWrapper:
+    error = ConfigParser.Error
+    def __init__(self, printer, fileconfig, access_tracking, section):
+        self.printer = printer
+        self.fileconfig = fileconfig
+        self.access_tracking = access_tracking
+        self.section = section
+    def get_printer(self):
+        return self.printer
+    def get_name(self):
+        return self.section
+    def _get_wrapper(self, parser, option, default,
+                     minval=None, maxval=None, above=None, below=None):
+        if (default is not sentinel
+            and not self.fileconfig.has_option(self.section, option)):
+            return default
+        self.access_tracking[(self.section.lower(), option.lower())] = 1
+        try:
+            v = parser(self.section, option)
+        except self.error as e:
+            raise
+        except:
+            raise error("Unable to parse option '%s' in section '%s'" % (
+                option, self.section))
+        if minval is not None and v < minval:
+            raise error(
+                "Option '%s' in section '%s' must have minimum of %s" % (
+                    option, self.section, minval))
+        if maxval is not None and v > maxval:
+            raise error(
+                "Option '%s' in section '%s' must have maximum of %s" % (
+                    option, self.section, maxval))
+        if above is not None and v <= above:
+            raise error("Option '%s' in section '%s' must be above %s" % (
+                option, self.section, above))
+        if below is not None and v >= below:
+            raise self.error("Option '%s' in section '%s' must be below %s" % (
+                option, self.section, below))
+        return v
+    def get(self, option, default=sentinel):
+        return self._get_wrapper(self.fileconfig.get, option, default)
+    def getint(self, option, default=sentinel, minval=None, maxval=None):
+        return self._get_wrapper(
+            self.fileconfig.getint, option, default, minval, maxval)
+    def getfloat(self, option, default=sentinel,
+                 minval=None, maxval=None, above=None, below=None):
+        return self._get_wrapper(self.fileconfig.getfloat, option, default,
+                                 minval, maxval, above, below)
+    def getboolean(self, option, default=sentinel):
+        return self._get_wrapper(self.fileconfig.getboolean, option, default)
+    def getchoice(self, option, choices, default=sentinel):
+        c = self.get(option, default)
+        if c not in choices:
+            raise error("Choice '%s' for option '%s' in section '%s'"
+                        " is not a valid choice" % (c, option, self.section))
+        return choices[c]
+    def getsection(self, section):
+        return ConfigWrapper(self.printer, self.fileconfig,
+                             self.access_tracking, section)
+    def has_section(self, section):
+        return self.fileconfig.has_section(section)
+    def get_prefix_sections(self, prefix):
+        return [self.getsection(s) for s in self.fileconfig.sections()
+                if s.startswith(prefix)]
+
+class ConfigLogger:
+    def __init__(self, fileconfig, printer):
+        self.lines = ["===== Config file ====="]
+        fileconfig.write(self)
+        self.lines.append("=======================")
+        printer.set_rollover_info("config", "\n".join(self.lines))
+    def write(self, data):
+        self.lines.append(data.strip())
+
+class PrinterConfig:
+    def __init__(self, printer):
+        self.printer = printer
+    def read_config(self, filename):
+        fileconfig = ConfigParser.RawConfigParser()
+        res = fileconfig.read(filename)
+        if not res:
+            raise error("Unable to open config file %s" % (filename,))
+        return ConfigWrapper(self.printer, fileconfig, {}, 'printer')
+    def read_main_config(self):
+        filename = self.printer.get_start_args()['config_file']
+        return self.read_config(filename)
+    def check_unused_options(self, config):
+        access_tracking = config.access_tracking
+        fileconfig = config.fileconfig
+        objects = dict(self.printer.lookup_objects())
+        # Validate that there are no undefined parameters in the config file
+        valid_sections = { s: 1 for s, o in access_tracking }
+        for section_name in fileconfig.sections():
+            section = section_name.lower()
+            if section not in valid_sections and section not in objects:
+                raise error("Section '%s' is not a valid config section" % (
+                    section,))
+            for option in fileconfig.options(section_name):
+                option = option.lower()
+                if (section, option) not in access_tracking:
+                    raise error("Option '%s' is not valid in section '%s'" % (
+                        option, section))
+    def log_config(self, config):
+        ConfigLogger(config.fileconfig, self.printer)