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feat: Remove the State from most of the code

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This commit is contained in:
Clément Renault 2018-09-09 13:35:12 +02:00
parent 31e04f0120
commit a49a21ac15
13 changed files with 983 additions and 491 deletions
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9
Cargo.lock generated
View File

@ -73,7 +73,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "fst"
version = "0.3.2"
source = "git+https://github.com/Kerollmops/fst.git?branch=automaton-for-deref#ca3a1ebb60a6f9123f1284de380c7a5fc05d16bb"
source = "git+https://github.com/Kerollmops/fst.git?branch=automaton-for-deref#6897dbe3b97772b7056279dd5a5d7088831b4cf0"
dependencies = [
"byteorder 1.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
"memmap 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
@ -238,6 +238,7 @@ dependencies = [
"lazy_static 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
"levenshtein_automata 0.1.1 (git+https://github.com/Kerollmops/levenshtein-automata.git?branch=new-custom-fst)",
"rocksdb 0.3.0 (git+https://github.com/pingcap/rust-rocksdb.git)",
"sdset 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
]
[[package]]
@ -278,6 +279,11 @@ name = "ryu"
version = "0.2.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "sdset"
version = "0.2.3"
source = "registry+https://github.com/rust-lang/crates.io-index"
[[package]]
name = "serde"
version = "1.0.75"
@ -407,6 +413,7 @@ dependencies = [
"checksum rand 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "8356f47b32624fef5b3301c1be97e5944ecdd595409cc5da11d05f211db6cfbd"
"checksum rocksdb 0.3.0 (git+https://github.com/pingcap/rust-rocksdb.git)" = "<none>"
"checksum ryu 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "e7c066b8e2923f05d4718a06d2622f189ff362bc642bfade6c6629f0440f3827"
"checksum sdset 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "d51ad726aa3a9c4d777b35be3a4d6d5f9d6cbc0978e81c7d690d31192f263843"
"checksum serde 1.0.75 (registry+https://github.com/rust-lang/crates.io-index)" = "22d340507cea0b7e6632900a176101fea959c7065d93ba555072da90aaaafc87"
"checksum serde_derive 1.0.75 (registry+https://github.com/rust-lang/crates.io-index)" = "234fc8b737737b148ccd625175fc6390f5e4dacfdaa543cb93a3430d984a9119"
"checksum serde_json 1.0.26 (registry+https://github.com/rust-lang/crates.io-index)" = "44dd2cfde475037451fa99b7e5df77aa3cfd1536575fa8e7a538ab36dcde49ae"

38
raptor-indexer/src/main.rs
View File

@ -3,13 +3,12 @@
#[macro_use] extern crate serde_derive;
use std::path::Path;
use std::collections::{HashSet, BTreeMap};
use std::fs::{self, File};
use std::io::{self, BufReader, BufRead};
use std::fs::File;
use std::io::{BufReader, BufRead};
use std::iter;
use raptor::{MetadataBuilder, Metadata, DocIndex};
use raptor::{MetadataBuilder, DocIndex};
use rocksdb::{SstFileWriter, EnvOptions, ColumnFamilyOptions};
use serde_json::from_str;
use unidecode::unidecode;
@ -21,18 +20,6 @@ struct Product {
ft: String,
}
fn set_readonly<P>(path: P, readonly: bool) -> io::Result<()>
where P: AsRef<Path>
{
let mut perms = fs::metadata(&path)?.permissions();
perms.set_readonly(readonly);
fs::set_permissions(&path, perms)
}
fn is_readonly<P: AsRef<Path>>(path: P) -> io::Result<bool> {
fs::metadata(&path).map(|m| m.permissions().readonly())
}
fn main() {
let data = File::open("products.json_lines").unwrap();
let data = BufReader::new(data);
@ -62,15 +49,6 @@ fn main() {
let idx_file = format!("{}.idx", random_name);
let sst_file = format!("{}.sst", random_name);
for file in &[&map_file, &idx_file, &sst_file] {
match is_readonly(file) {
Ok(true) => panic!("the {:?} file is readonly, please make it writeable", file),
Err(ref e) if e.kind() == io::ErrorKind::NotFound => (),
Err(e) => panic!("{:?}", e),
Ok(false) => (),
}
}
let env_options = EnvOptions::new();
let cf_options = ColumnFamilyOptions::new();
let mut sst_file_writer = SstFileWriter::new(env_options, cf_options);
@ -128,13 +106,5 @@ fn main() {
builder.finish().unwrap();
println!("Succesfully created files: {}, {}, {}", map_file, idx_file, sst_file);
set_readonly(&map_file, true).unwrap();
set_readonly(&idx_file, true).unwrap();
set_readonly(&sst_file, true).unwrap();
println!("Checking the dump consistency...");
unsafe { Metadata::from_paths(map_file, idx_file).unwrap() };
// TODO do it better!
println!("Succesfully created {:?} dump.", random_name);
}

5
raptor-search/src/main.rs
View File

@ -13,10 +13,7 @@ fn search(metadata: &Metadata, database: &DB, query: &str) {
automatons.push(lev);
}
let map = metadata.as_map();
let indexes = metadata.as_indexes();
let mut stream = RankedStream::new(&map, &indexes, automatons, 20);
let mut stream = RankedStream::new(&metadata, automatons, 20);
while let Some(document) = stream.next() {
print!("{:?}", document.document_id);

1
raptor/Cargo.toml
View File

@ -9,6 +9,7 @@ authors = ["Kerollmops <renault.cle@gmail.com>"]
[dependencies]
byteorder = "1.2"
fnv = "1.0"
sdset = "0.2"
lazy_static = "1.1"
[dependencies.fst]

43
raptor/src/automaton.rs
View File

@ -16,11 +16,37 @@ pub struct DfaExt {
automaton: DFA,
}
impl Deref for DfaExt {
type Target = DFA;
impl Automaton for DfaExt {
type State = <DFA as Automaton>::State;
fn deref(&self) -> &Self::Target {
&self.automaton
fn start(&self) -> Self::State {
self.automaton.start()
}
fn is_match(&self, state: &Self::State) -> bool {
self.automaton.is_match(state)
}
fn can_match(&self, state: &Self::State) -> bool {
self.automaton.can_match(state)
}
fn will_always_match(&self, state: &Self::State) -> bool {
self.automaton.will_always_match(state)
}
fn accept(&self, state: &Self::State, byte: u8) -> Self::State {
self.automaton.accept(state, byte)
}
}
impl AutomatonExt for DfaExt {
fn eval<B: AsRef<[u8]>>(&self, s: B) -> Distance {
self.automaton.eval(s)
}
fn query_len(&self) -> usize {
self.query_len
}
}
@ -39,12 +65,15 @@ pub trait AutomatonExt: Automaton {
fn query_len(&self) -> usize;
}
impl AutomatonExt for DfaExt {
impl<T> AutomatonExt for T
where T: Deref,
T::Target: AutomatonExt,
{
fn eval<B: AsRef<[u8]>>(&self, s: B) -> Distance {
self.automaton.eval(s)
(**self).eval(s)
}
fn query_len(&self) -> usize {
self.query_len
(**self).query_len()
}
}

7
raptor/src/lib.rs
View File

@ -2,13 +2,14 @@
pub mod rank;
pub mod metadata;
pub mod vec_read_only;
pub mod automaton;
pub use self::metadata::{
Metadata, MetadataBuilder,
Stream, StreamBuilder,
Union, OpBuilder,
IndexedValues,
// Stream, StreamBuilder,
// Union, OpBuilder,
// IndexedValues,
};
pub use self::rank::RankedStream;

425
raptor/src/metadata.rs
View File

@ -1,425 +0,0 @@
use std::sync::Arc;
use std::ops::Deref;
use std::error::Error;
use std::path::Path;
use std::collections::btree_map::{Entry, BTreeMap};
use std::slice::from_raw_parts;
use std::io::{self, Write};
use std::mem;
use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
use fst::{self, Map, MapBuilder, Automaton};
use fst::raw::MmapReadOnly;
use crate::DocIndex;
#[repr(C)]
struct Range {
start: u64,
end: u64,
}
#[derive(Clone)]
enum DocIndexesData {
Shared {
vec: Arc<Vec<u8>>,
offset: usize,
len: usize,
},
Mmap(MmapReadOnly),
}
impl Deref for DocIndexesData {
type Target = [u8];
fn deref(&self) -> &Self::Target {
match self {
DocIndexesData::Shared { vec, offset, len } => {
&vec[*offset..offset + len]
},
DocIndexesData::Mmap(m) => m.as_slice(),
}
}
}
#[derive(Clone)]
pub struct DocIndexes {
ranges: DocIndexesData,
indexes: DocIndexesData,
}
impl DocIndexes {
pub unsafe fn from_path<P: AsRef<Path>>(path: P) -> io::Result<Self> {
let mmap = MmapReadOnly::open_path(path)?;
let range_len = mmap.as_slice().read_u64::<LittleEndian>()?;
let range_len = range_len as usize * mem::size_of::<Range>();
let offset = mem::size_of::<u64>() as usize;
let ranges = DocIndexesData::Mmap(mmap.range(offset, range_len));
let len = mmap.len() - range_len - offset;
let offset = offset + range_len;
let indexes = DocIndexesData::Mmap(mmap.range(offset, len));
Ok(DocIndexes { ranges, indexes })
}
pub fn from_bytes(vec: Vec<u8>) -> io::Result<Self> {
let vec = Arc::new(vec);
let range_len = vec.as_slice().read_u64::<LittleEndian>()?;
let range_len = range_len as usize * mem::size_of::<Range>();
let offset = mem::size_of::<u64>() as usize;
let ranges = DocIndexesData::Shared {
vec: vec.clone(),
offset,
len: range_len
};
let len = vec.len() - range_len - offset;
let offset = offset + range_len;
let indexes = DocIndexesData::Shared { vec, offset, len };
Ok(DocIndexes { ranges, indexes })
}
pub fn get(&self, index: u64) -> Option<&[DocIndex]> {
self.ranges().get(index as usize).map(|Range { start, end }| {
let start = *start as usize;
let end = *end as usize;
&self.indexes()[start..end]
})
}
fn ranges(&self) -> &[Range] {
let slice = &self.ranges;
let ptr = slice.as_ptr() as *const Range;
let len = slice.len() / mem::size_of::<Range>();
unsafe { from_raw_parts(ptr, len) }
}
fn indexes(&self) -> &[DocIndex] {
let slice = &self.indexes;
let ptr = slice.as_ptr() as *const DocIndex;
let len = slice.len() / mem::size_of::<DocIndex>();
unsafe { from_raw_parts(ptr, len) }
}
}
pub struct Metadata {
map: Map,
indexes: DocIndexes,
}
impl Metadata {
pub unsafe fn from_paths<P, Q>(map: P, indexes: Q) -> Result<Self, Box<Error>>
where P: AsRef<Path>,
Q: AsRef<Path>,
{
let map = Map::from_path(map)?;
let indexes = DocIndexes::from_path(indexes)?;
Ok(Metadata::from_raw(map, indexes))
}
pub fn from_bytes(map: Vec<u8>, indexes: Vec<u8>) -> Result<Self, Box<Error>> {
let map = Map::from_bytes(map)?;
let indexes = DocIndexes::from_bytes(indexes)?;
Ok(Metadata::from_raw(map, indexes))
}
pub fn from_raw(map: Map, indexes: DocIndexes) -> Self {
Metadata { map, indexes }
}
pub fn get<K: AsRef<[u8]>>(&self, key: K) -> Option<&[DocIndex]> {
self.map.get(key).and_then(|index| self.indexes.get(index))
}
pub fn as_map(&self) -> &Map {
&self.map
}
pub fn as_indexes(&self) -> &DocIndexes {
&self.indexes
}
pub fn explode(self) -> (Map, DocIndexes) {
(self.map, self.indexes)
}
}
pub struct Inner {
keys: BTreeMap<String, u64>,
indexes: Vec<Vec<DocIndex>>,
number_docs: usize,
}
impl Inner {
pub fn new() -> Self {
Inner {
keys: BTreeMap::new(),
indexes: Vec::new(),
number_docs: 0,
}
}
pub fn number_doc_indexes(&self) -> usize {
self.number_docs
}
pub fn insert(&mut self, key: String, value: DocIndex) {
match self.keys.entry(key) {
Entry::Vacant(e) => {
let index = self.indexes.len() as u64;
self.indexes.push(vec![value]);
e.insert(index);
},
Entry::Occupied(e) => {
let index = *e.get();
let vec = &mut self.indexes[index as usize];
vec.push(value);
},
}
self.number_docs += 1;
}
}
pub struct MetadataBuilder<W, X> {
inner: Inner,
map: W,
indexes: X,
}
impl<W: Write, X: Write> MetadataBuilder<W, X>
{
pub fn new(map: W, indexes: X) -> Self {
Self { inner: Inner::new(), map, indexes }
}
pub fn insert(&mut self, key: String, index: DocIndex) {
self.inner.insert(key, index)
}
pub fn finish(self) -> Result<(), Box<Error>> {
self.into_inner().map(|_| ())
}
pub fn into_inner(mut self) -> Result<(W, X), Box<Error>> {
let number_docs = self.inner.number_doc_indexes();
let mut keys_builder = MapBuilder::new(self.map)?;
keys_builder.extend_iter(self.inner.keys)?;
let map = keys_builder.into_inner()?;
// write down doc_indexes into the indexes Writer
let (ranges, values) = into_sliced_ranges(self.inner.indexes, number_docs);
let len = ranges.len() as u64;
// TODO check if this is correct
self.indexes.write_u64::<LittleEndian>(len)?;
unsafe {
// write Ranges first
let slice = into_u8_slice(ranges.as_slice());
self.indexes.write_all(slice)?;
// write Values after
let slice = into_u8_slice(values.as_slice());
self.indexes.write_all(slice)?;
}
self.indexes.flush()?;
Ok((map, self.indexes))
}
}
fn into_sliced_ranges<T>(vecs: Vec<Vec<T>>, number_docs: usize) -> (Vec<Range>, Vec<T>) {
let cap = vecs.len();
let mut ranges = Vec::with_capacity(cap);
let mut values = Vec::with_capacity(number_docs);
for mut v in &vecs {
let len = v.len() as u64;
let start = ranges.last().map(|&Range { end, .. }| end).unwrap_or(0);
let range = Range { start, end: start + len };
ranges.push(range);
}
values.extend(vecs.into_iter().flatten());
(ranges, values)
}
unsafe fn into_u8_slice<T>(slice: &[T]) -> &[u8] {
let ptr = slice.as_ptr() as *const u8;
let len = slice.len() * mem::size_of::<T>();
from_raw_parts(ptr, len)
}
pub struct OpBuilder<'m, 'v> {
inner: fst::map::OpBuilder<'m>,
indexes: &'v DocIndexes,
}
impl<'m, 'v> OpBuilder<'m, 'v> {
pub fn new(indexes: &'v DocIndexes) -> Self {
Self {
inner: fst::map::OpBuilder::new(),
indexes: indexes,
}
}
pub fn add<I, S>(mut self, streamable: I) -> Self
where
I: for<'a> fst::IntoStreamer<'a, Into=S, Item=(&'a [u8], u64)>,
S: 'm + for<'a> fst::Streamer<'a, Item=(&'a [u8], u64)>,
{
self.push(streamable);
self
}
pub fn push<I, S>(&mut self, streamable: I)
where
I: for<'a> fst::IntoStreamer<'a, Into=S, Item=(&'a [u8], u64)>,
S: 'm + for<'a> fst::Streamer<'a, Item=(&'a [u8], u64)>,
{
self.inner.push(streamable);
}
pub fn union(self) -> Union<'m, 'v> {
Union {
inner: self.inner.union(),
outs: Vec::new(),
indexes: self.indexes,
}
}
}
#[derive(Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
pub struct IndexedValues<'a> {
pub index: usize,
pub values: &'a [DocIndex],
}
pub struct Union<'m, 'v> {
inner: fst::map::Union<'m>,
outs: Vec<IndexedValues<'v>>,
indexes: &'v DocIndexes,
}
impl<'a, 'm, 'v> fst::Streamer<'a> for Union<'m, 'v> {
type Item = (&'a [u8], &'a [IndexedValues<'a>]);
fn next(&'a mut self) -> Option<Self::Item> {
match self.inner.next() {
Some((s, ivalues)) => {
self.outs.clear();
self.outs.reserve(ivalues.len());
for ivalue in ivalues {
if let Some(values) = self.indexes.get(ivalue.value) {
let index = ivalue.index;
self.outs.push(IndexedValues { index, values })
}
}
Some((s, &self.outs))
},
None => None,
}
}
}
pub struct StreamBuilder<'m, 'v, A> {
inner: fst::map::StreamBuilder<'m, A>,
indexes: &'v DocIndexes,
}
impl<'m, 'v, 'a, A: 'a> fst::IntoStreamer<'a> for StreamBuilder<'m, 'v, A>
where
A: Automaton,
A::State: Clone,
{
type Item = <Self::Into as fst::Streamer<'a>>::Item;
type Into = Stream<'m, 'v, A>;
fn into_stream(self) -> Self::Into {
Stream {
inner: self.inner.into_stream(),
indexes: self.indexes,
}
}
}
pub struct Stream<'m, 'v, A: Automaton = fst::automaton::AlwaysMatch> {
inner: fst::map::Stream<'m, A>,
indexes: &'v DocIndexes,
}
impl<'m, 'v, 'a, A: 'a> fst::Streamer<'a> for Stream<'m, 'v, A>
where
A: Automaton,
{
type Item = (&'a [u8], &'a [DocIndex]);
fn next(&'a mut self) -> Option<Self::Item> {
match self.inner.next() {
Some((key, i)) => {
match self.indexes.get(i) {
Some(values) => Some((key, values)),
None => None,
}
},
None => None,
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn empty_serialize_deserialize() {
let mapw = Vec::new();
let indexesw = Vec::new();
let builder = MetadataBuilder::new(mapw, indexesw);
let (map, indexes) = builder.into_inner().unwrap();
let metas = Metadata::from_bytes(map, indexes).unwrap();
assert_eq!(metas.get("chameau"), None);
}
#[test]
fn one_doc_serialize_deserialize() {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
let doc = DocIndex { document: 12, attribute: 1, attribute_index: 22 };
builder.insert("chameau".into(), doc);
let (map, indexes) = builder.into_inner().unwrap();
let metas = Metadata::from_bytes(map, indexes).unwrap();
assert_eq!(metas.get("chameau"), Some(&[doc][..]));
}
#[test]
fn multiple_docs_serialize_deserialize() {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
let doc1 = DocIndex { document: 12, attribute: 1, attribute_index: 22 };
let doc2 = DocIndex { document: 31, attribute: 0, attribute_index: 1 };
builder.insert("chameau".into(), doc1);
builder.insert("chameau".into(), doc2);
let (map, indexes) = builder.into_inner().unwrap();
let metas = Metadata::from_bytes(map, indexes).unwrap();
assert_eq!(metas.get("chameau"), Some(&[doc1, doc2][..]));
}
}

203
raptor/src/metadata/doc_indexes.rs Normal file
View File

@ -0,0 +1,203 @@
use std::collections::btree_map::{BTreeMap, Iter, Entry};
use std::slice::from_raw_parts;
use std::io::{self, Write};
use std::path::Path;
use std::ops::Deref;
use std::sync::Arc;
use std::mem;
use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
use fst::raw::MmapReadOnly;
use crate::DocIndex;
#[repr(C)]
struct Range {
start: u64,
end: u64,
}
#[derive(Clone)]
enum DocIndexesData {
Shared {
vec: Arc<Vec<u8>>,
offset: usize,
len: usize,
},
Mmap(MmapReadOnly),
}
impl Deref for DocIndexesData {
type Target = [u8];
fn deref(&self) -> &Self::Target {
match self {
DocIndexesData::Shared { vec, offset, len } => {
&vec[*offset..offset + len]
},
DocIndexesData::Mmap(m) => m.as_slice(),
}
}
}
#[derive(Clone)]
pub struct DocIndexes {
ranges: DocIndexesData,
indexes: DocIndexesData,
}
impl DocIndexes {
pub unsafe fn from_path<P: AsRef<Path>>(path: P) -> io::Result<Self> {
let mmap = MmapReadOnly::open_path(path)?;
let range_len = mmap.as_slice().read_u64::<LittleEndian>()?;
let range_len = range_len as usize * mem::size_of::<Range>();
let offset = mem::size_of::<u64>() as usize;
let ranges = DocIndexesData::Mmap(mmap.range(offset, range_len));
let len = mmap.len() - range_len - offset;
let offset = offset + range_len;
let indexes = DocIndexesData::Mmap(mmap.range(offset, len));
Ok(DocIndexes { ranges, indexes })
}
pub fn from_bytes(vec: Vec<u8>) -> io::Result<Self> {
let vec = Arc::new(vec);
let range_len = vec.as_slice().read_u64::<LittleEndian>()?;
let range_len = range_len as usize * mem::size_of::<Range>();
let offset = mem::size_of::<u64>() as usize;
let ranges = DocIndexesData::Shared {
vec: vec.clone(),
offset,
len: range_len
};
let len = vec.len() - range_len - offset;
let offset = offset + range_len;
let indexes = DocIndexesData::Shared { vec, offset, len };
Ok(DocIndexes { ranges, indexes })
}
pub fn get(&self, index: u64) -> Option<&[DocIndex]> {
self.ranges().get(index as usize).map(|Range { start, end }| {
let start = *start as usize;
let end = *end as usize;
&self.indexes()[start..end]
})
}
fn ranges(&self) -> &[Range] {
let slice = &self.ranges;
let ptr = slice.as_ptr() as *const Range;
let len = slice.len() / mem::size_of::<Range>();
unsafe { from_raw_parts(ptr, len) }
}
fn indexes(&self) -> &[DocIndex] {
let slice = &self.indexes;
let ptr = slice.as_ptr() as *const DocIndex;
let len = slice.len() / mem::size_of::<DocIndex>();
unsafe { from_raw_parts(ptr, len) }
}
}
pub struct DocIndexesBuilder<W> {
keys: BTreeMap<String, u64>,
indexes: Vec<Vec<DocIndex>>,
number_docs: usize,
wtr: W,
}
impl<W: Write> DocIndexesBuilder<W> {
pub fn new(wtr: W) -> Self {
Self {
keys: BTreeMap::new(),
indexes: Vec::new(),
number_docs: 0,
wtr: wtr,
}
}
pub fn number_doc_indexes(&self) -> usize {
self.number_docs
}
pub fn insert(&mut self, key: String, value: DocIndex) {
match self.keys.entry(key) {
Entry::Vacant(e) => {
let index = self.indexes.len() as u64;
self.indexes.push(vec![value]);
e.insert(index);
},
Entry::Occupied(e) => {
let index = *e.get();
let vec = &mut self.indexes[index as usize];
vec.push(value);
},
}
self.number_docs += 1;
}
pub fn keys(&self) -> Iter<String, u64> {
self.keys.iter()
}
pub fn finish(self) -> io::Result<()> {
self.into_inner().map(|_| ())
}
pub fn into_inner(mut self) -> io::Result<W> {
for vec in &mut self.indexes {
vec.sort_unstable();
}
let (ranges, values) = into_sliced_ranges(self.indexes, self.number_docs);
let len = ranges.len() as u64;
// TODO check if this is correct
self.wtr.write_u64::<LittleEndian>(len)?;
unsafe {
// write Ranges first
let slice = into_u8_slice(ranges.as_slice());
self.wtr.write_all(slice)?;
// write Values after
let slice = into_u8_slice(values.as_slice());
self.wtr.write_all(slice)?;
}
self.wtr.flush()?;
Ok(self.wtr)
}
}
fn into_sliced_ranges<T>(vecs: Vec<Vec<T>>, number_docs: usize) -> (Vec<Range>, Vec<T>) {
let cap = vecs.len();
let mut ranges = Vec::with_capacity(cap);
let mut values = Vec::with_capacity(number_docs);
// @Improvement: remove bounds duplications: the left bound of a range
// is already the right bound of the previous range,
// we could use a slice window of size 2.
for v in &vecs {
let len = v.len() as u64;
let start = ranges.last().map(|&Range { end, .. }| end).unwrap_or(0);
let range = Range { start, end: start + len };
ranges.push(range);
}
values.extend(vecs.into_iter().flatten());
(ranges, values)
}
unsafe fn into_u8_slice<T>(slice: &[T]) -> &[u8] {
let ptr = slice.as_ptr() as *const u8;
let len = slice.len() * mem::size_of::<T>();
from_raw_parts(ptr, len)
}

138
raptor/src/metadata/mod.rs Normal file
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@ -0,0 +1,138 @@
// pub mod difference;
// pub mod stream_ops;
mod ops_indexed_value;
pub mod ops;
pub mod doc_indexes;
use fst::{Map, MapBuilder};
use self::doc_indexes::{DocIndexes, DocIndexesBuilder};
use std::error::Error;
use std::path::Path;
use std::io::Write;
use crate::DocIndex;
pub struct Metadata {
map: Map,
indexes: DocIndexes,
}
impl Metadata {
pub unsafe fn from_paths<P, Q>(map: P, indexes: Q) -> Result<Self, Box<Error>>
where P: AsRef<Path>,
Q: AsRef<Path>,
{
let map = Map::from_path(map)?;
let indexes = DocIndexes::from_path(indexes)?;
Ok(Metadata { map, indexes })
}
pub fn from_bytes(map: Vec<u8>, indexes: Vec<u8>) -> Result<Self, Box<Error>> {
let map = Map::from_bytes(map)?;
let indexes = DocIndexes::from_bytes(indexes)?;
Ok(Metadata { map, indexes })
}
pub fn get<K: AsRef<[u8]>>(&self, key: K) -> Option<&[DocIndex]> {
self.map.get(key).and_then(|index| self.indexes.get(index))
}
pub fn as_map(&self) -> &Map {
&self.map
}
pub fn as_indexes(&self) -> &DocIndexes {
&self.indexes
}
pub fn explode(self) -> (Map, DocIndexes) {
(self.map, self.indexes)
}
}
pub struct MetadataBuilder<W, X> {
map: W,
indexes: DocIndexesBuilder<X>,
}
impl<W: Write, X: Write> MetadataBuilder<W, X> {
pub fn new(map: W, indexes: X) -> Self {
Self { map, indexes: DocIndexesBuilder::new(indexes) }
}
pub fn insert(&mut self, key: String, index: DocIndex) {
self.indexes.insert(key, index)
}
pub fn finish(self) -> Result<(), Box<Error>> {
self.into_inner().map(|_| ())
}
pub fn into_inner(self) -> Result<(W, X), Box<Error>> {
// FIXME insert a magic number that indicates if the endianess
// of the input is the same as the machine that is reading it.
let map = {
let mut keys_builder = MapBuilder::new(self.map)?;
let keys = self.indexes.keys().map(|(s, v)| (s, *v));
keys_builder.extend_iter(keys)?;
keys_builder.into_inner()?
};
let indexes = self.indexes.into_inner()?;
Ok((map, indexes))
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::vec_read_only::VecReadOnly;
use crate::metadata::ops::IndexedDocIndexes;
#[test]
fn empty_serialize_deserialize() {
let mapw = Vec::new();
let indexesw = Vec::new();
let builder = MetadataBuilder::new(mapw, indexesw);
let (map, indexes) = builder.into_inner().unwrap();
let metas = Metadata::from_bytes(map, indexes).unwrap();
assert_eq!(metas.get("chameau"), None);
}
#[test]
fn one_doc_serialize_deserialize() {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
let doc = DocIndex { document: 12, attribute: 1, attribute_index: 22 };
builder.insert("chameau".into(), doc);
let (map, indexes) = builder.into_inner().unwrap();
let metas = Metadata::from_bytes(map, indexes).unwrap();
assert_eq!(metas.get("chameau"), Some(&[doc][..]));
}
#[test]
fn multiple_docs_serialize_deserialize() {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
let doc1 = DocIndex { document: 12, attribute: 1, attribute_index: 22 };
let doc2 = DocIndex { document: 31, attribute: 0, attribute_index: 1 };
builder.insert("chameau".into(), doc1);
builder.insert("chameau".into(), doc2);
let (map, indexes) = builder.into_inner().unwrap();
let metas = Metadata::from_bytes(map, indexes).unwrap();
assert_eq!(metas.get("chameau"), Some(&[doc1, doc2][..]));
}
}

332
raptor/src/metadata/ops.rs Normal file
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@ -0,0 +1,332 @@
use std::hash::{Hash, Hasher};
use std::collections::{HashMap, BTreeMap};
use fst::{map, Streamer, Automaton};
use fst::automaton::AlwaysMatch;
use sdset::multi::OpBuilder as SdOpBuilder;
use sdset::{SetOperation, Set};
use crate::metadata::ops_indexed_value::{
OpIndexedValueBuilder, UnionIndexedValue,
};
use crate::metadata::doc_indexes::DocIndexes;
use crate::metadata::Metadata;
use crate::automaton::AutomatonExt;
use crate::vec_read_only::VecReadOnly;
use crate::DocIndex;
pub struct OpBuilder<'m, A: Automaton> {
// the operation on the maps is always an union.
maps: OpIndexedValueBuilder<'m>,
automatons: Vec<A>,
indexes: Vec<&'m DocIndexes>,
}
impl<'m> OpBuilder<'m, AlwaysMatch> {
pub fn new() -> Self {
Self {
maps: OpIndexedValueBuilder::new(),
automatons: vec![AlwaysMatch],
indexes: Vec::new(),
}
}
}
/// Do a set operation on multiple maps with the same automatons.
impl<'m, A: 'm + Automaton> OpBuilder<'m, A> {
pub fn with_automatons(automatons: Vec<A>) -> Self {
Self {
maps: OpIndexedValueBuilder::new(),
automatons: automatons,
indexes: Vec::new(),
}
}
pub fn add(mut self, metadata: &'m Metadata) -> Self where A: Clone {
self.push(metadata);
self
}
pub fn push(&mut self, metadata: &'m Metadata) where A: Clone {
let mut op = map::OpBuilder::new();
for automaton in self.automatons.iter().cloned() {
let stream = metadata.as_map().search(automaton);
op.push(stream);
}
let stream = op.union();
let indexes = metadata.as_indexes();
self.maps.push(stream);
self.indexes.push(indexes);
}
pub fn union(self) -> Union<'m> {
Union::new(self.maps, self.indexes)
}
pub fn intersection(self) -> Intersection<'m> {
Intersection::new(self.maps, self.indexes)
}
pub fn difference(self) -> Difference<'m> {
Difference::new(self.maps, self.indexes)
}
pub fn symmetric_difference(self) -> SymmetricDifference<'m> {
SymmetricDifference::new(self.maps, self.indexes)
}
}
#[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
pub struct IndexedDocIndexes {
pub index: usize,
pub doc_indexes: VecReadOnly<DocIndex>,
}
struct SlotIndexedDocIndexes {
index: usize,
start: usize,
len: usize,
}
macro_rules! logical_operation {
(struct $name:ident, $operation:ident) => {
pub struct $name<'m> {
maps: UnionIndexedValue<'m>,
indexes: Vec<&'m DocIndexes>,
outs: Vec<IndexedDocIndexes>,
}
impl<'m> $name<'m> {
fn new(maps: OpIndexedValueBuilder<'m>, indexes: Vec<&'m DocIndexes>) -> Self
{
$name {
maps: maps.union(),
indexes: indexes,
outs: Vec::new(),
}
}
}
impl<'m, 'a> fst::Streamer<'a> for $name<'m> {
type Item = (&'a [u8], &'a [IndexedDocIndexes]);
fn next(&'a mut self) -> Option<Self::Item> {
match self.maps.next() {
Some((input, ivalues)) => {
self.outs.clear();
// @Improvement: better use a `Vec` instead,
// `aut indexes` follow them selfs
let mut builders = HashMap::new();
for iv in ivalues {
let builder = builders.entry(iv.aut_index).or_insert_with(BTreeMap::new);
builder.insert(iv.rdr_index, iv.value);
}
let mut doc_indexes = Vec::new();
let mut doc_indexes_slots = Vec::with_capacity(builders.len());
for (aut_index, values) in builders.into_iter() {
let mut builder = SdOpBuilder::with_capacity(values.len());
for (rdr_index, value) in values {
let indexes = self.indexes[rdr_index].get(value).expect("could not find indexes");
let indexes = Set::new_unchecked(indexes);
builder.push(indexes);
}
let start = doc_indexes.len();
builder.$operation().extend_vec(&mut doc_indexes);
let len = doc_indexes.len() - start;
if len == 0 { continue }
let slot = SlotIndexedDocIndexes {
index: aut_index,
start: start,
len: len,
};
doc_indexes_slots.push(slot);
}
let read_only = VecReadOnly::new(doc_indexes);
self.outs.reserve(doc_indexes_slots.len());
for slot in doc_indexes_slots {
let indexes = IndexedDocIndexes {
index: slot.index,
doc_indexes: read_only.range(slot.start, slot.len),
};
self.outs.push(indexes);
}
if self.outs.is_empty() { return None }
Some((input, &self.outs))
},
None => None,
}
}
}
}}
logical_operation!(struct Union, union);
logical_operation!(struct Intersection, intersection);
logical_operation!(struct Difference, difference);
logical_operation!(struct SymmetricDifference, symmetric_difference);
#[cfg(test)]
mod tests {
use super::*;
use crate::metadata::MetadataBuilder;
fn get_exact_key<'m, I, S>(stream: I, key: &[u8]) -> Option<VecReadOnly<DocIndex>>
where
I: for<'a> fst::IntoStreamer<'a, Into=S, Item=(&'a [u8], &'a [IndexedDocIndexes])>,
S: 'm + for<'a> fst::Streamer<'a, Item=(&'a [u8], &'a [IndexedDocIndexes])>,
{
let mut stream = stream.into_stream();
while let Some((string, indexes)) = stream.next() {
if string == key {
return Some(indexes[0].doc_indexes.clone())
}
}
None
}
#[test]
fn union_two_metadata() {
let doc1 = DocIndex { document: 12, attribute: 1, attribute_index: 22 };
let doc2 = DocIndex { document: 31, attribute: 0, attribute_index: 1 };
let meta1 = {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
builder.insert("chameau".into(), doc1);
let (map, indexes) = builder.into_inner().unwrap();
Metadata::from_bytes(map, indexes).unwrap()
};
let meta2 = {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
builder.insert("chameau".into(), doc2);
let (map, indexes) = builder.into_inner().unwrap();
Metadata::from_bytes(map, indexes).unwrap()
};
let metas = OpBuilder::new().add(&meta1).add(&meta2).union();
let value = get_exact_key(metas, b"chameau");
assert_eq!(&*value.unwrap(), &[doc1, doc2][..]);
}
#[test]
fn intersection_two_metadata() {
let doc1 = DocIndex { document: 31, attribute: 0, attribute_index: 1 };
let doc2 = DocIndex { document: 31, attribute: 0, attribute_index: 1 };
let meta1 = {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
builder.insert("chameau".into(), doc1);
let (map, indexes) = builder.into_inner().unwrap();
Metadata::from_bytes(map, indexes).unwrap()
};
let meta2 = {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
builder.insert("chameau".into(), doc2);
let (map, indexes) = builder.into_inner().unwrap();
Metadata::from_bytes(map, indexes).unwrap()
};
let metas = OpBuilder::new().add(&meta1).add(&meta2).intersection();
let value = get_exact_key(metas, b"chameau");
assert_eq!(&*value.unwrap(), &[doc1][..]);
}
#[test]
fn difference_two_metadata() {
let doc1 = DocIndex { document: 12, attribute: 1, attribute_index: 22 };
let doc2 = DocIndex { document: 31, attribute: 0, attribute_index: 1 };
let doc3 = DocIndex { document: 31, attribute: 0, attribute_index: 1 };
let meta1 = {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
builder.insert("chameau".into(), doc1);
builder.insert("chameau".into(), doc2);
let (map, indexes) = builder.into_inner().unwrap();
Metadata::from_bytes(map, indexes).unwrap()
};
let meta2 = {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
builder.insert("chameau".into(), doc3);
let (map, indexes) = builder.into_inner().unwrap();
Metadata::from_bytes(map, indexes).unwrap()
};
let metas = OpBuilder::new().add(&meta1).add(&meta2).difference();
let value = get_exact_key(metas, b"chameau");
assert_eq!(&*value.unwrap(), &[doc1][..]);
}
#[test]
fn symmetric_difference_two_metadata() {
let doc1 = DocIndex { document: 12, attribute: 1, attribute_index: 22 };
let doc2 = DocIndex { document: 31, attribute: 0, attribute_index: 1 };
let doc3 = DocIndex { document: 32, attribute: 0, attribute_index: 1 };
let doc4 = DocIndex { document: 34, attribute: 12, attribute_index: 1 };
let meta1 = {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
builder.insert("chameau".into(), doc1);
builder.insert("chameau".into(), doc2);
builder.insert("chameau".into(), doc3);
let (map, indexes) = builder.into_inner().unwrap();
Metadata::from_bytes(map, indexes).unwrap()
};
let meta2 = {
let mapw = Vec::new();
let indexesw = Vec::new();
let mut builder = MetadataBuilder::new(mapw, indexesw);
builder.insert("chameau".into(), doc2);
builder.insert("chameau".into(), doc3);
builder.insert("chameau".into(), doc4);
let (map, indexes) = builder.into_inner().unwrap();
Metadata::from_bytes(map, indexes).unwrap()
};
let metas = OpBuilder::new().add(&meta1).add(&meta2).symmetric_difference();
let value = get_exact_key(metas, b"chameau");
assert_eq!(&*value.unwrap(), &[doc1, doc4][..]);
}
}

197
raptor/src/metadata/ops_indexed_value.rs Normal file
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@ -0,0 +1,197 @@
use std::collections::BinaryHeap;
use std::rc::Rc;
use std::cmp;
use fst::raw::{self, Output};
use fst::{self, IntoStreamer, Streamer};
type BoxedStream<'f> = Box<for<'a> Streamer<'a, Item=(&'a [u8], &'a [raw::IndexedValue])> + 'f>;
pub struct OpIndexedValueBuilder<'f> {
streams: Vec<BoxedStream<'f>>,
}
impl<'f> OpIndexedValueBuilder<'f> {
pub fn new() -> Self {
Self { streams: Vec::new() }
}
pub fn push<I, S>(&mut self, stream: I)
where
I: for<'a> IntoStreamer<'a, Into=S, Item=(&'a [u8], &'a [raw::IndexedValue])>,
S: 'f + for<'a> Streamer<'a, Item=(&'a [u8], &'a [raw::IndexedValue])>,
{
self.streams.push(Box::new(stream.into_stream()));
}
pub fn union(self) -> UnionIndexedValue<'f> {
UnionIndexedValue {
heap: StreamIndexedValueHeap::new(self.streams),
outs: Vec::new(),
cur_slot: None,
}
}
}
pub struct UnionIndexedValue<'f> {
heap: StreamIndexedValueHeap<'f>,
outs: Vec<IndexedValue>,
cur_slot: Option<SlotIndexedValue>,
}
impl<'a, 'm> fst::Streamer<'a> for UnionIndexedValue<'m> {
type Item = (&'a [u8], &'a [IndexedValue]);
fn next(&'a mut self) -> Option<Self::Item> {
if let Some(slot) = self.cur_slot.take() {
self.heap.refill(slot);
}
let slot = match self.heap.pop() {
None => return None,
Some(slot) => {
self.cur_slot = Some(slot);
self.cur_slot.as_mut().unwrap()
}
};
self.outs.clear();
self.outs.push(slot.indexed_value());
while let Some(mut slot2) = self.heap.pop_if_equal(slot.input()) {
self.outs.push(slot2.indexed_value());
self.heap.refill(slot2);
}
Some((slot.input(), &self.outs))
}
}
struct StreamIndexedValueHeap<'f> {
rdrs: Vec<BoxedStream<'f>>,
heap: BinaryHeap<SlotIndexedValue>,
}
impl<'f> StreamIndexedValueHeap<'f> {
fn new(streams: Vec<BoxedStream<'f>>) -> StreamIndexedValueHeap<'f> {
let mut u = StreamIndexedValueHeap {
rdrs: streams,
heap: BinaryHeap::new(),
};
for i in 0..u.rdrs.len() {
u.refill(SlotIndexedValue::new(i));
}
u
}
fn pop(&mut self) -> Option<SlotIndexedValue> {
self.heap.pop()
}
fn peek_is_duplicate(&self, key: &[u8]) -> bool {
self.heap.peek().map(|s| s.input() == key).unwrap_or(false)
}
fn pop_if_equal(&mut self, key: &[u8]) -> Option<SlotIndexedValue> {
if self.peek_is_duplicate(key) {
self.pop()
} else {
None
}
}
fn pop_if_le(&mut self, key: &[u8]) -> Option<SlotIndexedValue> {
if self.heap.peek().map(|s| s.input() <= key).unwrap_or(false) {
self.pop()
} else {
None
}
}
fn num_slots(&self) -> usize {
self.rdrs.len()
}
fn refill(&mut self, mut slot: SlotIndexedValue) {
if let Some((input, ivalues)) = self.rdrs[slot.rdr_index].next() {
slot.set_input(input);
for values in ivalues {
slot.set_aut_index(values.index);
slot.set_output(values.value);
self.heap.push(slot.clone());
}
}
}
}
#[derive(Debug, Clone)]
struct SlotIndexedValue {
rdr_index: usize,
aut_index: usize,
input: Rc<Vec<u8>>,
output: Output,
}
#[derive(Debug)]
pub struct IndexedValue {
pub rdr_index: usize,
pub aut_index: usize,
pub value: u64,
}
impl PartialEq for SlotIndexedValue {
fn eq(&self, other: &Self) -> bool {
(&self.input, self.rdr_index, self.aut_index, self.output)
.eq(&(&other.input, other.rdr_index, other.aut_index, other.output))
}
}
impl Eq for SlotIndexedValue { }
impl PartialOrd for SlotIndexedValue {
fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
(&self.input, self.rdr_index, self.aut_index, self.output)
.partial_cmp(&(&other.input, other.rdr_index, other.aut_index, other.output))
.map(|ord| ord.reverse())
}
}
impl Ord for SlotIndexedValue {
fn cmp(&self, other: &Self) -> cmp::Ordering {
self.partial_cmp(other).unwrap()
}
}
impl SlotIndexedValue {
fn new(rdr_index: usize) -> SlotIndexedValue {
SlotIndexedValue {
rdr_index: rdr_index,
aut_index: 0,
input: Rc::new(Vec::with_capacity(64)),
output: Output::zero(),
}
}
fn indexed_value(&self) -> IndexedValue {
IndexedValue {
rdr_index: self.rdr_index,
aut_index: self.aut_index,
value: self.output.value(),
}
}
fn input(&self) -> &[u8] {
&self.input
}
fn set_aut_index(&mut self, aut_index: usize) {
self.aut_index = aut_index;
}
fn set_input(&mut self, input: &[u8]) {
if *self.input != input {
let inner = Rc::make_mut(&mut self.input);
inner.clear();
inner.extend(input);
}
}
fn set_output(&mut self, output: u64) {
self.output = Output::new(output);
}
}

32
raptor/src/rank/mod.rs
View File

@ -8,11 +8,13 @@ mod exact;
use std::cmp::Ordering;
use std::rc::Rc;
use std::{mem, vec};
use fst;
use fst::Streamer;
use fnv::FnvHashMap;
use group_by::GroupByMut;
use crate::automaton::{DfaExt, AutomatonExt};
use crate::metadata::{DocIndexes, OpBuilder, Union};
use crate::metadata::Metadata;
use crate::metadata::ops::{OpBuilder, Union};
use crate::metadata::doc_indexes::DocIndexes;
use crate::{Match, DocumentId};
use self::{
@ -83,20 +85,16 @@ fn matches_into_iter(matches: FnvHashMap<DocumentId, Vec<Match>>, limit: usize)
documents.into_iter()
}
pub struct RankedStream<'m, 'v>(RankedStreamInner<'m, 'v>);
impl<'m, 'v> RankedStream<'m, 'v> {
pub fn new(map: &'m fst::Map, indexes: &'v DocIndexes, automatons: Vec<DfaExt>, limit: usize) -> Self {
let mut op = OpBuilder::new(indexes);
pub struct RankedStream<'m>(RankedStreamInner<'m>);
impl<'m> RankedStream<'m> {
pub fn new(metadata: &'m Metadata, automatons: Vec<DfaExt>, limit: usize) -> Self {
let automatons: Vec<_> = automatons.into_iter().map(Rc::new).collect();
for automaton in automatons.iter().cloned() {
let stream = map.search(automaton);
op.push(stream);
}
let mut builder = OpBuilder::with_automatons(automatons.clone());
builder.push(metadata);
let inner = RankedStreamInner::Fed {
inner: op.union(),
inner: builder.union(),
automatons: automatons,
limit: limit,
matches: FnvHashMap::default(),
@ -106,7 +104,7 @@ impl<'m, 'v> RankedStream<'m, 'v> {
}
}
impl<'m, 'v, 'a> fst::Streamer<'a> for RankedStream<'m, 'v> {
impl<'m, 'a> fst::Streamer<'a> for RankedStream<'m> {
type Item = Document;
fn next(&'a mut self) -> Option<Self::Item> {
@ -114,9 +112,9 @@ impl<'m, 'v, 'a> fst::Streamer<'a> for RankedStream<'m, 'v> {
}
}
enum RankedStreamInner<'m, 'v> {
enum RankedStreamInner<'m> {
Fed {
inner: Union<'m, 'v>,
inner: Union<'m>,
automatons: Vec<Rc<DfaExt>>,
limit: usize,
matches: FnvHashMap<DocumentId, Vec<Match>>,
@ -126,7 +124,7 @@ enum RankedStreamInner<'m, 'v> {
},
}
impl<'m, 'v, 'a> fst::Streamer<'a> for RankedStreamInner<'m, 'v> {
impl<'m, 'a> fst::Streamer<'a> for RankedStreamInner<'m> {
type Item = Document;
fn next(&'a mut self) -> Option<Self::Item> {
@ -141,7 +139,7 @@ impl<'m, 'v, 'a> fst::Streamer<'a> for RankedStreamInner<'m, 'v> {
let distance = automaton.eval(string).to_u8();
let same_length = string.len() == automaton.query_len();
for di in iv.values {
for di in iv.doc_indexes.as_slice() {
let match_ = Match {
query_index: iv.index as u32,
distance: distance,

44
raptor/src/vec_read_only.rs Normal file
View File

@ -0,0 +1,44 @@
use std::ops::Deref;
use std::sync::Arc;
#[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
pub struct VecReadOnly<T> {
inner: Arc<Vec<T>>,
offset: usize,
len: usize,
}
impl<T> VecReadOnly<T> {
pub fn new(vec: Vec<T>) -> Self {
let len = vec.len();
Self {
inner: Arc::new(vec),
offset: 0,
len: len,
}
}
pub fn len(&self) -> usize {
self.len
}
pub fn range(&self, offset: usize, len: usize) -> Self {
Self {
inner: self.inner.clone(),
offset: self.offset + offset,
len: len,
}
}
pub fn as_slice(&self) -> &[T] {
&self.inner[self.offset..self.offset + self.len]
}
}
impl<T> Deref for VecReadOnly<T> {
type Target = [T];
fn deref(&self) -> &Self::Target {
self.as_slice()
}
}