ethereum.forks.gray_glacier.forkethereum.forks.paris.fork

Ethereum Specification.

.. contents:: Table of Contents :backlinks: none :local:

Introduction

Entry point for the Ethereum specification.

BLOCK_REWARD

74
BLOCK_REWARD = U256(2 * 10**18)

BASE_FEE_MAX_CHANGE_DENOMINATOR

71
BASE_FEE_MAX_CHANGE_DENOMINATOR = Uint(8)

ELASTICITY_MULTIPLIER

72
ELASTICITY_MULTIPLIER = Uint(2)

MINIMUM_DIFFICULTY

77
MINIMUM_DIFFICULTY = Uint(131072)

MAX_OMMER_DEPTH

78
MAX_OMMER_DEPTH = Uint(6)

BOMB_DELAY_BLOCKS

79
BOMB_DELAY_BLOCKS = 11400000

EMPTY_OMMER_HASH

73
EMPTY_OMMER_HASH = keccak256(rlp.encode([]))

BlockChain

History and current state of the block chain.

76
@final
77
@dataclass
class BlockChain:

blocks

83
    blocks: List[Block]

state

84
    state: State

chain_id

85
    chain_id: U64

apply_fork

Transforms the state from the previous hard fork (old) into the block chain object for this hard fork and returns it.

When forks need to implement an irregular state transition, this function is used to handle the irregularity. See the :ref:DAO Fork <dao-fork> for an example.

Parameters

old : Previous block chain object.

Returns

new : BlockChain Upgraded block chain object for this hard fork.

def apply_fork(old: BlockChain) -> BlockChain:
89
    <snip>
108
    return old

get_last_256_block_hashes

Obtain the list of hashes of the previous 256 blocks in order of increasing block number.

This function will return less hashes for the first 256 blocks.

The BLOCKHASH opcode needs to access the latest hashes on the chain, therefore this function retrieves them.

Parameters

chain : History and current state.

Returns

recent_block_hashes : List[Hash32] Hashes of the recent 256 blocks in order of increasing block number.

def get_last_256_block_hashes(chain: BlockChain) -> List[Hash32]:
112
    <snip>
132
    recent_blocks = chain.blocks[-255:]
133
    # TODO: This function has not been tested rigorously
134
    if len(recent_blocks) == 0:
135
        return []
136
137
    recent_block_hashes = []
138
139
    for block in recent_blocks:
140
        prev_block_hash = block.header.parent_hash
141
        recent_block_hashes.append(prev_block_hash)
142
143
    # We are computing the hash only for the most recent block and not for
144
    # the rest of the blocks as they have successors which have the hash of
145
    # the current block as parent hash.
146
    most_recent_block_hash = keccak256(rlp.encode(recent_blocks[-1].header))
147
    recent_block_hashes.append(most_recent_block_hash)
148
149
    return recent_block_hashes

state_transition

Attempts to apply a block to an existing block chain.

All parts of the block's contents need to be verified before being added to the chain. Blocks are verified by ensuring that the contents of the block make logical sense with the contents of the parent block. The information in the block's header must also match the corresponding information in the block.

To implement Ethereum, in theory clients are only required to store the most recent 255 blocks of the chain since as far as execution is concerned, only those blocks are accessed. Practically, however, clients should store more blocks to handle reorgs.

Parameters

chain : History and current state. block : Block to apply to chain.

def state_transition(chain: BlockChain, ​​block: Block) -> None:
153
    <snip>
175
    validate_header(chain, block.header)
183
    validate_ommers(block.ommers, block.header, chain)
176
    if block.ommers != ():
177
        raise InvalidBlock
178
179
    block_state = BlockState(pre_state=chain.state)
180
181
    block_env = vm.BlockEnvironment(
182
        chain_id=chain.chain_id,
183
        state=block_state,
184
        block_gas_limit=block.header.gas_limit,
185
        block_hashes=get_last_256_block_hashes(chain),
186
        coinbase=block.header.coinbase,
187
        number=block.header.number,
188
        base_fee_per_gas=block.header.base_fee_per_gas,
189
        time=block.header.timestamp,
196
        difficulty=block.header.difficulty,
190
        prev_randao=block.header.prev_randao,
191
    )
192
193
    block_output = apply_body(
194
        block_env=block_env,
195
        transactions=block.transactions,
202
        ommers=block.ommers,
196
    )
197
    block_diff = extract_block_diff(block_state)
198
    block_state_root, _ = chain.state.compute_state_root_and_trie_changes(
199
        block_diff.account_changes,
200
        block_diff.storage_changes,
201
        block_diff.storage_clears,
202
    )
203
    transactions_root = root(block_output.transactions_trie)
204
    receipt_root = root(block_output.receipts_trie)
205
    block_logs_bloom = logs_bloom(block_output.block_logs)
206
207
    if block_output.block_gas_used != block.header.gas_used:
208
        raise InvalidBlock(
209
            f"{block_output.block_gas_used} != {block.header.gas_used}"
210
        )
211
    if transactions_root != block.header.transactions_root:
212
        raise InvalidBlock
213
    if block_state_root != block.header.state_root:
214
        raise InvalidBlock
215
    if receipt_root != block.header.receipt_root:
216
        raise InvalidBlock
217
    if block_logs_bloom != block.header.bloom:
218
        raise InvalidBlock
219
220
    apply_changes_to_state(chain.state, block_diff)
221
    chain.blocks.append(block)
222
    if len(chain.blocks) > 255:
223
        # Real clients have to store more blocks to deal with reorgs, but the
224
        # protocol only requires the last 255
225
        chain.blocks = chain.blocks[-255:]

calculate_base_fee_per_gas

Calculates the base fee per gas for the block.

Parameters

block_gas_limit : Gas limit of the block for which the base fee is being calculated. parent_gas_limit : Gas limit of the parent block. parent_gas_used : Gas used in the parent block. parent_base_fee_per_gas : Base fee per gas of the parent block.

Returns

base_fee_per_gas : Uint Base fee per gas for the block.

def calculate_base_fee_per_gas(block_gas_limit: Uint, ​​parent_gas_limit: Uint, ​​parent_gas_used: Uint, ​​parent_base_fee_per_gas: Uint) -> Uint:
234
    <snip>
254
    parent_gas_target = parent_gas_limit // ELASTICITY_MULTIPLIER
255
    if not check_gas_limit(block_gas_limit, parent_gas_limit):
256
        raise InvalidBlock
257
258
    if parent_gas_used == parent_gas_target:
259
        expected_base_fee_per_gas = parent_base_fee_per_gas
260
    elif parent_gas_used > parent_gas_target:
261
        gas_used_delta = parent_gas_used - parent_gas_target
262
263
        parent_fee_gas_delta = parent_base_fee_per_gas * gas_used_delta
264
        target_fee_gas_delta = parent_fee_gas_delta // parent_gas_target
265
266
        base_fee_per_gas_delta = max(
267
            target_fee_gas_delta // BASE_FEE_MAX_CHANGE_DENOMINATOR,
268
            Uint(1),
269
        )
270
271
        expected_base_fee_per_gas = (
272
            parent_base_fee_per_gas + base_fee_per_gas_delta
273
        )
274
    else:
275
        gas_used_delta = parent_gas_target - parent_gas_used
276
277
        parent_fee_gas_delta = parent_base_fee_per_gas * gas_used_delta
278
        target_fee_gas_delta = parent_fee_gas_delta // parent_gas_target
279
280
        base_fee_per_gas_delta = (
281
            target_fee_gas_delta // BASE_FEE_MAX_CHANGE_DENOMINATOR
282
        )
283
284
        expected_base_fee_per_gas = (
285
            parent_base_fee_per_gas - base_fee_per_gas_delta
286
        )
287
288
    return Uint(expected_base_fee_per_gas)

validate_header

Verifies a block header.

In order to consider a block's header valid, the logic for the quantities in the header should match the logic for the block itself. For example the header timestamp should be greater than the block's parent timestamp because the block was created after the parent block. Additionally, the block's number should be directly following the parent block's number since it is the next block in the sequence.

Parameters

chain : History and current state. header : Header to check for correctness.

def validate_header(chain: BlockChain, ​​header: Header) -> None:
292
    <snip>
310
    if header.number < Uint(1):
311
        raise InvalidBlock
319
    parent_header_number = header.number - Uint(1)
320
    first_block_number = chain.blocks[0].header.number
321
    last_block_number = chain.blocks[-1].header.number
312
323
    if (
324
        parent_header_number < first_block_number
325
        or parent_header_number > last_block_number
326
    ):
327
        raise InvalidBlock
328
329
    parent_header = chain.blocks[
330
        parent_header_number - first_block_number
331
    ].header
313
    parent_header = chain.blocks[-1].header
314
315
    if header.gas_used > header.gas_limit:
316
        raise InvalidBlock
317
318
    expected_base_fee_per_gas = calculate_base_fee_per_gas(
319
        header.gas_limit,
320
        parent_header.gas_limit,
321
        parent_header.gas_used,
322
        parent_header.base_fee_per_gas,
323
    )
324
    if expected_base_fee_per_gas != header.base_fee_per_gas:
325
        raise InvalidBlock
344
345
    parent_has_ommers = parent_header.ommers_hash != EMPTY_OMMER_HASH
326
    if header.timestamp <= parent_header.timestamp:
327
        raise InvalidBlock
328
    if header.number != parent_header.number + Uint(1):
329
        raise InvalidBlock
330
    if len(header.extra_data) > 32:
331
        raise InvalidBlock
352
353
    block_difficulty = calculate_block_difficulty(
354
        header.number,
355
        header.timestamp,
356
        parent_header.timestamp,
357
        parent_header.difficulty,
358
        parent_has_ommers,
359
    )
360
    if header.difficulty != block_difficulty:
332
    if header.difficulty != 0:
333
        raise InvalidBlock
334
    if header.nonce != b"\x00\x00\x00\x00\x00\x00\x00\x00":
335
        raise InvalidBlock
336
    if header.ommers_hash != EMPTY_OMMER_HASH:
337
        raise InvalidBlock
338
339
    block_parent_hash = keccak256(rlp.encode(parent_header))
340
    if header.parent_hash != block_parent_hash:
365
        raise InvalidBlock
366
367
    validate_proof_of_work(header)
341
        raise InvalidBlock

generate_header_hash_for_pow

Generate rlp hash of the header which is to be used for Proof-of-Work verification.

In other words, the PoW artefacts mix_digest and nonce are ignored while calculating this hash.

A particular PoW is valid for a single hash, that hash is computed by this function. The nonce and mix_digest are omitted from this hash because they are being changed by miners in their search for a sufficient proof-of-work.

Parameters

header : The header object for which the hash is to be generated.

Returns

hash : Hash32 The PoW valid rlp hash of the passed in header.

def generate_header_hash_for_pow(header: Header) -> Hash32:
371
    <snip>
394
    header_data_without_pow_artefacts = (
395
        header.parent_hash,
396
        header.ommers_hash,
397
        header.coinbase,
398
        header.state_root,
399
        header.transactions_root,
400
        header.receipt_root,
401
        header.bloom,
402
        header.difficulty,
403
        header.number,
404
        header.gas_limit,
405
        header.gas_used,
406
        header.timestamp,
407
        header.extra_data,
408
        header.base_fee_per_gas,
409
    )
410
411
    return keccak256(rlp.encode(header_data_without_pow_artefacts))

validate_proof_of_work

Validates the Proof of Work constraints.

In order to verify that a miner's proof-of-work is valid for a block, a mix-digest and result are calculated using the hashimoto_light hash function. The mix digest is a hash of the header and the nonce that is passed through and it confirms whether or not proof-of-work was done on the correct block. The result is the actual hash value of the block.

Parameters

header : Header of interest.

def validate_proof_of_work(header: Header) -> None:
415
    <snip>
430
    header_hash = generate_header_hash_for_pow(header)
431
    # TODO: Memoize this somewhere and read from that data instead of
432
    # calculating cache for every block validation.
433
    cache = generate_cache(header.number)
434
    mix_digest, result = hashimoto_light(
435
        header_hash, header.nonce, cache, dataset_size(header.number)
436
    )
437
    if mix_digest != header.mix_digest:
438
        raise InvalidBlock
439
440
    limit = Uint(U256.MAX_VALUE) + Uint(1)
441
    if Uint.from_be_bytes(result) > (limit // header.difficulty):
442
        raise InvalidBlock

check_transaction

Check if the transaction is includable in the block.

Parameters

block_env : The block scoped environment. block_output : The block output for the current block. tx : The transaction. tx_state : The transaction state tracker.

Returns

sender_address : The sender of the transaction. effective_gas_price : The price to charge for gas when the transaction is executed.

Raises

InvalidBlock : If the transaction is not includable. GasUsedExceedsLimitError : If the gas used by the transaction exceeds the block's gas limit. NonceMismatchError : If the nonce of the transaction is not equal to the sender's nonce. InsufficientBalanceError : If the sender's balance is not enough to pay for the transaction. InvalidSenderError : If the transaction is from an address that does not exist anymore. PriorityFeeGreaterThanMaxFeeError:PriorityFeeGreaterThanMaxFeeError : If the priority fee is greater than the maximum fee per gas. InsufficientMaxFeePerGasError : If the maximum fee per gas is insufficient for the transaction.

def check_transaction(block_env: ethereum.forks.gray_glacier.vm.BlockEnvironmentethereum.forks.paris.vm.BlockEnvironment, ​​block_output: ethereum.forks.gray_glacier.vm.BlockOutputethereum.forks.paris.vm.BlockOutput, ​​tx: Transaction, ​​tx_state: TransactionState) -> Tuple[Address, Uint]:
350
    <snip>
389
    gas_available = block_env.block_gas_limit - block_output.block_gas_used
390
    if tx.gas > gas_available:
391
        raise GasUsedExceedsLimitError("gas used exceeds limit")
392
    sender_address = recover_sender(block_env.chain_id, tx)
393
    sender_account = get_account(tx_state, sender_address)
394
395
    if isinstance(tx, FeeMarketTransaction):
396
        if tx.max_fee_per_gas < tx.max_priority_fee_per_gas:
397
            raise PriorityFeeGreaterThanMaxFeeError(
398
                "priority fee greater than max fee"
399
            )
400
        if tx.max_fee_per_gas < block_env.base_fee_per_gas:
401
            raise InsufficientMaxFeePerGasError(
402
                tx.max_fee_per_gas, block_env.base_fee_per_gas
403
            )
404
405
        priority_fee_per_gas = min(
406
            tx.max_priority_fee_per_gas,
407
            tx.max_fee_per_gas - block_env.base_fee_per_gas,
408
        )
409
        effective_gas_price = priority_fee_per_gas + block_env.base_fee_per_gas
410
        max_gas_fee = tx.gas * tx.max_fee_per_gas
411
    else:
412
        if tx.gas_price < block_env.base_fee_per_gas:
413
            raise InvalidBlock
414
        effective_gas_price = tx.gas_price
415
        max_gas_fee = tx.gas * tx.gas_price
416
417
    if sender_account.nonce > Uint(tx.nonce):
418
        raise NonceMismatchError("nonce too low")
419
    elif sender_account.nonce < Uint(tx.nonce):
420
        raise NonceMismatchError("nonce too high")
421
    if Uint(sender_account.balance) < max_gas_fee + Uint(tx.value):
422
        raise InsufficientBalanceError("insufficient sender balance")
423
    if sender_account.code_hash != EMPTY_CODE_HASH:
424
        raise InvalidSenderError("not EOA")
425
426
    return sender_address, effective_gas_price

make_receipt

Make the receipt for a transaction that was executed.

Parameters

tx : The executed transaction. error : Error in the top level frame of the transaction, if any. cumulative_gas_used : The total gas used so far in the block after the transaction was executed. logs : The logs produced by the transaction.

Returns

receipt : The receipt for the transaction.

def make_receipt(tx: Transaction, ​​error: Optional[EthereumException], ​​cumulative_gas_used: Uint, ​​logs: Tuple[Log, ...]) -> Bytes | Receipt:
435
    <snip>
456
    receipt = Receipt(
457
        succeeded=error is None,
458
        cumulative_gas_used=cumulative_gas_used,
459
        bloom=logs_bloom(logs),
460
        logs=logs,
461
    )
462
463
    return encode_receipt(tx, receipt)

apply_body

Executes a block.

Many of the contents of a block are stored in data structures called tries. There is a transactions trie which is similar to a ledger of the transactions stored in the current block. There is also a receipts trie which stores the results of executing a transaction, like the post state and gas used. This function creates and executes the block that is to be added to the chain.

Parameters

block_env : The block scoped environment. transactions : Transactions included in the block. ommers : Headers of ancestor blocks which are not direct parents (formerly uncles.)

Returns

block_output : The block output for the current block.

def apply_body(block_env: ethereum.forks.gray_glacier.vm.BlockEnvironmentethereum.forks.paris.vm.BlockEnvironment, ​​transactions: Tuple[LegacyTransaction | Bytes, ...], ​​ommers: Tuple[Header, ...]) -> ethereum.forks.gray_glacier.vm.BlockOutputethereum.forks.paris.vm.BlockOutput:
470
    <snip>
493
    block_output = vm.BlockOutput()
494
495
    for i, tx in enumerate(map(decode_transaction, transactions)):
496
        process_transaction(block_env, block_output, tx, Uint(i))
497
603
    pay_rewards(block_env, ommers)
604
498
    return block_output

validate_ommers

Validates the ommers mentioned in the block.

An ommer block is a block that wasn't canonically added to the blockchain because it wasn't validated as fast as the canonical block but was mined at the same time.

To be considered valid, the ommers must adhere to the rules defined in the Ethereum protocol. The maximum amount of ommers is 2 per block and there cannot be duplicate ommers in a block. Many of the other ommer constraints are listed in the in-line comments of this function.

Parameters

ommers : List of ommers mentioned in the current block. block_header: The header of current block. chain : History and current state.

def validate_ommers(ommers: Tuple[Header, ...], ​​block_header: Header, ​​chain: BlockChain) -> None:
611
    <snip>
633
    block_hash = keccak256(rlp.encode(block_header))
634
    if keccak256(rlp.encode(ommers)) != block_header.ommers_hash:
635
        raise InvalidBlock
636
637
    if len(ommers) == 0:
638
        # Nothing to validate
639
        return
640
641
    # Check that each ommer satisfies the constraints of a header
642
    for ommer in ommers:
643
        if Uint(1) > ommer.number or ommer.number >= block_header.number:
644
            raise InvalidBlock
645
        validate_header(chain, ommer)
646
    if len(ommers) > 2:
647
        raise InvalidBlock
648
649
    ommers_hashes = [keccak256(rlp.encode(ommer)) for ommer in ommers]
650
    if len(ommers_hashes) != len(set(ommers_hashes)):
651
        raise InvalidBlock
652
653
    recent_canonical_blocks = chain.blocks[-(MAX_OMMER_DEPTH + Uint(1)) :]
654
    recent_canonical_block_hashes = {
655
        keccak256(rlp.encode(block.header))
656
        for block in recent_canonical_blocks
657
    }
658
    recent_ommers_hashes: Set[Hash32] = set()
659
    for block in recent_canonical_blocks:
660
        recent_ommers_hashes = recent_ommers_hashes.union(
661
            {keccak256(rlp.encode(ommer)) for ommer in block.ommers}
662
        )
663
664
    for ommer_index, ommer in enumerate(ommers):
665
        ommer_hash = ommers_hashes[ommer_index]
666
        if ommer_hash == block_hash:
667
            raise InvalidBlock
668
        if ommer_hash in recent_canonical_block_hashes:
669
            raise InvalidBlock
670
        if ommer_hash in recent_ommers_hashes:
671
            raise InvalidBlock
672
673
        # Ommer age with respect to the current block. For example, an age of
674
        # 1 indicates that the ommer is a sibling of previous block.
675
        ommer_age = block_header.number - ommer.number
676
        if Uint(1) > ommer_age or ommer_age > MAX_OMMER_DEPTH:
677
            raise InvalidBlock
678
        if ommer.parent_hash not in recent_canonical_block_hashes:
679
            raise InvalidBlock
680
        if ommer.parent_hash == block_header.parent_hash:
681
            raise InvalidBlock

pay_rewards

Pay rewards to the block miner as well as the ommers miners.

The miner of the canonical block is rewarded with the predetermined block reward, BLOCK_REWARD, plus a variable award based off of the number of ommer blocks that were mined around the same time, and included in the canonical block's header. An ommer block is a block that wasn't added to the canonical blockchain because it wasn't validated as fast as the accepted block but was mined at the same time. Although not all blocks that are mined are added to the canonical chain, miners are still paid a reward for their efforts. This reward is called an ommer reward and is calculated based on the number associated with the ommer block that they mined.

Parameters

block_env : The block scoped environment. ommers : List of ommers mentioned in the current block.

def pay_rewards(block_env: ethereum.forks.gray_glacier.vm.BlockEnvironment, ​​ommers: Tuple[Header, ...]) -> None:
688
    <snip>
710
    rewards_state = TransactionState(parent=block_env.state)
711
    ommer_count = U256(len(ommers))
712
    miner_reward = BLOCK_REWARD + (ommer_count * (BLOCK_REWARD // U256(32)))
713
    create_ether(rewards_state, block_env.coinbase, miner_reward)
714
715
    for ommer in ommers:
716
        # Ommer age with respect to the current block.
717
        ommer_age = U256(block_env.number - ommer.number)
718
        ommer_miner_reward = ((U256(8) - ommer_age) * BLOCK_REWARD) // U256(8)
719
        create_ether(rewards_state, ommer.coinbase, ommer_miner_reward)
720
721
    incorporate_tx_into_block(rewards_state)

process_transaction

Execute a transaction against the provided environment.

This function processes the actions needed to execute a transaction. It decrements the sender's account balance after calculating the gas fee and refunds them the proper amount after execution. Calling contracts, deploying code, and incrementing nonces are all examples of actions that happen within this function or from a call made within this function.

Accounts that are marked for deletion are processed and destroyed after execution.

Parameters

block_env : Environment for the Ethereum Virtual Machine. block_output : The block output for the current block. tx : Transaction to execute. index: Index of the transaction in the block.

def process_transaction(block_env: ethereum.forks.gray_glacier.vm.BlockEnvironmentethereum.forks.paris.vm.BlockEnvironment, ​​block_output: ethereum.forks.gray_glacier.vm.BlockOutputethereum.forks.paris.vm.BlockOutput, ​​tx: Transaction, ​​index: Uint) -> None:
507
    <snip>
531
    tx_state = TransactionState(parent=block_env.state)
532
533
    trie_set(
534
        block_output.transactions_trie,
535
        rlp.encode(index),
536
        encode_transaction(tx),
537
    )
538
539
    intrinsic_gas = validate_transaction(tx)
540
541
    (
542
        sender,
543
        effective_gas_price,
544
    ) = check_transaction(
545
        block_env=block_env,
546
        block_output=block_output,
547
        tx=tx,
548
        tx_state=tx_state,
549
    )
550
551
    sender_account = get_account(tx_state, sender)
552
553
    effective_gas_fee = tx.gas * effective_gas_price
554
555
    gas = tx.gas - intrinsic_gas
556
    increment_nonce(tx_state, sender)
557
558
    sender_balance_after_gas_fee = (
559
        Uint(sender_account.balance) - effective_gas_fee
560
    )
561
    set_account_balance(tx_state, sender, U256(sender_balance_after_gas_fee))
562
563
    access_list_addresses = set()
564
    access_list_storage_keys = set()
565
    if isinstance(tx, (AccessListTransaction, FeeMarketTransaction)):
566
        for access in tx.access_list:
567
            access_list_addresses.add(access.account)
568
            for slot in access.slots:
569
                access_list_storage_keys.add((access.account, slot))
570
571
    tx_env = vm.TransactionEnvironment(
572
        origin=sender,
573
        gas_price=effective_gas_price,
574
        gas=gas,
575
        access_list_addresses=access_list_addresses,
576
        access_list_storage_keys=access_list_storage_keys,
577
        state=tx_state,
578
        index_in_block=index,
579
        tx_hash=get_transaction_hash(encode_transaction(tx)),
580
    )
581
582
    message = prepare_message(block_env, tx_env, tx)
583
584
    tx_output = process_message_call(message)
585
586
    tx_gas_used_before_refund = tx.gas - tx_output.gas_left
587
    tx_gas_refund = min(
588
        tx_gas_used_before_refund // Uint(5), Uint(tx_output.refund_counter)
589
    )
590
    tx_gas_used_after_refund = tx_gas_used_before_refund - tx_gas_refund
591
    tx_gas_left = tx.gas - tx_gas_used_after_refund
592
    gas_refund_amount = tx_gas_left * effective_gas_price
593
594
    # For non-1559 transactions effective_gas_price == tx.gas_price
595
    priority_fee_per_gas = effective_gas_price - block_env.base_fee_per_gas
596
    transaction_fee = tx_gas_used_after_refund * priority_fee_per_gas
597
598
    # refund gas
599
    create_ether(tx_state, sender, U256(gas_refund_amount))
600
601
    # transfer miner fees
825
    coinbase_balance_after_mining_fee = get_account(
826
        tx_state, block_env.coinbase
827
    ).balance + U256(transaction_fee)
828
    if coinbase_balance_after_mining_fee != 0:
829
        set_account_balance(
830
            tx_state,
831
            block_env.coinbase,
832
            coinbase_balance_after_mining_fee,
833
        )
834
    elif account_exists_and_is_empty(tx_state, block_env.coinbase):
835
        destroy_account(tx_state, block_env.coinbase)
602
    create_ether(tx_state, block_env.coinbase, U256(transaction_fee))
603
604
    for address in tx_output.accounts_to_delete:
605
        destroy_account(tx_state, address)
839
840
    destroy_touched_empty_accounts(tx_state, tx_output.touched_accounts)
606
607
    block_output.block_gas_used += tx_gas_used_after_refund
608
609
    receipt = make_receipt(
610
        tx, tx_output.error, block_output.block_gas_used, tx_output.logs
611
    )
612
613
    receipt_key = rlp.encode(Uint(index))
614
    block_output.receipt_keys += (receipt_key,)
615
616
    trie_set(
617
        block_output.receipts_trie,
618
        receipt_key,
619
        receipt,
620
    )
621
622
    block_output.block_logs += tx_output.logs
623
624
    incorporate_tx_into_block(tx_state)

check_gas_limit

Validates the gas limit for a block.

The bounds of the gas limit, max_adjustment_delta, is set as the quotient of the parent block's gas limit and the LIMIT_ADJUSTMENT_FACTOR. Therefore, if the gas limit that is passed through as a parameter is greater than or equal to the sum of the parent's gas and the adjustment delta then the limit for gas is too high and fails this function's check. Similarly, if the limit is less than or equal to the difference of the parent's gas and the adjustment delta or the predefined LIMIT_MINIMUM then this function's check fails because the gas limit doesn't allow for a sufficient or reasonable amount of gas to be used on a block.

Parameters

gas_limit : Gas limit to validate.

parent_gas_limit : Gas limit of the parent block.

Returns

check : bool True if gas limit constraints are satisfied, False otherwise.

def check_gas_limit(gas_limit: Uint, ​​parent_gas_limit: Uint) -> bool:
628
    <snip>
656
    max_adjustment_delta = parent_gas_limit // GasCosts.LIMIT_ADJUSTMENT_FACTOR
657
    if gas_limit >= parent_gas_limit + max_adjustment_delta:
658
        return False
659
    if gas_limit <= parent_gas_limit - max_adjustment_delta:
660
        return False
661
    if gas_limit < GasCosts.LIMIT_MINIMUM:
662
        return False
663
664
    return True

calculate_block_difficulty

Computes difficulty of a block using its header and parent header.

The difficulty is determined by the time the block was created after its parent. The offset is calculated using the parent block's difficulty, parent_difficulty, and the timestamp between blocks. This offset is then added to the parent difficulty and is stored as the difficulty variable. If the time between the block and its parent is too short, the offset will result in a positive number thus making the sum of parent_difficulty and offset to be a greater value in order to avoid mass forking. But, if the time is long enough, then the offset results in a negative value making the block less difficult than its parent.

The base standard for a block's difficulty is the predefined value set for the genesis block since it has no parent. So, a block can't be less difficult than the genesis block, therefore each block's difficulty is set to the maximum value between the calculated difficulty and the MINIMUM_DIFFICULTY.

Parameters

block_number : Block number of the block. block_timestamp : Timestamp of the block. parent_timestamp : Timestamp of the parent block. parent_difficulty : difficulty of the parent block. parent_has_ommers: does the parent have ommers.

Returns

difficulty : ethereum.base_types.Uint Computed difficulty for a block.

def calculate_block_difficulty(block_number: Uint, ​​block_timestamp: U256, ​​parent_timestamp: U256, ​​parent_difficulty: Uint, ​​parent_has_ommers: bool) -> Uint:
909
    <snip>
948
    offset = (
949
        int(parent_difficulty)
950
        // 2048
951
        * max(
952
            (2 if parent_has_ommers else 1)
953
            - int(block_timestamp - parent_timestamp) // 9,
954
            -99,
955
        )
956
    )
957
    difficulty = int(parent_difficulty) + offset
958
    # Historical Note: The difficulty bomb was not present in Ethereum at the
959
    # start of Frontier, but was added shortly after launch. However since the
960
    # bomb has no effect prior to block 200000 we pretend it existed from
961
    # genesis.
962
    # See https://github.com/ethereum/go-ethereum/pull/1588
963
    num_bomb_periods = ((int(block_number) - BOMB_DELAY_BLOCKS) // 100000) - 2
964
    if num_bomb_periods >= 0:
965
        difficulty += 2**num_bomb_periods
966
967
    # Some clients raise the difficulty to `MINIMUM_DIFFICULTY` prior to adding
968
    # the bomb. This bug does not matter because the difficulty is always much
969
    # greater than `MINIMUM_DIFFICULTY` on Mainnet.
970
    return Uint(max(difficulty, int(MINIMUM_DIFFICULTY)))