Synnefo » snf-ganeti

#!/usr/bin/python

#

# Copyright (C) 2011 Google Inc.

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful, but

# WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

# General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

# 02110-1301, USA.

"""Script to generate RPC code.

"""

# pylint: disable=C0103

# [C0103] Invalid name

import sys

import re

import itertools

import textwrap

from cStringIO import StringIO

from ganeti import utils

from ganeti import compat

from ganeti import build

_SINGLE = "single-node"

_MULTI = "multi-node"

def _WritePreamble(sw):

  """Writes a preamble for the RPC wrapper output.

  """

  sw.Write("# This code is automatically generated at build time.")

  sw.Write("# Do not modify manually.")

  sw.Write("")

  sw.Write("\"\"\"Automatically generated RPC client wrappers.")

  sw.Write("")

  sw.Write("\"\"\"")

  sw.Write("")

def _WrapCode(line):

  """Wraps Python code.

  """

  return textwrap.wrap(line, width=70, expand_tabs=False,

                       fix_sentence_endings=False, break_long_words=False,

                       replace_whitespace=True,

                       subsequent_indent=utils.ShellWriter.INDENT_STR)

def _WriteDocstring(sw, name, timeout, kind, args, desc):

  """Writes a docstring for an RPC wrapper.

  """

  sw.Write("\"\"\"Wrapper for RPC call '%s'", name)

  sw.Write("")

  if desc:

    sw.Write(desc)

    sw.Write("")

  note = ["This is a %s call" % kind]

  if timeout:

    note.append(" with a timeout of %s" % utils.FormatSeconds(timeout))

  sw.Write("@note: %s", "".join(note))

  if kind == _SINGLE:

    sw.Write("@type node: string")

    sw.Write("@param node: Node name")

  else:

    sw.Write("@type node_list: list of string")

    sw.Write("@param node_list: List of node names")

  if args:

    for (argname, _, argtext) in args:

      if argtext:

        docline = "@param %s: %s" % (argname, argtext)

        for line in _WrapCode(docline):

          sw.Write(line)

  sw.Write("")

  sw.Write("\"\"\"")

def _WriteBaseClass(sw, clsname, calls):

  """Write RPC wrapper class.

  """

  sw.Write("")

  sw.Write("class %s(object):", clsname)

  sw.IncIndent()

  try:

    sw.Write("# E1101: Non-existent members")

    sw.Write("# R0904: Too many public methods")

    sw.Write("# pylint: disable=E1101,R0904")

    if not calls:

      sw.Write("pass")

      return

    for (name, kind, timeout, args, postproc, desc) in calls:

      funcargs = ["self"]

      if kind == _SINGLE:

        funcargs.append("node")

      elif kind == _MULTI:

        funcargs.append("node_list")

      else:

        raise Exception("Unknown kind '%s'" % kind)

      funcargs.extend(map(compat.fst, args))

      assert "read_timeout" not in funcargs

      funcargs.append("read_timeout=%s" % timeout)

      funcdef = "def call_%s(%s):" % (name, utils.CommaJoin(funcargs))

      for line in _WrapCode(funcdef):

        sw.Write(line)

      sw.IncIndent()

      try:

        _WriteDocstring(sw, name, timeout, kind, args, desc)

        buf = StringIO()

        buf.write("return ")

        # In case line gets too long and is wrapped in a bad spot

        buf.write("( ")

        if postproc:

          buf.write("%s(" % postproc)

        buf.write("self._Call(")

        if kind == _SINGLE:

          buf.write("[node]")

        else:

          buf.write("node_list")

        buf.write(", \"%s\", read_timeout, [%s], [%s])" %

                  (name,

                   # Argument definitions

                   utils.CommaJoin(map(compat.snd, args)),

                   # Function arguments

                   utils.CommaJoin(map(compat.fst, args))))

        if kind == _SINGLE:

          buf.write("[node]")

        if postproc:

          buf.write(")")

        buf.write(")")

        for line in _WrapCode(buf.getvalue()):

          sw.Write(line)

      finally:

        sw.DecIndent()

      sw.Write("")

  finally:

    sw.DecIndent()

def main():

  """Main function.

  """

  buf = StringIO()

  sw = utils.ShellWriter(buf)

  _WritePreamble(sw)

  for filename in sys.argv[1:]:

    sw.Write("# Definitions from '%s'", filename)

    module = build.LoadModule(filename)

    # Call types are re-defined in definitions file to avoid imports. Verify

    # here to ensure they're equal to local constants.

    assert module.SINGLE == _SINGLE

    assert module.MULTI == _MULTI

    for (clsname, calls) in module.CALLS.items():

      _WriteBaseClass(sw, clsname, calls)

  print buf.getvalue()

if __name__ == "__main__":

  main()