Remove file field from CacheFileReference

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/CacheDirectory.java

@@ -59,13 +59,11 @@ private class CacheFileReference implements CacheFile.EvictionListener {
 
         private final String fileName;
         private final long fileLength;
-        private final Path file;
         private final AtomicReference<CacheFile> cacheFile = new AtomicReference<>(); // null if evicted or not yet acquired
 
-        private CacheFileReference(String fileName, long fileLength, Path file) {
+        private CacheFileReference(String fileName, long fileLength) {
             this.fileName = fileName;
             this.fileLength = fileLength;
-            this.file = file;
         }
 
         @Nullable
@@ -75,7 +73,7 @@ CacheFile get() throws Exception {
                 return currentCacheFile;
             }
 
-            final CacheFile newCacheFile = cacheService.get(fileName, fileLength, file);
+            final CacheFile newCacheFile = cacheService.get(fileName, fileLength, cacheDir);
             synchronized (this) {
                 currentCacheFile = cacheFile.get();
                 if (currentCacheFile != null) {
@@ -117,7 +115,7 @@ public String toString() {
             return "CacheFileReference{" +
                 "fileName='" + fileName + '\'' +
                 ", fileLength=" + fileLength +
-                ", file=" + file +
+                ", cacheDir=" + cacheDir +
                 ", acquired=" + (cacheFile.get() != null) +
                 '}';
         }
@@ -135,7 +133,7 @@ public class CacheBufferedIndexInput extends BufferedIndexInput {
         private boolean isClone;
 
         CacheBufferedIndexInput(String fileName, long fileLength, IOContext ioContext) {
-            this(new CacheFileReference(fileName, fileLength, cacheDir.resolve(fileName)), ioContext,
+            this(new CacheFileReference(fileName, fileLength), ioContext,
                 "CachedBufferedIndexInput(" + fileName + ")", 0L, fileLength, false);
         }
 

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/CacheFile.java

@@ -55,9 +55,11 @@ protected void closeInternal() {
     private final Path file;
 
     private volatile Set<EvictionListener> listeners;
-    private volatile FileChannel channel;
     private volatile boolean evicted;
 
+    @Nullable // if evicted, or there are no listeners
+    private volatile FileChannel channel;
+
     CacheFile(String name, long length, Path file) {
         this.tracker = new SparseFileTracker(file.toString(), length);
         this.name = Objects.requireNonNull(name);

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/cache/CacheService.java

@@ -64,17 +64,17 @@ private void ensureLifecycleStarted() {
         }
     }
 
-    public CacheFile get(final String name, final long length, final Path file) throws Exception {
+    public CacheFile get(final String fileName, final long length, final Path cacheDir) throws Exception {
         ensureLifecycleStarted();
-        return cache.computeIfAbsent(toCacheKey(file), key -> {
+        return cache.computeIfAbsent(toCacheKey(cacheDir, fileName), key -> {
             ensureLifecycleStarted();
             // generate a random UUID for the name of the cache file on disk
             final String uuid = UUIDs.randomBase64UUID();
             // resolve the cache file on disk w/ the expected cached file
-            final Path path = file.getParent().resolve(uuid);
+            final Path path = cacheDir.resolve(uuid);
             assert Files.notExists(path) : "cache file already exists " + path;
 
-            return new CacheFile(name, length, path);
+            return new CacheFile(fileName, length, path);
         });
     }
 
@@ -94,11 +94,9 @@ public void removeFromCache(final Predicate<String> predicate) {
 
     /**
      * Computes the cache key associated to the given Lucene cached file
-     *
-     * @param cacheFile the cached file
-     * @return the cache key
      */
-    private static String toCacheKey(final Path cacheFile) { // TODO Fix this. Cache Key should be computed from snapshot id/index id/shard
-        return cacheFile.toAbsolutePath().toString();
+    private static String toCacheKey(final Path cacheDir, String fileName) {
+        // TODO Fix this. Cache Key should be computed from snapshot id/index id/shard
+        return cacheDir.resolve(fileName).toAbsolutePath().toString();
     }
 }