ex_rlp

View Source ExRLP (ex_rlp v0.6.0)

Elixir implementation of Ethereum's RLP (Recursive Length Prefix) encoding.

Link to this section Summary

Types

t()

Functions

decode(item, options \\ [encoding: :binary])

Given an RLP-encoded string, returns a decoded RPL structure (which is an array of RLP structures or binaries).

encode(item, options \\ [])

Given an RLP structure (i.e. anything), returns the encoding as a binary.

Link to this section Types

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t()

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@type t() :: any()

Link to this section Functions

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decode(item, options \\ [encoding: :binary])

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@spec decode(
  binary(),
  keyword()
) :: t() | {t(), binary()} | no_return()

Given an RLP-encoded string, returns a decoded RPL structure (which is an array of RLP structures or binaries).

If stream ([stream: true]) is enabled, it will just decode the first rlp sequence

examples

 Examples 

iex> ExRLP.decode(<<>>)
** (ExRLP.DecodeError) invalid rlp encoding

iex> ExRLP.decode(<<0xc8, 0x83, ?c, ?a, ?t, 0x83, ?d, ?o, ?g>>)
["cat", "dog"]

iex> ExRLP.decode(<<131, 99, 97, 116, 131, 99, 97, 116>>, stream: true)
{"cat", <<131, 99, 97, 116>>}

iex> ExRLP.decode(<<0x83, ?d, ?o, ?g>>)
"dog"

iex> ExRLP.decode("83646f67", encoding: :hex)
"dog"

iex> ExRLP.decode(<<184, 60, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65>>)
Enum.join(for _ <- 1..60, do: "A")

iex> ExRLP.decode(<<198, 51, 132, 99, 111, 111, 108>>)
["3", "cool"]

iex> ExRLP.decode(<<0x80>>)
""

iex> ExRLP.decode(<<0xc0>>)
[]

iex> ExRLP.decode(<<0x0f>>)
<<0x0f>>

iex> ExRLP.decode(<<0x82, 0x04, 0x00>>)
""

iex> ExRLP.decode(<<0xc7, 0xc0, 0xc1, 0xc0, 0xc3, 0xc0, 0xc1, 0xc0>>)
[[],[[]],[[],[[]]]]

iex> ExRLP.decode(<<248, 60, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192>>)
for _ <- 1..60, do: []

iex> ExRLP.decode(<<143, 2, 227, 142, 158, 4, 75, 160, 83, 84, 85, 150, 0, 0, 0, 0>>) |> :binary.decode_unsigned
15_000_000_000_000_000_000_000_000_000_000_000
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encode(item, options \\ [])

View Source 
@spec encode(
  t(),
  keyword()
) :: binary()

Given an RLP structure (i.e. anything), returns the encoding as a binary.

examples

 Examples 

iex> ExRLP.encode("dog")
<<0x83, ?d, ?o, ?g>>

iex> ExRLP.encode("dog", encoding: :hex)
"83646f67"

iex> ExRLP.encode(Enum.join(for _ <- 1..60, do: "A"))
<<184, 60, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65>>

iex> ExRLP.encode(["cat", "dog"])
<<0xc8, 0x83, ?c, ?a, ?t, 0x83, ?d, ?o, ?g>>

iex> ExRLP.encode("")
<<0x80>>

iex> ExRLP.encode([])
<<0xc0>>

iex> ExRLP.encode("")
<<0x0f>>

iex> ExRLP.encode(15)
<<0x0f>>

iex> ExRLP.encode(15_000_000_000_000_000_000_000_000_000_000_000)
<<143, 2, 227, 142, 158, 4, 75, 160, 83, 84, 85, 150, 0, 0, 0, 0>>

iex> ExRLP.encode(1024)
<<0x82, 0x04, 0x00>>

iex> ExRLP.encode("")
<<0x82, 0x04, 0x00>>

iex> ExRLP.encode([[],[[]],[[],[[]]]])
<<0xc7, 0xc0, 0xc1, 0xc0, 0xc3, 0xc0, 0xc1, 0xc0>>

iex> ExRLP.encode(for _ <- 1..60, do: [])
<<248, 60, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192>>