lance_index/
lib.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright The Lance Authors
3
4//! Lance secondary index library
5//!
6//! <section class="warning">
7//! This is internal crate used by <a href="https://github.com/lancedb/lance">the lance project</a>.
8//! <br/>
9//! API stability is not guaranteed.
10//! </section>
11
12use std::{any::Any, sync::Arc};
13
14use async_trait::async_trait;
15use deepsize::DeepSizeOf;
16use lance_core::{Error, Result};
17use roaring::RoaringBitmap;
18use serde::{Deserialize, Serialize};
19use snafu::location;
20use std::convert::TryFrom;
21
22pub mod frag_reuse;
23pub mod metrics;
24pub mod optimize;
25pub mod prefilter;
26pub mod scalar;
27pub mod traits;
28pub mod vector;
29
30pub use crate::traits::*;
31
32pub const INDEX_FILE_NAME: &str = "index.idx";
33/// The name of the auxiliary index file.
34///
35/// This file is used to store additional information about the index, to improve performance.
36/// - For 'IVF_HNSW' index, it stores the partitioned PQ Storage.
37pub const INDEX_AUXILIARY_FILE_NAME: &str = "auxiliary.idx";
38pub const INDEX_METADATA_SCHEMA_KEY: &str = "lance:index";
39
40pub mod pb {
41    #![allow(clippy::use_self)]
42    include!(concat!(env!("OUT_DIR"), "/lance.index.pb.rs"));
43}
44
45/// Generic methods common across all types of secondary indices
46///
47#[async_trait]
48pub trait Index: Send + Sync + DeepSizeOf {
49    /// Cast to [Any].
50    fn as_any(&self) -> &dyn Any;
51
52    /// Cast to [Index]
53    fn as_index(self: Arc<Self>) -> Arc<dyn Index>;
54
55    /// Cast to [vector::VectorIndex]
56    fn as_vector_index(self: Arc<Self>) -> Result<Arc<dyn vector::VectorIndex>>;
57
58    /// Retrieve index statistics as a JSON Value
59    fn statistics(&self) -> Result<serde_json::Value>;
60
61    /// Prewarm the index.
62    ///
63    /// This will load the index into memory and cache it.
64    async fn prewarm(&self) -> Result<()>;
65
66    /// Get the type of the index
67    fn index_type(&self) -> IndexType;
68
69    /// Read through the index and determine which fragment ids are covered by the index
70    ///
71    /// This is a kind of slow operation.  It's better to use the fragment_bitmap.  This
72    /// only exists for cases where the fragment_bitmap has become corrupted or missing.
73    async fn calculate_included_frags(&self) -> Result<RoaringBitmap>;
74}
75
76/// Index Type
77#[derive(Debug, PartialEq, Eq, Copy, Hash, Clone, DeepSizeOf)]
78pub enum IndexType {
79    // Preserve 0-100 for simple indices.
80    Scalar = 0, // Legacy scalar index, alias to BTree
81
82    BTree = 1, // BTree
83
84    Bitmap = 2, // Bitmap
85
86    LabelList = 3, // LabelList
87
88    Inverted = 4, // Inverted
89
90    NGram = 5, // NGram
91
92    FragmentReuse = 6,
93
94    // 100+ and up for vector index.
95    /// Flat vector index.
96    Vector = 100, // Legacy vector index, alias to IvfPq
97    IvfFlat = 101,
98    IvfSq = 102,
99    IvfPq = 103,
100    IvfHnswSq = 104,
101    IvfHnswPq = 105,
102}
103
104impl std::fmt::Display for IndexType {
105    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
106        match self {
107            Self::Scalar | Self::BTree => write!(f, "BTree"),
108            Self::Bitmap => write!(f, "Bitmap"),
109            Self::LabelList => write!(f, "LabelList"),
110            Self::Inverted => write!(f, "Inverted"),
111            Self::NGram => write!(f, "NGram"),
112            Self::FragmentReuse => write!(f, "FragmentReuse"),
113            Self::Vector | Self::IvfPq => write!(f, "IVF_PQ"),
114            Self::IvfFlat => write!(f, "IVF_FLAT"),
115            Self::IvfSq => write!(f, "IVF_SQ"),
116            Self::IvfHnswSq => write!(f, "IVF_HNSW_SQ"),
117            Self::IvfHnswPq => write!(f, "IVF_HNSW_PQ"),
118        }
119    }
120}
121
122impl TryFrom<i32> for IndexType {
123    type Error = Error;
124
125    fn try_from(value: i32) -> Result<Self> {
126        match value {
127            v if v == Self::Scalar as i32 => Ok(Self::Scalar),
128            v if v == Self::BTree as i32 => Ok(Self::BTree),
129            v if v == Self::Bitmap as i32 => Ok(Self::Bitmap),
130            v if v == Self::LabelList as i32 => Ok(Self::LabelList),
131            v if v == Self::NGram as i32 => Ok(Self::NGram),
132            v if v == Self::Inverted as i32 => Ok(Self::Inverted),
133            v if v == Self::Vector as i32 => Ok(Self::Vector),
134            v if v == Self::IvfFlat as i32 => Ok(Self::IvfFlat),
135            v if v == Self::IvfSq as i32 => Ok(Self::IvfSq),
136            v if v == Self::IvfPq as i32 => Ok(Self::IvfPq),
137            v if v == Self::IvfHnswSq as i32 => Ok(Self::IvfHnswSq),
138            v if v == Self::IvfHnswPq as i32 => Ok(Self::IvfHnswPq),
139            _ => Err(Error::InvalidInput {
140                source: format!("the input value {} is not a valid IndexType", value).into(),
141                location: location!(),
142            }),
143        }
144    }
145}
146
147impl IndexType {
148    pub fn is_scalar(&self) -> bool {
149        matches!(
150            self,
151            Self::Scalar
152                | Self::BTree
153                | Self::Bitmap
154                | Self::LabelList
155                | Self::Inverted
156                | Self::NGram
157        )
158    }
159
160    pub fn is_vector(&self) -> bool {
161        matches!(
162            self,
163            Self::Vector
164                | Self::IvfPq
165                | Self::IvfHnswSq
166                | Self::IvfHnswPq
167                | Self::IvfFlat
168                | Self::IvfSq
169        )
170    }
171
172    /// Returns the current format version of the index type,
173    /// bump this when the index format changes.
174    /// Indices which higher version than these will be ignored for compatibility,
175    /// This would happen when creating index in a newer version of Lance,
176    /// but then opening the index in older version of Lance
177    pub fn version(&self) -> i32 {
178        match self {
179            Self::Scalar => 0,
180            Self::BTree => 0,
181            Self::Bitmap => 0,
182            Self::LabelList => 0,
183            Self::Inverted => 0,
184            Self::NGram => 0,
185            Self::FragmentReuse => 0,
186
187            // for now all vector indices are built by the same builder,
188            // so they share the same version.
189            Self::Vector
190            | Self::IvfFlat
191            | Self::IvfSq
192            | Self::IvfPq
193            | Self::IvfHnswSq
194            | Self::IvfHnswPq => 1,
195        }
196    }
197}
198
199pub trait IndexParams: Send + Sync {
200    fn as_any(&self) -> &dyn Any;
201
202    fn index_type(&self) -> IndexType;
203
204    fn index_name(&self) -> &str;
205}
206
207#[derive(Serialize, Deserialize, Debug)]
208pub struct IndexMetadata {
209    #[serde(rename = "type")]
210    pub index_type: String,
211    pub distance_type: String,
212}
lance_index/lib.rs

lance_index/
lib.rs
