Move changes since API from streaming to non-streaming

Summary:
# Context

We are introducing EdenFS notifications to support scalable and ergonomic file system notifications for EdenFS mounts.

# This Diff

This diff moves the changes since API from the streaming interface to the non-streaming interface.

# Next Steps

* Collapsing journal entries
* .t tests, Python integration tests, C++ unit tests

# Discussion Points

None

Differential Revision: D66039653

fbshipit-source-id: 3d884bed0c632e59739433b8e372ad0601a0089f

third-party/watchman/src/eden/fs/service/eden.thrift

@@ -1753,7 +1753,7 @@ union CheckoutProgressInfoResponse {
 }
 
 /*
- * Structs/Unionts for changesSince API
+ * Structs/Unions for changesSinceV2 API
  */
 struct Added {
   1: Dtype fileType;
@@ -1810,6 +1810,22 @@ union ChangeNotification {
   2: LargeChangeNotification largeChange;
 }
 
+/**
+ * Return value of the changesSinceV2 API
+ */
+struct ChangesSinceV2Result {
+  1: JournalPosition toPosition;
+  2: list<ChangeNotification> changes;
+}
+
+/**
+ * Argument to changesSinceV2 API
+ */
+struct ChangesSinceV2Params {
+  1: PathString mountPoint;
+  2: JournalPosition fromPosition;
+}
+
 service EdenService extends fb303_core.BaseService {
   list<MountInfo> listMounts() throws (1: EdenError ex);
   void mount(1: MountArgument info) throws (1: EdenError ex);
@@ -2646,6 +2662,17 @@ service EdenService extends fb303_core.BaseService {
   void ensureMaterialized(1: EnsureMaterializedParams params) throws (
     1: EdenError ex,
   );
+
+  /**
+   * Returns a list of change notifications along with a new journal position for a given mount
+   * since a specific journal position.
+   *
+   * This does not resolve expensive operations like moving a directory or changing
+   * commits. Callers must query Sapling to evaluate those potentially expensive operations.
+   */
+  ChangesSinceV2Result changesSinceV2(1: ChangesSinceV2Params params) throws (
+    1: EdenError ex,
+  );
 }
 
 // The following were automatically generated and may benefit from renaming.

third-party/watchman/src/eden/fs/service/streamingeden.thrift

@@ -82,23 +82,6 @@ struct ChangesSinceResult {
   1: eden.JournalPosition toPosition;
 }
 
-/**
- * The value of a stream item in a streamChangedSinceV2 result stream.
- *
- * Each stream item refers to a single change notification
- * since the notification clock provided.
- */
-struct ChangeNotificationResult {
-  1: eden.ChangeNotification change;
-}
-
-/**
- * Return value of the streamChangedSinceV2 API
- */
-struct ChangesSinceV2Result {
-  1: eden.JournalPosition toPosition;
-}
-
 /**
  * Argument to streamChangesSince API.
  */
@@ -115,14 +98,6 @@ struct StreamSelectedChangesSinceParams {
   2: list<string> globs;
 }
 
-/**
- * Argument to streamChangedSinceV2 API
- */
-struct StreamChangesSinceV2Params {
-  1: eden.PathString mountPoint;
-  2: eden.JournalPosition fromPosition;
-}
-
 struct TraceTaskEventsRequest {}
 
 typedef binary EdenStartStatusUpdate
@@ -221,18 +196,6 @@ service StreamingEdenService extends eden.EdenService {
     1: eden.EdenError ex,
   );
 
-  /**
-   * Returns a stream of change notifications for a given path since a specific point in time.
-   *
-   * This does not resolve expensive operations like moving a directory or changing
-   * commits. Callers must query Sapling to evaluate those potentially expensive operations.
-   */
-  ChangesSinceV2Result, stream<
-    ChangeNotificationResult throws (1: eden.EdenError ex)
-  > streamChangesSinceV2(1: StreamChangesSinceV2Params params) throws (
-    1: eden.EdenError ex,
-  );
-
   /**
    * Same as the API above but only returns files that match the globs in filter.
    * This API is intend to replace the above API but it's currently under development.