close oldest indexes before opening new if over capacity

nouveau/src/main/java/org/apache/couchdb/nouveau/core/IndexManager.java

@@ -56,28 +56,8 @@ public final class IndexManager implements Managed {
 
  private class LRUMap extends LinkedHashMap<String, IndexHolder> {
 
- private int capacity;
-
  private LRUMap(final int capacity) {
  super(capacity, 0.75f, true);
- this.capacity = capacity;
- }
-
- @Override
- protected boolean removeEldestEntry(final java.util.Map.Entry<String, IndexHolder> eldest) {
- if (size() > capacity) {
- schedulerExecutorService.execute(() -> {
- try {
- unload(eldest.getKey(), false);
- } catch (final InterruptedException e) {
- Thread.currentThread().interrupt();
- LOGGER.warn("Interrupted while evicting eldest entry {}", eldest.getKey(), e);
- } catch (final IOException e) {
- LOGGER.warn("I/O exception while evicting eldest entry {}", eldest.getKey(), e);
- }
- });
- }
- return false;
  }
  }
 
@@ -124,11 +104,14 @@ private static class IndexHolder {
 
  public <R> R with(final String name, final IndexFunction<Index, R> indexFun)
  throws IOException, InterruptedException {
+ evictIfOverCapacity();
+
  retry:
  while (true) {
  if (!exists(name)) {
  throw new WebApplicationException("Index does not exist", Status.NOT_FOUND);
  }
+
  final IndexHolder holder;
  synchronized (cache) {
  holder = cache.computeIfAbsent(name, (k) -> new IndexHolder());
@@ -172,6 +155,19 @@ public <R> R with(final String name, final IndexFunction<Index, R> indexFun)
  }
  }
 
+ private void evictIfOverCapacity() throws IOException, InterruptedException {
+ while (true) {
+ final String candidate;
+ synchronized (cache) {
+ if (cache.size() <= maxIndexesOpen) {
+ return;
+ }
+ candidate = cache.entrySet().iterator().next().getKey();
+ }
+ unload(candidate, false);
+ }
+ }
+
  public void unload(final String name, final boolean forceDelete) throws IOException, InterruptedException {
  final IndexHolder holder;
  synchronized (cache) {