From 25e960441b2377cfde984da60080f9febfbfba52 Mon Sep 17 00:00:00 2001
From: Mike Dirolf <mike@10gen.com>
Date: Tue, 2 Jun 2009 11:24:52 -0400
Subject: [PATCH] API CHANGE: better, less redundant API for index_information

---
 lib/mongo/collection.rb | 12 ++++--------
 lib/mongo/db.rb         | 31 +++++++++----------------------
 tests/test_db_api.rb    | 27 +++++++++++++--------------
 3 files changed, 26 insertions(+), 44 deletions(-)

diff --git a/lib/mongo/collection.rb b/lib/mongo/collection.rb
index d54d7f0..2d23b91 100644
--- a/lib/mongo/collection.rb
+++ b/lib/mongo/collection.rb
@@ -190,14 +190,10 @@ EOS
                                    }))["result"]
         end
 
-        # Return an array of hashes, one for each index. Each hash contains:
-        #
-        # :name :: Index name
-        #
-        # :keys :: Hash whose keys are the names of the fields that make up
-        #          the key and values are integers.
-        #
-        # :ns :: Namespace; same as this collection's name.
+        # Get information on the indexes for the collection +collection_name+.
+        # Returns a hash where the keys are index names (as returned by
+        # Collection#create_index and the values are lists of [key, direction]
+        # pairs specifying the index (as passed to Collection#create_index).
         def index_information
           @db.index_information(@name)
         end
diff --git a/lib/mongo/db.rb b/lib/mongo/db.rb
index 78bb5b1..69c9494 100644
--- a/lib/mongo/db.rb
+++ b/lib/mongo/db.rb
@@ -425,31 +425,18 @@ module XGen
           raise "Error with drop_index command: #{doc.inspect}" unless ok?(doc)
         end
 
-        # Return an array of hashes, one for each index on +collection_name+.
-        # Normally called by Collection#index_information. Each hash contains:
-        #
-        # :name :: Index name
-        #
-        # :keys :: Hash whose keys are the names of the fields that make up
-        #          the key and values are integers.
-        #
-        # :ns :: Namespace; same as +collection_name+.
+        # Get information on the indexes for the collection +collection_name+.
+        # Normally called by Collection#index_information. Returns a hash where
+        # the keys are index names (as returned by Collection#create_index and
+        # the values are lists of [key, direction] pairs specifying the index
+        # (as passed to Collection#create_index).
         def index_information(collection_name)
           sel = {:ns => full_coll_name(collection_name)}
-          query(Collection.new(self, SYSTEM_INDEX_COLLECTION), Query.new(sel)).collect { |row|
-            h = {:name => row['name']}
-            raise "Name of index on return from db was nil. Coll = #{full_coll_name(collection_name)}" unless h[:name]
-
-            h[:keys] = row['key']
-            raise "Keys for index on return from db was nil. Coll = #{full_coll_name(collection_name)}" unless h[:keys]
-
-            h[:ns] = row['ns']
-            raise "Namespace for index on return from db was nil. Coll = #{full_coll_name(collection_name)}" unless h[:ns]
-            h[:ns].sub!(/.*\./, '')
-            raise "Error: ns != collection" unless h[:ns] == collection_name
-
-            h
+          info = {}
+          query(Collection.new(self, SYSTEM_INDEX_COLLECTION), Query.new(sel)).each { |index|
+            info[index['name']] = index['key'].to_a
           }
+          info
         end
 
         # Create a new index on +collection_name+. +field_or_spec+
diff --git a/tests/test_db_api.rb b/tests/test_db_api.rb
index 8547aac..8403bd5 100644
--- a/tests/test_db_api.rb
+++ b/tests/test_db_api.rb
@@ -282,29 +282,28 @@ class DBAPITest < Test::Unit::TestCase
   end
 
   def test_index_information
-    name = @@db.create_index(@@coll.name, 'a')
-    list = @@db.index_information(@@coll.name)
-    assert_equal @@coll.index_information, list
-    assert_equal 2, list.length
+    assert_equal @@coll.index_information.length, 1
 
-    info = list[1]
-    assert_equal name, 'a_1'
-    assert_equal name, info[:name]
-    assert_equal 1, info[:keys]['a']
+    name = @@db.create_index(@@coll.name, 'a')
+    info = @@db.index_information(@@coll.name)
+    assert_equal name, "a_1"
+    assert_equal @@coll.index_information, info
+    assert_equal 2, info.length
+
+    assert info.has_key? name
+    assert_equal info[name], [["a", ASCENDING]]
   ensure
     @@db.drop_index(@@coll.name, name)
   end
 
   def test_multiple_index_cols
     name = @@db.create_index(@@coll.name, [['a', DESCENDING], ['b', ASCENDING], ['c', DESCENDING]])
-    list = @@db.index_information(@@coll.name)
-    assert_equal 2, list.length
+    info = @@db.index_information(@@coll.name)
+    assert_equal 2, info.length
 
-    info = list[1]
     assert_equal name, 'a_-1_b_1_c_-1'
-    assert_equal name, info[:name]
-    keys = info[:keys].keys
-    assert_equal ['a', 'b', 'c'], keys.sort
+    assert info.has_key? name
+    assert_equal [['a', DESCENDING], ['b', ASCENDING], ['c', DESCENDING]], info[name]
   ensure
     @@db.drop_index(@@coll.name, name)
   end