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Remove getBlockIndexes method, rename orphan to stale #115

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Merged
merged 1 commit into from
Mar 23, 2024
Merged

Remove getBlockIndexes method, rename orphan to stale #115

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40 changes: 13 additions & 27 deletions blockchain_parser/blockchain.py
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Original file line number Diff line number Diff line change
Expand Up @@ -86,8 +86,6 @@ class Blockchain(object):

def __init__(self, path):
self.path = path
self.blockIndexes = None
self.indexPath = None

def get_unordered_blocks(self):
"""Yields the blocks contained in the .blk files as is,
Expand All @@ -97,20 +95,6 @@ def get_unordered_blocks(self):
for raw_block in get_blocks(blk_file):
yield Block(raw_block, None, os.path.split(blk_file)[1])

def __getBlockIndexes(self, index):
"""There is no method of leveldb to close the db (and release the lock).
This creates problem during concurrent operations.
This function also provides caching of indexes.
"""
if self.indexPath != index:
db = plyvel.DB(index, compression=None)
self.blockIndexes = [DBBlockIndex(format_hash(k[1:]), v)
for k, v in db.iterator() if k[0] == ord('b')]
db.close()
self.blockIndexes.sort(key=lambda x: x.height)
self.indexPath = index
return self.blockIndexes

def _index_confirmed(self, chain_indexes, num_confirmations=6):
"""Check if the first block index in "chain_indexes" has at least
"num_confirmation" (6) blocks built on top of it.
Expand Down Expand Up @@ -166,22 +150,24 @@ def get_ordered_blocks(self, index, start=0, end=None, cache=None):
blockIndexes = pickle.load(f)

if blockIndexes is None:
# build the block index
blockIndexes = self.__getBlockIndexes(index)
with plyvel.DB(index, compression=None) as db:
# Block index entries are stored with keys prefixed by 'b'
with db.iterator(prefix=b'b') as iterator:
blockIndexes = [DBBlockIndex(format_hash(k[1:]), v) for k, v in iterator]

if cache and not os.path.exists(cache):
# cache the block index for re-use next time
with open(cache, 'wb') as f:
pickle.dump(blockIndexes, f)

# remove small forks that may have occurred while the node was live.
# Occasionally a node will receive two different solutions to a block
# at the same time. The Leveldb index saves both, not pruning the
# at the same time. The node saves both to disk, not pruning the
# block that leads to a shorter chain once the fork is settled without
# "-reindex"ing the bitcoind block data. This leads to at least two
# blocks with the same height in the database.
# "-reindex"ing the bitcoind block data. This leads to sometimes there
# being two blocks with the same height in the database.
# We throw out blocks that don't have at least 6 other blocks on top of
# it (6 confirmations).
orphans = [] # hold blocks that are orphans with < 6 blocks on top
stale_blocks = [] # hold hashes of blocks that are stale with < 6 blocks on top
last_height = -1
for i, blockIdx in enumerate(blockIndexes):
if last_height > -1:
Expand All @@ -196,18 +182,18 @@ def get_ordered_blocks(self, index, start=0, end=None, cache=None):

# if this block is confirmed, the unconfirmed block is
# the previous one. Remove it.
orphans.append(blockIndexes[i - 1].hash)
stale_blocks.append(blockIndexes[i - 1].hash)
else:

# if this block isn't confirmed, remove it.
orphans.append(blockIndexes[i].hash)
stale_blocks.append(blockIndexes[i].hash)

last_height = blockIdx.height

# filter out the orphan blocks, so we are left only with block indexes
# filter out stale blocks, so we are left only with block indexes
# that have been confirmed
# (or are new enough that they haven't yet been confirmed)
blockIndexes = list(filter(lambda block: block.hash not in orphans, blockIndexes))
blockIndexes = list(filter(lambda block: block.hash not in stale_blocks, blockIndexes))

if end is None:
end = len(blockIndexes)
Expand Down