compare cached messages with new ones asap, continue only if necessary

app/src/main/kotlin/com/simplemobiletools/smsmessenger/activities/ThreadActivity.kt

@@ -104,7 +104,12 @@ class ThreadActivity : SimpleActivity() {
     private fun setupThread() {
         val privateCursor = getMyContactsCursor()?.loadInBackground()
         ensureBackgroundThread {
+            val cachedMessagesCode = messages.hashCode()
             messages = getMessages(threadId)
+            if (messages.hashCode() == cachedMessagesCode) {
+                return@ensureBackgroundThread
+            }
+
             setupParticipants()
 
             // check if no participant came from a privately stored contact in Simple Contacts
@@ -139,6 +144,10 @@ class ThreadActivity : SimpleActivity() {
                 participants.add(contact)
             }
 
+            messages.chunked(30).forEach { currentMessages ->
+                messagesDB.insertMessages(*currentMessages.toTypedArray())
+            }
+
             setupAttachmentSizes()
             setupAdapter()
             runOnUiThread {

app/src/main/kotlin/com/simplemobiletools/smsmessenger/extensions/Context.kt

@@ -105,10 +105,6 @@ fun Context.getMessages(threadId: Long): ArrayList<Message> {
     messages = messages.filter { it.participants.isNotEmpty() }
         .sortedWith(compareBy<Message> { it.date }.thenBy { it.id }).toMutableList() as ArrayList<Message>
 
-    messages.chunked(30).forEach { currentMessages ->
-        messagesDB.insertMessages(*currentMessages.toTypedArray())
-    }
-
     return messages
 }