Tomtomwombat/refactor hasher

.github/workflows/rust.yml

@@ -21,32 +21,48 @@ jobs:
     - name: Build
       run: cargo hack build --verbose --release --feature-powerset --exclude-features loom
     - name: Tests
-      run: cargo hack test --verbose --release --feature-powerset --exclude-features loom
+      run: cargo hack test --verbose --release --lib --bins --tests --feature-powerset --exclude-features loom
+    - name: Documentation tests
+      run: cargo test --verbose --release --doc
+    - name: No default hasher
+      run: cargo test --verbose --release --lib --bins --tests --no-default-features
+    - name: Non rand default seed
+      run: cargo test --lib --no-default-features --features default-hasher hasher::test
+    - name: Non rand without std
+      run: cargo check --no-default-features --features default-hasher
 
     - name: Install thumb target
       run: rustup target add thumbv7em-none-eabi
     - name: 32-bit embedded check
       run: cargo check --target thumbv7em-none-eabi --no-default-features
 
     - name: Loom build
-      run: cargo hack build --lib --bins --tests --feature-powerset --exclude-features serde,rand,default
+      run: cargo build --lib --bins --tests --no-default-features --features loom,default-hasher
     - name: Loom tests
-      run: cargo hack test loom --lib --bins --tests --feature-powerset --exclude-features serde,rand,default
+      run: cargo test loom --lib --bins --tests --no-default-features --features loom,default-hasher
 
   msrv:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: "1.70"
+          toolchain: "1.71"
           override: true
       - name: Install cargo-hack
         run: cargo install cargo-hack --version 0.6.37 --force --locked
       - name: Build
         run: cargo hack build --verbose --release --feature-powerset --exclude-features loom
       - name: Tests
-        run: cargo hack test --verbose --release --feature-powerset --exclude-features loom
+        run: cargo hack test --verbose --release --lib --bins --tests --feature-powerset --exclude-features loom
+      - name: Documentation tests
+        run: cargo test --verbose --release --doc
+      - name: No default hasher
+        run: cargo test --verbose --release --lib --bins --tests --no-default-features
+      - name: Non rand default seed
+        run: cargo test --lib --no-default-features --features default-hasher hasher::test
+      - name: Non rand without std
+        run: cargo check --no-default-features --features default-hasher
 
       - name: Install thumb target
         run: rustup target add thumbv7em-none-eabi

Cargo.toml

@@ -2,7 +2,7 @@
 name = "hyperloglockless"
 version = "0.5.0"
 edition = "2021"
-rust-version = "1.70.0"
+rust-version = "1.71.0"
 authors = ["tomtomwombat"]
 description = "High-performance HyperLogLog with bias correction and full concurrency support."
 license = "MIT OR Apache-2.0"
@@ -16,21 +16,21 @@ readme = "README.md"
 maintenance = { status = "actively-developed" }
 
 [features]
-default = ["std", "rand"]
+default = ["std", "default-hasher", "rand"]
 std = ["portable-atomic/std"]
 loom = ["dep:loom"]
-rand = ["std", "dep:rand"]
-serde = ["dep:serde", "twox-hash/serialize", "portable-atomic/serde"]
+default-hasher = ["dep:rapidhash"]
+rand = ["default-hasher", "std", "dep:rand"]
+serde = ["dep:serde", "portable-atomic/serde"]
 
 [dependencies]
-foldhash = { version = "0.2.0", default-features = false }
 loom = { version = "0.7.2", optional = true }
+rapidhash = { version = "4.5.1", default-features = false, optional = true }
 rand = { version = "0.9.0", optional = true }
 serde = { version = "1.0.203", features = ["derive"], optional = true }
-twox-hash = { version = "1.6.3", default-features = false }
 libm = "0.2"
 portable-atomic = { version = "1.13.1", default-features = false, features = ["fallback"] }
 
 [dev-dependencies]
 fastrand = "2.3.0"
-serde_cbor = "0.11.2"
+serde_cbor = "0.11.2"

README.md

@@ -39,10 +39,10 @@ let count = hll.count(); // ~27
 assert_eq!(hll.len(), 1 << precision); // 16384 bytes
 ```
 
-The default hasher is `twox_hash` because of its portability, MSRV, and reasonable speed. However, you may use any hasher:
+The default hasher uses rapidhash's `quality` flavor, which is designed for low collision rates in algorithms such as HyperLogLog. However, you may use any hasher:
 ```rust
 use hyperloglockless::HyperLogLog;
-use foldhash::fast::RandomState;
+use std::collections::hash_map::RandomState;
 
 let hll = HyperLogLog::with_hasher(14, RandomState::default());
 ```
@@ -93,7 +93,8 @@ Below measures and compares the amortized insert performance of `hyperloglockles
 
 ## Available Features
 
-- **`rand`** - Enabled by default, this has the `DefaultHasher` source its random state using `thread_rng()` instead of hardware sources. Getting entropy from a user-space source is considerably faster, but requires additional dependencies to achieve this. Disabling this feature by using `default-features = false` makes `DefaultHasher` source its entropy using `foldhash`, which will have a much simpler code footprint at the expense of speed.
+- **`default-hasher`** - Enabled by default. Provides Rapidhash's quality hasher as the default type for each sketch and does not require `std`. When enabled without `rand`, it uses Rapidhash's own random state for the default seed. Disabling this feature removes both the `rand` and `rapidhash` dependencies; sketches then require an explicit hasher type and can still use `new` when that hasher implements `Default`.
+- **`rand`** - Enabled by default. Implies `default-hasher` and `std`, and uses `rand`'s thread-local RNG to seed the default hasher instead of Rapidhash's random state.
 - **`serde`** - HyperLogLogs implement `Serialize` and `Deserialize` when possible.
 - **`loom`** - `AtomicHyperLogLog`s use [loom](https://github.com/tokio-rs/loom) atomics, making it compatible with loom testing.