Use JNI region calls in MemoryFile read and write.

This will reduce copying or pinning, depending on GC policies, which should
improve performance. See dalvik/docs/jni-tips.html#RegionCalls for more information.

Fixes http://b/issue?id=1887911

1 files changed, 2 insertions, 6 deletions

diff --git a/core/jni/android_os_MemoryFile.cpp b/core/jni/android_os_MemoryFile.cpp
index 9450e15..6c16150 100644
--- a/core/jni/android_os_MemoryFile.cpp
+++ b/core/jni/android_os_MemoryFile.cpp
@@ -82,9 +82,7 @@ static jint android_os_MemoryFile_read(JNIEnv* env, jobject clazz,
         return -1;
     }
 
-    jbyte* bytes = env->GetByteArrayElements(buffer, 0);
-    memcpy(bytes + destOffset, (const char *)address + srcOffset, count);
-    env->ReleaseByteArrayElements(buffer, bytes, 0);
+    env->SetByteArrayRegion(buffer, destOffset, count, (const jbyte *)address + srcOffset);
 
     if (unpinned) {
         ashmem_unpin_region(fd, 0, 0);
@@ -103,9 +101,7 @@ static jint android_os_MemoryFile_write(JNIEnv* env, jobject clazz,
         return -1;
     }
 
-    jbyte* bytes = env->GetByteArrayElements(buffer, 0);
-    memcpy((char *)address + destOffset, bytes + srcOffset, count);
-    env->ReleaseByteArrayElements(buffer, bytes, 0);
+    env->GetByteArrayRegion(buffer, srcOffset, count, (jbyte *)address + destOffset);
 
     if (unpinned) {
         ashmem_unpin_region(fd, 0, 0);