tantivy/examples/faceted_search.rs

// # Basic Example
//
// This example covers the basic functionalities of
// tantivy.
//
// We will :
// - define our schema
// = create an index in a directory
// - index few documents in our index
// - search for the best document matchings "sea whale"
// - retrieve the best document original content.

extern crate tempdir;

// ---
// Importing tantivy...
#[macro_use]
extern crate tantivy;
use tantivy::collector::FacetCollector;
use tantivy::query::AllQuery;
use tantivy::schema::*;
use tantivy::Index;

fn main() -> tantivy::Result<()> {
  // Let's create a temporary directory for the
  // sake of this example
  let index_path = TempDir::new("tantivy_facet_example_dir")?;
  let mut schema_builder = SchemaBuilder::default();

  schema_builder.add_text_field("name", TEXT | STORED);

  // this is our faceted field
  schema_builder.add_facet_field("tags");

  let schema = schema_builder.build();

  let index = Index::create_in_dir(&index_path, schema.clone())?;

  let mut index_writer = index.writer(50_000_000)?;

  let name = schema.get_field("name").unwrap();
  let tags = schema.get_field("tags").unwrap();

  // For convenience, tantivy also comes with a macro to
  // reduce the boilerplate above.
  index_writer.add_document(doc!(
        name => "the ditch",
        tags => Facet::from("/pools/north")
    ));

  index_writer.add_document(doc!(
        name => "little stacey",
        tags => Facet::from("/pools/south")
    ));

  index_writer.commit()?;

  index.load_searchers()?;

  let searcher = index.searcher();

  let mut facet_collector = FacetCollector::for_field(tags);
  facet_collector.add_facet("/pools");

  searcher.search(&AllQuery, &mut facet_collector).unwrap();

  let counts = facet_collector.harvest();
  // This lists all of the facet counts
  let facets: Vec<(&Facet, u64)> = counts.get("/pools").collect();
  assert_eq!(
    facets,
    vec![
      (&Facet::from("/pools/north"), 1),
      (&Facet::from("/pools/south"), 1)
    ]
  );

  Ok(())
}

use tempdir::TempDir;