From 28a007449703f8cdf66e32da84e53632cbab75ed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Renault?= <renault.cle@gmail.com>
Date: Tue, 25 Jun 2019 11:21:12 +0200
Subject: [PATCH] feat: Expose a function to compute the DocumentId from an
 Hashable value

---
 meilidb-data/src/lib.rs                       |  1 +
 meilidb-data/src/serde/extract_document_id.rs | 13 +++++++------
 meilidb-data/src/serde/mod.rs                 |  2 +-
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/meilidb-data/src/lib.rs b/meilidb-data/src/lib.rs
index cb8a7dc9f..4d9719370 100644
--- a/meilidb-data/src/lib.rs
+++ b/meilidb-data/src/lib.rs
@@ -9,3 +9,4 @@ pub use rocksdb;
 pub use self::database::{Database, Index, CustomSettings};
 pub use self::number::Number;
 pub use self::ranked_map::RankedMap;
+pub use self::serde::compute_document_id;
diff --git a/meilidb-data/src/serde/extract_document_id.rs b/meilidb-data/src/serde/extract_document_id.rs
index 990094104..3ec2c200b 100644
--- a/meilidb-data/src/serde/extract_document_id.rs
+++ b/meilidb-data/src/serde/extract_document_id.rs
@@ -16,10 +16,11 @@ where D: serde::Serialize,
     document.serialize(serializer)
 }
 
-fn calculate_hash<T: Hash>(t: &T) -> u64 {
+pub fn compute_document_id<T: Hash>(t: &T) -> DocumentId {
     let mut s = SipHasher::new();
     t.hash(&mut s);
-    s.finish()
+    let hash = s.finish();
+    DocumentId(hash)
 }
 
 struct ExtractDocumentId<'a> {
@@ -214,8 +215,8 @@ impl<'a> ser::SerializeMap for ExtractDocumentIdMapSerializer<'a> {
         if self.identifier == key {
             // TODO is it possible to have multiple ids?
             let id = bincode::serialize(value).unwrap();
-            let hash = calculate_hash(&id);
-            self.document_id = Some(DocumentId(hash));
+            let document_id = compute_document_id(&id);
+            self.document_id = Some(document_id);
         }
 
         Ok(())
@@ -245,8 +246,8 @@ impl<'a> ser::SerializeStruct for ExtractDocumentIdStructSerializer<'a> {
         if self.identifier == key {
             // TODO can it be possible to have multiple ids?
             let id = bincode::serialize(value).unwrap();
-            let hash = calculate_hash(&id);
-            self.document_id = Some(DocumentId(hash));
+            let document_id = compute_document_id(&id);
+            self.document_id = Some(document_id);
         }
 
         Ok(())
diff --git a/meilidb-data/src/serde/mod.rs b/meilidb-data/src/serde/mod.rs
index b536c63cc..9ffa619ed 100644
--- a/meilidb-data/src/serde/mod.rs
+++ b/meilidb-data/src/serde/mod.rs
@@ -16,7 +16,7 @@ mod indexer;
 mod serializer;
 
 pub use self::deserializer::Deserializer;
-pub use self::extract_document_id::extract_document_id;
+pub use self::extract_document_id::{extract_document_id, compute_document_id};
 pub use self::convert_to_string::ConvertToString;
 pub use self::convert_to_number::ConvertToNumber;
 pub use self::indexer::Indexer;