1 files changed, 48 insertions, 0 deletions
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/disk/LinearCleanupRule.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/disk/LinearCleanupRule.java
new file mode 100644
index 00000000000..3ef4e2e4f6a
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+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/disk/LinearCleanupRule.java
@@ -0,0 +1,48 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.hosted.node.admin.maintenance.disk;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.function.Function;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+
+import static com.yahoo.vespa.hosted.node.admin.task.util.file.FileFinder.FileAttributes;
+
+/**
+ * Prioritizes files by first scoring them with the given scoring function and then mapping the scores to a
+ * priority within the given range.
+ * The priority room is evenly split between given lowest and highest priority for range [0, 1.0). Scores below 0
+ * are assigned lowest, while scores at or higher than 1 are assigned highest priority.
+ *
+ * Typical use-case is for log files. The scoring function calculates the file age and normalizes it by dividing it
+ * by expected max age of log files. The oldest logs will then by prioritized by highest given priority.
+ *
+ * @author freva
+ */
+public class LinearCleanupRule implements DiskCleanupRule {
+    private final Supplier<List<FileAttributes>> lister;
+    private final Function<FileAttributes, Priority> prioritizer;
+
+    public LinearCleanupRule(Supplier<List<FileAttributes>> lister,
+                             Function<FileAttributes, Double> scorer, Priority lowest, Priority highest) {
+        if (lowest.ordinal() > highest.ordinal())
+            throw new IllegalArgumentException("Lowest priority: " + lowest + " is higher than highest priority: " + highest);
+
+        this.lister = lister;
+
+        Priority[] values = Priority.values();
+        int range = highest.ordinal() - lowest.ordinal() + 1;
+        this.prioritizer = fa -> {
+            int ordinal = (int) (lowest.ordinal() + scorer.apply(fa) * range);
+            return values[Math.max(lowest.ordinal(), Math.min(highest.ordinal(), ordinal))];
+        };
+    }
+
+    @Override
+    public Collection<PrioritizedFileAttributes> prioritize() {
+        return lister.get().stream()
+                .map(fa -> new PrioritizedFileAttributes(fa, prioritizer.apply(fa)))
+                .collect(Collectors.toList());
+    }
+}