Make the message trimming behaviour consistent across platform (#936)

* refactor: remove old trim behaviour and create new defaults

* refactor: add in trimming by before time

* refactor: remove old trim thread job, remove message processor scheduling trim thread

* refactor: remove spacing

* refactor: enable trimming by default

* refactor: remove trim now option in chat preference

libsession/src/main/java/org/session/libsession/database/StorageProtocol.kt

@@ -151,6 +151,8 @@ interface StorageProtocol {
     fun getThreadIdForMms(mmsId: Long): Long
     fun getLastUpdated(threadID: Long): Long
     fun trimThread(threadID: Long, threadLimit: Int)
+    fun trimThreadBefore(threadID: Long, timestamp: Long)
+    fun getMessageCount(threadID: Long): Long
 
     // Contacts
     fun getContactWithSessionID(sessionID: String): Contact?

libsession/src/main/java/org/session/libsession/messaging/jobs/JobQueue.kt

@@ -31,7 +31,6 @@ class JobQueue : JobDelegate {
     private val scope = CoroutineScope(Dispatchers.Default) + SupervisorJob()
     private val queue = Channel<Job>(UNLIMITED)
     private val pendingJobIds = mutableSetOf<String>()
-    private val pendingTrimThreadIds = mutableSetOf<Long>()
 
     private val openGroupChannels = mutableMapOf<String, Channel<Job>>()
 
@@ -115,15 +114,6 @@ class JobQueue : JobDelegate {
             val openGroupJob = processWithOpenGroupDispatcher(openGroupQueue, openGroupDispatcher, "openGroup")
 
             while (isActive) {
-                if (queue.isEmpty && pendingTrimThreadIds.isNotEmpty()) {
-                    // process trim thread jobs
-                    val pendingThreads = pendingTrimThreadIds.toList()
-                    pendingTrimThreadIds.clear()
-                    for (thread in pendingThreads) {
-                        Log.d("Loki", "Trimming thread $thread")
-                        queue.trySend(TrimThreadJob(thread, null))
-                    }
-                }
                 when (val job = queue.receive()) {
                     is NotifyPNServerJob, is AttachmentUploadJob, is MessageSendJob -> {
                         txQueue.send(job)
@@ -165,10 +155,6 @@ class JobQueue : JobDelegate {
         val shared: JobQueue by lazy { JobQueue() }
     }
 
-    fun queueThreadForTrim(threadId: Long) {
-        pendingTrimThreadIds += threadId
-    }
-
     fun add(job: Job) {
         addWithoutExecuting(job)
         queue.trySend(job) // offer always called on unlimited capacity

libsession/src/main/java/org/session/libsession/messaging/jobs/TrimThreadJob.kt

@@ -15,14 +15,19 @@ class TrimThreadJob(val threadId: Long, val openGroupId: String?) : Job {
         const val KEY: String = "TrimThreadJob"
         const val THREAD_ID = "thread_id"
         const val OPEN_GROUP_ID = "open_group"
+
+        const val TRIM_TIME_LIMIT = 15552000000L // trim messages older than this
+        const val THREAD_LENGTH_TRIGGER_SIZE = 2000
     }
 
     override fun execute() {
         val context = MessagingModuleConfiguration.shared.context
         val trimmingEnabled = TextSecurePreferences.isThreadLengthTrimmingEnabled(context)
-        val threadLengthLimit = TextSecurePreferences.getThreadTrimLength(context)
-        if (trimmingEnabled) {
-            MessagingModuleConfiguration.shared.storage.trimThread(threadId, threadLengthLimit)
+        val storage = MessagingModuleConfiguration.shared.storage
+        val messageCount = storage.getMessageCount(threadId)
+        if (trimmingEnabled && !openGroupId.isNullOrEmpty() && messageCount >= THREAD_LENGTH_TRIGGER_SIZE) {
+            val oldestMessageTime = System.currentTimeMillis() - TRIM_TIME_LIMIT
+            storage.trimThreadBefore(threadId, oldestMessageTime)
         }
         delegate?.handleJobSucceeded(this)
     }

libsession/src/main/java/org/session/libsession/utilities/TextSecurePreferences.kt

@@ -117,7 +117,6 @@ interface TextSecurePreferences {
     fun getNotificationLedPattern(): String?
     fun getNotificationLedPatternCustom(): String?
     fun isThreadLengthTrimmingEnabled(): Boolean
-    fun getThreadTrimLength(): Int
     fun isSystemEmojiPreferred(): Boolean
     fun getMobileMediaDownloadAllowed(): Set<String>?
     fun getWifiMediaDownloadAllowed(): Set<String>?
@@ -175,7 +174,6 @@ interface TextSecurePreferences {
 
         const val DISABLE_PASSPHRASE_PREF = "pref_disable_passphrase"
         const val LANGUAGE_PREF = "pref_language"
-        const val THREAD_TRIM_LENGTH = "pref_trim_length"
         const val THREAD_TRIM_NOW = "pref_trim_now"
         const val LAST_VERSION_CODE_PREF = "last_version_code"
         const val RINGTONE_PREF = "pref_key_ringtone"
@@ -705,12 +703,7 @@ interface TextSecurePreferences {
 
         @JvmStatic
         fun isThreadLengthTrimmingEnabled(context: Context): Boolean {
-            return getBooleanPreference(context, THREAD_TRIM_ENABLED, false)
-        }
-
-        @JvmStatic
-        fun getThreadTrimLength(context: Context): Int {
-            return getStringPreference(context, THREAD_TRIM_LENGTH, "500")!!.toInt()
+            return getBooleanPreference(context, THREAD_TRIM_ENABLED, true)
         }
 
         @JvmStatic
@@ -1329,11 +1322,7 @@ class AppTextSecurePreferences @Inject constructor(
     }
 
     override fun isThreadLengthTrimmingEnabled(): Boolean {
-        return getBooleanPreference(TextSecurePreferences.THREAD_TRIM_ENABLED, false)
-    }
-
-    override fun getThreadTrimLength(): Int {
-        return getStringPreference(TextSecurePreferences.THREAD_TRIM_LENGTH, "500")!!.toInt()
+        return getBooleanPreference(TextSecurePreferences.THREAD_TRIM_ENABLED, true)
     }
 
     override fun isSystemEmojiPreferred(): Boolean {