HDDS-14955. Simplify BigInteger instantiation for improved efficiency.

Author: ptlrs

dev-support/pmd/pmd-ruleset.xml

@@ -39,6 +39,7 @@
   <rule ref="category/java/performance.xml/AddEmptyString"/>
   <rule ref="category/java/performance.xml/AppendCharacterWithChar" />
   <rule ref="category/java/performance.xml/AvoidFileStream"/>
+  <rule ref="category/java/performance.xml/BigIntegerInstantiation"/>
   <rule ref="category/java/performance.xml/InefficientEmptyStringCheck"/>
   <rule ref="category/java/performance.xml/InefficientStringBuffering"/>
   <rule ref="category/java/performance.xml/StringInstantiation"/>

hadoop-hdds/framework/src/main/java/org/apache/hadoop/hdds/security/x509/certificate/client/DefaultCertificateClient.java

@@ -272,9 +272,8 @@ private void updateCachedData(
   }
 
   private synchronized void updateCachedRootCAId(String s) {
-    BigInteger candidateNewId = new BigInteger(s);
     if (rootCaCertId == null
-        || new BigInteger(rootCaCertId).compareTo(candidateNewId) < 0) {
+        || new BigInteger(rootCaCertId).compareTo(new BigInteger(s)) < 0) {
       rootCaCertId = s;
     }
   }

hadoop-hdds/framework/src/main/java/org/apache/hadoop/hdds/security/x509/certificate/utils/SelfSignedCertificate.java

@@ -117,7 +117,7 @@ private X509Certificate generateCertificate(BigInteger caCertSerialId) throws Op
 
     BigInteger serial;
     if (caCertSerialId == null) {
-      serial = new BigInteger(Long.toString(Time.monotonicNow()));
+      serial = BigInteger.valueOf(Time.monotonicNow());
     } else {
       serial = caCertSerialId;
     }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/security/RootCARotationManager.java

@@ -378,8 +378,7 @@ public void run() {
           CertificateServer newRootCAServer = null;
           BigInteger newId = BigInteger.ONE;
           try {
-            newId = new BigInteger(String.valueOf(
-                sequenceIdGen.getNextId(CERTIFICATE_ID)));
+            newId = BigInteger.valueOf(sequenceIdGen.getNextId(CERTIFICATE_ID));
             newRootCAServer =
                 HASecurityUtils.initializeRootCertificateServer(secConf,
                     scm.getCertificateStore(), scmStorageConfig, newId,

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/security/TestRootCARotationManager.java

@@ -92,7 +92,7 @@ public class TestRootCARotationManager {
   private File testDir;
   private String cID = UUID.randomUUID().toString();
   private String scmID = UUID.randomUUID().toString();
-  private BigInteger certID = new BigInteger("1");
+  private BigInteger certID = BigInteger.ONE;
 
   @BeforeEach
   public void init() throws IOException, TimeoutException,