Memory

A extendable memory used by the evm interpreter.

Properties

struct {
  /// The inner allocator used to grow the memory
  allocator: Allocator
  /// The underlaying memory buffer.
  buffer: []u8
  /// Set of memory checkpoints
  checkpoints: ArrayList(usize)
  /// The last memory checkpoint
  last_checkpoint: usize
  /// The max memory size
  memory_limit: u64
  /// The total allocated capacity of this memory.
  total_capacity: usize
}

Error

Set of errors when resizing errors.

error{MaxMemoryReached}

InitEmpty

Create the interpreter's memory. This will not error. No initial capacity is set. It's essentially empty memory.

Signature

pub fn initEmpty(allocator: Allocator, limit: ?u64) Memory

InitWithDefaultCapacity

Creates the memory with default 4096 capacity.

Signature

pub fn initWithDefaultCapacity(allocator: Allocator, limit: ?u64) Allocator.Error!Memory

InitWithCapacity

Creates the memory with capacity.

Signature

pub fn initWithCapacity(allocator: Allocator, capacity: usize, limit: ?u64) Allocator.Error!Memory

FreeContext

Prepares the memory for returning to the previous context.

Signature

pub fn freeContext(self: *Memory) void

GetCurrentMemorySize

Gets the current size of the Memory range.

Signature

pub fn getCurrentMemorySize(self: Memory) u64

GetMemoryByte

Gets a byte from the list's buffer.

Signature

pub fn getMemoryByte(self: Memory, offset: usize) u8

GetMemoryWord

Gets a Word from memory of in other words it gets a slice of 32 bytes from the inner memory buffer.

Signature

pub fn getMemoryWord(self: Memory, offset: usize) Word

GetSlice

Gets a memory slice based on the last checkpoints until the end of the buffer.

Signature

pub fn getSlice(self: Memory) []u8

MemoryCopy

Copies elements from one part of the buffer to another part of itself. Asserts that the provided indexes are not out of bound.

Signature

pub fn memoryCopy(self: *Memory, destination: usize, source: usize, length: usize) void

NewContext

Prepares the memory for a new context.

Signature

pub fn newContext(self: *Memory) Allocator.Error!void

Resize

Resizes the underlaying memory buffer. Uses the allocator's resize method in case it's possible. If the new len is lower than the current buffer size data will be lost.

Signature

pub fn resize(self: *Memory, new_len: usize) (Allocator.Error || Memory.Error)!void

WordToInt

Converts a memory "Word" into a u256 number. This reads the word as Big endian.

Signature

pub fn wordToInt(self: Memory, offset: usize) u256

WriteByte

Writes a single byte into this memory buffer. This can overwrite to existing memory.

Signature

pub fn writeByte(self: Memory, offset: usize, byte: u8) void

WriteWord

Writes a memory Word into the memory buffer. This can overwrite existing memory.

Signature

pub fn writeWord(self: Memory, offset: usize, word: [32]u8) void

WriteInt

Writes a u256 number into the memory buffer. This can overwrite to existing memory.

Signature

pub fn writeInt(self: Memory, offset: usize, data: u256) void

Write

Writes a slice to the memory buffer based on a offset. This can overwrite to existing memory.

Signature

pub fn write(self: Memory, offset: usize, data: []const u8) void

WriteData

Writes a slice to a given offset in memory + the provided data's offset. This can overwrite existing memory.

Signature

pub fn writeData(self: Memory, offset: usize, data_offset: usize, len: usize, data: []u8) void

Deinit

Frees the underlaying memory buffers.

Signature

pub fn deinit(self: Memory) void

Error

Set of errors when resizing errors.

error{MaxMemoryReached}

AvailableWords

Returns number of words what would fit to provided number of bytes, It rounds up the number bytes to number of words.

Signature

pub inline fn availableWords(size: u64) usize