README change

1 files changed, 163 insertions, 0 deletions

diff --git a/grc/python/FlowGraph.py b/grc/python/FlowGraph.py
new file mode 100644
index 000000000..376c2e337
--- /dev/null
+++ b/grc/python/FlowGraph.py
@@ -0,0 +1,163 @@
+"""
+Copyright 2008-2011 Free Software Foundation, Inc.
+This file is part of GNU Radio
+
+GNU Radio Companion 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.
+
+GNU Radio Companion 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
+"""
+
+import expr_utils
+from .. base.FlowGraph import FlowGraph as _FlowGraph
+from .. gui.FlowGraph import FlowGraph as _GUIFlowGraph
+import re
+
+_variable_matcher = re.compile('^(variable\w*)$')
+_parameter_matcher = re.compile('^(parameter)$')
+
+class FlowGraph(_FlowGraph, _GUIFlowGraph):
+
+	def __init__(self, **kwargs):
+		_FlowGraph.__init__(self, **kwargs)
+		_GUIFlowGraph.__init__(self)
+		self._eval_cache = dict()
+
+	def _eval(self, code, namespace, namespace_hash):
+		"""
+		Evaluate the code with the given namespace.
+		@param code a string with python code
+		@param namespace a dict representing the namespace
+		@param namespace_hash a unique hash for the namespace
+		@return the resultant object
+		"""
+		if not code: raise Exception, 'Cannot evaluate empty statement.'
+		my_hash = hash(code) ^ namespace_hash
+		#cache if does not exist
+		if not self._eval_cache.has_key(my_hash):
+			self._eval_cache[my_hash] = eval(code, namespace, namespace)
+		#return from cache
+		return self._eval_cache[my_hash]
+
+	def get_io_signaturev(self, direction):
+		"""
+		Get a list of io signatures for this flow graph.
+		@param direction a string of 'in' or 'out'
+		@return a list of dicts with: type, label, vlen, size
+		"""
+		sorted_pads = {
+			'in': self.get_pad_sources(),
+			'out': self.get_pad_sinks(),
+		}[direction]
+        # we only want stream ports
+		sorted_pads = filter(lambda b: b.get_param('type').get_evaluated() != 'message', sorted_pads);
+		#load io signature
+		return [{
+			'label': str(pad.get_param('label').get_evaluated()),
+			'type': str(pad.get_param('type').get_evaluated()),
+			'vlen': str(pad.get_param('vlen').get_evaluated()),
+			'size': pad.get_param('type').get_opt('size'),
+			'optional': bool(pad.get_param('optional').get_evaluated()),
+		} for pad in sorted_pads]
+
+	def get_pad_sources(self):
+		"""
+		Get a list of pad source blocks sorted by id order.
+		@return a list of pad source blocks in this flow graph
+		"""
+		pads = filter(lambda b: b.get_key() == 'pad_source', self.get_enabled_blocks())
+		return sorted(pads, lambda x, y: cmp(x.get_id(), y.get_id()))
+
+	def get_pad_sinks(self):
+		"""
+		Get a list of pad sink blocks sorted by id order.
+		@return a list of pad sink blocks in this flow graph
+		"""
+		pads = filter(lambda b: b.get_key() == 'pad_sink', self.get_enabled_blocks())
+		return sorted(pads, lambda x, y: cmp(x.get_id(), y.get_id()))
+
+	def get_msg_pad_sources(self):
+		ps = self.get_pad_sources();
+		return filter(lambda b: b.get_param('type').get_evaluated() == 'message', ps);
+
+	def get_msg_pad_sinks(self):
+		ps = self.get_pad_sinks();
+		return filter(lambda b: b.get_param('type').get_evaluated() == 'message', ps);
+
+	def get_imports(self):
+		"""
+		Get a set of all import statments in this flow graph namespace.
+		@return a set of import statements
+		"""
+		imports = sum([block.get_imports() for block in self.get_enabled_blocks()], [])
+		imports = sorted(set(imports))
+		return imports
+
+	def get_variables(self):
+		"""
+		Get a list of all variables in this flow graph namespace.
+		Exclude paramterized variables.
+		@return a sorted list of variable blocks in order of dependency (indep -> dep)
+		"""
+		variables = filter(lambda b: _variable_matcher.match(b.get_key()), self.get_enabled_blocks())
+		return expr_utils.sort_objects(variables, lambda v: v.get_id(), lambda v: v.get_var_make())
+
+	def get_parameters(self):
+		"""
+		Get a list of all paramterized variables in this flow graph namespace.
+		@return a list of paramterized variables
+		"""
+		parameters = filter(lambda b: _parameter_matcher.match(b.get_key()), self.get_enabled_blocks())
+		return parameters
+
+	def rewrite(self):
+		"""
+		Flag the namespace to be renewed.
+		"""
+		self._renew_eval_ns = True
+		_FlowGraph.rewrite(self)
+
+	def evaluate(self, expr):
+		"""
+		Evaluate the expression.
+		@param expr the string expression
+		@throw Exception bad expression
+		@return the evaluated data
+		"""
+		if self._renew_eval_ns:
+			self._renew_eval_ns = False
+			#reload namespace
+			n = dict()
+			#load imports
+			for imp in self.get_imports():
+				try: exec imp in n
+				except: pass
+			#load parameters
+			np = dict()
+			for parameter in self.get_parameters():
+				try:
+					e = eval(parameter.get_param('value').to_code(), n, n)
+					np[parameter.get_id()] = e
+				except: pass
+			n.update(np) #merge param namespace
+			#load variables
+			for variable in self.get_variables():
+				try:
+					e = eval(variable.get_param('value').to_code(), n, n)
+					n[variable.get_id()] = e
+				except: pass
+			#make namespace public
+			self.n = n
+			self.n_hash = hash(str(n))
+		#evaluate
+		e = self._eval(expr, self.n, self.n_hash)
+		return e