eth2.0-specs/scripts/phase0/build_spec.py

import sys
import function_puller
from optparse import OptionParser

def build_phase0_spec(sourcefile, outfile):
    code_lines = []
    code_lines.append("""
from typing import (
    Any,
    Dict,
    List,
    NewType,
    Tuple,
)
from eth2spec.utils.minimal_ssz import *
from eth2spec.utils.bls_stub import *

""")
    for i in (1, 2, 3, 4, 8, 32, 48, 96):
        code_lines.append("def int_to_bytes%d(x): return x.to_bytes(%d, 'little')" % (i, i))

    code_lines.append("""

# stub, will get overwritten by real var
SLOTS_PER_EPOCH = 64


Slot = NewType('Slot', int)  # uint64
Epoch = NewType('Epoch', int)  # uint64
Shard = NewType('Shard', int)  # uint64
ValidatorIndex = NewType('ValidatorIndex', int)  # uint64
Gwei = NewType('Gwei', int)  # uint64
Bytes32 = NewType('Bytes32', bytes)  # bytes32
BLSPubkey = NewType('BLSPubkey', bytes)  # bytes48
BLSSignature = NewType('BLSSignature', bytes)  # bytes96
Store = None
""")

    code_lines += function_puller.get_spec(sourcefile)

    code_lines.append("""
# Monkey patch validator compute committee code
_compute_committee = compute_committee
committee_cache = {}


def compute_committee(indices: List[ValidatorIndex], seed: Bytes32, index: int, count: int) -> List[ValidatorIndex]:
    param_hash = (hash_tree_root(indices), seed, index, count)

    if param_hash in committee_cache:
        return committee_cache[param_hash]
    else:
        ret = _compute_committee(indices, seed, index, count)
        committee_cache[param_hash] = ret
        return ret


# Monkey patch hash cache
_hash = hash
hash_cache = {}


def hash(x):
    if x in hash_cache:
        return hash_cache[x]
    else:
        ret = _hash(x)
        hash_cache[x] = ret
        return ret

# Access to overwrite spec constants based on configuration
def apply_constants_preset(preset: Dict[str, Any]):
    global_vars = globals()
    for k, v in preset.items():
        global_vars[k] = v

    # Deal with derived constants
    global_vars['GENESIS_EPOCH'] = slot_to_epoch(GENESIS_SLOT)

    # Initialize SSZ types again, to account for changed lengths
    init_SSZ_types()
""")

    with open(outfile, 'w') as out:
        out.write("\n".join(code_lines))


def build_phase1_spec(sourcefile, outfile):
    code_lines = []
    code_lines.append("""
from eth2spec.phase0.spec import *

""")

    code_lines += function_puller.get_spec(sourcefile)

    with open(outfile, 'w') as out:
        out.write("\n".join(code_lines))


if __name__ == '__main__':
    parser = OptionParser()
    parser.add_option("-p", "--phase", dest="phase", type="int", default=0,
                  help="Build for phase #")

    (options, args) = parser.parse_args()

    if len(args) < 2:
        parser.print_help()
    
    if options.phase == 0:
        build_phase0_spec(args[0], args[1])
        print(args[0])
        print(args[1])
    elif options.phase == 1:
        build_phase1_spec(args[0], args[1])
    else:
        print("Invalid phase: {0}".format(options["phase"]))