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#[macro_use]
extern crate lazy_static;
extern crate phf;
extern crate regex;
extern crate serde;
#[macro_use]
extern crate serde_derive;
extern crate serde_json;
#[cfg(test)]
#[macro_use]
extern crate maplit;
pub const ELASTICLUNR_VERSION: &str = "0.9.5";
mod document_store;
mod inverted_index;
mod pipeline;
mod stemmer;
use std::collections::HashMap;
use pipeline::Pipeline;
use inverted_index::InvertedIndex;
use document_store::DocumentStore;
pub struct IndexBuilder {
save: bool,
fields: Vec<String>,
ref_field: String,
}
impl IndexBuilder {
pub fn new() -> Self {
IndexBuilder {
save: true,
fields: Vec::new(),
ref_field: "id".into(),
}
}
pub fn save_docs(mut self, save: bool) -> Self {
self.save = save;
self
}
pub fn add_field(mut self, field: &str) -> Self {
self.fields.push(field.into());
self
}
pub fn set_ref(mut self, ref_field: &str) -> Self {
self.ref_field = ref_field.into();
self
}
pub fn build(self) -> Index {
let index = self.fields
.iter()
.map(|f| (f.clone(), InvertedIndex::new()))
.collect();
Index {
index,
fields: self.fields,
ref_field: self.ref_field,
document_store: DocumentStore::new(self.save),
pipeline: Pipeline::default(),
version: ::ELASTICLUNR_VERSION,
}
}
}
#[derive(Serialize, Debug)]
#[serde(rename_all = "camelCase")]
pub struct Index {
fields: Vec<String>,
pipeline: Pipeline,
#[serde(rename = "ref")]
ref_field: String,
version: &'static str,
index: HashMap<String, InvertedIndex>,
document_store: DocumentStore,
}
impl Index {
pub fn new<S, I: IntoIterator<Item = S>>(fields: I) -> Self
where
S: AsRef<str>,
{
let mut indices = HashMap::new();
let mut field_vec = Vec::new();
for field in fields {
let field = field.as_ref().to_string();
field_vec.push(field.clone());
indices.insert(field, InvertedIndex::new());
}
Index {
fields: field_vec,
index: indices,
pipeline: Pipeline::default(),
ref_field: "id".into(),
version: ::ELASTICLUNR_VERSION,
document_store: DocumentStore::new(true),
}
}
pub fn add_doc<S, I: IntoIterator<Item = S>>(&mut self, doc_ref: &str, data: I)
where
S: AsRef<str>,
{
let mut doc = HashMap::new();
doc.insert(self.ref_field.clone(), doc_ref.into());
let mut token_freq = HashMap::new();
for (field, value) in self.fields.iter().zip(data) {
doc.insert(field.clone(), value.as_ref().to_string());
if field == &self.ref_field {
continue;
}
let tokens = self.pipeline.run(pipeline::tokenize(value.as_ref()));
self.document_store.add_field_length(
doc_ref,
field,
tokens.len(),
);
for token in tokens {
*token_freq.entry(token).or_insert(0u64) += 1;
}
for (token, count) in &token_freq {
let freq = (*count as f64).sqrt();
self.index
.get_mut(field)
.expect(&format!("InvertedIndex does not exist for field {}", field))
.add_token(doc_ref, token, freq);
}
}
self.document_store.add_doc(doc_ref, doc);
}
pub fn get_fields(&self) -> &[String] {
&self.fields
}
pub fn to_json_pretty(&self) -> String {
serde_json::to_string_pretty(&self.index).unwrap()
}
pub fn to_json(&self) -> String {
serde_json::to_string(&self.index).unwrap()
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn add_field_to_builder() {
let idx = IndexBuilder::new().add_field("foo").build();
assert_eq!(idx.get_fields()[0], "foo");
}
#[test]
fn adding_document_to_index() {
let mut idx = Index::new(&["body"]);
idx.add_doc("1", &["this is a test"]);
assert_eq!(idx.document_store.len(), 1);
assert_eq!(
idx.document_store.get_doc("1").unwrap(),
hashmap!{
"id".into() => "1".into(),
"body".into() => "this is a test".into(),
}
);
}
#[test]
fn adding_document_with_empty_field() {
let mut idx = Index::new(&["title", "body"]);
idx.add_doc("1", &["", "test"]);
assert_eq!(idx.index["body"].get_doc_frequency("test"), 1);
assert_eq!(idx.index["body"].get_docs("test").unwrap()["1"], 1.);
}
}