ethereum.arrow_glacier.vm.instructions.storage
Ethereum Virtual Machine (EVM) Storage Instructions ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. contents:: Table of Contents :backlinks: none :local:
Introduction
Implementations of the EVM storage related instructions.
sload
Loads to the stack, the value corresponding to a certain key from the storage of the current account.
Parameters
evm : The current EVM frame.
def sload(evm: Evm) -> None:
32 | """ |
---|---|
33 | Loads to the stack, the value corresponding to a certain key from the |
34 | storage of the current account. |
35 |
|
36 | Parameters |
37 | ---------- |
38 | evm : |
39 | The current EVM frame. |
40 |
|
41 | """ |
42 | # STACK |
43 | key = pop(evm.stack).to_be_bytes32() |
44 | |
45 | # GAS |
46 | if (evm.message.current_target, key) in evm.accessed_storage_keys: |
47 | charge_gas(evm, GAS_WARM_ACCESS) |
48 | else: |
49 | evm.accessed_storage_keys.add((evm.message.current_target, key)) |
50 | charge_gas(evm, GAS_COLD_SLOAD) |
51 | |
52 | # OPERATION |
53 | value = get_storage(evm.env.state, evm.message.current_target, key) |
54 | |
55 | push(evm.stack, value) |
56 | |
57 | # PROGRAM COUNTER |
58 | evm.pc += Uint(1) |
sstore
Stores a value at a certain key in the current context's storage.
Parameters
evm : The current EVM frame.
def sstore(evm: Evm) -> None:
62 | """ |
---|---|
63 | Stores a value at a certain key in the current context's storage. |
64 |
|
65 | Parameters |
66 | ---------- |
67 | evm : |
68 | The current EVM frame. |
69 |
|
70 | """ |
71 | # STACK |
72 | key = pop(evm.stack).to_be_bytes32() |
73 | new_value = pop(evm.stack) |
74 | if evm.gas_left <= GAS_CALL_STIPEND: |
75 | raise OutOfGasError |
76 | |
77 | original_value = get_storage_original( |
78 | evm.env.state, evm.message.current_target, key |
79 | ) |
80 | current_value = get_storage(evm.env.state, evm.message.current_target, key) |
81 | |
82 | gas_cost = Uint(0) |
83 | |
84 | if (evm.message.current_target, key) not in evm.accessed_storage_keys: |
85 | evm.accessed_storage_keys.add((evm.message.current_target, key)) |
86 | gas_cost += GAS_COLD_SLOAD |
87 | |
88 | if original_value == current_value and current_value != new_value: |
89 | if original_value == 0: |
90 | gas_cost += GAS_STORAGE_SET |
91 | else: |
92 | gas_cost += GAS_STORAGE_UPDATE - GAS_COLD_SLOAD |
93 | else: |
94 | gas_cost += GAS_WARM_ACCESS |
95 | |
96 | # Refund Counter Calculation |
97 | if current_value != new_value: |
98 | if original_value != 0 and current_value != 0 and new_value == 0: |
99 | # Storage is cleared for the first time in the transaction |
100 | evm.refund_counter += int(GAS_STORAGE_CLEAR_REFUND) |
101 |
|
102 | if original_value != 0 and current_value == 0: |
103 | # Gas refund issued earlier to be reversed |
104 | evm.refund_counter -= int(GAS_STORAGE_CLEAR_REFUND) |
105 |
|
106 | if original_value == new_value: |
107 | # Storage slot being restored to its original value |
108 | if original_value == 0: |
109 | # Slot was originally empty and was SET earlier |
110 | evm.refund_counter += int(GAS_STORAGE_SET - GAS_WARM_ACCESS) |
111 | else: |
112 | # Slot was originally non-empty and was UPDATED earlier |
113 | evm.refund_counter += int( |
114 | GAS_STORAGE_UPDATE - GAS_COLD_SLOAD - GAS_WARM_ACCESS |
115 | ) |
116 | |
117 | charge_gas(evm, gas_cost) |
118 | if evm.message.is_static: |
119 | raise WriteInStaticContext |
120 | set_storage(evm.env.state, evm.message.current_target, key, new_value) |
121 | |
122 | # PROGRAM COUNTER |
123 | evm.pc += Uint(1) |