From 3368a5eb47ae88fb6db260a916a41eab663cce69 Mon Sep 17 00:00:00 2001
From: Chris Conlon <chris@wolfssl.com>
Date: Thu, 1 May 2025 15:04:25 -0600
Subject: [PATCH] JNI: optimize out CallIntMethod/CallBooleanMethod() calls
 from WolfSSLSession.read(ByteBuffer), improves performance

---
 native/com_wolfssl_WolfSSLSession.c      | 31 +++++-------------------
 native/com_wolfssl_WolfSSLSession.h      |  6 ++---
 src/java/com/wolfssl/WolfSSLSession.java | 13 ++++++++--
 3 files changed, 20 insertions(+), 30 deletions(-)

diff --git a/native/com_wolfssl_WolfSSLSession.c b/native/com_wolfssl_WolfSSLSession.c
index b7c3019..e3767fa 100644
--- a/native/com_wolfssl_WolfSSLSession.c
+++ b/native/com_wolfssl_WolfSSLSession.c
@@ -1361,18 +1361,15 @@ JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLSession_read__J_3BIII
     return size;
 }
 
-JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLSession_read__JLjava_nio_ByteBuffer_2II
-  (JNIEnv* jenv, jobject jcl, jlong sslPtr, jobject buf, jint length, jint timeout)
+JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLSession_read__JLjava_nio_ByteBuffer_2IIZII
+  (JNIEnv* jenv, jobject jcl, jlong sslPtr, jobject buf, jint position,
+   jint limit, jboolean hasArray, jint length, jint timeout)
 {
     int size = 0;
     int maxOutputSz;
     int outSz = length;
     byte* data = NULL;
     WOLFSSL* ssl = (WOLFSSL*)(uintptr_t)sslPtr;
-
-    jint position;
-    jint limit;
-    jboolean hasArray;
     jbyteArray bufArr = NULL;
 
     (void)jcl;
@@ -1382,17 +1379,6 @@ JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLSession_read__JLjava_nio_ByteBuff
     }
 
     if (length > 0) {
-        /* Get ByteBuffer position */
-        position = (*jenv)->CallIntMethod(jenv, buf, g_bufferPositionMethodId);
-        if ((*jenv)->ExceptionCheck(jenv)) {
-            return SSL_FAILURE;
-        }
-
-        /* Get ByteBuffer limit */
-        limit = (*jenv)->CallIntMethod(jenv, buf, g_bufferLimitMethodId);
-        if ((*jenv)->ExceptionCheck(jenv)) {
-            return SSL_FAILURE;
-        }
 
         /* Only read up to maximum space we have in this ByteBuffer */
         maxOutputSz = (limit - position);
@@ -1404,13 +1390,6 @@ JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLSession_read__JLjava_nio_ByteBuff
             return BAD_FUNC_ARG;
         }
 
-        /* Get and call ByteBuffer.hasArray() before calling array() */
-        hasArray = (*jenv)->CallBooleanMethod(jenv, buf,
-            g_bufferHasArrayMethodId);
-        if ((*jenv)->ExceptionCheck(jenv)) {
-            return SSL_FAILURE;
-        }
-
         if (hasArray) {
             /* Get reference to underlying byte[] from ByteBuffer */
             bufArr = (jbyteArray)(*jenv)->CallObjectMethod(jenv, buf,
@@ -1460,7 +1439,9 @@ JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLSession_read__JLjava_nio_ByteBuff
             }
         }
 
-        /* Update ByteBuffer position() based on bytes written, on success */
+        /* Update ByteBuffer position() based on bytes written, on success.
+         * This seems to be more performant if we do it from JNI rather
+         * than back in Java after the return of this method. */
         if (size > 0) {
             (*jenv)->CallVoidMethod(jenv, buf, g_bufferSetPositionMethodId,
                 position + size);
diff --git a/native/com_wolfssl_WolfSSLSession.h b/native/com_wolfssl_WolfSSLSession.h
index d50019d..12a4cd4 100644
--- a/native/com_wolfssl_WolfSSLSession.h
+++ b/native/com_wolfssl_WolfSSLSession.h
@@ -106,10 +106,10 @@ JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLSession_read__J_3BIII
 /*
  * Class:     com_wolfssl_WolfSSLSession
  * Method:    read
- * Signature: (JLjava/nio/ByteBuffer;II)I
+ * Signature: (JLjava/nio/ByteBuffer;IIZII)I
  */
-JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLSession_read__JLjava_nio_ByteBuffer_2II
-  (JNIEnv *, jobject, jlong, jobject, jint, jint);
+JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLSession_read__JLjava_nio_ByteBuffer_2IIZII
+  (JNIEnv *, jobject, jlong, jobject, jint, jint, jboolean, jint, jint);
 
 /*
  * Class:     com_wolfssl_WolfSSLSession
diff --git a/src/java/com/wolfssl/WolfSSLSession.java b/src/java/com/wolfssl/WolfSSLSession.java
index c20b55e..2b16836 100644
--- a/src/java/com/wolfssl/WolfSSLSession.java
+++ b/src/java/com/wolfssl/WolfSSLSession.java
@@ -382,7 +382,8 @@ public class WolfSSLSession {
         int timeout);
     private native int read(long ssl, byte[] data, int offset, int sz,
         int timeout);
-    private native int read(long ssl, ByteBuffer data, int sz, int timeout)
+    private native int read(long ssl, ByteBuffer data, final int position,
+        final int limit, boolean hasArray, int sz, int timeout)
         throws WolfSSLException;
     private native int pending(long ssl);
     private native int accept(long ssl, int timeout);
@@ -1323,6 +1324,9 @@ public class WolfSSLSession {
         final int err;
         final int readSz = sz;
         final int readTimeout = timeout;
+        final int bbPosition;
+        final int bbLimit;
+        boolean hasArray;
         long localPtr;
 
         confirmObjectIsActive();
@@ -1344,7 +1348,12 @@ public class WolfSSLSession {
          * could timeout waiting for corresponding write() operation to
          * occur if needed */
         try {
-            ret = read(localPtr, data, readSz, readTimeout);
+            bbPosition = data.position();
+            bbLimit = data.limit();
+            hasArray = data.hasArray();
+
+            ret = read(localPtr, data, bbPosition, bbLimit, hasArray,
+                readSz, readTimeout);
             err = getError(ret);
         } catch (WolfSSLException e) {
             /* JNI code may throw WolfSSLException on JNI specific errors */