ethereum.gray_glacier.vm.memory
Ethereum Virtual Machine (EVM) Memory ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. contents:: Table of Contents :backlinks: none :local:
Introduction
EVM memory operations.
memory_write
Writes to memory.
Parameters
memory : Memory contents of the EVM. start_position : Starting pointer to the memory. value : Data to write to memory.
def memory_write(memory: bytearray, start_position: U256, value: Bytes) -> None:
23 | """ |
---|---|
24 | Writes to memory. |
25 |
|
26 | Parameters |
27 | ---------- |
28 | memory : |
29 | Memory contents of the EVM. |
30 | start_position : |
31 | Starting pointer to the memory. |
32 | value : |
33 | Data to write to memory. |
34 | """ |
35 | memory[start_position : int(start_position) + len(value)] = value |
memory_read_bytes
Read bytes from memory.
Parameters
memory :
Memory contents of the EVM.
start_position :
Starting pointer to the memory.
size :
Size of the data that needs to be read from start_position
.
Returns
data_bytes : Data read from memory.
def memory_read_bytes(memory: bytearray, start_position: U256, size: U256) -> bytearray:
41 | """ |
---|---|
42 | Read bytes from memory. |
43 |
|
44 | Parameters |
45 | ---------- |
46 | memory : |
47 | Memory contents of the EVM. |
48 | start_position : |
49 | Starting pointer to the memory. |
50 | size : |
51 | Size of the data that needs to be read from `start_position`. |
52 |
|
53 | Returns |
54 | ------- |
55 | data_bytes : |
56 | Data read from memory. |
57 | """ |
58 | return memory[start_position : Uint(start_position) + Uint(size)] |
buffer_read
Read bytes from a buffer. Padding with zeros if necessary.
Parameters
buffer :
Memory contents of the EVM.
start_position :
Starting pointer to the memory.
size :
Size of the data that needs to be read from start_position
.
Returns
data_bytes : Data read from memory.
def buffer_read(buffer: Bytes, start_position: U256, size: U256) -> Bytes:
62 | """ |
---|---|
63 | Read bytes from a buffer. Padding with zeros if necessary. |
64 |
|
65 | Parameters |
66 | ---------- |
67 | buffer : |
68 | Memory contents of the EVM. |
69 | start_position : |
70 | Starting pointer to the memory. |
71 | size : |
72 | Size of the data that needs to be read from `start_position`. |
73 |
|
74 | Returns |
75 | ------- |
76 | data_bytes : |
77 | Data read from memory. |
78 | """ |
79 | return right_pad_zero_bytes( |
80 | buffer[start_position : Uint(start_position) + Uint(size)], size |
81 | ) |