return list(self)
-def _spec(fn, name=None):
- if name is None:
- return fn()
- varnames = dict(inspect.getmembers(fn.__code__))['co_varnames']
- if 'name' in varnames:
- return fn(name=name)
- return fn()
-
-
class PrevControl(Elaboratable):
""" contains signals that come *from* the previous stage (both in and out)
* valid_i: previous stage indicating all incoming data is valid.
def ports(self):
return list(self)
-
-class StageCls(metaclass=ABCMeta):
- """ Class-based "Stage" API. requires instantiation (after derivation)
-
- see "Stage API" above.. Note: python does *not* require derivation
- from this class. All that is required is that the pipelines *have*
- the functions listed in this class. Derivation from this class
- is therefore merely a "courtesy" to maintainers.
- """
- @abstractmethod
- def ispec(self): pass # REQUIRED
- @abstractmethod
- def ospec(self): pass # REQUIRED
- #@abstractmethod
- #def setup(self, m, i): pass # OPTIONAL
- #@abstractmethod
- #def process(self, i): pass # OPTIONAL
-
-
-class Stage(metaclass=ABCMeta):
- """ Static "Stage" API. does not require instantiation (after derivation)
-
- see "Stage API" above. Note: python does *not* require derivation
- from this class. All that is required is that the pipelines *have*
- the functions listed in this class. Derivation from this class
- is therefore merely a "courtesy" to maintainers.
- """
- @staticmethod
- @abstractmethod
- def ispec(): pass
-
- @staticmethod
- @abstractmethod
- def ospec(): pass
-
- #@staticmethod
- #@abstractmethod
- #def setup(m, i): pass
-
- #@staticmethod
- #@abstractmethod
- #def process(i): pass
-
-
-class StageChain(StageCls):
- """ pass in a list of stages, and they will automatically be
- chained together via their input and output specs into a
- combinatorial chain, to create one giant combinatorial block.
-
- the end result basically conforms to the exact same Stage API.
-
- * input to this class will be the input of the first stage
- * output of first stage goes into input of second
- * output of second goes into input into third
- * ... (etc. etc.)
- * the output of this class will be the output of the last stage
-
- NOTE: whilst this is very similar to ControlBase.connect(), it is
- *really* important to appreciate that StageChain is pure
- combinatorial and bypasses (does not involve, at all, ready/valid
- signalling of any kind).
-
- ControlBase.connect on the other hand respects, connects, and uses
- ready/valid signalling.
-
- Arguments:
-
- * :chain: a chain of combinatorial blocks conforming to the Stage API
- NOTE: StageChain.ispec and ospect have to have something
- to return (beginning and end specs of the chain),
- therefore the chain argument must be non-zero length
-
- * :specallocate: if set, new input and output data will be allocated
- and connected (eq'd) to each chained Stage.
- in some cases if this is not done, the nmigen warning
- "driving from two sources, module is being flattened"
- will be issued.
-
- NOTE: do NOT use StageChain with combinatorial blocks that have
- side-effects (state-based / clock-based input) or conditional
- (inter-chain) dependencies, unless you really know what you are doing.
- """
- def __init__(self, chain, specallocate=False):
- assert len(chain) > 0, "stage chain must be non-zero length"
- self.chain = chain
- self.specallocate = specallocate
-
- def ispec(self):
- """ returns the ispec of the first of the chain
- """
- return _spec(self.chain[0].ispec, "chainin")
-
- def ospec(self):
- """ returns the ospec of the last of the chain
- """
- return _spec(self.chain[-1].ospec, "chainout")
-
- def _specallocate_setup(self, m, i):
- for (idx, c) in enumerate(self.chain):
- if hasattr(c, "setup"):
- c.setup(m, i) # stage may have some module stuff
- ofn = self.chain[idx].ospec # last assignment survives
- o = _spec(ofn, 'chainin%d' % idx)
- m.d.comb += nmoperator.eq(o, c.process(i)) # process input into "o"
- if idx == len(self.chain)-1:
- break
- ifn = self.chain[idx+1].ispec # new input on next loop
- i = _spec(ifn, 'chainin%d' % (idx+1))
- m.d.comb += nmoperator.eq(i, o) # assign to next input
- return o # last loop is the output
-
- def _noallocate_setup(self, m, i):
- for (idx, c) in enumerate(self.chain):
- if hasattr(c, "setup"):
- c.setup(m, i) # stage may have some module stuff
- i = o = c.process(i) # store input into "o"
- return o # last loop is the output
-
- def setup(self, m, i):
- if self.specallocate:
- self.o = self._specallocate_setup(m, i)
- else:
- self.o = self._noallocate_setup(m, i)
-
- def process(self, i):
- return self.o # conform to Stage API: return last-loop output
-
-
-class StageHelper(Stage):
- """ a convenience wrapper around something that is Stage-API-compliant.
- (that "something" may be a static class, for example).
-
- StageHelper happens to also be compliant with the Stage API,
- except that all the "optional" functions are provided
- (hence the designation "convenience wrapper")
- """
- def __init__(self, stage):
- self.stage = stage
-
- def ospec(self, name):
- assert self.stage is not None
- return _spec(self.stage.ospec, name)
-
- def ispec(self, name):
- assert self.stage is not None
- return _spec(self.stage.ispec, name)
-
- def process(self, i):
- if self.stage and hasattr(self.stage, "process"):
- return self.stage.process(i)
- return i
-
- def setup(self, m, i):
- if self.stage is not None and hasattr(self.stage, "setup"):
- self.stage.setup(m, i)
-
- def _postprocess(self, i): # XXX DISABLED
- return i # RETURNS INPUT
- if hasattr(self.stage, "postprocess"):
- return self.stage.postprocess(i)
- return i
-
-
-class ControlBase(StageHelper, Elaboratable):
- """ Common functions for Pipeline API. Note: a "pipeline stage" only
- exists (conceptually) when a ControlBase derivative is handed
- a Stage (combinatorial block)
-
- NOTE: ControlBase derives from StageHelper, making it accidentally
- compliant with the Stage API. Using those functions directly
- *BYPASSES* a ControlBase instance ready/valid signalling, which
- clearly should not be done without a really, really good reason.
- """
- def __init__(self, stage=None, in_multi=None, stage_ctl=False):
- """ Base class containing ready/valid/data to previous and next stages
-
- * p: contains ready/valid to the previous stage
- * n: contains ready/valid to the next stage
-
- Except when calling Controlbase.connect(), user must also:
- * add data_i member to PrevControl (p) and
- * add data_o member to NextControl (n)
- Calling ControlBase._new_data is a good way to do that.
- """
- StageHelper.__init__(self, stage)
-
- # set up input and output IO ACK (prev/next ready/valid)
- self.p = PrevControl(in_multi, stage_ctl)
- self.n = NextControl(stage_ctl)
-
- # set up the input and output data
- if stage is not None:
- self._new_data(self, self, "data")
-
- def _new_data(self, p, n, name):
- """ allocates new data_i and data_o
- """
- self.p.data_i = _spec(p.stage.ispec, "%s_i" % name)
- self.n.data_o = _spec(n.stage.ospec, "%s_o" % name)
-
- @property
- def data_r(self):
- return self.process(self.p.data_i)
-
- def connect_to_next(self, nxt):
- """ helper function to connect to the next stage data/valid/ready.
- """
- return self.n.connect_to_next(nxt.p)
-
- def _connect_in(self, prev):
- """ internal helper function to connect stage to an input source.
- do not use to connect stage-to-stage!
- """
- return self.p._connect_in(prev.p)
-
- def _connect_out(self, nxt):
- """ internal helper function to connect stage to an output source.
- do not use to connect stage-to-stage!
- """
- return self.n._connect_out(nxt.n)
-
- def connect(self, pipechain):
- """ connects a chain (list) of Pipeline instances together and
- links them to this ControlBase instance:
-
- in <----> self <---> out
- | ^
- v |
- [pipe1, pipe2, pipe3, pipe4]
- | ^ | ^ | ^
- v | v | v |
- out---in out--in out---in
-
- Also takes care of allocating data_i/data_o, by looking up
- the data spec for each end of the pipechain. i.e It is NOT
- necessary to allocate self.p.data_i or self.n.data_o manually:
- this is handled AUTOMATICALLY, here.
-
- Basically this function is the direct equivalent of StageChain,
- except that unlike StageChain, the Pipeline logic is followed.
-
- Just as StageChain presents an object that conforms to the
- Stage API from a list of objects that also conform to the
- Stage API, an object that calls this Pipeline connect function
- has the exact same pipeline API as the list of pipline objects
- it is called with.
-
- Thus it becomes possible to build up larger chains recursively.
- More complex chains (multi-input, multi-output) will have to be
- done manually.
-
- Argument:
-
- * :pipechain: - a sequence of ControlBase-derived classes
- (must be one or more in length)
-
- Returns:
-
- * a list of eq assignments that will need to be added in
- an elaborate() to m.d.comb
- """
- assert len(pipechain) > 0, "pipechain must be non-zero length"
- eqs = [] # collated list of assignment statements
-
- # connect inter-chain
- for i in range(len(pipechain)-1):
- pipe1 = pipechain[i] # earlier
- pipe2 = pipechain[i+1] # later (by 1)
- eqs += pipe1.connect_to_next(pipe2) # earlier n to later p
-
- # connect front and back of chain to ourselves
- front = pipechain[0] # first in chain
- end = pipechain[-1] # last in chain
- self._new_data(front, end, "chain") # NOTE: REPLACES existing data
- eqs += front._connect_in(self) # front p to our p
- eqs += end._connect_out(self) # end n to out n
-
- return eqs
-
- def set_input(self, i):
- """ helper function to set the input data (used in unit tests)
- """
- return nmoperator.eq(self.p.data_i, i)
-
- def __iter__(self):
- yield from self.p # yields ready/valid/data (data also gets yielded)
- yield from self.n # ditto
-
- def ports(self):
- return list(self)
-
- def elaborate(self, platform):
- """ handles case where stage has dynamic ready/valid functions
- """
- m = Module()
- m.submodules.p = self.p
- m.submodules.n = self.n
-
- self.setup(m, self.p.data_i)
-
- if not self.p.stage_ctl:
- return m
-
- # intercept the previous (outgoing) "ready", combine with stage ready
- m.d.comb += self.p.s_ready_o.eq(self.p._ready_o & self.stage.d_ready)
-
- # intercept the next (incoming) "ready" and combine it with data valid
- sdv = self.stage.d_valid(self.n.ready_i)
- m.d.comb += self.n.d_valid.eq(self.n.ready_i & sdv)
-
- return m
-
StageChain, however when passed to UnbufferedPipeline they
can be used to introduce a single clock delay.
+ ControlBase:
+ -----------
+
+ The base class for pipelines. Contains previous and next ready/valid/data.
+ Also has an extremely useful "connect" function that can be used to
+ connect a chain of pipelines and present the exact same prev/next
+ ready/valid/data API.
+
+ Note: pipelines basically do not become pipelines as such until
+ handed to a derivative of ControlBase. ControlBase itself is *not*
+ strictly considered a pipeline class. Wishbone and AXI4 (master or
+ slave) could be derived from ControlBase, for example.
UnbufferedPipeline:
------------------
from nmigen.cli import verilog, rtlil
from nmigen.lib.fifo import SyncFIFO, SyncFIFOBuffered
from nmigen.hdl.ast import ArrayProxy
-from nmigen.hdl.rec import Record, Layout
+from nmigen.hdl.rec import Record
from abc import ABCMeta, abstractmethod
from collections.abc import Sequence, Iterable
import inspect
import nmoperator
-from iocontrol import (Object, RecordObject, _spec,
- PrevControl, NextControl, StageCls, Stage,
- ControlBase, StageChain)
+from iocontrol import (Object, RecordObject)
+from stageapi import (_spec, PrevControl, NextControl, StageCls, Stage,
+ StageChain, StageHelper)
+
+class ControlBase(StageHelper, Elaboratable):
+ """ Common functions for Pipeline API. Note: a "pipeline stage" only
+ exists (conceptually) when a ControlBase derivative is handed
+ a Stage (combinatorial block)
+
+ NOTE: ControlBase derives from StageHelper, making it accidentally
+ compliant with the Stage API. Using those functions directly
+ *BYPASSES* a ControlBase instance ready/valid signalling, which
+ clearly should not be done without a really, really good reason.
+ """
+ def __init__(self, stage=None, in_multi=None, stage_ctl=False):
+ """ Base class containing ready/valid/data to previous and next stages
+
+ * p: contains ready/valid to the previous stage
+ * n: contains ready/valid to the next stage
+
+ Except when calling Controlbase.connect(), user must also:
+ * add data_i member to PrevControl (p) and
+ * add data_o member to NextControl (n)
+ Calling ControlBase._new_data is a good way to do that.
+ """
+ StageHelper.__init__(self, stage)
+
+ # set up input and output IO ACK (prev/next ready/valid)
+ self.p = PrevControl(in_multi, stage_ctl)
+ self.n = NextControl(stage_ctl)
+
+ # set up the input and output data
+ if stage is not None:
+ self._new_data(self, self, "data")
+
+ def _new_data(self, p, n, name):
+ """ allocates new data_i and data_o
+ """
+ self.p.data_i = _spec(p.stage.ispec, "%s_i" % name)
+ self.n.data_o = _spec(n.stage.ospec, "%s_o" % name)
+
+ @property
+ def data_r(self):
+ return self.process(self.p.data_i)
+
+ def connect_to_next(self, nxt):
+ """ helper function to connect to the next stage data/valid/ready.
+ """
+ return self.n.connect_to_next(nxt.p)
+
+ def _connect_in(self, prev):
+ """ internal helper function to connect stage to an input source.
+ do not use to connect stage-to-stage!
+ """
+ return self.p._connect_in(prev.p)
+
+ def _connect_out(self, nxt):
+ """ internal helper function to connect stage to an output source.
+ do not use to connect stage-to-stage!
+ """
+ return self.n._connect_out(nxt.n)
+
+ def connect(self, pipechain):
+ """ connects a chain (list) of Pipeline instances together and
+ links them to this ControlBase instance:
+
+ in <----> self <---> out
+ | ^
+ v |
+ [pipe1, pipe2, pipe3, pipe4]
+ | ^ | ^ | ^
+ v | v | v |
+ out---in out--in out---in
+
+ Also takes care of allocating data_i/data_o, by looking up
+ the data spec for each end of the pipechain. i.e It is NOT
+ necessary to allocate self.p.data_i or self.n.data_o manually:
+ this is handled AUTOMATICALLY, here.
+
+ Basically this function is the direct equivalent of StageChain,
+ except that unlike StageChain, the Pipeline logic is followed.
+
+ Just as StageChain presents an object that conforms to the
+ Stage API from a list of objects that also conform to the
+ Stage API, an object that calls this Pipeline connect function
+ has the exact same pipeline API as the list of pipline objects
+ it is called with.
+
+ Thus it becomes possible to build up larger chains recursively.
+ More complex chains (multi-input, multi-output) will have to be
+ done manually.
+
+ Argument:
+
+ * :pipechain: - a sequence of ControlBase-derived classes
+ (must be one or more in length)
+
+ Returns:
+
+ * a list of eq assignments that will need to be added in
+ an elaborate() to m.d.comb
+ """
+ assert len(pipechain) > 0, "pipechain must be non-zero length"
+ eqs = [] # collated list of assignment statements
+
+ # connect inter-chain
+ for i in range(len(pipechain)-1):
+ pipe1 = pipechain[i] # earlier
+ pipe2 = pipechain[i+1] # later (by 1)
+ eqs += pipe1.connect_to_next(pipe2) # earlier n to later p
+
+ # connect front and back of chain to ourselves
+ front = pipechain[0] # first in chain
+ end = pipechain[-1] # last in chain
+ self._new_data(front, end, "chain") # NOTE: REPLACES existing data
+ eqs += front._connect_in(self) # front p to our p
+ eqs += end._connect_out(self) # end n to out n
+
+ return eqs
+
+ def set_input(self, i):
+ """ helper function to set the input data (used in unit tests)
+ """
+ return nmoperator.eq(self.p.data_i, i)
+
+ def __iter__(self):
+ yield from self.p # yields ready/valid/data (data also gets yielded)
+ yield from self.n # ditto
+
+ def ports(self):
+ return list(self)
+
+ def elaborate(self, platform):
+ """ handles case where stage has dynamic ready/valid functions
+ """
+ m = Module()
+ m.submodules.p = self.p
+ m.submodules.n = self.n
+
+ self.setup(m, self.p.data_i)
+
+ if not self.p.stage_ctl:
+ return m
+
+ # intercept the previous (outgoing) "ready", combine with stage ready
+ m.d.comb += self.p.s_ready_o.eq(self.p._ready_o & self.stage.d_ready)
+
+ # intercept the next (incoming) "ready" and combine it with data valid
+ sdv = self.stage.d_valid(self.n.ready_i)
+ m.d.comb += self.n.d_valid.eq(self.n.ready_i & sdv)
+
+ return m
+
class RecordBasedStage(Stage):
""" convenience class which provides a Records-based layout.
honestly it's a lot easier just to create a direct Records-based
--- /dev/null
+""" Stage API
+
+ Associated development bugs:
+ * http://bugs.libre-riscv.org/show_bug.cgi?id=64
+ * http://bugs.libre-riscv.org/show_bug.cgi?id=57
+
+ Stage API:
+ ---------
+
+ stage requires compliance with a strict API that may be
+ implemented in several means, including as a static class.
+
+ Stages do not HOLD data, and they definitely do not contain
+ signalling (ready/valid). They do however specify the FORMAT
+ of the incoming and outgoing data, and they provide a means to
+ PROCESS that data (from incoming format to outgoing format).
+
+ Stage Blocks really must be combinatorial blocks. It would be ok
+ to have input come in from sync'd sources (clock-driven) however by
+ doing so they would no longer be deterministic, and chaining such
+ blocks with such side-effects together could result in unexpected,
+ unpredictable, unreproduceable behaviour.
+ So generally to be avoided, then unless you know what you are doing.
+
+ the methods of a stage instance must be as follows:
+
+ * ispec() - Input data format specification. Takes a bit of explaining.
+ The requirements are: something that eventually derives from
+ nmigen Value must be returned *OR* an iterator or iterable
+ or sequence (list, tuple etc.) or generator must *yield*
+ thing(s) that (eventually) derive from the nmigen Value class.
+
+ Complex to state, very simple in practice:
+ see test_buf_pipe.py for over 25 worked examples.
+
+ * ospec() - Output data format specification.
+ format requirements identical to ispec.
+
+ * process(m, i) - Optional function for processing ispec-formatted data.
+ returns a combinatorial block of a result that
+ may be assigned to the output, by way of the "nmoperator.eq"
+ function. Note that what is returned here can be
+ extremely flexible. Even a dictionary can be returned
+ as long as it has fields that match precisely with the
+ Record into which its values is intended to be assigned.
+ Again: see example unit tests for details.
+
+ * setup(m, i) - Optional function for setting up submodules.
+ may be used for more complex stages, to link
+ the input (i) to submodules. must take responsibility
+ for adding those submodules to the module (m).
+ the submodules must be combinatorial blocks and
+ must have their inputs and output linked combinatorially.
+
+ Both StageCls (for use with non-static classes) and Stage (for use
+ by static classes) are abstract classes from which, for convenience
+ and as a courtesy to other developers, anything conforming to the
+ Stage API may *choose* to derive. See Liskov Substitution Principle:
+ https://en.wikipedia.org/wiki/Liskov_substitution_principle
+
+ StageChain:
+ ----------
+
+ A useful combinatorial wrapper around stages that chains them together
+ and then presents a Stage-API-conformant interface. By presenting
+ the same API as the stages it wraps, it can clearly be used recursively.
+
+ StageHelper:
+ ----------
+
+ A convenience wrapper around a Stage-API-compliant "thing" which
+ complies with the Stage API and provides mandatory versions of
+ all the optional bits.
+"""
+
+from nmigen import Signal, Cat, Const, Mux, Module, Value, Elaboratable
+from nmigen.cli import verilog, rtlil
+from nmigen.hdl.rec import Record
+
+from abc import ABCMeta, abstractmethod
+from collections.abc import Sequence, Iterable
+from collections import OrderedDict
+import inspect
+
+from iocontrol import PrevControl, NextControl
+import nmoperator
+
+
+def _spec(fn, name=None):
+ if name is None:
+ return fn()
+ varnames = dict(inspect.getmembers(fn.__code__))['co_varnames']
+ if 'name' in varnames:
+ return fn(name=name)
+ return fn()
+
+
+class StageCls(metaclass=ABCMeta):
+ """ Class-based "Stage" API. requires instantiation (after derivation)
+
+ see "Stage API" above.. Note: python does *not* require derivation
+ from this class. All that is required is that the pipelines *have*
+ the functions listed in this class. Derivation from this class
+ is therefore merely a "courtesy" to maintainers.
+ """
+ @abstractmethod
+ def ispec(self): pass # REQUIRED
+ @abstractmethod
+ def ospec(self): pass # REQUIRED
+ #@abstractmethod
+ #def setup(self, m, i): pass # OPTIONAL
+ #@abstractmethod
+ #def process(self, i): pass # OPTIONAL
+
+
+class Stage(metaclass=ABCMeta):
+ """ Static "Stage" API. does not require instantiation (after derivation)
+
+ see "Stage API" above. Note: python does *not* require derivation
+ from this class. All that is required is that the pipelines *have*
+ the functions listed in this class. Derivation from this class
+ is therefore merely a "courtesy" to maintainers.
+ """
+ @staticmethod
+ @abstractmethod
+ def ispec(): pass
+
+ @staticmethod
+ @abstractmethod
+ def ospec(): pass
+
+ #@staticmethod
+ #@abstractmethod
+ #def setup(m, i): pass
+
+ #@staticmethod
+ #@abstractmethod
+ #def process(i): pass
+
+
+class StageChain(StageCls):
+ """ pass in a list of stages, and they will automatically be
+ chained together via their input and output specs into a
+ combinatorial chain, to create one giant combinatorial block.
+
+ the end result basically conforms to the exact same Stage API.
+
+ * input to this class will be the input of the first stage
+ * output of first stage goes into input of second
+ * output of second goes into input into third
+ * ... (etc. etc.)
+ * the output of this class will be the output of the last stage
+
+ NOTE: whilst this is very similar to ControlBase.connect(), it is
+ *really* important to appreciate that StageChain is pure
+ combinatorial and bypasses (does not involve, at all, ready/valid
+ signalling of any kind).
+
+ ControlBase.connect on the other hand respects, connects, and uses
+ ready/valid signalling.
+
+ Arguments:
+
+ * :chain: a chain of combinatorial blocks conforming to the Stage API
+ NOTE: StageChain.ispec and ospect have to have something
+ to return (beginning and end specs of the chain),
+ therefore the chain argument must be non-zero length
+
+ * :specallocate: if set, new input and output data will be allocated
+ and connected (eq'd) to each chained Stage.
+ in some cases if this is not done, the nmigen warning
+ "driving from two sources, module is being flattened"
+ will be issued.
+
+ NOTE: do NOT use StageChain with combinatorial blocks that have
+ side-effects (state-based / clock-based input) or conditional
+ (inter-chain) dependencies, unless you really know what you are doing.
+ """
+ def __init__(self, chain, specallocate=False):
+ assert len(chain) > 0, "stage chain must be non-zero length"
+ self.chain = chain
+ self.specallocate = specallocate
+
+ def ispec(self):
+ """ returns the ispec of the first of the chain
+ """
+ return _spec(self.chain[0].ispec, "chainin")
+
+ def ospec(self):
+ """ returns the ospec of the last of the chain
+ """
+ return _spec(self.chain[-1].ospec, "chainout")
+
+ def _specallocate_setup(self, m, i):
+ for (idx, c) in enumerate(self.chain):
+ if hasattr(c, "setup"):
+ c.setup(m, i) # stage may have some module stuff
+ ofn = self.chain[idx].ospec # last assignment survives
+ o = _spec(ofn, 'chainin%d' % idx)
+ m.d.comb += nmoperator.eq(o, c.process(i)) # process input into "o"
+ if idx == len(self.chain)-1:
+ break
+ ifn = self.chain[idx+1].ispec # new input on next loop
+ i = _spec(ifn, 'chainin%d' % (idx+1))
+ m.d.comb += nmoperator.eq(i, o) # assign to next input
+ return o # last loop is the output
+
+ def _noallocate_setup(self, m, i):
+ for (idx, c) in enumerate(self.chain):
+ if hasattr(c, "setup"):
+ c.setup(m, i) # stage may have some module stuff
+ i = o = c.process(i) # store input into "o"
+ return o # last loop is the output
+
+ def setup(self, m, i):
+ if self.specallocate:
+ self.o = self._specallocate_setup(m, i)
+ else:
+ self.o = self._noallocate_setup(m, i)
+
+ def process(self, i):
+ return self.o # conform to Stage API: return last-loop output
+
+
+class StageHelper(Stage):
+ """ a convenience wrapper around something that is Stage-API-compliant.
+ (that "something" may be a static class, for example).
+
+ StageHelper happens to also be compliant with the Stage API,
+ except that all the "optional" functions are provided
+ (hence the designation "convenience wrapper")
+ """
+ def __init__(self, stage):
+ self.stage = stage
+
+ def ospec(self, name):
+ assert self.stage is not None
+ return _spec(self.stage.ospec, name)
+
+ def ispec(self, name):
+ assert self.stage is not None
+ return _spec(self.stage.ispec, name)
+
+ def process(self, i):
+ if self.stage and hasattr(self.stage, "process"):
+ return self.stage.process(i)
+ return i
+
+ def setup(self, m, i):
+ if self.stage is not None and hasattr(self.stage, "setup"):
+ self.stage.setup(m, i)
+
+ def _postprocess(self, i): # XXX DISABLED
+ return i # RETURNS INPUT
+ if hasattr(self.stage, "postprocess"):
+ return self.stage.postprocess(i)
+ return i
+
projects / ieee754fpu.git / commitdiff