Operations that don't fit in memory are now faster. Temporary file handling was changed.

h2/src/main/org/h2/store/FileStore.java

@@ -249,7 +249,6 @@ public class FileStore {
     public void closeAndDeleteSilently() {
         if (file != null) {
             closeSilently();
-            tempFileDeleter.updateAutoDelete(autoDeleteReference);
             tempFileDeleter.deleteFile(autoDeleteReference, name);
             name = null;
         }
@@ -462,8 +461,6 @@ public class FileStore {
     public void autoDelete() {
         if (autoDeleteReference == null) {
             autoDeleteReference = tempFileDeleter.addFile(name, this);
-        } else {
-            tempFileDeleter.updateAutoDelete(autoDeleteReference);
         }
     }
 

h2/src/main/org/h2/store/fs/FileSystem.java

@@ -10,13 +10,21 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.ArrayList;
+import org.h2.util.MathUtils;
 import org.h2.util.New;
+import org.h2.util.Utils;
 
 /**
  * The file system is a storage abstraction.
  */
 public abstract class FileSystem {
 
+    /**
+     * The prefix for temporary files. See also TestClearReferences.
+     */
+    private static String tempRandom;
+    private static long tempSequence;
+
     private static boolean defaultServicesRegistered;
 
     private static final ArrayList<FileSystem> SERVICES = New.arrayList();
@@ -134,19 +142,6 @@ public abstract class FileSystem {
      */
     public abstract boolean tryDelete(String fileName);
 
-    /**
-     * Create a new temporary file.
-     *
-     * @param prefix the prefix of the file name (including directory name if
-     *            required)
-     * @param suffix the suffix
-     * @param deleteOnExit if the file should be deleted when the virtual
-     *            machine exists
-     * @param inTempDir if the file should be stored in the temporary directory
-     * @return the name of the created file
-     */
-    public abstract String createTempFile(String prefix, String suffix, boolean deleteOnExit, boolean inTempDir) throws IOException;
-
     /**
      * List the files in the given directory.
      *
@@ -295,4 +290,43 @@ public abstract class FileSystem {
      */
     public abstract InputStream openFileInputStream(String fileName) throws IOException;
 
+    /**
+     * Get the next temporary file name part (the part in the middle).
+     *
+     * @param newRandom if the random part of the filename should change
+     * @return the file name part
+     */
+    protected synchronized String getNextTempFileNamePart(boolean newRandom) {
+        if (newRandom || tempRandom == null) {
+            byte[] prefix = new byte[8];
+            MathUtils.randomBytes(prefix);
+            tempRandom = Utils.convertBytesToString(prefix) + ".";
+        }
+        return tempRandom + tempSequence++;
+    }
+
+    /**
+     * Create a new temporary file.
+     *
+     * @param prefix the prefix of the file name (including directory name if
+     *            required)
+     * @param suffix the suffix
+     * @param deleteOnExit if the file should be deleted when the virtual
+     *            machine exists
+     * @param inTempDir if the file should be stored in the temporary directory
+     * @return the name of the created file
+     */
+    public String createTempFile(String name, String suffix, boolean deleteOnExit, boolean inTempDir) throws IOException {
+        while (true) {
+            String n = name + getNextTempFileNamePart(false) + suffix;
+            if (exists(n)) {
+                // in theory, the random number could collide
+                getNextTempFileNamePart(true);
+            }
+            // creates the file (not thread safe)
+            openFileObject(n, "rw").close();
+            return n;
+        }
+    }
+
 }

h2/src/main/org/h2/store/fs/FileSystemDisk.java

@@ -183,10 +183,16 @@ public class FileSystemDisk extends FileSystem {
             dir = new File(name).getAbsoluteFile().getParentFile();
             IOUtils.mkdirs(dir);
         }
-        if (prefix.length() < 3) {
-            prefix += "0";
+        File f;
+        while (true) {
+            f = new File(dir, prefix + getNextTempFileNamePart(false) + suffix);
+            if (f.exists()) {
+                // in theory, the random number could collide
+                getNextTempFileNamePart(true);
+            } else {
+                break;
+            }
         }
-        File f = File.createTempFile(prefix, suffix, dir);
         if (deleteOnExit) {
             try {
                 f.deleteOnExit();

h2/src/main/org/h2/store/fs/FileSystemMemory.java

@@ -14,7 +14,6 @@ import java.util.Iterator;
 import java.util.TreeMap;
 import org.h2.message.DbException;
 import org.h2.util.IOUtils;
-import org.h2.util.MathUtils;
 import org.h2.util.New;
 
 /**
@@ -88,19 +87,6 @@ public class FileSystemMemory extends FileSystem {
         return true;
     }
 
-    public String createTempFile(String name, String suffix, boolean deleteOnExit, boolean inTempDir) {
-        name += ".";
-        synchronized (MEMORY_FILES) {
-            for (int i = 0;; i++) {
-                String n = name + (MathUtils.secureRandomLong() >>> 1) + suffix;
-                if (!exists(n)) {
-                    getMemoryFile(n);
-                    return n;
-                }
-            }
-        }
-    }
-
     public String[] listFiles(String path) {
         ArrayList<String> list = New.arrayList();
         synchronized (MEMORY_FILES) {

h2/src/main/org/h2/util/TempFileDeleter.java

@@ -20,7 +20,7 @@ import org.h2.message.DbException;
 public class TempFileDeleter {
 
     private final ReferenceQueue<Object> queue = new ReferenceQueue<Object>();
-    private final HashMap<PhantomReference< ? >, TempFile> refMap = New.hashMap();
+    private final HashMap<PhantomReference< ? >, String> refMap = New.hashMap();
 
     private TempFileDeleter() {
         // utility class
@@ -30,22 +30,6 @@ public class TempFileDeleter {
         return new TempFileDeleter();
     }
 
-    /**
-     * Contains information about a file.
-     */
-    static class TempFile {
-
-        /**
-         * The file name.
-         */
-        String fileName;
-
-        /**
-         * The last modified date of this file.
-         */
-        long lastModified;
-    }
-
     /**
      * Add a file to the list of temp files to delete. The file is deleted once
      * the file object is garbage collected.
@@ -57,30 +41,11 @@ public class TempFileDeleter {
     public synchronized Reference< ? > addFile(String fileName, Object file) {
         IOUtils.trace("TempFileDeleter.addFile", fileName, file);
         PhantomReference< ? > ref = new PhantomReference<Object>(file, queue);
-        TempFile f = new TempFile();
-        f.fileName = fileName;
-        f.lastModified = IOUtils.getLastModified(fileName);
-        refMap.put(ref, f);
+        refMap.put(ref, fileName);
         deleteUnused();
         return ref;
     }
 
-    /**
-     * Update the last modified date of the auto-delete reference. If the file
-     * was modified after that, it will not be deleted (because it might have
-     * been deleted and then re-created).
-     *
-     * @param ref the reference
-     */
-    public synchronized void updateAutoDelete(Reference< ? > ref) {
-        TempFile f2 = refMap.get(ref);
-        if (f2 != null) {
-            String fileName = f2.fileName;
-            long mod = IOUtils.getLastModified(fileName);
-            f2.lastModified = mod;
-        }
-    }
-
     /**
      * Delete the given file now. This will remove the reference from the list.
      *
@@ -89,18 +54,12 @@ public class TempFileDeleter {
      */
     public synchronized void deleteFile(Reference< ? > ref, String fileName) {
         if (ref != null) {
-            TempFile f2 = refMap.remove(ref);
+            String f2 = refMap.remove(ref);
             if (f2 != null) {
-                if (SysProperties.CHECK && fileName != null && !f2.fileName.equals(fileName)) {
-                    DbException.throwInternalError("f2:" + f2.fileName + " f:" + fileName);
-                }
-                fileName = f2.fileName;
-                long mod = IOUtils.getLastModified(fileName);
-                if (mod != f2.lastModified) {
-                    // the file has been deleted and a new one created
-                    // or it has been modified afterwards
-                    return;
+                if (SysProperties.CHECK && fileName != null && !f2.equals(fileName)) {
+                    DbException.throwInternalError("f2:" + f2 + " f:" + fileName);
                 }
+                fileName = f2;
             }
         }
         if (fileName != null && IOUtils.exists(fileName)) {
@@ -117,8 +76,8 @@ public class TempFileDeleter {
      * Delete all registered temp files.
      */
     public void deleteAll() {
-        for (TempFile tempFile : refMap.values()) {
-            deleteFile(null, tempFile.fileName);
+        for (String tempFile : refMap.values()) {
+            deleteFile(null, tempFile);
         }
         deleteUnused();
     }
@@ -146,9 +105,9 @@ public class TempFileDeleter {
     public void stopAutoDelete(Reference< ? > ref, String fileName) {
         IOUtils.trace("TempFileDeleter.stopAutoDelete", fileName, ref);
         if (ref != null) {
-            TempFile f2 = refMap.remove(ref);
-            if (SysProperties.CHECK && (f2 == null || !f2.fileName.equals(fileName))) {
-                DbException.throwInternalError("f2:" + f2 + " " + (f2 == null ? "" : f2.fileName) + " f:" + fileName);
+            String f2 = refMap.remove(ref);
+            if (SysProperties.CHECK && (f2 == null || !f2.equals(fileName))) {
+                DbException.throwInternalError("f2:" + f2 + " " + (f2 == null ? "" : f2) + " f:" + fileName);
             }
         }
         deleteUnused();

h2/src/test/org/h2/test/unit/FileSystemDatabase.java

@@ -240,18 +240,6 @@ public class FileSystemDatabase extends FileSystem {
         }
     }
 
-    public String createTempFile(String name, String suffix, boolean deleteOnExit, boolean inTempDir) throws IOException {
-        name += ".";
-        for (int i = 0;; i++) {
-            String n = name + i + suffix;
-            if (!exists(n)) {
-                // creates the file (not thread safe)
-                openFileObject(n, "rw").close();
-                return n;
-            }
-        }
-    }
-
     public synchronized void delete(String fileName) {
         try {
             long id = getId(fileName, false);

h2/src/test/org/h2/test/unit/TestClearReferences.java

@@ -33,7 +33,8 @@ public class TestClearReferences extends TestBase {
         "org.h2.util.MemoryUtils.reserveMemory",
         "org.h2.util.NetUtils.cachedLocalAddress",
         "org.h2.util.MathUtils.cachedSecureRandom",
-        "org.h2.value.CompareMode.lastUsed"
+        "org.h2.value.CompareMode.lastUsed",
+        "org.h2.store.fs.FileSystem.tempRandom",
     };
 
     private boolean hasError;