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      1 /*
      2  * Copyright (c) 1997, 1999, Oracle and/or its affiliates. All rights reserved.
      3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
      4  *
      5  * This code is free software; you can redistribute it and/or modify it
      6  * under the terms of the GNU General Public License version 2 only, as
      7  * published by the Free Software Foundation.  Oracle designates this
      8  * particular file as subject to the "Classpath" exception as provided
      9  * by Oracle in the LICENSE file that accompanied this code.
     10  *
     11  * This code is distributed in the hope that it will be useful, but WITHOUT
     12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
     14  * version 2 for more details (a copy is included in the LICENSE file that
     15  * accompanied this code).
     16  *
     17  * You should have received a copy of the GNU General Public License version
     18  * 2 along with this work; if not, write to the Free Software Foundation,
     19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
     20  *
     21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
     22  * or visit www.oracle.com if you need additional information or have any
     23  * questions.
     24  */
     25 
     26 /*
     27  * Native method support for java.util.zip.CRC32
     28  */
     29 
     30 #include "JNIHelp.h"
     31 #include "jni.h"
     32 #include "jni_util.h"
     33 #include <zlib.h>
     34 
     35 
     36 #define NATIVE_METHOD(className, functionName, signature) \
     37 { #functionName, signature, (void*)(className ## _ ## functionName) }
     38 
     39 JNIEXPORT jint JNICALL
     40 CRC32_update(JNIEnv *env, jclass cls, jint crc, jint b)
     41 {
     42     Bytef buf[1];
     43 
     44     buf[0] = (Bytef)b;
     45     return crc32(crc, buf, 1);
     46 }
     47 
     48 JNIEXPORT jint JNICALL
     49 CRC32_updateBytes(JNIEnv *env, jclass cls, jint crc,
     50                                      jarray b, jint off, jint len)
     51 {
     52     Bytef *buf = (*env)->GetPrimitiveArrayCritical(env, b, 0);
     53     if (buf) {
     54         crc = crc32(crc, buf + off, len);
     55         (*env)->ReleasePrimitiveArrayCritical(env, b, buf, 0);
     56     }
     57     return crc;
     58 }
     59 
     60 JNIEXPORT jint ZIP_CRC32(jint crc, const jbyte *buf, jint len)
     61 {
     62     return crc32(crc, (Bytef*)buf, len);
     63 }
     64 
     65 static JNINativeMethod gMethods[] = {
     66   NATIVE_METHOD(CRC32, update, "(II)I"),
     67   NATIVE_METHOD(CRC32, updateBytes, "(I[BII)I"),
     68 };
     69 
     70 void register_java_util_zip_CRC32(JNIEnv* env) {
     71   jniRegisterNativeMethods(env, "java/util/zip/CRC32", gMethods, NELEM(gMethods));
     72 }
     73