41 lines
1.4 KiB
Python
41 lines
1.4 KiB
Python
from lbrynet.conf import MIN_BLOB_DATA_PAYMENT_RATE
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def get_default_price_model(blob_tracker, **kwargs):
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return MeanAvailabilityWeightedPrice(blob_tracker, **kwargs)
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class MeanAvailabilityWeightedPrice(object):
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"""
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Calculate mean-blob-availability and stream-position weighted price for a blob
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Attributes:
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min_price (float): minimum accepted price
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base_price (float): base price to shift from
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alpha (float): constant used to more highly value blobs at the beginning of a stream
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alpha defaults to 1.0, which has a null effect
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blob_tracker (BlobAvailabilityTracker): blob availability tracker
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"""
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def __init__(self, tracker, base_price=MIN_BLOB_DATA_PAYMENT_RATE, alpha=1.0):
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self.blob_tracker = tracker
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self.base_price = base_price
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self.alpha = alpha
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def calculate_price(self, blob):
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mean_availability = self.blob_tracker.last_mean_availability
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availability = self.blob_tracker.availability.get(blob, [])
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index = 0 # blob.index
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price = self.base_price * (mean_availability / max(1, len(availability))) / self._frontload(index)
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return round(price, 5)
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def _frontload(self, index):
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"""
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Get frontload multipler
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@param index: blob position in stream
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@return: frontload multipler
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"""
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return 2.0 - (self.alpha ** index)
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