142 lines
4.1 KiB
Python
142 lines
4.1 KiB
Python
from pycsdr.modules import Buffer
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from typing import Union, Callable
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class Chain:
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def __init__(self, workers):
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self.reader = None
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self.writer = None
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self.clientReader = None
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self.workers = workers
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for i in range(1, len(self.workers)):
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self._connect(self.workers[i - 1], self.workers[i])
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def _connect(self, w1, w2):
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writer = Buffer(w1.getOutputFormat())
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w1.setWriter(writer)
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w2.setReader(writer.getReader())
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def setReader(self, reader):
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if self.reader is reader:
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return
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self.reader = reader
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if self.workers:
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self.workers[0].setReader(reader)
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def setWriter(self, writer):
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if self.writer is writer:
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return
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self.writer = writer
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if self.workers:
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self.workers[-1].setWriter(writer)
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def indexOf(self, search: Union[Callable, object]) -> int:
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def searchFn(x):
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if callable(search):
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return search(x)
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else:
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return x is search
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try:
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return next(i for i, v in enumerate(self.workers) if searchFn(v))
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except StopIteration:
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return -1
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def replace(self, index, newWorker):
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if index >= len(self.workers):
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raise IndexError("Index {} does not exist".format(index))
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self.workers[index].stop()
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self.workers[index] = newWorker
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error = None
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if index == 0:
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if self.reader is not None:
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newWorker.setReader(self.reader)
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else:
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try:
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previousWorker = self.workers[index - 1]
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self._connect(previousWorker, newWorker)
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except ValueError as e:
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# store error for later raising, but still attempt the second connection
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error = e
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if index == len(self.workers) - 1:
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if self.writer is not None:
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newWorker.setWriter(self.writer)
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else:
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try:
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nextWorker = self.workers[index + 1]
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self._connect(newWorker, nextWorker)
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except ValueError as e:
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error = e
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if error is not None:
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raise e
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def append(self, newWorker):
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previousWorker = None
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if self.workers:
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previousWorker = self.workers[-1]
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self.workers.append(newWorker)
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if previousWorker:
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self._connect(previousWorker, newWorker)
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elif self.reader is not None:
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newWorker.setReader(self.reader)
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if self.writer is not None:
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newWorker.setWriter(self.writer)
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def remove(self, index):
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removedWorker = self.workers[index]
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self.workers.remove(removedWorker)
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removedWorker.stop()
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if index == 0:
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if self.reader is not None:
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self.workers[0].setReader(self.reader)
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elif index == len(self.workers):
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if self.writer is not None:
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self.workers[-1].setWriter(self.writer)
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else:
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previousWorker = self.workers[index - 1]
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nextWorker = self.workers[index]
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self._connect(previousWorker, nextWorker)
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def stop(self):
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for w in self.workers:
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w.stop()
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if self.clientReader is not None:
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# TODO should be covered by finalize
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self.clientReader.stop()
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self.clientReader = None
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def getOutputFormat(self):
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if self.workers:
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return self.workers[-1].getOutputFormat()
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else:
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raise BufferError("getOutputFormat on empty chain")
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def pump(self, write):
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if self.writer is None:
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self.setWriter(Buffer(self.getOutputFormat()))
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self.clientReader = self.writer.getReader()
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def copy():
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run = True
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while run:
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data = None
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try:
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data = self.clientReader.read()
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except ValueError:
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pass
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if data is None:
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run = False
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else:
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write(data)
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return copy
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