From c2183be6f551021a24aab2e4742261e3b8161504 Mon Sep 17 00:00:00 2001
From: Sergey Matvienko <smatvienko@thingsboard.io>
Date: Fri, 8 Mar 2024 10:39:56 +0100
Subject: [PATCH] BaseTimeseriesService Memory footprint reduced. replaced
 Lists.newArrayListWithExpectedSize with new ArrayList(size) as we are always
 use fixed size array and never exceed the initial size. The
 newArrayListWithExpectedSize implementation adds some additional space to
 grow beyond initial size.

---
 .../dao/timeseries/BaseTimeseriesService.java       | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/dao/src/main/java/org/thingsboard/server/dao/timeseries/BaseTimeseriesService.java b/dao/src/main/java/org/thingsboard/server/dao/timeseries/BaseTimeseriesService.java
index 50c884f86e..cfba6786f3 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/timeseries/BaseTimeseriesService.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/timeseries/BaseTimeseriesService.java
@@ -16,7 +16,6 @@
 package org.thingsboard.server.dao.timeseries;
 
 import com.google.common.base.Function;
-import com.google.common.collect.Lists;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.MoreExecutors;
@@ -138,7 +137,7 @@ public class BaseTimeseriesService implements TimeseriesService {
     @Override
     public List<TsKvEntry> findLatestSync(TenantId tenantId, EntityId entityId, Collection<String> keys) {
         validate(entityId);
-        List<TsKvEntry> latestEntries = new ArrayList(keys.size());
+        List<TsKvEntry> latestEntries = new ArrayList<>(keys.size());
         keys.forEach(key -> Validator.validateString(key, k -> "Incorrect key " + k));
         for (String key : keys) {
             latestEntries.add(timeseriesLatestDao.findLatestSync(tenantId, entityId, key));
@@ -170,7 +169,7 @@ public class BaseTimeseriesService implements TimeseriesService {
     @Override
     public ListenableFuture<Integer> save(TenantId tenantId, EntityId entityId, TsKvEntry tsKvEntry) {
         validate(entityId);
-        List<ListenableFuture<Integer>> futures = Lists.newArrayListWithExpectedSize(INSERTS_PER_ENTRY);
+        List<ListenableFuture<Integer>> futures = new ArrayList<>(INSERTS_PER_ENTRY);
         saveAndRegisterFutures(tenantId, futures, entityId, tsKvEntry, 0L);
         return Futures.transform(Futures.allAsList(futures), SUM_ALL_INTEGERS, MoreExecutors.directExecutor());
     }
@@ -187,7 +186,7 @@ public class BaseTimeseriesService implements TimeseriesService {
 
     private ListenableFuture<Integer> doSave(TenantId tenantId, EntityId entityId, List<TsKvEntry> tsKvEntries, long ttl, boolean saveLatest) {
         int inserts = saveLatest ? INSERTS_PER_ENTRY : INSERTS_PER_ENTRY_WITHOUT_LATEST;
-        List<ListenableFuture<Integer>> futures = Lists.newArrayListWithExpectedSize(tsKvEntries.size() * inserts);
+        List<ListenableFuture<Integer>> futures = new ArrayList<>(tsKvEntries.size() * inserts);
         for (TsKvEntry tsKvEntry : tsKvEntries) {
             if (saveLatest) {
                 saveAndRegisterFutures(tenantId, futures, entityId, tsKvEntry, ttl);
@@ -200,7 +199,7 @@ public class BaseTimeseriesService implements TimeseriesService {
 
     @Override
     public ListenableFuture<List<Void>> saveLatest(TenantId tenantId, EntityId entityId, List<TsKvEntry> tsKvEntries) {
-        List<ListenableFuture<Void>> futures = Lists.newArrayListWithExpectedSize(tsKvEntries.size());
+        List<ListenableFuture<Void>> futures = new ArrayList<>(tsKvEntries.size());
         for (TsKvEntry tsKvEntry : tsKvEntries) {
             futures.add(timeseriesLatestDao.saveLatest(tenantId, entityId, tsKvEntry));
         }
@@ -247,7 +246,7 @@ public class BaseTimeseriesService implements TimeseriesService {
     public ListenableFuture<List<TsKvLatestRemovingResult>> remove(TenantId tenantId, EntityId entityId, List<DeleteTsKvQuery> deleteTsKvQueries) {
         validate(entityId);
         deleteTsKvQueries.forEach(BaseTimeseriesService::validate);
-        List<ListenableFuture<TsKvLatestRemovingResult>> futures = Lists.newArrayListWithExpectedSize(deleteTsKvQueries.size() * DELETES_PER_ENTRY);
+        List<ListenableFuture<TsKvLatestRemovingResult>> futures = new ArrayList<>(deleteTsKvQueries.size() * DELETES_PER_ENTRY);
         for (DeleteTsKvQuery tsKvQuery : deleteTsKvQueries) {
             deleteAndRegisterFutures(tenantId, futures, entityId, tsKvQuery);
         }
@@ -257,7 +256,7 @@ public class BaseTimeseriesService implements TimeseriesService {
     @Override
     public ListenableFuture<List<TsKvLatestRemovingResult>> removeLatest(TenantId tenantId, EntityId entityId, Collection<String> keys) {
         validate(entityId);
-        List<ListenableFuture<TsKvLatestRemovingResult>> futures = Lists.newArrayListWithExpectedSize(keys.size());
+        List<ListenableFuture<TsKvLatestRemovingResult>> futures = new ArrayList<>(keys.size());
         for (String key : keys) {
             DeleteTsKvQuery query = new BaseDeleteTsKvQuery(key, 0, System.currentTimeMillis(), false);
             futures.add(timeseriesLatestDao.removeLatest(tenantId, entityId, query));