Expose additional disk buffering configuration (#596)

* expose configurable settings for max write file age and min/max file read age.

* spotless

core/src/main/java/io/opentelemetry/android/OpenTelemetryRumBuilder.java

@@ -333,12 +333,15 @@ private StorageConfiguration createStorageConfiguration(ServiceManager serviceMa
             throws IOException {
         Preferences preferences = serviceManager.getPreferences();
         CacheStorage storage = serviceManager.getCacheStorage();
-        DiskManager diskManager =
-                new DiskManager(storage, preferences, config.getDiskBufferingConfiguration());
+        DiskBufferingConfiguration config = this.config.getDiskBufferingConfiguration();
+        DiskManager diskManager = new DiskManager(storage, preferences, config);
         return StorageConfiguration.builder()
+                .setRootDir(diskManager.getSignalsBufferDir())
                 .setMaxFileSize(diskManager.getMaxCacheFileSize())
                 .setMaxFolderSize(diskManager.getMaxFolderSize())
-                .setRootDir(diskManager.getSignalsBufferDir())
+                .setMaxFileAgeForWriteMillis(config.getMaxFileAgeForWriteMillis())
+                .setMaxFileAgeForReadMillis(config.getMaxFileAgeForReadMillis())
+                .setMinFileAgeForReadMillis(config.getMinFileAgeForReadMillis())
                 .setTemporaryFileProvider(
                         new SimpleTemporaryFileProvider(diskManager.getTemporaryDir()))
                 .build();

core/src/main/java/io/opentelemetry/android/features/diskbuffering/DiskBufferingConfiguration.java

@@ -7,19 +7,29 @@
 
 import io.opentelemetry.android.features.diskbuffering.scheduler.DefaultExportScheduleHandler;
 import io.opentelemetry.android.features.diskbuffering.scheduler.ExportScheduleHandler;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /** Configuration for disk buffering. */
 public final class DiskBufferingConfiguration {
+    private static final int DEFAULT_MAX_CACHE_SIZE = 60 * 1024 * 1024;
+    private static final int MAX_FILE_SIZE = 1024 * 1024;
+
     private final boolean enabled;
     private final int maxCacheSize;
     private final ExportScheduleHandler exportScheduleHandler;
-    private static final int DEFAULT_MAX_CACHE_SIZE = 60 * 1024 * 1024;
-    private static final int MAX_FILE_SIZE = 1024 * 1024;
+    private final long maxFileAgeForWriteMillis;
+    private final long minFileAgeForReadMillis;
+    private final long maxFileAgeForReadMillis;
 
     private DiskBufferingConfiguration(Builder builder) {
-        this.enabled = builder.enabled;
-        this.maxCacheSize = builder.maxCacheSize;
-        this.exportScheduleHandler = builder.exportScheduleHandler;
+        enabled = builder.enabled;
+        maxCacheSize = builder.maxCacheSize;
+        exportScheduleHandler = builder.exportScheduleHandler;
+        maxFileAgeForWriteMillis = builder.maxFileAgeForWriteMillis;
+        minFileAgeForReadMillis = builder.minFileAgeForReadMillis;
+        maxFileAgeForReadMillis = builder.maxFileAgeForReadMillis;
     }
 
     public static Builder builder() {
@@ -42,9 +52,25 @@ public ExportScheduleHandler getExportScheduleHandler() {
         return exportScheduleHandler;
     }
 
+    public long getMaxFileAgeForWriteMillis() {
+        return maxFileAgeForWriteMillis;
+    }
+
+    public long getMaxFileAgeForReadMillis() {
+        return maxFileAgeForReadMillis;
+    }
+
+    public long getMinFileAgeForReadMillis() {
+        return minFileAgeForReadMillis;
+    }
+
     public static final class Builder {
         private boolean enabled = false;
         private int maxCacheSize = DEFAULT_MAX_CACHE_SIZE;
+        private long maxFileAgeForWriteMillis = TimeUnit.SECONDS.toMillis(30);
+        private long minFileAgeForReadMillis = TimeUnit.SECONDS.toMillis(33);
+        private long maxFileAgeForReadMillis = TimeUnit.HOURS.toMillis(18);
+
         private ExportScheduleHandler exportScheduleHandler = DefaultExportScheduleHandler.create();
 
         /** Enables or disables disk buffering. */
@@ -53,6 +79,30 @@ public Builder setEnabled(boolean enabled) {
             return this;
         }
 
+        /** Sets the max amount of time a file can receive new data. Default is 30 seconds. */
+        public Builder setMaxFileAgeForWriteMillis(long maxFileAgeForWriteMillis) {
+            this.maxFileAgeForWriteMillis = maxFileAgeForWriteMillis;
+            return this;
+        }
+
+        /**
+         * Sets the min amount of time that must pass before a file is read. This value must be
+         * greater than maxFileAgeForWriteMillis.
+         */
+        public Builder setMinFileAgeForReadMillis(long minFileAgeForReadMillis) {
+            this.minFileAgeForReadMillis = minFileAgeForReadMillis;
+            return this;
+        }
+
+        /**
+         * Sets the max age in ms for which a file is considered not-stale. Files older than this
+         * will be dropped.
+         */
+        public Builder setMaxFileAgeForReadMillis(long maxFileAgeForReadMillis) {
+            this.maxFileAgeForReadMillis = maxFileAgeForReadMillis;
+            return this;
+        }
+
         /**
          * Sets the maximum amount of bytes that this tool can use to store cached signals in disk.
          * A smaller amount of space will be used if there's not enough space in disk to allocate
@@ -73,6 +123,21 @@ public Builder setExportScheduleHandler(ExportScheduleHandler exportScheduleHand
         }
 
         public DiskBufferingConfiguration build() {
+            // See note in StorageConfiguration.getMinFileAgeForReadMillis()
+            if (minFileAgeForReadMillis <= maxFileAgeForWriteMillis) {
+                Logger logger = Logger.getLogger(DiskBufferingConfiguration.class.getName());
+                logger.log(
+                        Level.WARNING,
+                        "minFileAgeForReadMillis must be greater than maxFileAgeForWriteMillis");
+                logger.log(
+                        Level.WARNING,
+                        "overriding minFileAgeForReadMillis from "
+                                + minFileAgeForReadMillis
+                                + " to "
+                                + minFileAgeForReadMillis
+                                + 5);
+                minFileAgeForReadMillis = maxFileAgeForWriteMillis + 5;
+            }
             return new DiskBufferingConfiguration(this);
         }
     }