jdk/test/java/io/FileInputStream/LargeFileAvailable.java
changeset 7519 1488bb354081
child 8158 77d9c0f1c19f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/io/FileInputStream/LargeFileAvailable.java	Wed Dec 01 15:58:49 2010 -0800
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2010, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 6402006
+ * @summary Test if available returns correct value when reading
+ *          a large file.
+ */
+
+import java.io.*;
+import java.nio.ByteBuffer;
+import java.nio.channels.*;
+import static java.nio.file.StandardOpenOption.*;
+
+public class LargeFileAvailable {
+    private static final long FILESIZE = 7405576182L;
+    public static void main(String args[]) throws Exception {
+        File file = createLargeFile(FILESIZE);
+        try (FileInputStream fis = new FileInputStream(file)) {
+            if (file.length() != FILESIZE) {
+                throw new RuntimeException("unexpected file size = " + file.length());
+            }
+
+            long bigSkip = 3110608882L;
+            long remaining = FILESIZE;
+            remaining -= skipBytes(fis, bigSkip, remaining);
+            remaining -= skipBytes(fis, 10L, remaining);
+            remaining -= skipBytes(fis, bigSkip, remaining);
+            if (fis.available() != (int) remaining) {
+                 throw new RuntimeException("available() returns " +
+                     fis.available() +
+                     " but expected " + remaining);
+            }
+        } finally {
+            file.delete();
+        }
+    }
+
+    // Skip toSkip number of bytes and expect that the available() method
+    // returns avail number of bytes.
+    private static long skipBytes(InputStream is, long toSkip, long avail)
+            throws IOException {
+        long skip = is.skip(toSkip);
+        if (skip != toSkip) {
+            throw new RuntimeException("skip() returns " + skip +
+                " but expected " + toSkip);
+        }
+        long remaining = avail - skip;
+        int expected = remaining >= Integer.MAX_VALUE
+                           ? Integer.MAX_VALUE
+                           : (int) remaining;
+
+        System.out.println("Skipped " + skip + " bytes " +
+            " available() returns " + expected +
+            " remaining=" + remaining);
+        if (is.available() != expected) {
+            throw new RuntimeException("available() returns " +
+                is.available() + " but expected " + expected);
+        }
+        return skip;
+    }
+
+    private static File createLargeFile(long filesize) throws Exception {
+        // Create a large file as a sparse file if possible
+        File largefile = File.createTempFile("largefile", null);
+        // re-create as a sparse file
+        largefile.toPath().delete();
+        try (FileChannel fc =
+                FileChannel.open(largefile.toPath(),
+                                 CREATE_NEW, WRITE, SPARSE)) {
+            ByteBuffer bb = ByteBuffer.allocate(1).put((byte)1);
+            bb.rewind();
+            int rc = fc.write(bb, filesize-1);
+            if (rc != 1) {
+                throw new RuntimeException("Failed to write 1 byte to the large file");
+            }
+        }
+        return largefile;
+    }
+}