91 lines
3.4 KiB
Nim
91 lines
3.4 KiB
Nim
# Nimbus
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# Copyright (c) 2018 Status Research & Development GmbH
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# Licensed under either of
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# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
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# * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
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# at your option. This file may not be copied, modified, or distributed except according to those terms.
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import
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strformat, times, options,
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eth/[common, rlp],
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../validation, ./difficulty, ../vm/interpreter/vm_forks, ../constants
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export BlockHeader
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proc hasUncles*(header: BlockHeader): bool = header.ommersHash != EMPTY_UNCLE_HASH
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proc `$`*(header: BlockHeader): string =
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result = &"BlockHeader(timestamp: {header.timestamp} difficulty: {header.difficulty} blockNumber: {header.blockNumber} gasLimit: {header.gasLimit})"
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proc gasLimitBounds*(parent: BlockHeader): (GasInt, GasInt) =
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## Compute the boundaries for the block gas limit based on the parent block.
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let
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boundaryRange = (parent.gasLimit div GAS_LIMIT_ADJUSTMENT_FACTOR)
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upperBound = if GAS_LIMIT_MAXIMUM - boundaryRange < parent.gasLimit:
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GAS_LIMIT_MAXIMUM else: parent.gasLimit + boundaryRange
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lowerBound = max(GAS_LIMIT_MINIMUM, parent.gasLimit - boundaryRange)
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return (lowerBound, upperBound)
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proc computeGasLimit*(parent: BlockHeader, gasLimitFloor: GasInt): GasInt =
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#[
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For each block:
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- decrease by 1/1024th of the gas limit from the previous block
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- increase by 50% of the total gas used by the previous block
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If the value is less than the given `gas_limit_floor`:
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- increase the gas limit by 1/1024th of the gas limit from the previous block.
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If the value is less than the GAS_LIMIT_MINIMUM:
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- use the GAS_LIMIT_MINIMUM as the new gas limit.
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]#
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if gasLimitFloor < GAS_LIMIT_MINIMUM:
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raise newException(ValueError,
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&"""
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The `gasLimitFloor` value must be greater than the GAS_LIMIT_MINIMUM.
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Got {gasLimitFloor}. Must be greater than {GAS_LIMIT_MINIMUM}
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"""
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)
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let decay = parent.gasLimit div GAS_LIMIT_EMA_DENOMINATOR
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var usageIncrease: GasInt
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if parent.gasUsed > 0:
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usageIncrease = (
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parent.gas_used * GAS_LIMIT_USAGE_ADJUSTMENT_NUMERATOR
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) div GAS_LIMIT_USAGE_ADJUSTMENT_DENOMINATOR div GAS_LIMIT_EMA_DENOMINATOR
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let gasLimit = max(
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GAS_LIMIT_MINIMUM,
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parent.gasLimit - decay + usageIncrease
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)
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if gasLimit < GAS_LIMIT_MINIMUM:
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return GAS_LIMIT_MINIMUM
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elif gasLimit < gasLimitFloor:
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return parent.gasLimit + decay
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else:
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return gasLimit
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proc generateHeaderFromParentHeader*(parent: BlockHeader,
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coinbase: EthAddress, fork: Fork, timestamp: Option[EthTime],
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gasLimit: Option[GasInt], extraData: Blob): BlockHeader =
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var lcTimestamp: EthTime
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if timestamp.isNone:
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lcTimeStamp = max(getTime(), parent.timestamp + 1.milliseconds) # Note: Py-evm uses +1 second, not ms
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else:
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lcTimestamp = timestamp.get()
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if lcTimestamp <= parent.timestamp:
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raise newException(ValueError, "header.timestamp should be higher than parent.timestamp")
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result = BlockHeader(
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timestamp: lcTimestamp,
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blockNumber: (parent.blockNumber + 1),
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difficulty: calcDifficulty(lcTimestamp, parent, fork),
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gasLimit: if gasLimit.isSome: gasLimit.get() else: computeGasLimit(parent, gasLimitFloor = GENESIS_GAS_LIMIT),
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stateRoot: parent.stateRoot,
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coinbase: coinbase,
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extraData: extraData,
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)
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