From a3578a6e60b845fb35c63537eec3a314fb9225ff Mon Sep 17 00:00:00 2001
From: Hadi Moshayedi <hadi@moshayedi.net>
Date: Wed, 21 Aug 2019 12:59:57 -0700
Subject: [PATCH] Sort load_shard_placement_array by worker name/port

---
 .../distributed/test/distribution_metadata.c  | 36 ++++++++++++++++++-
 .../expected/multi_distribution_metadata.out  |  4 +--
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/src/backend/distributed/test/distribution_metadata.c b/src/backend/distributed/test/distribution_metadata.c
index 4b959a435..8df36d56f 100644
--- a/src/backend/distributed/test/distribution_metadata.c
+++ b/src/backend/distributed/test/distribution_metadata.c
@@ -40,6 +40,11 @@
 #include "utils/palloc.h"
 
 
+/* forward declaration of local functions */
+static int CompareShardPlacementsByWorker(const void *leftElement,
+										  const void *rightElement);
+
+
 /* declarations for dynamic loading */
 PG_FUNCTION_INFO_V1(load_shard_id_array);
 PG_FUNCTION_INFO_V1(load_shard_interval_array);
@@ -143,7 +148,7 @@ load_shard_placement_array(PG_FUNCTION_ARGS)
 		placementList = ShardPlacementList(shardId);
 	}
 
-	placementList = SortList(placementList, CompareShardPlacements);
+	placementList = SortList(placementList, CompareShardPlacementsByWorker);
 
 	placementCount = list_length(placementList);
 	placementDatumArray = palloc0(placementCount * sizeof(Datum));
@@ -166,6 +171,35 @@ load_shard_placement_array(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * CompareShardPlacementsByWorker compares two shard placements by their
+ * worker node name and port.
+ */
+static int
+CompareShardPlacementsByWorker(const void *leftElement, const void *rightElement)
+{
+	const ShardPlacement *leftPlacement = *((const ShardPlacement **) leftElement);
+	const ShardPlacement *rightPlacement = *((const ShardPlacement **) rightElement);
+
+	int nodeNameCmp = strncmp(leftPlacement->nodeName, rightPlacement->nodeName,
+							  WORKER_LENGTH);
+	if (nodeNameCmp != 0)
+	{
+		return nodeNameCmp;
+	}
+	else if (leftPlacement->nodePort > rightPlacement->nodePort)
+	{
+		return 1;
+	}
+	else if (leftPlacement->nodePort < rightPlacement->nodePort)
+	{
+		return -1;
+	}
+
+	return 0;
+}
+
+
 /*
  * partition_column_id simply finds a distributed table using the provided Oid
  * and returns the column_id of its partition column. If the specified table is
diff --git a/src/test/regress/expected/multi_distribution_metadata.out b/src/test/regress/expected/multi_distribution_metadata.out
index ca7f8bb58..1d5e4f849 100644
--- a/src/test/regress/expected/multi_distribution_metadata.out
+++ b/src/test/regress/expected/multi_distribution_metadata.out
@@ -109,7 +109,7 @@ ERROR:  could not find valid entry for shard 540005
 SELECT load_shard_placement_array(540001, false);
     load_shard_placement_array     
 -----------------------------------
- {localhost:57638,localhost:57637}
+ {localhost:57637,localhost:57638}
 (1 row)
 
 -- only one of which is finalized
@@ -123,7 +123,7 @@ SELECT load_shard_placement_array(540001, true);
 SELECT load_shard_placement_array(540001, false);
     load_shard_placement_array     
 -----------------------------------
- {localhost:57638,localhost:57637}
+ {localhost:57637,localhost:57638}
 (1 row)
 
 -- should see column id of 'name'