From 6a5405cccf8bf5786b373d6deb3a24f48d00d93e Mon Sep 17 00:00:00 2001 From: terence tsao Date: Wed, 24 Apr 2019 14:32:16 -0700 Subject: [PATCH 1/2] Update 0_fork-choice.md --- specs/core/0_fork-choice.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/specs/core/0_fork-choice.md b/specs/core/0_fork-choice.md index 6fdb97067..ac2e5797d 100644 --- a/specs/core/0_fork-choice.md +++ b/specs/core/0_fork-choice.md @@ -46,9 +46,9 @@ Note: Nodes needs to have a clock that is roughly (i.e. within `SECONDS_PER_SLOT ### Beacon chain fork choice rule -The beacon chain fork choice rule is a hybrid that combines justification and finality with Latest Message Driven (LMD) Greediest Heaviest Observed SubTree (GHOST). At any point in time a [validator](#dfn-validator) `v` subjectively calculates the beacon chain head as follows. +The beacon chain fork choice rule is a hybrid that combines justification and finality with Latest Message Driven (LMD) Greediest Heaviest Observed SubTree (GHOST). At any point in time a [validator](0_beacon-chain.md#dfn-validator) `v` subjectively calculates the beacon chain head as follows. -* Abstractly define `Store` as the type of storage object for the chain data and `store` be the set of attestations and blocks that the [validator](#dfn-validator) `v` has observed and verified (in particular, block ancestors must be recursively verified). Attestations not yet included in any chain are still included in `store`. +* Abstractly define `Store` as the type of storage object for the chain data and `store` be the set of attestations and blocks that the [validator](0_beacon-chain.md#dfn-validator) `v` has observed and verified (in particular, block ancestors must be recursively verified). Attestations not yet included in any chain are still included in `store`. * Let `finalized_head` be the finalized block with the highest epoch. (A block `B` is finalized if there is a descendant of `B` in `store` the processing of which sets `B` as finalized.) * Let `justified_head` be the descendant of `finalized_head` with the highest epoch that has been justified for at least 1 epoch. (A block `B` is justified if there is a descendant of `B` in `store` the processing of which sets `B` as justified.) If no such descendant exists set `justified_head` to `finalized_head`. * Let `get_ancestor(store: Store, block: BeaconBlock, slot: Slot) -> BeaconBlock` be the ancestor of `block` with slot number `slot`. The `get_ancestor` function can be defined recursively as: From 768f3ed813f61516a83ed8cf5359c93037d8396c Mon Sep 17 00:00:00 2001 From: Danny Ryan Date: Wed, 24 Apr 2019 16:57:44 -0600 Subject: [PATCH 2/2] remove validator link refs from fork choice doc --- specs/core/0_fork-choice.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/specs/core/0_fork-choice.md b/specs/core/0_fork-choice.md index ac2e5797d..b8dd2937b 100644 --- a/specs/core/0_fork-choice.md +++ b/specs/core/0_fork-choice.md @@ -46,9 +46,9 @@ Note: Nodes needs to have a clock that is roughly (i.e. within `SECONDS_PER_SLOT ### Beacon chain fork choice rule -The beacon chain fork choice rule is a hybrid that combines justification and finality with Latest Message Driven (LMD) Greediest Heaviest Observed SubTree (GHOST). At any point in time a [validator](0_beacon-chain.md#dfn-validator) `v` subjectively calculates the beacon chain head as follows. +The beacon chain fork choice rule is a hybrid that combines justification and finality with Latest Message Driven (LMD) Greediest Heaviest Observed SubTree (GHOST). At any point in time a validator `v` subjectively calculates the beacon chain head as follows. -* Abstractly define `Store` as the type of storage object for the chain data and `store` be the set of attestations and blocks that the [validator](0_beacon-chain.md#dfn-validator) `v` has observed and verified (in particular, block ancestors must be recursively verified). Attestations not yet included in any chain are still included in `store`. +* Abstractly define `Store` as the type of storage object for the chain data and `store` be the set of attestations and blocks that the validator `v` has observed and verified (in particular, block ancestors must be recursively verified). Attestations not yet included in any chain are still included in `store`. * Let `finalized_head` be the finalized block with the highest epoch. (A block `B` is finalized if there is a descendant of `B` in `store` the processing of which sets `B` as finalized.) * Let `justified_head` be the descendant of `finalized_head` with the highest epoch that has been justified for at least 1 epoch. (A block `B` is justified if there is a descendant of `B` in `store` the processing of which sets `B` as justified.) If no such descendant exists set `justified_head` to `finalized_head`. * Let `get_ancestor(store: Store, block: BeaconBlock, slot: Slot) -> BeaconBlock` be the ancestor of `block` with slot number `slot`. The `get_ancestor` function can be defined recursively as: @@ -66,7 +66,7 @@ def get_ancestor(store: Store, block: BeaconBlock, slot: Slot) -> BeaconBlock: return get_ancestor(store, store.get_parent(block), slot) ``` -* Let `get_latest_attestation(store: Store, index: ValidatorIndex) -> Attestation` be the attestation with the highest slot number in `store` from the validator with the given `index`. If several such attestations exist, use the one the [validator](#dfn-validator) `v` observed first. +* Let `get_latest_attestation(store: Store, index: ValidatorIndex) -> Attestation` be the attestation with the highest slot number in `store` from the validator with the given `index`. If several such attestations exist, use the one the validator `v` observed first. * Let `get_latest_attestation_target(store: Store, index: ValidatorIndex) -> BeaconBlock` be the target block in the attestation `get_latest_attestation(store, index)`. * Let `get_children(store: Store, block: BeaconBlock) -> List[BeaconBlock]` returns the child blocks of the given `block`. * Let `justified_head_state` be the resulting `BeaconState` object from processing the chain up to the `justified_head`.