RFR(10): 8181147: JNU_GetStringPlatformChars should have a fast path for UTF-8

[Martin Buchholz]

+/* Optimized for char set UTF-8 */

"charset" is a (poor misnomer!) jargon term, not two words.

---

+    for (b = str[len]; b != '\0'; len++, b = str[len]) {
+        if (isAscii && b & 0x80) {
+            isAscii = JNI_FALSE;
+        }
+    }

I would write this more like

const signed char *p;
int isAscii;

for (isAscii = 0, p = (const signed char *) str; *p != '\0'; p++) isAscii
&= (*p >= 0);

Then length is (p - str)

---

+    jbyteArray hab = NULL;

I'm having a hard time decoding the name "hab"

---

The code below is not UTF-8 specific. Can it be refactored?

+    hab = (*env)->NewByteArray(env, len);
+    if (hab != 0) {
+        jclass strClazz = JNU_ClassString(env);
+        CHECK_NULL_RETURN(strClazz, 0);
+        (*env)->SetByteArrayRegion(env, hab, 0, len, (jbyte *)str);
+        result = (*env)->NewObject(env, strClazz,
+                                       String_init_ID, hab, jnuEncoding);
+        (*env)->DeleteLocalRef(env, hab);
+        return result;
+    }

---

We probably want to use unicode escapes in out java sources to keep all
source files strictly ASCII.