Fix for HER-1906 checkpointing gives error on Windows

* HardLinker.java makeHardLink() - wrap unix link() and windows CreateHardLink() and choose depending on platform * BdbModule.java doCheckpoint() - use HardLinker.makeHardLink()
2026-07-17 13:07:22 +00:00 · 2011-06-24 19:24:28 +00:00
parent 39091dc82c
commit 041554fa5d
2 changed files with 97 additions and 2 deletions
@@ -43,6 +43,7 @@ import org.archive.checkpointing.Checkpoint;
 import org.archive.checkpointing.Checkpointable;
 import org.archive.spring.ConfigPath;
 import org.archive.util.CLibrary;
+import org.archive.util.HardLinker;
 import org.archive.util.IdentityCacheable;
 import org.archive.util.ObjectIdentityBdbManualCache;
 import org.archive.util.ObjectIdentityCache;
@@ -486,8 +487,7 @@ public class BdbModule implements Lifecycle, Checkpointable, Closeable {
                    filedata[i] += ","+f.length();
                    if(getUseHardLinkCheckpoints()) {
                        File hardLink = new File(envCpDir,filedata[i]);
-                        int status = CLibrary.INSTANCE.link(f.getAbsolutePath(), hardLink.getAbsolutePath()); 
-                        if(status!=0) {
+                        if (!HardLinker.makeHardLink(f.getAbsolutePath(), hardLink.getAbsolutePath())) {
                            LOGGER.log(Level.SEVERE, "unable to create required checkpoint link "+hardLink); 
                        }
                    }
@@ -0,0 +1,95 @@
+/*
+ *  This file is part of the Heritrix web crawler (crawler.archive.org).
+ *
+ *  Licensed to the Internet Archive (IA) by one or more individual 
+ *  contributors. 
+ *
+ *  The IA licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package org.archive.util;
+import java.io.File;
+import java.io.IOException;
+
+import com.sun.jna.Native;
+import com.sun.jna.Platform;
+import com.sun.jna.Pointer;
+import com.sun.jna.Structure;
+import com.sun.jna.win32.StdCallLibrary;
+
+/**
+ * Wrapper for platform-dependent hard link creation.
+ * 
+ * @see http://stackoverflow.com/questions/783075/creating-a-hard-link-in-java/3023349#3023349
+ */
+public class HardLinker {
+    
+    // see https://github.com/twall/jna/blob/master/www/GettingStarted.md
+    public interface Kernel32Library extends StdCallLibrary {
+        Kernel32Library INSTANCE = (Kernel32Library) (Platform.isWindows() 
+                ? Native.loadLibrary("kernel32", Kernel32Library.class)
+                : null);
+        
+        /* http://msdn.microsoft.com/en-us/library/aa379560%28VS.85%29.aspx
+         * http://en.wikipedia.org/wiki/Java_Native_Access
+         * 
+         * typedef struct _SECURITY_ATTRIBUTES {
+         *   DWORD  nLength;
+         *   LPVOID lpSecurityDescriptor;
+         *   BOOL   bInheritHandle;
+         * } SECURITY_ATTRIBUTES, *PSECURITY_ATTRIBUTES, *LPSECURITY_ATTRIBUTES;
+         */
+        public static class LPSECURITY_ATTRIBUTES extends Structure {
+            public int nLength;
+            public Pointer lpSecurityDescriptor;
+            public boolean bInheritHandle;
+        }
+
+        /*
+         * http://msdn.microsoft.com/en-us/library/aa363860%28VS.85%29.aspx
+         * CreateHardLink is a macro that maps to CreateHardLinkA (ansi) or
+         * CreateHardLinkW (unicode). In initial testing CreateHardLinkW()
+         * worked, but then it stopped working... go figure.
+         */
+        boolean CreateHardLinkA(String newPath, String existingPath, LPSECURITY_ATTRIBUTES lpSecurityAttributes);
+        // boolean CreateHardLinkW(String newPath, String existingPath, LPSECURITY_ATTRIBUTES lpSecurityAttributes);
+    }
+    
+    /**
+     * Wrapper over platform-dependent system calls to create a hard link.
+     * 
+     * @return true on success
+     */
+    public static boolean makeHardLink(String existingPath, String newPath) {
+        if (Platform.isWindows()) {
+            return Kernel32Library.INSTANCE.CreateHardLinkA(newPath, existingPath, null);
+        } else {
+            int status = CLibrary.INSTANCE.link(existingPath, newPath);
+            return status == 0;
+        }
+    }
+
+    public static void main(String[] args) throws IOException {
+        File existingPath = File.createTempFile("heritrixHardLinkTestExistingFile", ".tmp");
+        File newPath = File.createTempFile("heritrixHardLinkTestNewFile", ".tmp");
+        newPath.delete();
+        
+        if (HardLinker.makeHardLink(existingPath.getAbsolutePath(), newPath.getAbsolutePath())) {
+            System.out.println("success - made hard link from " + newPath.getAbsolutePath() + " to " + existingPath.getAbsolutePath());
+        } else {
+            System.out.println("failed to make hard link from " + newPath.getAbsolutePath() + " to " + existingPath.getAbsolutePath());
+        }
+    }
+}
+
+