SERVER-35899 Have mongos produce an aggregation plan that correctly uses an $exchange.

1 files changed, 76 insertions, 0 deletions

diff --git a/src/mongo/db/pipeline/exchange_spec.idl b/src/mongo/db/pipeline/exchange_spec.idl
new file mode 100644
index 00000000000..c400a427226
--- /dev/null
+++ b/src/mongo/db/pipeline/exchange_spec.idl
@@ -0,0 +1,76 @@
+# Copyright (C) 2018 MongoDB Inc.
+#
+# This program is free software: you can redistribute it and/or  modify
+# it under the terms of the GNU Affero General Public License, version 3,
+# as published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# As a special exception, the copyright holders give permission to link the
+# code of portions of this program with the OpenSSL library under certain
+# conditions as described in each individual source file and distribute
+# linked combinations including the program with the OpenSSL library. You
+# must comply with the GNU Affero General Public License in all respects for
+# all of the code used other than as permitted herein. If you modify file(s)
+# with this exception, you may extend this exception to your version of the
+# file(s), but you are not obligated to do so. If you do not wish to do so,
+# delete this exception statement from your version. If you delete this
+# exception statement from all source files in the program, then also delete
+# it in the license file.
+
+# Document source exchange stage IDL file
+
+global:
+   cpp_namespace: "mongo"
+
+imports:
+    - "mongo/idl/basic_types.idl"
+
+enums:
+    ExchangePolicy:
+        description: "The type of an exchange distribution policy"
+        type: string
+        values:
+            kBroadcast: "broadcast"
+            kRoundRobin: "roundrobin"
+            kRange: "range"
+            kHash: "hash"
+
+structs:
+  ExchangeSpec:
+    description: "exchange aggregation request specification"
+    fields:
+      policy:
+        type: ExchangePolicy
+        description: A string indicating a policy of how documents are distributed to consumers.
+      consumers:
+        type: int
+        description: Number of consumers.
+      orderPreserving:
+        type: bool
+        default: false
+        description: A flag indicating documents are merged while preserving the order.
+      bufferSize:
+        type: int
+        default: 16777216
+        description: The size of exchange buffers.
+      key:
+        type: object
+        default: "BSONObj()"
+        description: A key used for document distribution to consumers. The same description as
+                     sorting/sharding.
+      boundaries:
+        type: array<object>
+        optional: true
+        description: Range/hash split points.
+      consumerIds:
+        type: array<int>
+        optional: true
+        description: Mapping from a range index to a consumer id.
+