add unsend request proto

libsession/src/main/java/org/session/libsession/messaging/messages/control/UnsendRequest.kt

@@ -0,0 +1,55 @@
+package org.session.libsession.messaging.messages.control
+
+import org.session.libsignal.protos.SignalServiceProtos
+import org.session.libsignal.utilities.Log
+
+class UnsendRequest(): ControlMessage() {
+    var timestamp: Long? = null
+    var author: String? = null
+
+    override val isSelfSendValid: Boolean = true
+
+    // region Validation
+    override fun isValid(): Boolean {
+        if (!super.isValid()) return false
+        return timestamp != null && author != null
+    }
+    // endregion
+
+    companion object {
+        const val TAG = "UnsendRequest"
+
+        fun fromProto(proto: SignalServiceProtos.Content): UnsendRequest? {
+            val unsendRequestProto = if (proto.hasUnsendRequest()) proto.unsendRequest else return null
+            val timestamp = unsendRequestProto.timestamp
+            val author = unsendRequestProto.author
+            return UnsendRequest(timestamp, author)
+        }
+    }
+
+    constructor(timestamp: Long, author: String) : this() {
+        this.timestamp = timestamp
+        this.author = author
+    }
+
+    override fun toProto(): SignalServiceProtos.Content? {
+        val timestamp = timestamp
+        val author = author
+        if (timestamp == null || author == null) {
+            Log.w(TAG, "Couldn't construct unsend request proto from: $this")
+            return null
+        }
+        val unsendRequestProto = SignalServiceProtos.UnsendRequest.newBuilder()
+        unsendRequestProto.timestamp = timestamp
+        unsendRequestProto.author = author
+        val contentProto = SignalServiceProtos.Content.newBuilder()
+        try {
+            contentProto.unsendRequest = unsendRequestProto.build()
+            return contentProto.build()
+        } catch (e: Exception) {
+            Log.w(TAG, "Couldn't construct unsend request proto from: $this")
+            return null
+        }
+    }
+
+}

libsignal/protobuf/SignalService.proto

@@ -35,12 +35,20 @@ message TypingMessage {
     required Action action    = 2;
 }
 
+message UnsendRequest {
+  // @required
+  required uint64 timestamp = 1;
+  // @required
+  required string author    = 2;
+}
+
 message Content {
   optional DataMessage                dataMessage                = 1;
   optional ReceiptMessage             receiptMessage             = 5;
   optional TypingMessage              typingMessage              = 6;
   optional ConfigurationMessage       configurationMessage       = 7;
   optional DataExtractionNotification dataExtractionNotification = 8;
+  optional UnsendRequest              unsendRequest              = 9;
 }
 
 message KeyPair {