diff --git a/app/services/git/providers/gitlab.rb b/app/services/git/providers/gitlab.rb
index 5a0f0a921..61303c52f 100644
--- a/app/services/git/providers/gitlab.rb
+++ b/app/services/git/providers/gitlab.rb
@@ -8,35 +8,46 @@ def url
   end
 
   def create_file(path, content)
+    new_path_file = tree_item_at_path(path)
+    action = new_path_file.nil? ? 'create' : 'update'
+
     batch << {
-      action: 'create',
+      action: action,
       file_path: path,
       content: content
     }
   end
 
   def update_file(path, previous_path, content)
-    file = find previous_path
-    if file.present? && previous_path != path
+    previous_path_file = tree_item_at_path(previous_path)
+    new_path_file = tree_item_at_path(path)
+    # En cas de dissonnance entre l'analyzer et le provider, on raise une erreur
+    if previous_path_file.nil? && new_path_file.nil?
+      raise "File to update does not exist on Git (repository: #{repository}, previous_path: #{previous_path}, path: #{path})"
+    end
+
+    # We will remove file at previous path and create or update it at new path
+    if previous_path != path && previous_path_file.present?
       batch << {
-        action: 'move',
-        file_path: path,
-        previous_path: previous_path
+        action: 'delete',
+        file_path: previous_path
       }
     end
+
+    action = new_path_file.present? ? 'update' : 'create'
     batch << {
-      action: 'update',
+      action: action,
       file_path: path,
       content: content
     }
   end
 
   def destroy_file(path)
-    file = find path
+    file = tree_item_at_path(path)
     return if file.nil?
     batch << {
       action: 'delete',
-      file_path: path,
+      file_path: path
     }
   end
 
@@ -58,23 +69,25 @@ def push(commit_message)
                           branch,
                           commit_message,
                           batch
+    # The repo changed, invalidate the tree
+    @tree = nil
+    @tree_items_by_path = nil
+    #
     true
   end
 
   def computed_sha(string)
-    OpenSSL::Digest::SHA256.hexdigest string
+    # Git SHA-1 is calculated from the String "blob <length>\x00<contents>"
+    # Source: https://alblue.bandlem.com/2011/08/git-tip-of-week-objects.html
+    OpenSSL::Digest::SHA1.hexdigest "blob #{string.bytesize}\x00#{string}"
   end
 
   # https://gitlab.com/gitlab-org/gitlab/-/issues/23504
   # TODO : Il faudrait, comme sur GitHub, stocker le tree pour éviter N requêtes pour N objets.
   def git_sha(path)
-    begin
-      file = find path
-      sha = file['content_sha256']
-    rescue
-      sha = nil
-    end
-    sha
+    return if path.nil?
+    # Try to find in stored tree to avoid multiple queries
+    tree_item_at_path(path)&.dig(:sha)
   end
 
   def valid?
@@ -89,22 +102,15 @@ def valid?
   end
 
   def branch
-    super.present?  ? super
-                    : 'main'
+    super.presence || 'main'
   end
 
-  # TODO
   def files_in_the_repository
-    super
+    @files_in_the_repository ||= tree.map { |file| file[:path] }
   end
 
   protected
 
-  def endpoint
-    @endpoint.blank?  ? DEFAULT_ENDPOINT
-                      : @endpoint
-  end
-
   def client
     @client ||= Gitlab.client(
       endpoint: endpoint,
@@ -112,6 +118,11 @@ def client
     )
   end
 
+  def endpoint
+    @endpoint.blank?  ? DEFAULT_ENDPOINT
+                      : @endpoint
+  end
+
   def find(path)
     client.get_file repository,
                     path,
@@ -120,4 +131,31 @@ def find(path)
     nil
   end
 
+  def tree_item_at_path(path)
+    tree_items_by_path[path] if tree_items_by_path.has_key? path
+  end
+
+  def tree_items_by_path
+    unless @tree_items_by_path
+      @tree_items_by_path = {}
+      tree.each do |hash|
+        path = hash["path"]
+        @tree_items_by_path[path] = {
+          mode: hash["mode"],
+          type: hash["type"],
+          sha: hash["id"]
+        }
+      end
+    end
+    @tree_items_by_path
+  end
+
+  def tree
+    @tree ||= client.tree(repository, {
+      ref: branch,
+      recursive: true,
+      per_page: 100
+    }).auto_paginate
+  end
+
 end