ariesdevil commented on code in PR #146: URL: https://github.com/apache/datasketches-rust/pull/146#discussion_r3558711635
########## datasketches/src/theta/mod.rs: ########## @@ -52,14 +53,18 @@ pub use self::sketch::ThetaSketchBuilder; pub use self::sketch::ThetaSketchView; /// Maximum theta value (signed max for compatibility with Java) -const MAX_THETA: u64 = i64::MAX as u64; +pub(crate) const MAX_THETA: u64 = i64::MAX as u64; /// Minimum log2 of K -const MIN_LG_K: u8 = 5; +pub(crate) const MIN_LG_K: u8 = 5; /// Maximum log2 of K -const MAX_LG_K: u8 = 26; +pub(crate) const MAX_LG_K: u8 = 26; /// Default log2 of K -const DEFAULT_LG_K: u8 = 12; +pub(crate) const DEFAULT_LG_K: u8 = 12; /// Resize threshold (0.5 = 50% load factor) -const HASH_TABLE_RESIZE_THRESHOLD: f64 = 0.5; +pub(crate) const HASH_TABLE_RESIZE_THRESHOLD: f64 = 0.5; /// Rebuild threshold (15/16 = 93.75% load factor) -const HASH_TABLE_REBUILD_THRESHOLD: f64 = 15.0 / 16.0; +pub(crate) const HASH_TABLE_REBUILD_THRESHOLD: f64 = 15.0 / 16.0; +/// Stride hash bits (7 bits for stride calculation) +pub(crate) const STRIDE_HASH_BITS: u8 = 7; +/// Stride mask +pub(crate) const STRIDE_MASK: u64 = (1 << STRIDE_HASH_BITS) - 1; Review Comment: These are defined as `pub(crate)` because they will be used in subsequent PRs in the stacked PRs; the tuple implementation requires using these constants. If you feel this PR shouldn't be written this way, I can make the changes. FYI: https://github.com/apache/datasketches-rust/pull/138/changes#diff-f3568728db442efe8852306fd065409eb9c4286921170ef66c3cde0b9d452be4R31-R33 ########## datasketches/src/theta/raw_hash_table.rs: ########## @@ -0,0 +1,400 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use std::hash::Hash; + +use crate::common::ResizeFactor; +use crate::hash::MurmurHash3X64128; +use crate::hash::compute_seed_hash; +use crate::theta::HASH_TABLE_REBUILD_THRESHOLD; +use crate::theta::HASH_TABLE_RESIZE_THRESHOLD; +use crate::theta::MAX_THETA; +use crate::theta::MIN_LG_K; +use crate::theta::STRIDE_MASK; + +pub(crate) trait RawHashTableEntry { + fn hash(&self) -> u64; +} + +/// Generic hash-table mechanics shared by Theta and Tuple sketches. +/// +/// The entry type supplies the retained hash and any sketch-specific payload. The table owns all +/// theta screening, probing, resizing, rebuilding, trimming, and logical-empty state. +#[derive(Debug)] +pub(crate) struct RawHashTable<E> { + pub(crate) lg_cur_size: u8, + pub(crate) lg_nom_size: u8, + pub(crate) lg_max_size: u8, + pub(crate) resize_factor: ResizeFactor, + pub(crate) sampling_probability: f32, + pub(crate) hash_seed: u64, + + // Logical emptiness of the source set. + // + // * `false` if any update has been attempted (even if screened by theta) + // * `true` if no updates have been attempted. + // + // This can be false even when `num_retained` is 0. + pub(crate) is_empty: bool, + + pub(crate) theta: u64, + + pub(crate) entries: Vec<Option<E>>, + + // Number of retained non-zero hashes currently stored in `entries`. + pub(crate) num_retained: usize, +} Review Comment: ditto -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
