[geary/mjog/invert-folder-class-hierarchy: 69/72] engine: Allow endpoints to be specified for RemoteFolder.expand vector

[Michael Gratton <mjog src gnome org>]

commit 46188c7413e45f5d21981423cdea4c8973418661
Author: Michael Gratton <mike vee net>
Date:   Wed Mar 3 20:56:04 2021 +1100

    engine: Allow endpoints to be specified for RemoteFolder.expand vector
    
    Allow callers to specify either or both a minimum number and a date by
    which to expand a remote folder's vector from the remote. Implement in
    `MinimalFolder` using new `ExpandVector` replay op.

 src/engine/api/geary-remote-folder.vala            |  9 +++-
 .../imap-engine/imap-engine-minimal-folder.vala    | 53 ++++++++++++++++++++--
 test/mock/mock-remote-folder.vala                  |  9 +++-
 3 files changed, 65 insertions(+), 6 deletions(-)
---
diff --git a/src/engine/api/geary-remote-folder.vala b/src/engine/api/geary-remote-folder.vala
index 1d5497579..e280289e7 100644
--- a/src/engine/api/geary-remote-folder.vala
+++ b/src/engine/api/geary-remote-folder.vala
@@ -160,10 +160,17 @@ public interface Geary.RemoteFolder : Folder {
      * connection to the server, having the remote folder open, and so
      * on.
      *
+     * The vector will be attempted to be extended back to both the
+     * date (if given) and by the number of email messages (if
+     * given). If neither are specified no attempt will be made to
+     * expand the vector.
+     *
      * This method requires the host is online, an error will be
      * thrown if the remote server cannot be reached.
      */
-    public abstract async void expand_vector(GLib.Cancellable? cancellable)
+    public abstract async void expand_vector(GLib.DateTime? target_date,
+                                             uint? target_count,
+                                             GLib.Cancellable? cancellable)
         throws GLib.Error;
 
 }
diff --git a/src/engine/imap-engine/imap-engine-minimal-folder.vala 
b/src/engine/imap-engine/imap-engine-minimal-folder.vala
index a3c05b188..e32981c41 100644
--- a/src/engine/imap-engine/imap-engine-minimal-folder.vala
+++ b/src/engine/imap-engine/imap-engine-minimal-folder.vala
@@ -39,7 +39,8 @@ private class Geary.ImapEngine.MinimalFolder : BaseObject,
     [Flags]
     private enum OpenReason {
         MONITOR,
-        SYNCHRONISE;
+        SYNCHRONISE,
+        EXPAND_VECTOR,
     }
 
 
@@ -215,9 +216,23 @@ private class Geary.ImapEngine.MinimalFolder : BaseObject,
     }
 
     /** {@inheritDoc} */
-    public async void expand_vector(GLib.Cancellable? cancellable)
+    public async void expand_vector(GLib.DateTime? target_date,
+                                    uint? target_count,
+                                    GLib.Cancellable? cancellable)
         throws GLib.Error {
-
+        if (target_date != null || target_count != null) {
+            if (!(OpenReason.EXPAND_VECTOR in this.remote_opens)) {
+                this.remote_opens |= SYNCHRONISE;
+                try {
+                    yield expand_vector_impl(
+                        target_date, target_count, cancellable
+                    );
+                } finally {
+                    this.remote_opens &= ~OpenReason.EXPAND_VECTOR;
+                    yield check_remote_session();
+                }
+            }
+        }
     }
 
     /**
@@ -1313,6 +1328,38 @@ private class Geary.ImapEngine.MinimalFolder : BaseObject,
         return op.created_id;
     }
 
+    /**
+     * Expands the owning folder's vector.
+     */
+    private async void expand_vector_impl(GLib.DateTime? target_date,
+                                          uint? target_count,
+                                          GLib.Cancellable cancellable
+    ) throws GLib.Error {
+        var remote = yield claim_remote_session(cancellable);
+
+        // include marked for removed in the count in case this is
+        // being called while a removal is in process, in which case
+        // don't want to expand vector this moment because the vector
+        // is in flux
+        int local_count = yield this.local_folder.get_email_count_async(
+            INCLUDE_MARKED_FOR_REMOVE, cancellable
+        );
+
+        // watch out for attempts to expand vector when it's expanded
+        // as far as it will go
+        if (remote.folder.properties.email_total > local_count) {
+            var op = new ExpandVector(
+                this,
+                this._account.local.required_email_fields,
+                target_date,
+                target_count,
+                cancellable
+            );
+            this.replay_queue.schedule(op);
+            yield op.wait_for_ready_async(cancellable);
+        }
+    }
+
     /**
      * Checks for changes to {@link EmailFlags} after a folder opens.
      */
diff --git a/test/mock/mock-remote-folder.vala b/test/mock/mock-remote-folder.vala
index 74a700084..e64493ad6 100644
--- a/test/mock/mock-remote-folder.vala
+++ b/test/mock/mock-remote-folder.vala
@@ -186,9 +186,14 @@ public class Mock.RemoteFolder : GLib.Object,
         yield void_call_async("synchronise", { cancellable });
     }
 
-    public async void expand_vector(GLib.Cancellable? cancellable)
+    public async void expand_vector(GLib.DateTime? target_date,
+                                    uint? target_count,
+                                    GLib.Cancellable? cancellable)
         throws GLib.Error {
-        yield void_call_async("expand_vector", { cancellable });
+        yield void_call_async(
+            "expand_vector",
+            { box_arg(target_date), box_arg(target_count), cancellable }
+        );
     }
 
     public virtual Geary.Logging.State to_logging_state() {