Files
lancedb/docs/web-tests/rs/embedding.rs
Jack Ye b21fb2a4dc docs: bring the open-source documentation into this repository
The pages describing this code lived in lancedb/docs, a repository with ten
stars that neither contributing guide mentioned. A user who hit a wrong page
while reading the source had to find a separate, near-invisible repository to
fix it. These 102 pages now sit beside the code, and a documentation fix is a
pull request in the repository the reader already had open.

`docs/web` is a complete Mintlify site: `cd docs/web && mint dev` serves it with
no other checkout. Enterprise pages stay private and are merged in when the
published site is assembled, so links into them do not resolve here — every
open-source page does.

`docs/web-tests` holds the tests the code examples are extracted from. They ran
against a published wheel before; here they can run against this repository's
own SDK, so an example that stops compiling fails the pull request that broke
it rather than being noticed later.

Both directories sit beside `docs/src` and are invisible to it: mkdocs reads
`docs_dir: src`, so the SDK reference builds and deploys exactly as before.
2026-09-02 21:09:30 -07:00

183 lines
5.5 KiB
Rust

// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: Copyright The LanceDB Authors
// --8<-- [start:openai_embeddings]
use std::{iter::once, sync::Arc};
use arrow_array::{record_batch, StringArray};
use arrow_schema::{DataType, Field, Schema};
use futures::StreamExt;
use lancedb::{
connect,
embeddings::{openai::OpenAIEmbeddingFunction, EmbeddingDefinition, EmbeddingFunction},
query::{ExecutableQuery, QueryBase},
Result,
};
#[tokio::main]
async fn main() -> Result<()> {
let db = connect("./mydb").execute().await?;
let api_key = std::env::var("OPENAI_API_KEY").expect("OPENAI_API_KEY is not set");
let embedding = Arc::new(OpenAIEmbeddingFunction::new_with_model(
api_key,
"text-embedding-3-large",
)?);
db.embedding_registry().register("openai", embedding.clone())?;
let schema = Arc::new(Schema::new(vec![Field::new("text", DataType::Utf8, false)]));
let table = db
.create_empty_table("mytable", schema)
.add_embedding(EmbeddingDefinition::new("text", "openai", Some("vector")))?
.execute()
.await?;
table
.add(record_batch!(("text", Utf8, ["This is a test.", "Another example."]))?)
.execute()
.await?;
let query = Arc::new(StringArray::from_iter_values(once("test example")));
let query_vector = embedding.compute_query_embeddings(query)?;
let mut results = table.vector_search(query_vector)?.limit(5).execute().await?;
while let Some(batch) = results.next().await {
println!("{:?}", batch?);
}
Ok(())
}
// --8<-- [end:openai_embeddings]
// --8<-- [start:create_embedding_function]
use std::sync::Arc;
use lancedb::embeddings::openai::OpenAIEmbeddingFunction;
let api_key = std::env::var("OPENAI_API_KEY").expect("OPENAI_API_KEY is not set");
let embedding = Arc::new(
OpenAIEmbeddingFunction::new_with_model(api_key, "text-embedding-3-small")
.expect("failed to create OpenAI embedding function"),
);
// --8<-- [end:create_embedding_function]
// --8<-- [start:manual_query_embeddings]
use std::{iter::once, sync::Arc};
use arrow_array::{record_batch, StringArray};
use arrow_schema::{DataType, Field, Schema};
use futures::StreamExt;
use lancedb::{
connect,
embeddings::{openai::OpenAIEmbeddingFunction, EmbeddingDefinition, EmbeddingFunction},
query::{ExecutableQuery, QueryBase},
Result,
};
#[tokio::main]
async fn main() -> Result<()> {
let db = connect("./mydb").execute().await?;
let api_key = std::env::var("OPENAI_API_KEY").expect("OPENAI_API_KEY is not set");
let embedding = Arc::new(OpenAIEmbeddingFunction::new_with_model(
api_key,
"text-embedding-3-large",
)?);
db.embedding_registry().register("openai", embedding.clone())?;
let schema = Arc::new(Schema::new(vec![Field::new("text", DataType::Utf8, false)]));
let table = db
.create_empty_table("mytable", schema)
.add_embedding(EmbeddingDefinition::new("text", "openai", Some("vector")))?
.execute()
.await?;
table
.add(record_batch!(("text", Utf8, ["This is a test.", "Another example."]))?)
.execute()
.await?;
// Manually generate embeddings for the query (Enterprise path)
let query = Arc::new(StringArray::from_iter_values(once("test example")));
let query_vector = embedding.compute_query_embeddings(query)?;
// --8<-- [start:manual_query_search]
// query_vector is assumed to already be generated by your embedding function
let mut results = table.vector_search(query_vector)?.limit(5).execute().await?;
while let Some(batch) = results.next().await {
println!("{:?}", batch?);
}
// --8<-- [end:manual_query_search]
Ok(())
}
// --8<-- [end:manual_query_embeddings]
// --8<-- [start:embedding_function]
use std::{borrow::Cow, sync::Arc};
use arrow_array::{Array, FixedSizeListArray, Float32Array};
use arrow_schema::{DataType, Field, Schema};
use lancedb::{
connect,
embeddings::{EmbeddingDefinition, EmbeddingFunction},
Result,
};
#[derive(Debug, Clone)]
struct MyTextEmbedder {
dim: usize,
}
impl EmbeddingFunction for MyTextEmbedder {
fn name(&self) -> &str {
"my-embedder"
}
fn source_type(&self) -> Result<Cow<'_, DataType>> {
Ok(Cow::Owned(DataType::Utf8))
}
fn dest_type(&self) -> Result<Cow<'_, DataType>> {
Ok(Cow::Owned(DataType::new_fixed_size_list(
DataType::Float32,
self.dim as i32,
true,
)))
}
fn compute_source_embeddings(&self, source: Arc<dyn Array>) -> Result<Arc<dyn Array>> {
let values = Arc::new(Float32Array::from(vec![1.0f32; source.len() * self.dim]));
let field = Arc::new(Field::new("item", DataType::Float32, true));
Ok(Arc::new(FixedSizeListArray::new(
field,
self.dim as i32,
values,
None,
)))
}
fn compute_query_embeddings(&self, _input: Arc<dyn Array>) -> Result<Arc<dyn Array>> {
unimplemented!()
}
}
#[tokio::main]
async fn main() -> Result<()> {
let db = connect("./mydb").execute().await?;
db.embedding_registry()
.register("my-embedder", Arc::new(MyTextEmbedder { dim: 3 }))?;
let schema = Arc::new(Schema::new(vec![Field::new("text", DataType::Utf8, false)]));
db.create_empty_table("mytable", schema)
.add_embedding(EmbeddingDefinition::new(
"text",
"my-embedder",
Some("vector"),
))?
.execute()
.await?;
Ok(())
}
// --8<-- [end:embedding_function]