8324048: (fc) Make FileKey fields final

Reviewed-by: djelinski, alanb, jpai

Author: Brian Burkhalter

src/java.base/unix/classes/sun/nio/ch/FileKey.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -33,15 +33,18 @@
  */
 public class FileKey {
 
-    private long st_dev;    // ID of device
-    private long st_ino;    // Inode number
+    private final long st_dev;    // ID of device
+    private final long st_ino;    // Inode number
 
-    private FileKey() { }
+    private FileKey(long st_dev, long st_ino) {
+        this.st_dev = st_dev;
+        this.st_ino = st_ino;
+    }
 
     public static FileKey create(FileDescriptor fd) throws IOException {
-        FileKey fk = new FileKey();
-        fk.init(fd);
-        return fk;
+        long finfo[] = new long[2];
+        init(fd, finfo);
+        return new FileKey(finfo[0], finfo[1]);
     }
 
     @Override
@@ -59,10 +62,10 @@ public boolean equals(Object obj) {
                 && (this.st_ino == other.st_ino);
     }
 
-    private native void init(FileDescriptor fd) throws IOException;
-    private static native void initIDs();
+    private static native void init(FileDescriptor fd, long[] finfo)
+        throws IOException;
 
     static {
-        initIDs();
+        IOUtil.load();
     }
 }

src/java.base/unix/native/libnio/ch/FileKey.c

@@ -30,29 +30,21 @@
 #include "nio_util.h"
 #include "sun_nio_ch_FileKey.h"
 
-static jfieldID key_st_dev;    /* id for FileKey.st_dev */
-static jfieldID key_st_ino;    /* id for FileKey.st_ino */
-
-
-JNIEXPORT void JNICALL
-Java_sun_nio_ch_FileKey_initIDs(JNIEnv *env, jclass clazz)
-{
-    CHECK_NULL(key_st_dev = (*env)->GetFieldID(env, clazz, "st_dev", "J"));
-    CHECK_NULL(key_st_ino = (*env)->GetFieldID(env, clazz, "st_ino", "J"));
-}
-
-
 JNIEXPORT void JNICALL
-Java_sun_nio_ch_FileKey_init(JNIEnv *env, jobject this, jobject fdo)
+Java_sun_nio_ch_FileKey_init(JNIEnv* env, jclass clazz, jobject fdo,
+    jlongArray finfo)
 {
     struct stat fbuf;
     int res;
+    jlong deviceAndInode[2];
 
-    RESTARTABLE(fstat(fdval(env, fdo), &fbuf), res);
+    int fd = fdval(env, fdo);
+    RESTARTABLE(fstat(fd, &fbuf), res);
     if (res < 0) {
         JNU_ThrowIOExceptionWithLastError(env, "fstat failed");
     } else {
-        (*env)->SetLongField(env, this, key_st_dev, (jlong)fbuf.st_dev);
-        (*env)->SetLongField(env, this, key_st_ino, (jlong)fbuf.st_ino);
+        deviceAndInode[0] = (jlong)fbuf.st_dev;
+        deviceAndInode[1] = (jlong)fbuf.st_ino;
+        (*env)->SetLongArrayRegion(env, finfo, 0, 2, deviceAndInode);
     }
 }

src/java.base/windows/classes/sun/nio/ch/FileKey.java

@@ -33,16 +33,21 @@
  */
 public class FileKey {
 
-    private int dwVolumeSerialNumber;
-    private int nFileIndexHigh;
-    private int nFileIndexLow;
+    private final int dwVolumeSerialNumber;
+    private final int nFileIndexHigh;
+    private final int nFileIndexLow;
 
-    private FileKey() { }
+    private FileKey(int dwVolumeSerialNumber, int nFileIndexHigh,
+        int nFileIndexLow) {
+        this.dwVolumeSerialNumber = dwVolumeSerialNumber;
+        this.nFileIndexHigh = nFileIndexHigh;
+        this.nFileIndexLow = nFileIndexLow;
+    }
 
     public static FileKey create(FileDescriptor fd) throws IOException {
-        FileKey fk = new FileKey();
-        fk.init(fd);
-        return fk;
+        int finfo[] = new int[3];
+        init(fd, finfo);
+        return new FileKey(finfo[0], finfo[1], finfo[2]);
     }
 
     @Override
@@ -60,11 +65,10 @@ public boolean equals(Object obj) {
                 && this.nFileIndexLow == other.nFileIndexLow;
     }
 
-    private native void init(FileDescriptor fd) throws IOException;
-    private static native void initIDs();
+    private static native void init(FileDescriptor fd, int[] finfo)
+        throws IOException;
 
     static {
         IOUtil.load();
-        initIDs();
     }
 }

src/java.base/windows/native/libnio/ch/FileKey.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -30,32 +30,20 @@
 #include "nio_util.h"
 #include "sun_nio_ch_FileKey.h"
 
-static jfieldID key_volumeSN;    /* id for FileKey.dwVolumeSerialNumber */
-static jfieldID key_indexHigh;   /* id for FileKey.nFileIndexHigh */
-static jfieldID key_indexLow;    /* id for FileKey.nFileIndexLow */
-
-
-JNIEXPORT void JNICALL
-Java_sun_nio_ch_FileKey_initIDs(JNIEnv *env, jclass clazz)
-{
-    CHECK_NULL(key_volumeSN = (*env)->GetFieldID(env, clazz, "dwVolumeSerialNumber", "I"));
-    CHECK_NULL(key_indexHigh = (*env)->GetFieldID(env, clazz, "nFileIndexHigh", "I"));
-    CHECK_NULL(key_indexLow = (*env)->GetFieldID(env, clazz, "nFileIndexLow", "I"));
-}
-
-
 JNIEXPORT void JNICALL
-Java_sun_nio_ch_FileKey_init(JNIEnv *env, jobject this, jobject fdo)
+Java_sun_nio_ch_FileKey_init(JNIEnv *env, jclass clazz, jobject fdo, jintArray finfo)
 {
-    HANDLE fileHandle = (HANDLE)(handleval(env, fdo));
+    HANDLE fileHandle = (HANDLE)handleval(env, fdo);
     BOOL result;
     BY_HANDLE_FILE_INFORMATION fileInfo;
+    jint info[3];
 
     result = GetFileInformationByHandle(fileHandle, &fileInfo);
     if (result) {
-        (*env)->SetIntField(env, this, key_volumeSN, fileInfo.dwVolumeSerialNumber);
-        (*env)->SetIntField(env, this, key_indexHigh, fileInfo.nFileIndexHigh);
-        (*env)->SetIntField(env, this, key_indexLow, fileInfo.nFileIndexLow);
+        info[0] = (jint)fileInfo.dwVolumeSerialNumber;
+        info[1] = (jint)fileInfo.nFileIndexHigh;
+        info[2] = (jint)fileInfo.nFileIndexLow;
+        (*env)->SetIntArrayRegion(env, finfo, 0, 3, info);
     } else {
         JNU_ThrowIOExceptionWithLastError(env, "GetFileInformationByHandle failed");
     }