From 572fb3a51d76d0e92d7e0841e770758757509106 Mon Sep 17 00:00:00 2001
From: Louis Dureuil <louis@meilisearch.com>
Date: Wed, 27 Mar 2024 11:48:00 +0100
Subject: [PATCH] Finer granularity for embedder needs reindex

---
 milli/src/update/settings.rs |  7 ++++-
 milli/src/vector/settings.rs | 60 ++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/milli/src/update/settings.rs b/milli/src/update/settings.rs
index 9f47768c1..b784b3f92 100644
--- a/milli/src/update/settings.rs
+++ b/milli/src/update/settings.rs
@@ -976,7 +976,12 @@ impl<'a, 't, 'i> Settings<'a, 't, 'i> {
                     match joined {
                         // updated config
                         EitherOrBoth::Both((name, mut old), (_, new)) => {
-                            changed |= old.apply(new);
+                            changed |= EmbeddingSettings::apply_and_need_reindex(&mut old, new);
+                            if changed {
+                                tracing::debug!(embedder = name, "need reindex");
+                            } else {
+                                tracing::debug!(embedder = name, "skip reindex");
+                            }
                             let new = validate_embedding_settings(old, &name)?;
                             new_configs.insert(name, new);
                         }
diff --git a/milli/src/vector/settings.rs b/milli/src/vector/settings.rs
index 78f83cbea..18a86368f 100644
--- a/milli/src/vector/settings.rs
+++ b/milli/src/vector/settings.rs
@@ -210,6 +210,66 @@ impl EmbeddingSettings {
             *model = Setting::Set(openai::EmbeddingModel::default().name().to_owned())
         }
     }
+
+    pub(crate) fn apply_and_need_reindex(
+        old: &mut Setting<EmbeddingSettings>,
+        new: Setting<EmbeddingSettings>,
+    ) -> bool {
+        match (old, new) {
+            (
+                Setting::Set(EmbeddingSettings {
+                    source: old_source,
+                    model: old_model,
+                    revision: old_revision,
+                    api_key: old_api_key,
+                    dimensions: old_dimensions,
+                    document_template: old_document_template,
+                    url: old_url,
+                    query: old_query,
+                    input_field: old_input_field,
+                    path_to_embeddings: old_path_to_embeddings,
+                    embedding_object: old_embedding_object,
+                    input_type: old_input_type,
+                    distribution: old_distribution,
+                }),
+                Setting::Set(EmbeddingSettings {
+                    source: new_source,
+                    model: new_model,
+                    revision: new_revision,
+                    api_key: new_api_key,
+                    dimensions: new_dimensions,
+                    document_template: new_document_template,
+                    url: new_url,
+                    query: new_query,
+                    input_field: new_input_field,
+                    path_to_embeddings: new_path_to_embeddings,
+                    embedding_object: new_embedding_object,
+                    input_type: new_input_type,
+                    distribution: new_distribution,
+                }),
+            ) => {
+                let mut needs_reindex = false;
+
+                needs_reindex |= old_source.apply(new_source);
+                needs_reindex |= old_model.apply(new_model);
+                needs_reindex |= old_revision.apply(new_revision);
+                needs_reindex |= old_dimensions.apply(new_dimensions);
+                needs_reindex |= old_document_template.apply(new_document_template);
+                needs_reindex |= old_url.apply(new_url);
+                needs_reindex |= old_query.apply(new_query);
+                needs_reindex |= old_input_field.apply(new_input_field);
+                needs_reindex |= old_path_to_embeddings.apply(new_path_to_embeddings);
+                needs_reindex |= old_embedding_object.apply(new_embedding_object);
+                needs_reindex |= old_input_type.apply(new_input_type);
+
+                old_distribution.apply(new_distribution);
+                old_api_key.apply(new_api_key);
+                needs_reindex
+            }
+            (Setting::Reset, Setting::Reset) | (_, Setting::NotSet) => false,
+            _ => true,
+        }
+    }
 }
 
 #[derive(Debug, Clone, Copy, Default, Serialize, Deserialize, PartialEq, Eq, Deserr)]