ethereum.forks.dao_fork.vm.gas
Ethereum Virtual Machine (EVM) Gas.
.. contents:: Table of Contents :backlinks: none :local:
Introduction
EVM gas constants and calculators.
GasCosts ¶
Constant gas values for the EVM.
class GasCosts:
BASE¶
| 35 | BASE = Uint(2) |
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VERY_LOW¶
| 36 | VERY_LOW = Uint(3) |
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LOW¶
| 37 | LOW = Uint(5) |
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MID¶
| 38 | MID = Uint(8) |
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HIGH¶
| 39 | HIGH = Uint(10) |
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SLOAD¶
| 42 | SLOAD = Uint(50) |
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STORAGE_SET¶
| 45 | STORAGE_SET = Uint(20000) |
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COLD_STORAGE_WRITE¶
| 46 | COLD_STORAGE_WRITE = Uint(5000) |
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CALL_VALUE¶
| 49 | CALL_VALUE = Uint(9000) |
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CALL_STIPEND¶
| 50 | CALL_STIPEND = Uint(2300) |
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NEW_ACCOUNT¶
| 51 | NEW_ACCOUNT = Uint(25000) |
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CODE_DEPOSIT_PER_BYTE¶
| 54 | CODE_DEPOSIT_PER_BYTE = Uint(200) |
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ZERO¶
| 57 | ZERO = Uint(0) |
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MEMORY_PER_WORD¶
| 58 | MEMORY_PER_WORD = Uint(3) |
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REFUND_STORAGE_CLEAR¶
| 61 | REFUND_STORAGE_CLEAR = 15000 |
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REFUND_SELF_DESTRUCT¶
| 62 | REFUND_SELF_DESTRUCT = Uint(24000) |
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PRECOMPILE_ECRECOVER¶
| 65 | PRECOMPILE_ECRECOVER = Uint(3000) |
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PRECOMPILE_SHA256_BASE¶
| 66 | PRECOMPILE_SHA256_BASE = Uint(60) |
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PRECOMPILE_SHA256_PER_WORD¶
| 67 | PRECOMPILE_SHA256_PER_WORD = Uint(12) |
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PRECOMPILE_RIPEMD160_BASE¶
| 68 | PRECOMPILE_RIPEMD160_BASE = Uint(600) |
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PRECOMPILE_RIPEMD160_PER_WORD¶
| 69 | PRECOMPILE_RIPEMD160_PER_WORD = Uint(120) |
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PRECOMPILE_IDENTITY_BASE¶
| 70 | PRECOMPILE_IDENTITY_BASE = Uint(15) |
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PRECOMPILE_IDENTITY_PER_WORD¶
| 71 | PRECOMPILE_IDENTITY_PER_WORD = Uint(3) |
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TX_BASE¶
| 74 | TX_BASE = Uint(21000) |
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TX_CREATE¶
| 75 | TX_CREATE = Uint(32000) |
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TX_DATA_PER_ZERO¶
| 76 | TX_DATA_PER_ZERO = Uint(4) |
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TX_DATA_PER_NON_ZERO¶
| 77 | TX_DATA_PER_NON_ZERO = Uint(68) |
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LIMIT_ADJUSTMENT_FACTOR¶
| 80 | LIMIT_ADJUSTMENT_FACTOR = Uint(1024) |
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LIMIT_MINIMUM¶
| 81 | LIMIT_MINIMUM = Uint(5000) |
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OPCODE_ADD¶
| 84 | OPCODE_ADD = VERY_LOW |
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OPCODE_SUB¶
| 85 | OPCODE_SUB = VERY_LOW |
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OPCODE_MUL¶
| 86 | OPCODE_MUL = LOW |
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OPCODE_DIV¶
| 87 | OPCODE_DIV = LOW |
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OPCODE_SDIV¶
| 88 | OPCODE_SDIV = LOW |
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OPCODE_MOD¶
| 89 | OPCODE_MOD = LOW |
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OPCODE_SMOD¶
| 90 | OPCODE_SMOD = LOW |
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OPCODE_ADDMOD¶
| 91 | OPCODE_ADDMOD = MID |
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OPCODE_MULMOD¶
| 92 | OPCODE_MULMOD = MID |
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OPCODE_SIGNEXTEND¶
| 93 | OPCODE_SIGNEXTEND = LOW |
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OPCODE_LT¶
| 94 | OPCODE_LT = VERY_LOW |
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OPCODE_GT¶
| 95 | OPCODE_GT = VERY_LOW |
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OPCODE_SLT¶
| 96 | OPCODE_SLT = VERY_LOW |
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OPCODE_SGT¶
| 97 | OPCODE_SGT = VERY_LOW |
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OPCODE_EQ¶
| 98 | OPCODE_EQ = VERY_LOW |
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OPCODE_ISZERO¶
| 99 | OPCODE_ISZERO = VERY_LOW |
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OPCODE_AND¶
| 100 | OPCODE_AND = VERY_LOW |
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OPCODE_OR¶
| 101 | OPCODE_OR = VERY_LOW |
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OPCODE_XOR¶
| 102 | OPCODE_XOR = VERY_LOW |
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OPCODE_NOT¶
| 103 | OPCODE_NOT = VERY_LOW |
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OPCODE_BYTE¶
| 104 | OPCODE_BYTE = VERY_LOW |
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OPCODE_JUMP¶
| 105 | OPCODE_JUMP = MID |
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OPCODE_JUMPI¶
| 106 | OPCODE_JUMPI = HIGH |
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OPCODE_JUMPDEST¶
| 107 | OPCODE_JUMPDEST = Uint(1) |
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OPCODE_CALLDATALOAD¶
| 108 | OPCODE_CALLDATALOAD = VERY_LOW |
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OPCODE_BLOCKHASH¶
| 109 | OPCODE_BLOCKHASH = Uint(20) |
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OPCODE_COINBASE¶
| 110 | OPCODE_COINBASE = BASE |
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OPCODE_POP¶
| 111 | OPCODE_POP = BASE |
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OPCODE_MSIZE¶
| 112 | OPCODE_MSIZE = BASE |
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OPCODE_PC¶
| 113 | OPCODE_PC = BASE |
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OPCODE_GAS¶
| 114 | OPCODE_GAS = BASE |
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OPCODE_ADDRESS¶
| 115 | OPCODE_ADDRESS = BASE |
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OPCODE_ORIGIN¶
| 116 | OPCODE_ORIGIN = BASE |
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OPCODE_CALLER¶
| 117 | OPCODE_CALLER = BASE |
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OPCODE_CALLVALUE¶
| 118 | OPCODE_CALLVALUE = BASE |
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OPCODE_CALLDATASIZE¶
| 119 | OPCODE_CALLDATASIZE = BASE |
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OPCODE_CODESIZE¶
| 120 | OPCODE_CODESIZE = BASE |
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OPCODE_GASPRICE¶
| 121 | OPCODE_GASPRICE = BASE |
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OPCODE_TIMESTAMP¶
| 122 | OPCODE_TIMESTAMP = BASE |
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OPCODE_NUMBER¶
| 123 | OPCODE_NUMBER = BASE |
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OPCODE_GASLIMIT¶
| 124 | OPCODE_GASLIMIT = BASE |
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OPCODE_DIFFICULTY¶
| 125 | OPCODE_DIFFICULTY = BASE |
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OPCODE_PUSH¶
| 126 | OPCODE_PUSH = VERY_LOW |
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OPCODE_DUP¶
| 127 | OPCODE_DUP = VERY_LOW |
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OPCODE_SWAP¶
| 128 | OPCODE_SWAP = VERY_LOW |
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OPCODE_CALLDATACOPY_BASE¶
| 131 | OPCODE_CALLDATACOPY_BASE = VERY_LOW |
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OPCODE_CODECOPY_BASE¶
| 132 | OPCODE_CODECOPY_BASE = VERY_LOW |
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OPCODE_MLOAD_BASE¶
| 133 | OPCODE_MLOAD_BASE = VERY_LOW |
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OPCODE_MSTORE_BASE¶
| 134 | OPCODE_MSTORE_BASE = VERY_LOW |
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OPCODE_MSTORE8_BASE¶
| 135 | OPCODE_MSTORE8_BASE = VERY_LOW |
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OPCODE_COPY_PER_WORD¶
| 136 | OPCODE_COPY_PER_WORD = Uint(3) |
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OPCODE_CREATE_BASE¶
| 137 | OPCODE_CREATE_BASE = Uint(32000) |
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OPCODE_EXP_BASE¶
| 138 | OPCODE_EXP_BASE = Uint(10) |
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OPCODE_EXP_PER_BYTE¶
| 139 | OPCODE_EXP_PER_BYTE = Uint(10) |
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OPCODE_KECCAK256_BASE¶
| 140 | OPCODE_KECCAK256_BASE = Uint(30) |
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OPCODE_KECCACK256_PER_WORD¶
| 141 | OPCODE_KECCACK256_PER_WORD = Uint(6) |
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OPCODE_LOG_BASE¶
| 142 | OPCODE_LOG_BASE = Uint(375) |
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OPCODE_LOG_DATA_PER_BYTE¶
| 143 | OPCODE_LOG_DATA_PER_BYTE = Uint(8) |
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OPCODE_LOG_TOPIC¶
| 144 | OPCODE_LOG_TOPIC = Uint(375) |
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OPCODE_EXTERNAL_BASE¶
| 145 | OPCODE_EXTERNAL_BASE = Uint(20) |
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OPCODE_BALANCE¶
| 146 | OPCODE_BALANCE = Uint(20) |
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OPCODE_CALL_BASE¶
| 147 | OPCODE_CALL_BASE = Uint(40) |
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ExtendMemory ¶
Define the parameters for memory extension in opcodes.
cost: ethereum.base_types.Uint
The gas required to perform the extension
expand_by: ethereum.base_types.Uint
The size by which the memory will be extended
| 150 | @dataclass |
|---|
class ExtendMemory:
cost¶
| 161 | cost: Uint |
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expand_by¶
| 162 | expand_by: Uint |
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MessageCallGas ¶
Define the gas cost and gas given to the sub-call for executing the call opcodes.
cost: ethereum.base_types.Uint
The gas required to execute the call opcode, excludes
memory expansion costs.
sub_call: ethereum.base_types.Uint
The portion of gas available to sub-calls that is refundable
if not consumed.
| 165 | @dataclass |
|---|
class MessageCallGas:
cost¶
| 179 | cost: Uint |
|---|
sub_call¶
| 180 | sub_call: Uint |
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charge_gas ¶
Subtracts amount from evm.gas_left.
Parameters
evm : The current EVM. amount : The amount of gas the current operation requires.
def charge_gas(evm: Evm, amount: Uint) -> None:
| 184 | """ |
|---|---|
| 185 | Subtracts `amount` from `evm.gas_left`. |
| 186 | |
| 187 | Parameters |
| 188 | ---------- |
| 189 | evm : |
| 190 | The current EVM. |
| 191 | amount : |
| 192 | The amount of gas the current operation requires. |
| 193 | |
| 194 | """ |
| 195 | evm_trace(evm, GasAndRefund(int(amount))) |
| 196 | |
| 197 | if evm.gas_left < amount: |
| 198 | raise OutOfGasError |
| 199 | else: |
| 200 | evm.gas_left -= amount |
calculate_memory_gas_cost ¶
Calculates the gas cost for allocating memory to the smallest multiple of 32 bytes, such that the allocated size is at least as big as the given size.
Parameters
size_in_bytes : The size of the data in bytes.
Returns
total_gas_cost : ethereum.base_types.Uint
The gas cost for storing data in memory.
def calculate_memory_gas_cost(size_in_bytes: Uint) -> Uint:
| 204 | """ |
|---|---|
| 205 | Calculates the gas cost for allocating memory |
| 206 | to the smallest multiple of 32 bytes, |
| 207 | such that the allocated size is at least as big as the given size. |
| 208 | |
| 209 | Parameters |
| 210 | ---------- |
| 211 | size_in_bytes : |
| 212 | The size of the data in bytes. |
| 213 | |
| 214 | Returns |
| 215 | ------- |
| 216 | total_gas_cost : `ethereum.base_types.Uint` |
| 217 | The gas cost for storing data in memory. |
| 218 | |
| 219 | """ |
| 220 | size_in_words = ceil32(size_in_bytes) // Uint(32) |
| 221 | linear_cost = size_in_words * GasCosts.MEMORY_PER_WORD |
| 222 | quadratic_cost = size_in_words ** Uint(2) // Uint(512) |
| 223 | total_gas_cost = linear_cost + quadratic_cost |
| 224 | try: |
| 225 | return total_gas_cost |
| 226 | except ValueError as e: |
| 227 | raise OutOfGasError from e |
calculate_gas_extend_memory ¶
Calculates the gas amount to extend memory.
Parameters
memory : Memory contents of the EVM. extensions: List of extensions to be made to the memory. Consists of a tuple of start position and size.
Returns
extend_memory: ExtendMemory
def calculate_gas_extend_memory(memory: bytearray, extensions: List[Tuple[U256, U256]]) -> ExtendMemory:
| 233 | """ |
|---|---|
| 234 | Calculates the gas amount to extend memory. |
| 235 | |
| 236 | Parameters |
| 237 | ---------- |
| 238 | memory : |
| 239 | Memory contents of the EVM. |
| 240 | extensions: |
| 241 | List of extensions to be made to the memory. |
| 242 | Consists of a tuple of start position and size. |
| 243 | |
| 244 | Returns |
| 245 | ------- |
| 246 | extend_memory: `ExtendMemory` |
| 247 | |
| 248 | """ |
| 249 | size_to_extend = Uint(0) |
| 250 | to_be_paid = Uint(0) |
| 251 | current_size = ulen(memory) |
| 252 | for start_position, size in extensions: |
| 253 | if size == 0: |
| 254 | continue |
| 255 | before_size = ceil32(current_size) |
| 256 | after_size = ceil32(Uint(start_position) + Uint(size)) |
| 257 | if after_size <= before_size: |
| 258 | continue |
| 259 | |
| 260 | size_to_extend += after_size - before_size |
| 261 | already_paid = calculate_memory_gas_cost(before_size) |
| 262 | total_cost = calculate_memory_gas_cost(after_size) |
| 263 | to_be_paid += total_cost - already_paid |
| 264 | |
| 265 | current_size = after_size |
| 266 | |
| 267 | return ExtendMemory(to_be_paid, size_to_extend) |
calculate_message_call_gas ¶
Calculates the gas amount for executing Opcodes CALL and CALLCODE.
Parameters
state :
The current state.
gas :
The amount of gas provided to the message-call.
to:
The address of the recipient account.
value:
The amount of ETH that needs to be transferred.
Returns
message_call_gas: MessageCallGas
def calculate_message_call_gas(state: State, gas: Uint, to: Address, value: U256) -> MessageCallGas:
| 273 | """ |
|---|---|
| 274 | Calculates the gas amount for executing Opcodes `CALL` and `CALLCODE`. |
| 275 | |
| 276 | Parameters |
| 277 | ---------- |
| 278 | state : |
| 279 | The current state. |
| 280 | gas : |
| 281 | The amount of gas provided to the message-call. |
| 282 | to: |
| 283 | The address of the recipient account. |
| 284 | value: |
| 285 | The amount of `ETH` that needs to be transferred. |
| 286 | |
| 287 | Returns |
| 288 | ------- |
| 289 | message_call_gas: `MessageCallGas` |
| 290 | |
| 291 | """ |
| 292 | create_gas_cost = ( |
| 293 | Uint(0) if account_exists(state, to) else GasCosts.NEW_ACCOUNT |
| 294 | ) |
| 295 | transfer_gas_cost = Uint(0) if value == 0 else GasCosts.CALL_VALUE |
| 296 | cost = ( |
| 297 | GasCosts.OPCODE_CALL_BASE + gas + create_gas_cost + transfer_gas_cost |
| 298 | ) |
| 299 | stipend = gas if value == 0 else GasCosts.CALL_STIPEND + gas |
| 300 | return MessageCallGas(cost, stipend) |