* Added initial code for high-level module for using rrdtool in an

  object-oriented manner.
* Updated README.
* Updated setup script to include the high-level module, as well as
  building the low-level extension.

Author: Christian Jurk

README.md

@@ -1,4 +1,66 @@
 rrdtool-py3k
 ============
 
-rrdtool bindings for Python 3
+Python 3 bindings for rrdtool with a native C extension and an object-oriented way to work with Round Robin Databases.
+
+The bindings are based on the code of the original Python 2 bindings for rrdtool by Hye-Shik Chang.
+
+Installation
+------------
+
+In order to build the native C extension (which is an required step), you'll need librrd and its headers installed. Having rrdtool installed should be enough on most distributions.
+
+**How to Install? **
+
+1. Download a copy of the repository.
+2. Run `python setup.py install` to build an install the native C extension as well as the RRD module.
+
+Usage
+-----
+
+You can either use the low-level `rrdtool` module (which offers almost the same functions as the old Python 2 bindings for rrdtool provided), or the `RRDtool` module, which represents a object-oriented interface to rrdtool.
+
+Unlike the Python 2 binding, this binding is able to create graphs entirely in-memory, which makes it ideal for generating a large amount of graphs without having high I/O. This feature is currently available on POSIX platforms only, because I wasn't able to find a portable way to redirect stdout to a memory allocated buffer (which is required for that). To use this feature, specify "-" as the output filename in graphs (low-level extension), or `None` in the high-level module.
+
+### Using the low-level `rrdtool` module
+
+```python
+import rrdtool
+
+# Create Round Robin Database
+rrdtool.create('test.rrd', '--start', 'now', '--step', '300', 'RRA:AVERAGE:0.5:1:1200', 'DS:temp:GAUGE:600:-273:5000')
+
+# Feed updates to the RRD
+rrdtool.update('test.rrd', 'N:32')
+```
+
+### Using the high-level `RRDtool` module
+
+```python
+import RRDtool
+
+# Create a Round Robin Database
+rrd = RRDtool.create('test.rrd', '--start', 'now', '--step', '300', 'RRA:AVERAGE:0.5:1:1200', 'DS:temp:GAUGE:600:-273:5000')
+
+# Update the RRD
+rrd.update([(None, 32)])
+
+# Create a graph from it
+rrd.graph('test.png', '--end', 'now', '--start', 'end-5minutes', '--width', '400', 'DEF:ds0a=test.rrd:temp:AVERAGE', 'LINE1:ds0a#0000FF:"temperature\l"')
+
+# Same, but keep data in memory.
+data = rrd.graph(None, '--end', 'now', '--start', 'end-5minutes', '--width', '400', 'DEF:ds0a=test.rrd:temp:AVERAGE', 'LINE1:ds0a#0000FF:"temperature\l"')
+
+# You can also use file-like objects
+from io import BytesIO
+rrd.graph(io, ...)
+```
+
+Author
+------
+
+Christian Jurk <commx@commx.ws>
+
+This binding was created because I am currently porting some existing Python 2 code to Python 3 and try to help the community by contributing a updated binding extension. Hope someone can benefit from it.
+
+If you encounter any bugs (which I expected at time of writing this), please submit them in the issue tracker here on the project page on Github. Thank you.

RRDtool.py

@@ -0,0 +1,118 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+#
+#  rrdtool-py3k, rrdtool bindings for Python 3.
+#  Based on the rrdtool Python bindings for Python 2 from
+#  Hye-Shik Chang <perky@fallin.lv>.
+#
+#  Copyright 2012 Christian Jurk <commx@commx.ws>
+#
+#  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.
+#
+#
+
+from datetime import datetime
+from io import BytesIO
+import os
+import rrdtool
+from time import mktime
+
+def create(filename, *args):
+	"Create a Round Robin Database and return a RRD object on success."
+	rrdtool.create(filename, *args)
+
+	if not os.access(filename, os.F_OK):
+		raise rrdtool.OperationalError('RRD file was not created')
+
+	return RRD(filename)
+
+class RRD:
+	"""An object-based interface to the rrdtool module."""
+
+	def __init__(self, filename, check_type=True):
+		"Initialize the class instance with a filename."
+
+		if not os.access(filename, os.F_OK | os.R_OK):
+			raise rrdtool.OperationalError('RRD {!s} cannot be opened.' \
+			  .format(filename))
+
+		# Use rrdinfo to test whether the file is a valid RRD file
+		if check_type is True:
+			rrdtool.info(filename)
+
+		self.readonly = not os.access(filename, os.W_OK)
+		self.filename = filename
+
+	def graph(self, output_file, *args):
+		"Create a graph based on one or more RRDs."
+		buffered = True
+		outfile = '-'
+
+		# write straigt into file using wrapper functions
+		if isinstance(output_file, str):
+			buffered = False
+			outfile = output_file
+
+		gdata = rrdtool.graph(outfile, *args)
+
+		if isinstance(gdata, tuple) and len(gdata) >= 4:
+			if output_file is None:
+				return gdata[3]
+			elif isinstance(output_file, BytesIO):
+				output_file.write(gdata[3])
+				return output_file
+
+		return None
+
+	def info(self):
+		return rrdtool.info(self.filename)
+
+	def update(self, values, *args):
+		vl = []
+
+		if self.readonly:
+			raise rrdtool.OperationalError('RRD file is read-only: {!s}' \
+			  .format(self.filename))
+		elif not isinstance(values, (list, tuple)):
+			raise rrdtool.ProgrammingError('The values parameter must be a ' \
+			  'list or tuple')
+		else:
+			for row in values:
+				if isinstance(row, str):
+					vl.append(row)
+				elif isinstance(row, (list, tuple)):
+					if len(row) < 2:
+						raise rrdtool.ProgrammingError('Value {!r} has too ' \
+						  'few elements in sequence object'.format(row))
+					else:
+						ts = row[0]
+						if ts is None:
+							ts = 'N'
+						elif isinstance(ts, datetime):
+							ts = int(mktime(ts.timetuple()))
+						elif isinstance(ts, str):
+							ts = int(ts)
+						elif not isinstance(ts, int):
+							raise ValueError('Unsupported type')
+
+					v = '{}:{}'.format(ts, ':'.join([str(x) for x in row[1:]]))
+					vl.append(v)
+
+		arglist = tuple(vl + list(args))
+		return rrdtool.update(self.filename, *arglist)
+
+	def __repr__(self):
+		return '<RRD {!r}>'.format(self.filename)

rrdtool-py3k.c

@@ -113,11 +113,13 @@ convert_args(char *command, PyObject *args)
 static PyObject *
 _rrdtool_util_info2dict(const rrd_info_t *data)
 {
-    PyObject *dict, *val = NULL;
+    PyObject *dict, *val;
 
     dict = PyDict_New();
 
     while (data) {
+        val = NULL;
+
         switch (data->type) {
             case RD_I_VAL:
                 if (isnan(data->value.u_val)) {
@@ -144,11 +146,10 @@ _rrdtool_util_info2dict(const rrd_info_t *data)
                   (char *)data->value.u_blo.ptr, data->value.u_blo.size);
                 break;
             default:
-                val = NULL;
                 break;
         }
 
-        if (val) {
+        if (val != NULL) {
             PyDict_SetItemString(dict, data->key, val);
             Py_DECREF(val);
         }
@@ -675,6 +676,15 @@ _rrdtool_info(PyObject *self, PyObject *args)
     return ret;
 }
 
+static char _rrdtool_lib_version__doc__[] = "Get the version this binding "\
+  "was compiled against.";
+
+static PyObject *
+_rrdtool_lib_version(PyObject *self, PyObject *args)
+{
+    return PyUnicode_FromString(rrd_strversion());
+}
+
 static PyMethodDef rrdtool_methods[] = {
 	{"create", (PyCFunction)_rrdtool_create,
      METH_VARARGS, _rrdtool_create__doc__},
@@ -700,6 +710,8 @@ static PyMethodDef rrdtool_methods[] = {
      METH_VARARGS, _rrdtool_resize__doc__},
     {"info", (PyCFunction)_rrdtool_info,
      METH_VARARGS, _rrdtool_info__doc__},
+    {"lib_version", (PyCFunction)_rrdtool_lib_version,
+     METH_VARARGS, _rrdtool_lib_version__doc__},
 	{NULL, NULL, 0, NULL}
 };
 

setup.py

@@ -1,11 +1,21 @@
 from distutils.core import setup, Extension
-from glob import glob
 
-sources = glob('*.c')
-module = Extension('rrdtool', sources=sources, libraries=['rrd'])
+def main():
+    module = Extension('rrdtool', sources=['rrdtool-py3k.c'],
+                       libraries=['rrd'])
 
-setup(name='rrdtool',
-      version='1.0',
-      description='rrdtool bindings for Python 3',
-      ext_modules=[module])
+    kwargs = dict(
+        name='python-rrdtool',
+        version='0.1.0',
+        description='rrdtool bindings for Python 3',
+        keywords=['rrdtool'],
+        author='Christian Jurk, Hye-Shik Chang',
+        author_email='commx@commx.ws',
+        ext_modules=[module],
+        py_modules=['RRDtool']
+    )
 
+    setup(**kwargs)
+
+if __name__ == '__main__':
+    main()