90 lines
3.4 KiB
Python
90 lines
3.4 KiB
Python
# standard imports
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import logging
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# third-party imports
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import moolb
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# local imports
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from cic_cache.db import list_transactions_mined
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from cic_cache.db import list_transactions_account_mined
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logg = logging.getLogger()
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class BloomCache:
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def __init__(self, session):
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self.session = session
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@staticmethod
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def __get_filter_size(n):
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n = 8192 * 8
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logg.warning('filter size hardcoded to {}'.format(n))
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return n
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def load_transactions(self, offset, limit):
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"""Retrieves a list of transactions from cache and creates a bloom filter pointing to blocks and transactions.
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Block and transaction numbers are serialized as 32-bit big-endian numbers. The input to the second bloom filter is the concatenation of the serialized block number and transaction index.
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For example, if the block number is 13 and the transaction index is 42, the input are:
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block filter: 0x0d000000
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block+tx filter: 0x0d0000002a0000000
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:param offset: Offset in data set to return transactions from
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:type offset: int
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:param limit: Max number of transactions to retrieve
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:type limit: int
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:return: Lowest block, bloom filter for blocks, bloom filter for blocks|tx
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:rtype: tuple
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"""
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rows = list_transactions_mined(self.session, offset, limit)
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f_block = moolb.Bloom(BloomCache.__get_filter_size(limit), 3)
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f_blocktx = moolb.Bloom(BloomCache.__get_filter_size(limit), 3)
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highest_block = -1
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lowest_block = -1
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for r in rows:
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if highest_block == -1:
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highest_block = r[0]
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lowest_block = r[0]
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block = r[0].to_bytes(4, byteorder='big')
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tx = r[1].to_bytes(4, byteorder='big')
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f_block.add(block)
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f_blocktx.add(block + tx)
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logg.debug('added block {} tx {} lo {} hi {}'.format(r[0], r[1], lowest_block, highest_block))
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return (lowest_block, highest_block, f_block.to_bytes(), f_blocktx.to_bytes(),)
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def load_transactions_account(self, address, offset, limit):
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"""Same as load_transactions(...), but only retrieves transactions where the specified account address is sender or recipient.
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:param address: Address to retrieve transactions for.
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:type address: str, 0x-hex
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:param offset: Offset in data set to return transactions from
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:type offset: int
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:param limit: Max number of transactions to retrieve
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:type limit: int
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:return: Lowest block, bloom filter for blocks, bloom filter for blocks|tx
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:rtype: tuple
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"""
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rows = list_transactions_account_mined(self.session, address, offset, limit)
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f_block = moolb.Bloom(BloomCache.__get_filter_size(limit), 3)
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f_blocktx = moolb.Bloom(BloomCache.__get_filter_size(limit), 3)
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highest_block = -1;
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lowest_block = -1;
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for r in rows:
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if highest_block == -1:
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highest_block = r[0]
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lowest_block = r[0]
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block = r[0].to_bytes(4, byteorder='big')
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tx = r[1].to_bytes(4, byteorder='big')
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f_block.add(block)
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f_blocktx.add(block + tx)
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logg.debug('added block {} tx {} lo {} hi {}'.format(r[0], r[1], lowest_block, highest_block))
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return (lowest_block, highest_block, f_block.to_bytes(), f_blocktx.to_bytes(),)
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