F3.IO.Memory (F3 v0.1.0)

In-memory byte source.

The struct keeps the caller's binary until close/1, which drops this source's reference. Inspect does not print the bytes.

Summary

Types

t()

In-memory source.

Functions

close(state)

Drops this source's binary. A second close returns the same closed handle.

open(data)

Wraps data. The binary may be empty. Any other term is :invalid_argument and does not raise.

pread(memory, offset, length)

Reads at most length bytes at offset.

size(memory)

Byte length stored at open. A closed handle is :closed.

Types

t()

@type t() :: %F3.IO.Memory{closed: boolean(), data: binary(), size: non_neg_integer()}

In-memory source.

data is the caller's binary until close, then <<>>. size is the length at open and does not change. closed is true after close/1.

Functions

close(state)

Drops this source's binary. A second close returns the same closed handle.

Examples

iex> {:ok, state} = F3.IO.Memory.open(<<1>>)
iex> {:ok, closed} = F3.IO.Memory.close(state)
iex> closed.closed
true
iex> {:error, error} = F3.IO.Memory.size(closed)
iex> error.category
:closed

open(data)

@spec open(binary()) :: {:ok, t()} | {:error, F3.Error.t()}

Wraps data. The binary may be empty. Any other term is :invalid_argument and does not raise.

Examples

iex> {:ok, state} = F3.IO.Memory.open(<<1, 2, 3, 4>>)
iex> state.size
4

iex> {:error, error} = F3.IO.Memory.open(:nope)
iex> error.category
:invalid_argument

pread(memory, offset, length)

Reads at most length bytes at offset.

A start at or past the end is {:ok, ""}. A negative offset or length is :invalid_argument. A closed handle is :closed.

Examples

iex> {:ok, state} = F3.IO.Memory.open(<<1, 2, 3, 4>>)
iex> F3.IO.Memory.pread(state, 1, 2)
{:ok, <<2, 3>>}
iex> F3.IO.Memory.pread(state, 4, 2)
{:ok, <<>>}

size(memory)

Byte length stored at open. A closed handle is :closed.

Examples

iex> {:ok, state} = F3.IO.Memory.open("abcd")
iex> F3.IO.Memory.size(state)
{:ok, 4}