MeiliSearch/meilidb/examples/query-database.rs
2019-04-29 14:32:03 +02:00

209 lines
6.5 KiB
Rust

#[global_allocator]
static ALLOC: jemallocator::Jemalloc = jemallocator::Jemalloc;
use std::collections::btree_map::{BTreeMap, Entry};
use std::collections::{HashMap, HashSet};
use std::iter::FromIterator;
use std::io::{self, Write};
use std::time::Instant;
use std::path::PathBuf;
use std::error::Error;
use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
use structopt::StructOpt;
use meilidb_core::Match;
use meilidb_data::schema::SchemaAttr;
use meilidb_data::Database;
#[derive(Debug, StructOpt)]
pub struct Opt {
/// The destination where the database must be created
#[structopt(parse(from_os_str))]
pub database_path: PathBuf,
/// Fields that must be displayed.
pub displayed_fields: Vec<String>,
/// The number of returned results
#[structopt(short = "n", long = "number-results", default_value = "10")]
pub number_results: usize,
/// The number of characters before and after the first match
#[structopt(short = "C", long = "context", default_value = "35")]
pub char_context: usize,
}
type Document = HashMap<String, String>;
fn display_highlights(text: &str, ranges: &[usize]) -> io::Result<()> {
let mut stdout = StandardStream::stdout(ColorChoice::Always);
let mut highlighted = false;
for range in ranges.windows(2) {
let [start, end] = match range { [start, end] => [*start, *end], _ => unreachable!() };
if highlighted {
stdout.set_color(ColorSpec::new().set_fg(Some(Color::Yellow)))?;
}
write!(&mut stdout, "{}", &text[start..end])?;
stdout.reset()?;
highlighted = !highlighted;
}
Ok(())
}
fn char_to_byte_range(index: usize, length: usize, text: &str) -> (usize, usize) {
let mut byte_index = 0;
let mut byte_length = 0;
for (n, (i, c)) in text.char_indices().enumerate() {
if n == index {
byte_index = i;
}
if n + 1 == index + length {
byte_length = i - byte_index + c.len_utf8();
break;
}
}
(byte_index, byte_length)
}
fn create_highlight_areas(text: &str, matches: &[Match]) -> Vec<usize> {
let mut byte_indexes = BTreeMap::new();
for match_ in matches {
let char_index = match_.char_index as usize;
let char_length = match_.char_length as usize;
let (byte_index, byte_length) = char_to_byte_range(char_index, char_length, text);
match byte_indexes.entry(byte_index) {
Entry::Vacant(entry) => { entry.insert(byte_length); },
Entry::Occupied(mut entry) => {
if *entry.get() < byte_length {
entry.insert(byte_length);
}
},
}
}
let mut title_areas = Vec::new();
title_areas.push(0);
for (byte_index, length) in byte_indexes {
title_areas.push(byte_index);
title_areas.push(byte_index + length);
}
title_areas.push(text.len());
title_areas.sort_unstable();
title_areas
}
/// note: matches must have been sorted by `char_index` and `char_length` before being passed.
///
/// ```no_run
/// matches.sort_unstable_by_key(|m| (m.char_index, m.char_length));
///
/// let matches = matches.matches.iter().filter(|m| SchemaAttr::new(m.attribute) == attr).cloned();
///
/// let (text, matches) = crop_text(&text, matches, 35);
/// ```
fn crop_text(
text: &str,
matches: impl IntoIterator<Item=Match>,
context: usize,
) -> (String, Vec<Match>)
{
let mut matches = matches.into_iter().peekable();
let char_index = matches.peek().map(|m| m.char_index as usize).unwrap_or(0);
let start = char_index.saturating_sub(context);
let text = text.chars().skip(start).take(context * 2).collect();
let matches = matches
.take_while(|m| {
(m.char_index as usize) + (m.char_length as usize) <= start + (context * 2)
})
.map(|match_| {
Match { char_index: match_.char_index - start as u16, ..match_ }
})
.collect();
(text, matches)
}
fn main() -> Result<(), Box<Error>> {
let _ = env_logger::init();
let opt = Opt::from_args();
let start = Instant::now();
let database = Database::start_default(&opt.database_path)?;
let mut buffer = String::new();
let input = io::stdin();
let index = database.open_index("default")?.unwrap();
let schema = index.schema();
println!("database prepared for you in {:.2?}", start.elapsed());
let fields = opt.displayed_fields.iter().map(String::as_str);
let fields = HashSet::from_iter(fields);
loop {
print!("Searching for: ");
io::stdout().flush()?;
if input.read_line(&mut buffer)? == 0 { break }
let query = buffer.trim_end_matches('\n');
let start = Instant::now();
let builder = index.query_builder();
let documents = builder.query(query, 0..opt.number_results);
let number_of_documents = documents.len();
for mut doc in documents {
doc.matches.sort_unstable_by_key(|m| (m.char_index, m.char_index));
match index.document::<Document>(Some(&fields), doc.id) {
Ok(Some(document)) => {
for (name, text) in document {
print!("{}: ", name);
let attr = schema.attribute(&name).unwrap();
let matches = doc.matches.iter()
.filter(|m| SchemaAttr::new(m.attribute) == attr)
.cloned();
let (text, matches) = crop_text(&text, matches, opt.char_context);
let areas = create_highlight_areas(&text, &matches);
display_highlights(&text, &areas)?;
println!();
}
},
Ok(None) => eprintln!("missing document"),
Err(e) => eprintln!("{}", e),
}
let mut matching_attributes = HashSet::new();
for _match in doc.matches {
let attr = SchemaAttr::new(_match.attribute);
let name = schema.attribute_name(attr);
matching_attributes.insert(name);
}
let matching_attributes = Vec::from_iter(matching_attributes);
println!("matching in: {:?}", matching_attributes);
println!();
}
eprintln!("===== Found {} results in {:.2?} =====", number_of_documents, start.elapsed());
buffer.clear();
}
Ok(())
}