Log memory and when system calls App#onTrimMemory()

app/src/main/java/com/stevesoltys/seedvault/App.kt

@@ -6,6 +6,8 @@
 package com.stevesoltys.seedvault
 
 import android.Manifest.permission.INTERACT_ACROSS_USERS_FULL
+import android.app.ActivityManager
+import android.app.ActivityManager.RunningAppProcessInfo
 import android.app.Application
 import android.app.backup.BackupManager
 import android.app.backup.BackupManager.PACKAGE_MANAGER_SENTINEL
@@ -17,15 +19,16 @@ import android.os.ServiceManager.getService
 import android.os.StrictMode
 import android.os.UserHandle
 import android.os.UserManager
+import android.util.Log
 import androidx.work.ExistingPeriodicWorkPolicy.UPDATE
 import androidx.work.WorkManager
 import com.google.android.material.color.DynamicColors
+import com.stevesoltys.seedvault.MemoryLogger.getMemStr
 import com.stevesoltys.seedvault.backend.BackendManager
 import com.stevesoltys.seedvault.backend.saf.storagePluginModuleSaf
 import com.stevesoltys.seedvault.backend.webdav.storagePluginModuleWebDav
 import com.stevesoltys.seedvault.crypto.cryptoModule
 import com.stevesoltys.seedvault.header.headerModule
-import com.stevesoltys.seedvault.metadata.MetadataManager
 import com.stevesoltys.seedvault.metadata.metadataModule
 import com.stevesoltys.seedvault.restore.install.installModule
 import com.stevesoltys.seedvault.restore.restoreUiModule
@@ -154,6 +157,15 @@ open class App : Application() {
     private val backendManager: BackendManager by inject()
     private val backupStateManager: BackupStateManager by inject()
 
+    override fun onTrimMemory(level: Int) {
+        Log.w("Seedvault", "onTrimMemory($level) ${getMemStr()}")
+        val processInfo = RunningAppProcessInfo()
+        ActivityManager.getMyMemoryState(processInfo)
+        Log.w("Seedvault", "  lastTrimLevel: ${processInfo.lastTrimLevel}")
+        Log.w("Seedvault", "  importance: ${processInfo.importance}")
+        super.onTrimMemory(level)
+    }
+
     /**
      * Disables the framework scheduling in favor of our own.
      * Introduced in the first half of 2024 and can be removed after a suitable migration period.

app/src/main/java/com/stevesoltys/seedvault/MemoryLogger.kt

@@ -0,0 +1,24 @@
+/*
+ * SPDX-FileCopyrightText: 2024 The Calyx Institute
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.stevesoltys.seedvault
+
+import android.util.Log
+
+object MemoryLogger {
+
+    fun log() {
+        Log.d("MemoryLogger", getMemStr())
+    }
+
+    fun getMemStr(): String {
+        val r = Runtime.getRuntime()
+        val total = r.totalMemory() / 1024 / 1024
+        val free = r.freeMemory() / 1024 / 1024
+        val max = r.maxMemory() / 1024 / 1024
+        val used = total - free
+        return "$free MiB free - $used of $total (max $max)"
+    }
+}

app/src/main/java/com/stevesoltys/seedvault/transport/backup/AppBackupManager.kt

@@ -6,6 +6,7 @@
 package com.stevesoltys.seedvault.transport.backup
 
 import androidx.annotation.WorkerThread
+import com.stevesoltys.seedvault.MemoryLogger
 import com.stevesoltys.seedvault.backend.BackendManager
 import com.stevesoltys.seedvault.crypto.Crypto
 import com.stevesoltys.seedvault.settings.SettingsManager
@@ -52,6 +53,7 @@ internal class AppBackupManager(
 
     @WorkerThread
     suspend fun afterBackupFinished(success: Boolean): com.stevesoltys.seedvault.proto.Snapshot? {
+        MemoryLogger.log()
         log.info { "After backup finished. Success: $success" }
         // free up memory by clearing blobs cache
         blobCache.clear()
@@ -72,6 +74,7 @@ internal class AppBackupManager(
             null
         } finally {
             snapshotCreator = null
+            MemoryLogger.log()
         }
     }
 

app/src/main/java/com/stevesoltys/seedvault/transport/backup/BlobCache.kt

@@ -7,6 +7,7 @@ package com.stevesoltys.seedvault.transport.backup
 
 import android.content.Context
 import android.content.Context.MODE_APPEND
+import com.stevesoltys.seedvault.MemoryLogger
 import com.stevesoltys.seedvault.proto.Snapshot
 import com.stevesoltys.seedvault.proto.Snapshot.Blob
 import io.github.oshai.kotlinlogging.KotlinLogging
@@ -41,6 +42,7 @@ class BlobCache(
     fun populateCache(blobs: List<FileInfo>, snapshots: List<Snapshot>) {
         log.info { "Getting all blobs from backend..." }
         blobMap.clear()
+        MemoryLogger.log()
         // create map of blobId to size of blob on backend
         val blobIds = blobs.associate {
             Pair(it.fileHandle.name, it.size.toInt())
@@ -51,6 +53,7 @@ class BlobCache(
         snapshots.forEach { snapshot ->
             onSnapshotLoaded(snapshot, blobIds)
         }
+        MemoryLogger.log()
     }
 
     /**

app/src/main/java/com/stevesoltys/seedvault/transport/backup/BlobCreator.kt

@@ -8,6 +8,7 @@ package com.stevesoltys.seedvault.transport.backup
 import androidx.annotation.WorkerThread
 import com.github.luben.zstd.ZstdOutputStream
 import com.google.protobuf.ByteString
+import com.stevesoltys.seedvault.MemoryLogger
 import com.stevesoltys.seedvault.backend.BackendManager
 import com.stevesoltys.seedvault.crypto.Crypto
 import com.stevesoltys.seedvault.header.VERSION
@@ -61,6 +62,7 @@ internal class BlobCreator(
             // we could just write 0s, but because of defense in depth, we use random bytes
             cryptoStream.write(crypto.getRandomBytes(paddingSize))
         }
+        MemoryLogger.log()
         payloadBuffer.clear()
 
         // compute hash and save blob