Merge pull request #227 from sigp/slot_height

Add `SlotHeight` type.
2019-02-15 00:27:15 +11:00 · 2019-02-15 00:27:15 +11:00 · 88c42bf3fb
commit 88c42bf3fb
parent 1f8efffd6d 066f0090dd
4 changed files with 324 additions and 53 deletions
--- a/eth2/types/Cargo.toml
+++ b/eth2/types/Cargo.toml
@ -1,7 +1,7 @@
 [package]
 name = "types"
 version = "0.1.0"
-authors = ["Paul Hauner <paul@paulhauner.com>"]
+authors = ["Paul Hauner <paul@paulhauner.com>", "Age Manning <Age@AgeManning.com>"]
 edition = "2018"

 [dependencies]
--- a/eth2/types/src/lib.rs
+++ b/eth2/types/src/lib.rs
@ -24,7 +24,8 @@ pub mod readers;
 pub mod shard_reassignment_record;
 pub mod slashable_attestation;
 pub mod slashable_vote_data;
-pub mod slot_epoch_height;
+pub mod slot_epoch;
+pub mod slot_height;
 pub mod spec;
 pub mod validator;
 pub mod validator_registry;
@ -55,7 +56,8 @@ pub use crate::proposal_signed_data::ProposalSignedData;
 pub use crate::proposer_slashing::ProposerSlashing;
 pub use crate::slashable_attestation::SlashableAttestation;
 pub use crate::slashable_vote_data::SlashableVoteData;
-pub use crate::slot_epoch_height::{Epoch, Slot};
+pub use crate::slot_epoch::{Epoch, Slot};
+pub use crate::slot_height::SlotHeight;
 pub use crate::spec::ChainSpec;
 pub use crate::validator::{StatusFlags as ValidatorStatusFlags, Validator};
 pub use crate::validator_registry_delta_block::ValidatorRegistryDeltaBlock;
--- a/eth2/types/src/slot_epoch_height.rs
+++ b/eth2/types/src/slot_epoch_height.rs
@ -1,14 +1,15 @@
-/// The `Slot` `Epoch`, `Height` types are defined as newtypes over u64 to enforce type-safety between
-/// the three types.
+use crate::slot_height::SlotHeight;
+/// The `Slot` and `Epoch` types are defined as newtypes over u64 to enforce type-safety between
+/// the two types.
 ///
-/// `Slot`, `Epoch` and `Height` have implementations which permit conversion, comparison and math operations
+/// `Slot` and `Epoch` have implementations which permit conversion, comparison and math operations
 /// between each and `u64`, however specifically not between each other.
 ///
 /// All math operations on `Slot` and `Epoch` are saturating, they never wrap.
 ///
 /// It would be easy to define `PartialOrd` and other traits generically across all types which
-/// implement `Into<u64>`, however this would allow operations between `Slots`, `Epochs` and
-/// `Heights` which may lead to programming errors which are not detected by the compiler.
+/// implement `Into<u64>`, however this would allow operations between `Slots` and `Epochs` which
+/// may lead to programming errors which are not detected by the compiler.
 use crate::test_utils::TestRandom;
 use rand::RngCore;
 use serde_derive::Serialize;
@ -42,23 +43,6 @@ macro_rules! impl_from_into_u64 {
    };
 }

-// need to truncate for some fork-choice algorithms
-macro_rules! impl_into_u32 {
-    ($main: ident) => {
-        impl Into<u32> for $main {
-            fn into(self) -> u32 {
-                self.0 as u32
-            }
-        }
-
-        impl $main {
-            pub fn as_u32(&self) -> u32 {
-                self.0 as u32
-            }
-        }
-    };
-}
-
 macro_rules! impl_from_into_usize {
    ($main: ident) => {
        impl From<usize> for $main {
@ -286,21 +270,13 @@ macro_rules! impl_common {
    };
 }

-/// Beacon block slot.
 #[derive(Eq, Debug, Clone, Copy, Default, Serialize)]
 pub struct Slot(u64);

-/// Beacon block height, effectively `Slot/GENESIS_START_BLOCK`.
-#[derive(Eq, Debug, Clone, Copy, Default, Serialize)]
-pub struct Height(u64);
-
-/// Beacon Epoch, effectively `Slot / EPOCH_LENGTH`.
 #[derive(Eq, Debug, Clone, Copy, Default, Serialize)]
 pub struct Epoch(u64);

 impl_common!(Slot);
-impl_common!(Height);
-impl_into_u32!(Height); // height can be converted to u32
 impl_common!(Epoch);

 impl Slot {
@ -312,8 +288,8 @@ impl Slot {
        Epoch::from(self.0 / epoch_length)
    }

-    pub fn height(self, genesis_slot: Slot) -> Height {
-        Height::from(self.0.saturating_sub(genesis_slot.as_u64()))
+    pub fn height(self, genesis_slot: Slot) -> SlotHeight {
+        SlotHeight::from(self.0.saturating_sub(genesis_slot.as_u64()))
    }

    pub fn max_value() -> Slot {
@ -321,24 +297,6 @@ impl Slot {
    }
 }

-impl Height {
-    pub fn new(slot: u64) -> Height {
-        Height(slot)
-    }
-
-    pub fn slot(self, genesis_slot: Slot) -> Slot {
-        Slot::from(self.0.saturating_add(genesis_slot.as_u64()))
-    }
-
-    pub fn epoch(self, genesis_slot: u64, epoch_length: u64) -> Epoch {
-        Epoch::from(self.0.saturating_add(genesis_slot) / epoch_length)
-    }
-
-    pub fn max_value() -> Height {
-        Height(u64::max_value())
-    }
-}
-
 impl Epoch {
    pub fn new(slot: u64) -> Epoch {
        Epoch(slot)
--- a/eth2/types/src/slot_height.rs
+++ b/eth2/types/src/slot_height.rs
@ -0,0 +1,311 @@
+// Copyright 2019 Sigma Prime Pty Ltd.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+use crate::slot_epoch::{Epoch, Slot};
+use serde_derive::Serialize;
+use slog;
+use ssz::{hash, ssz_encode, Decodable, DecodeError, Encodable, SszStream, TreeHash};
+use std::cmp::{Ord, Ordering};
+use std::fmt;
+use std::hash::{Hash, Hasher};
+use std::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Rem, Sub, SubAssign};
+
+macro_rules! impl_from_into_u64 {
+    ($main: ident) => {
+        impl From<u64> for $main {
+            fn from(n: u64) -> $main {
+                $main(n)
+            }
+        }
+
+        impl Into<u64> for $main {
+            fn into(self) -> u64 {
+                self.0
+            }
+        }
+
+        impl $main {
+            pub fn as_u64(&self) -> u64 {
+                self.0
+            }
+        }
+    };
+}
+
+// need to truncate for some fork-choice algorithms
+macro_rules! impl_into_u32 {
+    ($main: ident) => {
+        impl Into<u32> for $main {
+            fn into(self) -> u32 {
+                self.0 as u32
+            }
+        }
+
+        impl $main {
+            pub fn as_u32(&self) -> u32 {
+                self.0 as u32
+            }
+        }
+    };
+}
+macro_rules! impl_from_into_usize {
+    ($main: ident) => {
+        impl From<usize> for $main {
+            fn from(n: usize) -> $main {
+                $main(n as u64)
+            }
+        }
+
+        impl Into<usize> for $main {
+            fn into(self) -> usize {
+                self.0 as usize
+            }
+        }
+
+        impl $main {
+            pub fn as_usize(&self) -> usize {
+                self.0 as usize
+            }
+        }
+    };
+}
+
+macro_rules! impl_math_between {
+    ($main: ident, $other: ident) => {
+        impl PartialOrd<$other> for $main {
+            /// Utilizes `partial_cmp` on the underlying `u64`.
+            fn partial_cmp(&self, other: &$other) -> Option<Ordering> {
+                Some(self.0.cmp(&(*other).into()))
+            }
+        }
+
+        impl PartialEq<$other> for $main {
+            fn eq(&self, other: &$other) -> bool {
+                let other: u64 = (*other).into();
+                self.0 == other
+            }
+        }
+
+        impl Add<$other> for $main {
+            type Output = $main;
+
+            fn add(self, other: $other) -> $main {
+                $main::from(self.0.saturating_add(other.into()))
+            }
+        }
+
+        impl AddAssign<$other> for $main {
+            fn add_assign(&mut self, other: $other) {
+                self.0 = self.0.saturating_add(other.into());
+            }
+        }
+
+        impl Sub<$other> for $main {
+            type Output = $main;
+
+            fn sub(self, other: $other) -> $main {
+                $main::from(self.0.saturating_sub(other.into()))
+            }
+        }
+
+        impl SubAssign<$other> for $main {
+            fn sub_assign(&mut self, other: $other) {
+                self.0 = self.0.saturating_sub(other.into());
+            }
+        }
+
+        impl Mul<$other> for $main {
+            type Output = $main;
+
+            fn mul(self, rhs: $other) -> $main {
+                let rhs: u64 = rhs.into();
+                $main::from(self.0.saturating_mul(rhs))
+            }
+        }
+
+        impl MulAssign<$other> for $main {
+            fn mul_assign(&mut self, rhs: $other) {
+                let rhs: u64 = rhs.into();
+                self.0 = self.0.saturating_mul(rhs)
+            }
+        }
+
+        impl Div<$other> for $main {
+            type Output = $main;
+
+            fn div(self, rhs: $other) -> $main {
+                let rhs: u64 = rhs.into();
+                if rhs == 0 {
+                    panic!("Cannot divide by zero-valued Slot/Epoch")
+                }
+                $main::from(self.0 / rhs)
+            }
+        }
+
+        impl DivAssign<$other> for $main {
+            fn div_assign(&mut self, rhs: $other) {
+                let rhs: u64 = rhs.into();
+                if rhs == 0 {
+                    panic!("Cannot divide by zero-valued Slot/Epoch")
+                }
+                self.0 = self.0 / rhs
+            }
+        }
+
+        impl Rem<$other> for $main {
+            type Output = $main;
+
+            fn rem(self, modulus: $other) -> $main {
+                let modulus: u64 = modulus.into();
+                $main::from(self.0 % modulus)
+            }
+        }
+    };
+}
+
+macro_rules! impl_math {
+    ($type: ident) => {
+        impl $type {
+            pub fn saturating_sub<T: Into<$type>>(&self, other: T) -> $type {
+                *self - other.into()
+            }
+
+            pub fn saturating_add<T: Into<$type>>(&self, other: T) -> $type {
+                *self + other.into()
+            }
+
+            pub fn checked_div<T: Into<$type>>(&self, rhs: T) -> Option<$type> {
+                let rhs: $type = rhs.into();
+                if rhs == 0 {
+                    None
+                } else {
+                    Some(*self / rhs)
+                }
+            }
+
+            pub fn is_power_of_two(&self) -> bool {
+                self.0.is_power_of_two()
+            }
+        }
+
+        impl Ord for $type {
+            fn cmp(&self, other: &$type) -> Ordering {
+                let other: u64 = (*other).into();
+                self.0.cmp(&other)
+            }
+        }
+    };
+}
+
+macro_rules! impl_display {
+    ($type: ident) => {
+        impl fmt::Display for $type {
+            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                write!(f, "{}", self.0)
+            }
+        }
+
+        impl slog::Value for $type {
+            fn serialize(
+                &self,
+                record: &slog::Record,
+                key: slog::Key,
+                serializer: &mut slog::Serializer,
+            ) -> slog::Result {
+                self.0.serialize(record, key, serializer)
+            }
+        }
+    };
+}
+
+macro_rules! impl_ssz {
+    ($type: ident) => {
+        impl Encodable for $type {
+            fn ssz_append(&self, s: &mut SszStream) {
+                s.append(&self.0);
+            }
+        }
+
+        impl Decodable for $type {
+            fn ssz_decode(bytes: &[u8], i: usize) -> Result<(Self, usize), DecodeError> {
+                let (value, i) = <_>::ssz_decode(bytes, i)?;
+
+                Ok(($type(value), i))
+            }
+        }
+
+        impl TreeHash for $type {
+            fn hash_tree_root(&self) -> Vec<u8> {
+                let mut result: Vec<u8> = vec![];
+                result.append(&mut self.0.hash_tree_root());
+                hash(&result)
+            }
+        }
+    };
+}
+
+macro_rules! impl_hash {
+    ($type: ident) => {
+        // Implemented to stop clippy lint:
+        // https://rust-lang.github.io/rust-clippy/master/index.html#derive_hash_xor_eq
+        impl Hash for $type {
+            fn hash<H: Hasher>(&self, state: &mut H) {
+                ssz_encode(self).hash(state)
+            }
+        }
+    };
+}
+
+macro_rules! impl_common {
+    ($type: ident) => {
+        impl_from_into_u64!($type);
+        impl_from_into_usize!($type);
+        impl_math_between!($type, $type);
+        impl_math_between!($type, u64);
+        impl_math!($type);
+        impl_display!($type);
+        impl_ssz!($type);
+        impl_hash!($type);
+    };
+}
+/// Beacon block height, effectively `Slot/GENESIS_START_BLOCK`.
+#[derive(Eq, Debug, Clone, Copy, Default, Serialize)]
+pub struct SlotHeight(u64);
+
+impl_common!(SlotHeight);
+impl_into_u32!(SlotHeight); // SlotHeight can be converted to u32
+
+impl SlotHeight {
+    pub fn new(slot: u64) -> SlotHeight {
+        SlotHeight(slot)
+    }
+
+    pub fn slot(self, genesis_slot: Slot) -> Slot {
+        Slot::from(self.0.saturating_add(genesis_slot.as_u64()))
+    }
+
+    pub fn epoch(self, genesis_slot: u64, epoch_length: u64) -> Epoch {
+        Epoch::from(self.0.saturating_add(genesis_slot) / epoch_length)
+    }
+
+    pub fn max_value() -> SlotHeight {
+        SlotHeight(u64::max_value())
+    }
+}