Returns the total available gas left for all transactions in this block. This is the total gas limit minus the gas used in transactions.

Examples

iex> Block.Header.available_gas(%Block.Header{gas_limit: 50_000, gas_used: 30_000})
20_000

Deserializes a block header from an RLP encodable structure. This effectively undoes the encoding defined in L_H Eq.(32) of the Yellow Paper.

Examples

iex> Block.Header.deserialize([<<1::256>>, <<2::256>>, <<3::160>>, <<4::256>>, <<5::256>>, <<6::256>>, <<>>, <<5>>, <<1>>, <<5>>, <<3>>, <<6>>, "Hi mom", <<7::256>>, <<8::64>>])
%Block.Header{parent_hash: <<1::256>>, ommers_hash: <<2::256>>, beneficiary: <<3::160>>, state_root: <<4::256>>, transactions_root: <<5::256>>, receipts_root: <<6::256>>, logs_bloom: <<>>, difficulty: 5, number: 1, gas_limit: 5, gas_used: 3, timestamp: 6, extra_data: "Hi mom", mix_hash: <<7::256>>, nonce: <<8::64>>}

Calculates the difficulty of a new block header. This implements Eq.(39), Eq.(40), Eq.(41), Eq.(42), Eq.(43) and Eq.(44) of the Yellow Paper.

Examples

iex> Block.Header.get_difficulty(
...>   %Block.Header{number: 0, timestamp: 55},
...>   nil
...> )
131_072

iex> Block.Header.get_difficulty(
...>   %Block.Header{number: 1, timestamp: 1479642530},
...>   %Block.Header{number: 0, timestamp: 0, difficulty: 1_048_576}
...> )
1_048_064

iex> Block.Header.get_difficulty(
...>  %Block.Header{number: 33, timestamp: 66},
...>  %Block.Header{number: 32, timestamp: 55, difficulty: 300_000}
...> )
300_146

iex> Block.Header.get_difficulty(
...>  %Block.Header{number: 33, timestamp: 88},
...>  %Block.Header{number: 32, timestamp: 55, difficulty: 300_000}
...> )
299_854

# TODO: Is this right? These numbers are quite a jump
iex> Block.Header.get_difficulty(
...>  %Block.Header{number: 3_000_001, timestamp: 66},
...>  %Block.Header{number: 3_000_000, timestamp: 55, difficulty: 300_000}
...> )
268_735_456

iex> Block.Header.get_difficulty(
...>  %Block.Header{number: 3_000_001, timestamp: 155},
...>  %Block.Header{number: 3_000_000, timestamp: 55, difficulty: 300_000}
...> )
268_734_142

Test actual Ropsten genesis block
iex> Block.Header.get_difficulty(
...>   %Block.Header{number: 0, timestamp: 0},
...>   nil,
...>   0x100000,
...>   0x020000,
...>   0x0800,
...>   0
...> )
1_048_576

# Test actual Ropsten first block
iex> Block.Header.get_difficulty(
...>   %Block.Header{number: 1, timestamp: 1_479_642_530},
...>   %Block.Header{number: 0, timestamp: 0, difficulty: 1_048_576},
...>   0x100000,
...>   0x020000,
...>   0x0800,
...>   0
...> )
997_888

Computes hash of a block header, which is simply the hash of the serialized block header.

This is defined in Eq.(37) of the Yellow Paper.

Examples

iex> %Block.Header{number: 5, parent_hash: <<1, 2, 3>>, beneficiary: <<2, 3, 4>>, difficulty: 100, timestamp: 11, mix_hash: <<1>>, nonce: <<2>>}
...> |> Block.Header.hash()
<<78, 28, 127, 10, 192, 253, 127, 239, 254, 179, 39, 34, 245, 44, 152, 98, 128, 71, 238, 155, 100, 161, 199, 71, 243, 223, 172, 191, 74, 99, 128, 63>>

iex> %Block.Header{number: 0, parent_hash: <<1, 2, 3>>, beneficiary: <<2, 3, 4>>, difficulty: 100, timestamp: 11, mix_hash: <<1>>, nonce: <<2>>}
...> |> Block.Header.hash()
<<218, 225, 46, 241, 196, 160, 136, 96, 109, 216, 73, 167, 92, 174, 91, 228, 85, 112, 234, 129, 99, 200, 158, 61, 223, 166, 165, 132, 187, 24, 142, 193>>

Returns the block that defines the start of Homestead.

This should be a constant, but it’s configurable on different chains, and as such, as allow you to pass that configuration variable (which ends up making this the identity function, if so).

Returns true if a given block is at or after the Homestead block.

Examples

iex> Block.Header.is_after_homestead?(%Block.Header{number: 5})
false

iex> Block.Header.is_after_homestead?(%Block.Header{number: 5_000_000})
true

iex> Block.Header.is_after_homestead?(%Block.Header{number: 1_150_000})
true

iex> Block.Header.is_after_homestead?(%Block.Header{number: 5}, 6)
false

Returns true if a given block is before the Homestead block.

Examples

iex> Block.Header.is_before_homestead?(%Block.Header{number: 5})
true

iex> Block.Header.is_before_homestead?(%Block.Header{number: 5_000_000})
false

iex> Block.Header.is_before_homestead?(%Block.Header{number: 1_150_000})
false

iex> Block.Header.is_before_homestead?(%Block.Header{number: 5}, 6)
true

iex> Block.Header.is_before_homestead?(%Block.Header{number: 5}, 4)
false

Function to determine if the gas limit set is valid. The miner gets to specify a gas limit, so long as it’s in range. This allows about a 0.1% change per block.

This function directly implements Eq.(45), Eq.(46) and Eq.(47).

Examples

iex> Block.Header.is_gas_limit_valid?(1_000_000, nil)
true

iex> Block.Header.is_gas_limit_valid?(1_000, nil)
false

iex> Block.Header.is_gas_limit_valid?(1_000_000, 1_000_000)
true

iex> Block.Header.is_gas_limit_valid?(1_000_000, 2_000_000)
false

iex> Block.Header.is_gas_limit_valid?(1_000_000, 500_000)
false

iex> Block.Header.is_gas_limit_valid?(1_000_000, 999_500)
true

iex> Block.Header.is_gas_limit_valid?(1_000_000, 999_000)
false

iex> Block.Header.is_gas_limit_valid?(1_000_000, 2_000_000, 1)
true

iex> Block.Header.is_gas_limit_valid?(1_000, nil, 1024, 500)
true

Returns true if the block header is valid. This defines Eq.(50), Eq.(51), Eq.(52), Eq.(53), Eq.(54), Eq.(55), Eq.(56), Eq.(57) and Eq.(58) of the Yellow Paper, commonly referred to as V(H).

TODO: Add proof of work check

Examples

iex> Block.Header.is_valid?(%Block.Header{number: 0, difficulty: 131_072, gas_limit: 200_000}, nil)
:valid

iex> Block.Header.is_valid?(%Block.Header{number: 0, difficulty: 5, gas_limit: 5}, nil, true)
{:invalid, [:invalid_difficulty, :invalid_gas_limit]}

iex> Block.Header.is_valid?(%Block.Header{number: 1, difficulty: 131_136, gas_limit: 200_000, timestamp: 65}, %Block.Header{number: 0, difficulty: 131_072, gas_limit: 200_000, timestamp: 55})
:valid

iex> Block.Header.is_valid?(%Block.Header{number: 1, difficulty: 131_000, gas_limit: 200_000, timestamp: 65}, %Block.Header{number: 0, difficulty: 131_072, gas_limit: 200_000, timestamp: 55}, true)
{:invalid, [:invalid_difficulty]}

iex> Block.Header.is_valid?(%Block.Header{number: 1, difficulty: 131_136, gas_limit: 200_000, timestamp: 45}, %Block.Header{number: 0, difficulty: 131_072, gas_limit: 200_000, timestamp: 55})
{:invalid, [:child_timestamp_invalid]}

iex> Block.Header.is_valid?(%Block.Header{number: 1, difficulty: 131_136, gas_limit: 300_000, timestamp: 65}, %Block.Header{number: 0, difficulty: 131_072, gas_limit: 200_000, timestamp: 55})
{:invalid, [:invalid_gas_limit]}

iex> Block.Header.is_valid?(%Block.Header{number: 2, difficulty: 131_136, gas_limit: 200_000, timestamp: 65}, %Block.Header{number: 0, difficulty: 131_072, gas_limit: 200_000, timestamp: 55})
{:invalid, [:child_number_invalid]}

iex> Block.Header.is_valid?(%Block.Header{number: 1, difficulty: 131_136, gas_limit: 200_000, timestamp: 65, extra_data: "0123456789012345678901234567890123456789"}, %Block.Header{number: 0, difficulty: 131_072, gas_limit: 200_000, timestamp: 55})
{:invalid, [:extra_data_too_large]}

# TODO: Add tests for setting homestead_block
# TODO: Add tests for setting initial_difficulty
# TODO: Add tests for setting minimum_difficulty
# TODO: Add tests for setting difficulty_bound_divisor
# TODO: Add tests for setting gas_limit_bound_divisor
# TODO: Add tests for setting min_gas_limit

This functions encode a header into a value that can be RLP encoded. This is defined as L_H Eq.(32) in the Yellow Paper.

Examples

iex> Block.Header.serialize(%Block.Header{parent_hash: <<1::256>>, ommers_hash: <<2::256>>, beneficiary: <<3::160>>, state_root: <<4::256>>, transactions_root: <<5::256>>, receipts_root: <<6::256>>, logs_bloom: <<>>, difficulty: 5, number: 1, gas_limit: 5, gas_used: 3, timestamp: 6, extra_data: "Hi mom", mix_hash: <<7::256>>, nonce: <<8::64>>})
[<<1::256>>, <<2::256>>, <<3::160>>, <<4::256>>, <<5::256>>, <<6::256>>, <<>>, 5, 1, 5, 3, 6, "Hi mom", <<7::256>>, <<8::64>>]