From 6aad6a161863a8ee2bddaf27b04fb30e7583fed5 Mon Sep 17 00:00:00 2001
From: CalDescent <caldescent@protonmail.com>
Date: Fri, 11 Mar 2022 10:59:07 +0000
Subject: [PATCH] fileListCache is now an immutable Map, which is thread safe.
 Thanks to catbref for this idea.

---
 .../qortal/repository/BlockArchiveReader.java | 30 +++++++++----------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/src/main/java/org/qortal/repository/BlockArchiveReader.java b/src/main/java/org/qortal/repository/BlockArchiveReader.java
index b6d7cdd6..47e4e7fc 100644
--- a/src/main/java/org/qortal/repository/BlockArchiveReader.java
+++ b/src/main/java/org/qortal/repository/BlockArchiveReader.java
@@ -63,7 +63,7 @@ public class BlockArchiveReader {
                 map.put(filename, new Triple(startHeight, endHeight, range));
             }
         }
-        this.fileListCache = map;
+        this.fileListCache = Map.copyOf(map);
     }
 
     public Triple<BlockData, List<TransactionData>, List<ATStateData>> fetchBlockAtHeight(int height) {
@@ -145,22 +145,20 @@ public class BlockArchiveReader {
     }
 
     private String getFilenameForHeight(int height) {
-        synchronized (this.fileListCache) {
-            Iterator it = this.fileListCache.entrySet().iterator();
-            while (it.hasNext()) {
-                Map.Entry pair = (Map.Entry) it.next();
-                if (pair == null && pair.getKey() == null && pair.getValue() == null) {
-                    continue;
-                }
-                Triple<Integer, Integer, Integer> heightInfo = (Triple<Integer, Integer, Integer>) pair.getValue();
-                Integer startHeight = heightInfo.getA();
-                Integer endHeight = heightInfo.getB();
+        Iterator it = this.fileListCache.entrySet().iterator();
+        while (it.hasNext()) {
+            Map.Entry pair = (Map.Entry) it.next();
+            if (pair == null && pair.getKey() == null && pair.getValue() == null) {
+                continue;
+            }
+            Triple<Integer, Integer, Integer> heightInfo = (Triple<Integer, Integer, Integer>) pair.getValue();
+            Integer startHeight = heightInfo.getA();
+            Integer endHeight = heightInfo.getB();
 
-                if (height >= startHeight && height <= endHeight) {
-                    // Found the correct file
-                    String filename = (String) pair.getKey();
-                    return filename;
-                }
+            if (height >= startHeight && height <= endHeight) {
+                // Found the correct file
+                String filename = (String) pair.getKey();
+                return filename;
             }
         }