54 lines
1.2 KiB
Markdown
54 lines
1.2 KiB
Markdown
# merkle-tree-stream
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[](https://drone.autonomic.zone/hyperpy/merkle-tree-stream)
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## A stream that generates a merkle tree based on the incoming data
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> A hash tree or merkle tree is a tree in which every leaf node is labelled
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> with the hash of a data block and every non-leaf node is labelled with the
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> cryptographic hash of the labels of its child nodes. Merkle trees in Dat are
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> specialized flat trees that contain the content of the archives.
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## Install
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```sh
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$ pip install merkle-tree-stream
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```
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## Example
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```python
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import hashlib
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from merkle_tree_stream import MerkleTreeGenerator
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def _leaf(node, roots=None):
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return hashlib.sha256(node.data).digest()
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def _parent(first, second):
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sha256 = hashlib.sha256()
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sha256.update(first.data)
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sha256.update(second.data)
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return sha256.digest()
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merkle = MerkleTreeGenerator(leaf=_leaf, parent=_parent)
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merkle.write(b"a")
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merkle.write(b"b")
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print(merkle._nodes)
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```
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Output:
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```sh
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[
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MerkleTreeNode(index=0, parent=1, size=1, data=b'a', hash=b'...'),
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MerkleTreeNode(index=2, parent=1, size=1, data=b'b', hash=b'...'),
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MerkleTreeNode(index=1, parent=3, size=2, data=b'', hash=b'...')
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]
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```
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