From 776196e66d593cb988474549fc5b6c13fb393043 Mon Sep 17 00:00:00 2001 From: dankrad Date: Wed, 6 Mar 2019 14:46:52 +0100 Subject: [PATCH 1/3] Add tuple lengths Adding tuple lengths in BeaconState objects (this changes merkleization/serialization as no length mixin required) --- specs/core/0_beacon-chain.md | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md index 6bff0f705..2771d19fa 100644 --- a/specs/core/0_beacon-chain.md +++ b/specs/core/0_beacon-chain.md @@ -522,7 +522,7 @@ The following data structures are defined as [SimpleSerialize (SSZ)](https://git 'validator_registry_update_epoch': 'uint64', # Randomness and committees - 'latest_randao_mixes': ['bytes32'], + 'latest_randao_mixes': ['bytes32', LATEST_RANDAO_MIXES_LENGTH], 'previous_shuffling_start_shard': 'uint64', 'current_shuffling_start_shard': 'uint64', 'previous_shuffling_epoch': 'uint64', @@ -537,10 +537,10 @@ The following data structures are defined as [SimpleSerialize (SSZ)](https://git 'finalized_epoch': 'uint64', # Recent state - 'latest_crosslinks': [Crosslink], - 'latest_block_roots': ['bytes32'], - 'latest_active_index_roots': ['bytes32'], - 'latest_slashed_balances': ['uint64'], # Balances slashed at every withdrawal period + 'latest_crosslinks': [Crosslink, SHARD_COUNT], + 'latest_block_roots': ['bytes32', SLOTS_PER_HISTORICAL_ROOT], + 'latest_active_index_roots': ['bytes32', LATEST_ACTIVE_INDEX_ROOTS_LENGTH], + 'latest_slashed_balances': ['uint64', LATEST_SLASHED_EXIT_LENGTH], # Balances slashed at every withdrawal period 'latest_attestations': [PendingAttestation], 'batched_block_roots': ['bytes32'], From eece029cdfdf6672a929a9b9d8c960a53bd2fac1 Mon Sep 17 00:00:00 2001 From: Dankrad Feist Date: Wed, 6 Mar 2019 17:46:40 +0100 Subject: [PATCH 2/3] Array spec to [type] and tuple to [type, N]. Also make notation consistent: use "base" for base types --- specs/simple-serialize.md | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/specs/simple-serialize.md b/specs/simple-serialize.md index a452213b5..bb15bb6da 100644 --- a/specs/simple-serialize.md +++ b/specs/simple-serialize.md @@ -10,8 +10,8 @@ This is a **work in progress** describing typing, serialization and Merkleizatio - [Composite types](#composite-types) - [Aliases](#aliases) - [Serialization](#serialization) - - [`uintN`](#uintn) - - [`bool`](#bool) + - [`"uintN"`](#uintn) + - [`"bool"`](#bool) - [Tuples, containers, lists](#tuples-containers-lists) - [Deserialization](#deserialization) - [Merkleization](#merkleization) @@ -28,29 +28,29 @@ This is a **work in progress** describing typing, serialization and Merkleizatio ## Typing ### Basic types -* `uintN`: `N`-bit unsigned integer (where `N in [8, 16, 32, 64, 128, 256]`) -* `bool`: `True` or `False` +* `"uintN"`: `N`-bit unsigned integer (where `N in [8, 16, 32, 64, 128, 256]`) +* `"bool"`: `True` or `False` ### Composite types * **container**: ordered heterogenous collection of values * key-pair curly bracket notation `{}`, e.g. `{'foo': "uint64", 'bar': "bool"}` * **tuple**: ordered fixed-length homogeneous collection of values - * angle bracket notation `[N]`, e.g. `uint64[N]` + * angle bracket notation `[type, N]`, e.g. `["uint64", N]` * **list**: ordered variable-length homogenous collection of values - * angle bracket notation `[]`, e.g. `uint64[]` + * angle bracket notation `[type]`, e.g. `["uint64"]` ### Aliases For convenience we alias: -* `byte` to `uint8` -* `bytes` to `byte[]` -* `bytesN` to `byte[N]` +* `"byte"` to `"uint8"` +* `"bytes"` to `["byte"]` +* `"bytesN"` to `["byte", N]` ## Serialization -We recursively define the `serialize` function which consumes an object `value` (of the type specified) and returns a bytestring of type `bytes`. +We recursively define the `serialize` function which consumes an object `value` (of the type specified) and returns a bytestring of type `"bytes"`. *Note*: In the function definitions below (`serialize`, `hash_tree_root`, `signed_root`, etc.) objects implicitly carry their type. @@ -95,7 +95,7 @@ We first define helper functions: * `pack`: Given ordered objects of the same basic type, serialize them, pack them into `BYTES_PER_CHUNK`-byte chunks, right-pad the last chunk with zero bytes, and return the chunks. * `merkleize`: Given ordered `BYTES_PER_CHUNK`-byte chunks, if necessary append zero chunks so that the number of chunks is a power of two, Merkleize the chunks, and return the root. -* `mix_in_length`: Given a Merkle root `root` and a length `length` (`uint256` little-endian serialization) return `hash(root + length)`. +* `mix_in_length`: Given a Merkle root `root` and a length `length` (`"uint256"` little-endian serialization) return `hash(root + length)`. We now define Merkleization `hash_tree_root(value)` of an object `value` recursively: @@ -106,7 +106,7 @@ We now define Merkleization `hash_tree_root(value)` of an object `value` recursi ## Self-signed containers -Let `value` be a self-signed container object. The convention is that the signature (e.g. a `bytes96` BLS12-381 signature) be the last field of `value`. Further, the signed message for `value` is `signed_root(value) = hash_tree_root(truncate_last(value))` where `truncate_last` truncates the last element of `value`. +Let `value` be a self-signed container object. The convention is that the signature (e.g. a `"bytes96"` BLS12-381 signature) be the last field of `value`. Further, the signed message for `value` is `signed_root(value) = hash_tree_root(truncate_last(value))` where `truncate_last` truncates the last element of `value`. ## Implementations From 81f48ea1c3bc16c5b48429da7eb1dce57463b095 Mon Sep 17 00:00:00 2001 From: Dankrad Feist Date: Wed, 6 Mar 2019 21:11:50 +0100 Subject: [PATCH 3/3] Also fix length of Deposit.proof --- specs/core/0_beacon-chain.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md index 2031587cf..b50f4c36a 100644 --- a/specs/core/0_beacon-chain.md +++ b/specs/core/0_beacon-chain.md @@ -387,7 +387,7 @@ The following data structures are defined as [SimpleSerialize (SSZ)](https://git ```python { # Branch in the deposit tree - 'proof': ['bytes32'], + 'proof': ['bytes32', DEPOSIT_CONTRACT_TREE_DEPTH], # Index in the deposit tree 'index': 'uint64', # Data