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use crate::{
constants::DESCRIBE_MAX,
hash::{Hash, HashPrimitive},
table::general::{Bucket, HashTables},
utils::{all_eq, increase_capacity},
DataPoint, DataPointSlice, Error, Result,
};
use fnv::{FnvHashMap as HashMap, FnvHashSet};
use serde::{Deserialize, Serialize};
use std::iter::FromIterator;
#[derive(Debug, Deserialize, Serialize)]
pub struct VecStore {
pub map: Vec<DataPoint>,
}
impl VecStore {
fn push(&mut self, d: DataPoint) -> u32 {
self.map.push(d);
(self.map.len() - 1) as u32
}
fn position(&self, d: &DataPointSlice) -> Option<u32> {
self.map.iter().position(|x| all_eq(x, d)).map(|x| x as u32)
}
fn get(&self, idx: u32) -> &DataPoint {
&self.map[idx as usize]
}
fn increase_storage(&mut self, size: usize) {
increase_capacity(size, &mut self.map);
}
}
#[derive(Deserialize, Serialize)]
pub struct MemoryTable {
hash_tables: Vec<HashMap<Hash, Bucket>>,
n_hash_tables: usize,
pub vec_store: VecStore,
only_index_storage: bool,
counter: u32,
}
impl MemoryTable {
fn remove_idx(&mut self, idx: u32, hash: &Hash, hash_table: usize) -> Result<()> {
let tbl = &mut self.hash_tables[hash_table];
let bucket = tbl.get_mut(hash);
match bucket {
None => return Err(Error::NotFound),
Some(bucket) => {
bucket.remove(&idx);
Ok(())
}
}
}
fn insert_idx(&mut self, idx: u32, hash: Hash, hash_table: usize) {
let tbl = &mut self.hash_tables[hash_table];
let bucket = tbl.entry(hash).or_insert_with(|| FnvHashSet::default());
bucket.insert(idx);
}
}
impl HashTables for MemoryTable {
fn new(n_hash_tables: usize, only_index_storage: bool, _: &str) -> Result<Box<Self>> {
let hash_tables = vec![HashMap::default(); n_hash_tables];
let vector_store = VecStore { map: vec![] };
let m = MemoryTable {
hash_tables,
n_hash_tables,
vec_store: vector_store,
only_index_storage,
counter: 0,
};
Ok(Box::new(m))
}
fn put(&mut self, hash: Hash, d: &DataPointSlice, hash_table: usize) -> Result<u32> {
let idx = self.counter;
self.insert_idx(idx, hash, hash_table);
if (hash_table == 0) && (!self.only_index_storage) {
self.vec_store.push(d.to_vec());
} else if hash_table == self.n_hash_tables - 1 {
self.counter += 1
}
Ok(idx)
}
fn delete(&mut self, hash: &Hash, d: &DataPointSlice, hash_table: usize) -> Result<()> {
let idx = match self.vec_store.position(d) {
None => return Ok(()),
Some(idx) => idx,
};
self.remove_idx(idx, &hash, hash_table)
}
fn update_by_idx(
&mut self,
old_hash: &Hash,
new_hash: Hash,
idx: u32,
hash_table: usize,
) -> Result<()> {
self.remove_idx(idx, old_hash, hash_table)?;
self.insert_idx(idx, new_hash, hash_table);
Ok(())
}
fn query_bucket(&self, hash: &Hash, hash_table: usize) -> Result<Bucket> {
let tbl = &self.hash_tables[hash_table];
match tbl.get(hash) {
None => Err(Error::NotFound),
Some(bucket) => Ok(bucket.clone()),
}
}
fn idx_to_datapoint(&self, idx: u32) -> Result<&DataPoint> {
Ok(self.vec_store.get(idx))
}
fn increase_storage(&mut self, size: usize) {
increase_capacity(size, &mut self.hash_tables);
self.vec_store.increase_storage(size);
}
fn describe(&self) -> Result<String> {
let mut lengths = vec![];
let mut max_len = 0;
let mut min_len = 1000000;
let mut set: FnvHashSet<HashPrimitive> = FnvHashSet::default();
for map in self.hash_tables.iter() {
for ((k, v), _) in map.iter().zip(0..DESCRIBE_MAX) {
let len = v.len();
let hash_values: FnvHashSet<HashPrimitive> =
FnvHashSet::from_iter(k.iter().copied());
set = set.union(&hash_values).copied().collect();
lengths.push(len);
if len > max_len {
max_len = len
}
if len < min_len {
min_len = len
}
}
}
let avg = lengths.iter().sum::<usize>() as f32 / lengths.len() as f32;
let var = lengths
.iter()
.map(|&v| (avg - v as f32).powf(2.))
.sum::<f32>()
/ lengths.len() as f32;
let std_dev = var.powf(0.5);
let mut out = String::from(&format!("No. of tables: {}\n", self.n_hash_tables));
out.push_str(&format!("Unique hash values:\n{:?}\n", set));
out.push_str("\nHash collisions:\n");
out.push_str(&format!("avg:\t{:?}\n", avg));
out.push_str(&format!("std-dev:\t{:?}\n", std_dev));
out.push_str(&format!("min:\t{:?}\n", min_len));
out.push_str(&format!("max:\t{:?}\n", max_len));
Ok(out)
}
fn get_unique_hash_int(&self) -> FnvHashSet<HashPrimitive> {
let mut hash_numbers = FnvHashSet::default();
for ht in &self.hash_tables {
for ((hash, _), _i) in ht.iter().zip(0..100) {
for &v in hash {
hash_numbers.insert(v);
}
}
}
hash_numbers
}
}
impl std::fmt::Debug for MemoryTable {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "hash_tables:\nhash, \t buckets\n")?;
for ht in self.hash_tables.iter() {
write!(f, "{:?}\n", ht)?;
}
Ok(())
}
}