From cbc5af2b5b7902ebcad1153d86bbe2df2b5dd26b Mon Sep 17 00:00:00 2001
From: Thorsten Eckel <te@znuny.com>
Date: Fri, 5 May 2017 10:48:40 +0200
Subject: [PATCH] Working on issue #981 - Improved performance to search only
 needed arguments of a LDAP entry.

---
 lib/import/ldap/user_factory.rb | 8 +++++++-
 lib/ldap.rb                     | 4 +++-
 lib/ldap/group.rb               | 4 ++--
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/lib/import/ldap/user_factory.rb b/lib/import/ldap/user_factory.rb
index edd1b8a5c..2cdc8cf1c 100644
--- a/lib/import/ldap/user_factory.rb
+++ b/lib/import/ldap/user_factory.rb
@@ -24,7 +24,13 @@ module Import
 
         import_job       = kargs[:import_job]
         import_job_count = 0
-        @ldap.search(config[:user_filter]) do |entry|
+
+        # limit the fetched attributes for an entry to only
+        # those which are needed to improve the performance
+        relevant_attributes = config[:user_attributes].keys
+        relevant_attributes.push('dn')
+
+        @ldap.search(config[:user_filter], attributes: relevant_attributes) do |entry|
           backend_instance = create_instance(entry, config, user_roles, signup_role_ids, kargs)
           post_import_hook(entry, backend_instance, config, user_roles, signup_role_ids, kargs)
 
diff --git a/lib/ldap.rb b/lib/ldap.rb
index f96398c08..461cd025c 100644
--- a/lib/ldap.rb
+++ b/lib/ldap.rb
@@ -54,6 +54,7 @@ class Ldap
   # @param filter [String] The filter that should get applied to the search.
   # @param base [String] The base DN on which the search should get executed. Default is initialization parameter.
   # @param scope [Net::LDAP::SearchScope] The search scope as defined in Net::LDAP SearchScopes. Default is WholeSubtree.
+  # @param attributes [Array<String>] Limits the requested entry attributes to the given list of attributes which increses the performance.
   #
   # @example
   #  ldap.search('(objectClass=group)') do |entry|
@@ -62,7 +63,7 @@ class Ldap
   #  #=> <Net::LDAP::Entry...>
   #
   # @return [true] Returns always true
-  def search(filter, base: nil, scope: nil)
+  def search(filter, base: nil, scope: nil, attributes: nil)
 
     base  ||= base_dn()
     scope ||= Net::LDAP::SearchScope_WholeSubtree
@@ -71,6 +72,7 @@ class Ldap
       base:          base,
       filter:        filter,
       scope:         scope,
+      attributes:    attributes,
       return_result: false, # improves performance
     ) do |entry|
       # needed for the #entries? method -> returns nil on break
diff --git a/lib/ldap/group.rb b/lib/ldap/group.rb
index d7c5f2bf7..eb3a10cc7 100644
--- a/lib/ldap/group.rb
+++ b/lib/ldap/group.rb
@@ -58,7 +58,7 @@ class Ldap
       return {} if filter.blank?
 
       groups = {}
-      @ldap.search(filter, base: base_dn) { |entry|
+      @ldap.search(filter, base: base_dn, attributes: %w(dn)) { |entry|
         groups[entry.dn.downcase] = entry.dn.downcase
       }
       groups
@@ -80,7 +80,7 @@ class Ldap
       filter ||= filter()
 
       result = {}
-      @ldap.search(filter) do |entry|
+      @ldap.search(filter, attributes: %w(dn member)) do |entry|
 
         members = entry[:member]
         next if members.blank?