From 1228c2948d8ce2f8e31d38c0bd97c80991e81485 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Renault?= <clement@meilisearch.com>
Date: Wed, 28 Oct 2020 11:17:36 +0100
Subject: [PATCH] Add a comment about the ClearDocuments operation in the
 DeleteDocuments

---
 src/subcommand/serve.rs           | 4 +---
 src/update/delete_documents.rs    | 5 +++++
 src/update/index_documents/mod.rs | 2 ++
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/subcommand/serve.rs b/src/subcommand/serve.rs
index 379bb68db..471a1da52 100644
--- a/src/subcommand/serve.rs
+++ b/src/subcommand/serve.rs
@@ -264,9 +264,7 @@ pub fn run(opt: Opt) -> anyhow::Result<()> {
 
             let meta = match result {
                 Ok(()) => format!("valid update content"),
-                Err(e) => {
-                    format!("error while processing update content: {}", e)
-                }
+                Err(e) => format!("error while processing update content: {:?}", e),
             };
 
             let processed = UpdateStatus::Processed { update_id, meta: meta.clone() };
diff --git a/src/update/delete_documents.rs b/src/update/delete_documents.rs
index 6a5d02068..b72140791 100644
--- a/src/update/delete_documents.rs
+++ b/src/update/delete_documents.rs
@@ -57,6 +57,11 @@ impl<'t, 'u, 'i> DeleteDocuments<'t, 'u, 'i> {
         documents_ids.intersect_with(&self.documents_ids);
         self.index.put_documents_ids(self.wtxn, &documents_ids)?;
 
+        // TODO we should be able to execute a ClearDocuments operation when the number of documents
+        //      to delete is exactly the number of documents in the database, however it seems that
+        //      clearing a database in LMDB requires a commit for it to be effective, we can't clear
+        //      and assume that the database is empty in the same wtxn or something.
+
         let fields_ids_map = self.index.fields_ids_map(self.wtxn)?;
         let id_field = fields_ids_map.id("id").expect(r#"the field "id" to be present"#);
 
diff --git a/src/update/index_documents/mod.rs b/src/update/index_documents/mod.rs
index d8ffbca43..1b3b1d36c 100644
--- a/src/update/index_documents/mod.rs
+++ b/src/update/index_documents/mod.rs
@@ -398,6 +398,8 @@ impl<'t, 'u, 'i> IndexDocuments<'t, 'u, 'i> {
             WriteMethod::Append
         };
 
+        debug!("Writing using the write method: {:?}", write_method);
+
         // We write the fields ids map into the main database
         self.index.put_fields_ids_map(self.wtxn, &fields_ids_map)?;