offer-zlib-compression

comp-test.py

import zlib

from chia.wallet.puzzles.load_clvm import load_clvm
from chia.wallet.puzzles import p2_delegated_puzzle_or_hidden_puzzle as standard_puzzle
from chia.wallet.puzzles.cc_loader import CC_MOD

OFFER_MOD = load_clvm("settlement_payments.clvm")

puzzle_dict = bytes(OFFER_MOD) + bytes(standard_puzzle.MOD) + bytes(CC_MOD)

offer_stream = bytes.fromhex(open("test.offer").read())

comp_obj = zlib.compressobj(zdict=puzzle_dict)
comp_offer = comp_obj.compress(offer_stream)
comp_offer += comp_obj.flush()
print(len(comp_offer))

do = zlib.decompressobj(zdict = puzzle_dict)

o1 = do.decompress(comp_offer)
print(len(o1))
print(o1 == offer_stream)

offer-compression.py

# this code is rough and not tested and quite ugly

ZDICT = [
    bytes(OFFER_MOD) + bytes(standard_puzzle.MOD) + bytes(CC_MOD),
    # more dictionaries go here
]


def zdict_for_version(version: int) -> bytes:
    assert version == 1  # expand more later
    return ZDICT[version]


def decompress_offer_blob(offer_blob: bytes) -> SpendBundle:
    assert offer_blob[:4] == "OFFR"
    version = int.from_bytes(offer_blob[4:6], "big")
    zdict = zdict_for_version(version)
    sb_bytes = decompress_magic(zdict, offer_blob[6:])  # do the decompression, as in the other python file
    return SpendBundle.deserialize(sb_bytes)


def compress_offer(sb: SpendBundle, version: int) -> bytes:
    version_blob = version.to_bytes(length=2, byteorder="big")
    zdict = zdict_for_version(version)
    offer_blob_sb = compress_magic(zdict, bytes(sb))  # do the compression, as in the other python file
    return b"OFFR" + version_blob + offer_blob_sb