From 2ee210483f2ead933f6c12c4d7deeee2ce09af9f Mon Sep 17 00:00:00 2001
From: Tamo <tamo@meilisearch.com>
Date: Tue, 12 Apr 2022 15:22:47 +0200
Subject: [PATCH] fix(search): remove the back and forth between the IndexMap
 and the serde_json::Map

This is ok because we're using the preserve_order feature in serde_json which is already internally using an IndexMap.
---
 .../src/routes/indexes/settings.rs            |  8 +++----
 meilisearch-lib/src/index/search.rs           | 21 +++----------------
 2 files changed, 7 insertions(+), 22 deletions(-)

diff --git a/meilisearch-http/src/routes/indexes/settings.rs b/meilisearch-http/src/routes/indexes/settings.rs
index 601f0d833..ab7d42e6f 100644
--- a/meilisearch-http/src/routes/indexes/settings.rs
+++ b/meilisearch-http/src/routes/indexes/settings.rs
@@ -21,11 +21,11 @@ macro_rules! make_setting_route {
             use meilisearch_lib::milli::update::Setting;
             use meilisearch_lib::{index::Settings, index_controller::Update, MeiliSearch};
 
-            use crate::analytics::Analytics;
-            use crate::extractors::authentication::{policies::*, GuardedData};
-            use crate::extractors::sequential_extractor::SeqHandler;
-            use crate::task::SummarizedTaskView;
             use meilisearch_error::ResponseError;
+            use $crate::analytics::Analytics;
+            use $crate::extractors::authentication::{policies::*, GuardedData};
+            use $crate::extractors::sequential_extractor::SeqHandler;
+            use $crate::task::SummarizedTaskView;
 
             pub async fn delete(
                 meilisearch: GuardedData<ActionPolicy<{ actions::SETTINGS_UPDATE }>, MeiliSearch>,
diff --git a/meilisearch-lib/src/index/search.rs b/meilisearch-lib/src/index/search.rs
index c63be6aab..8d7b900f5 100644
--- a/meilisearch-lib/src/index/search.rs
+++ b/meilisearch-lib/src/index/search.rs
@@ -4,7 +4,6 @@ use std::str::FromStr;
 use std::time::Instant;
 
 use either::Either;
-use indexmap::IndexMap;
 use milli::tokenizer::{Analyzer, AnalyzerConfig, Token};
 use milli::{AscDesc, FieldId, FieldsIdsMap, Filter, MatchingWords, SortError};
 use regex::Regex;
@@ -16,7 +15,7 @@ use crate::index::error::FacetError;
 use super::error::{IndexError, Result};
 use super::index::Index;
 
-pub type Document = IndexMap<String, Value>;
+pub type Document = serde_json::Map<String, Value>;
 type MatchesInfo = BTreeMap<String, Vec<MatchInfo>>;
 
 #[derive(Serialize, Debug, Clone, PartialEq)]
@@ -499,10 +498,6 @@ fn make_document(
         .map(|&fid| field_ids_map.name(fid).expect("Missing field name"));
 
     let document = permissive_json_pointer::select_values(&document, attributes_to_retrieve);
-
-    // then we need to convert the `serde_json::Map` into an `IndexMap`.
-    let document = document.into_iter().collect();
-
     Ok(document)
 }
 
@@ -513,12 +508,6 @@ fn format_fields<A: AsRef<[u8]>>(
     matching_words: &impl Matcher,
     formatted_options: &BTreeMap<FieldId, FormatOptions>,
 ) -> Result<Document> {
-    // Convert the `IndexMap` into a `serde_json::Map`.
-    let document = document
-        .iter()
-        .map(|(k, v)| (k.clone(), v.clone()))
-        .collect();
-
     let selectors: Vec<_> = formatted_options
         .keys()
         // This unwrap must be safe since we got the ids from the fields_ids_map just
@@ -526,7 +515,7 @@ fn format_fields<A: AsRef<[u8]>>(
         .map(|&fid| field_ids_map.name(fid).unwrap())
         .collect();
 
-    let mut document = permissive_json_pointer::select_values(&document, selectors.iter().copied());
+    let mut document = permissive_json_pointer::select_values(document, selectors.iter().copied());
 
     permissive_json_pointer::map_leaf_values(&mut document, selectors, |key, value| {
         // To get the formatting option of each key we need to see all the rules that applies
@@ -542,13 +531,9 @@ fn format_fields<A: AsRef<[u8]>>(
             .fold(FormatOptions::default(), |acc, (_, option)| {
                 acc.merge(*option)
             });
-        // TODO: remove this useless clone
-        *value = formatter.format_value(value.clone(), matching_words, format);
+        *value = formatter.format_value(std::mem::take(value), matching_words, format);
     });
 
-    // we need to convert back the `serde_json::Map` into an `IndexMap`.
-    let document = document.into_iter().collect();
-
     Ok(document)
 }