ethereum.cancun.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:
38 | """ |
---|---|
39 | Loads to the stack, the value corresponding to a certain key from the |
40 | storage of the current account. |
41 |
|
42 | Parameters |
43 | ---------- |
44 | evm : |
45 | The current EVM frame. |
46 |
|
47 | """ |
48 | # STACK |
49 | key = pop(evm.stack).to_be_bytes32() |
50 | |
51 | # GAS |
52 | if (evm.message.current_target, key) in evm.accessed_storage_keys: |
53 | charge_gas(evm, GAS_WARM_ACCESS) |
54 | else: |
55 | evm.accessed_storage_keys.add((evm.message.current_target, key)) |
56 | charge_gas(evm, GAS_COLD_SLOAD) |
57 | |
58 | # OPERATION |
59 | value = get_storage(evm.env.state, evm.message.current_target, key) |
60 | |
61 | push(evm.stack, value) |
62 | |
63 | # PROGRAM COUNTER |
64 | 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:
68 | """ |
---|---|
69 | Stores a value at a certain key in the current context's storage. |
70 |
|
71 | Parameters |
72 | ---------- |
73 | evm : |
74 | The current EVM frame. |
75 |
|
76 | """ |
77 | # STACK |
78 | key = pop(evm.stack).to_be_bytes32() |
79 | new_value = pop(evm.stack) |
80 | if evm.gas_left <= GAS_CALL_STIPEND: |
81 | raise OutOfGasError |
82 | |
83 | original_value = get_storage_original( |
84 | evm.env.state, evm.message.current_target, key |
85 | ) |
86 | current_value = get_storage(evm.env.state, evm.message.current_target, key) |
87 | |
88 | gas_cost = Uint(0) |
89 | |
90 | if (evm.message.current_target, key) not in evm.accessed_storage_keys: |
91 | evm.accessed_storage_keys.add((evm.message.current_target, key)) |
92 | gas_cost += GAS_COLD_SLOAD |
93 | |
94 | if original_value == current_value and current_value != new_value: |
95 | if original_value == 0: |
96 | gas_cost += GAS_STORAGE_SET |
97 | else: |
98 | gas_cost += GAS_STORAGE_UPDATE - GAS_COLD_SLOAD |
99 | else: |
100 | gas_cost += GAS_WARM_ACCESS |
101 | |
102 | # Refund Counter Calculation |
103 | if current_value != new_value: |
104 | if original_value != 0 and current_value != 0 and new_value == 0: |
105 | # Storage is cleared for the first time in the transaction |
106 | evm.refund_counter += int(GAS_STORAGE_CLEAR_REFUND) |
107 |
|
108 | if original_value != 0 and current_value == 0: |
109 | # Gas refund issued earlier to be reversed |
110 | evm.refund_counter -= int(GAS_STORAGE_CLEAR_REFUND) |
111 |
|
112 | if original_value == new_value: |
113 | # Storage slot being restored to its original value |
114 | if original_value == 0: |
115 | # Slot was originally empty and was SET earlier |
116 | evm.refund_counter += int(GAS_STORAGE_SET - GAS_WARM_ACCESS) |
117 | else: |
118 | # Slot was originally non-empty and was UPDATED earlier |
119 | evm.refund_counter += int( |
120 | GAS_STORAGE_UPDATE - GAS_COLD_SLOAD - GAS_WARM_ACCESS |
121 | ) |
122 | |
123 | charge_gas(evm, gas_cost) |
124 | if evm.message.is_static: |
125 | raise WriteInStaticContext |
126 | set_storage(evm.env.state, evm.message.current_target, key, new_value) |
127 | |
128 | # PROGRAM COUNTER |
129 | evm.pc += Uint(1) |
tload
Loads to the stack, the value corresponding to a certain key from the transient storage of the current account. Parameters
evm : The current EVM frame.
def tload(evm: Evm) -> None:
133 | """ |
---|---|
134 | Loads to the stack, the value corresponding to a certain key from the |
135 | transient storage of the current account. |
136 | Parameters |
137 | ---------- |
138 | evm : |
139 | The current EVM frame. |
140 | """ |
141 | # STACK |
142 | key = pop(evm.stack).to_be_bytes32() |
143 | |
144 | # GAS |
145 | charge_gas(evm, GAS_WARM_ACCESS) |
146 | |
147 | # OPERATION |
148 | value = get_transient_storage( |
149 | evm.env.transient_storage, evm.message.current_target, key |
150 | ) |
151 | push(evm.stack, value) |
152 | |
153 | # PROGRAM COUNTER |
154 | evm.pc += Uint(1) |
tstore
Stores a value at a certain key in the current context's transient storage. Parameters
evm : The current EVM frame.
def tstore(evm: Evm) -> None:
158 | """ |
---|---|
159 | Stores a value at a certain key in the current context's transient storage. |
160 | Parameters |
161 | ---------- |
162 | evm : |
163 | The current EVM frame. |
164 | """ |
165 | # STACK |
166 | key = pop(evm.stack).to_be_bytes32() |
167 | new_value = pop(evm.stack) |
168 | |
169 | # GAS |
170 | charge_gas(evm, GAS_WARM_ACCESS) |
171 | if evm.message.is_static: |
172 | raise WriteInStaticContext |
173 | set_transient_storage( |
174 | evm.env.transient_storage, evm.message.current_target, key, new_value |
175 | ) |
176 | |
177 | # PROGRAM COUNTER |
178 | evm.pc += Uint(1) |