Merge pull request #1147 from katzyn/misc

Assorted minor optimizations

h2/src/main/org/h2/command/dml/Insert.java

@@ -415,7 +415,7 @@ public class Insert extends Prepared implements ResultTarget {
         for (Column column : duplicateKeyAssignmentMap.keySet()) {
             buff.appendExceptFirst(", ");
             Expression ex = duplicateKeyAssignmentMap.get(column);
-            buff.append(column.getSQL()).append("=").append(ex.getSQL());
+            buff.append(column.getSQL()).append('=').append(ex.getSQL());
         }
         buff.append(" WHERE ");
         Index foundIndex = (Index) de.getSource();

h2/src/main/org/h2/command/dml/Select.java

@@ -1164,7 +1164,7 @@ public class Select extends Query {
                         buff.appendExceptFirst(",");
                         buff.append(c.getName());
                     }
-                    buff.append(") AS ").append(t.getSQL()).append("\n");
+                    buff.append(") AS ").append(t.getSQL()).append('\n');
                 }
             }
         }

h2/src/main/org/h2/expression/Function.java

@@ -2492,7 +2492,7 @@ public class Function extends Expression implements FunctionCall {
         StatementBuilder buff = new StatementBuilder(info.name);
         if (info.type == CASE) {
             if (args[0] != null) {
-                buff.append(" ").append(args[0].getSQL());
+                buff.append(' ').append(args[0].getSQL());
             }
             for (int i = 1, len = args.length - 1; i < len; i += 2) {
                 buff.append(" WHEN ").append(args[i].getSQL());

h2/src/main/org/h2/fulltext/FullTextSettings.java

@@ -10,11 +10,12 @@ import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
 import org.h2.util.SoftHashMap;
 
 /**
@@ -45,8 +46,7 @@ final class FullTextSettings {
     /**
      * The set of indexes in this database.
      */
-    private final Map<Integer, IndexInfo> indexes = Collections
-            .synchronizedMap(new HashMap<Integer, IndexInfo>());
+    private final ConcurrentHashMap<Integer, IndexInfo> indexes = new ConcurrentHashMap<>();
 
     /**
      * The prepared statement cache.

h2/src/main/org/h2/index/PageDataIndex.java

@@ -491,8 +491,7 @@ public class PageDataIndex extends PageIndex {
 
     Iterator<Row> getDelta() {
         if (delta == null) {
-            List<Row> e = Collections.emptyList();
-            return e.iterator();
+            return Collections.emptyIterator();
         }
         return delta.iterator();
     }

h2/src/main/org/h2/index/ScanIndex.java

@@ -251,8 +251,7 @@ public class ScanIndex extends BaseIndex {
 
     Iterator<Row> getDelta() {
         if (delta == null) {
-            List<Row> e = Collections.emptyList();
-            return e.iterator();
+            return Collections.emptyIterator();
         }
         return delta.iterator();
     }

h2/src/main/org/h2/mvstore/db/MVPrimaryIndex.java

@@ -258,7 +258,7 @@ public class MVPrimaryIndex extends BaseIndex {
         ValueLong v = (ValueLong) (first ? map.firstKey() : map.lastKey());
         if (v == null) {
             return new MVStoreCursor(session,
-                    Collections.<Entry<Value, Value>> emptyList().iterator());
+                    Collections.<Entry<Value, Value>> emptyIterator());
         }
         Value value = map.get(v);
         Entry<Value, Value> e = new AbstractMap.SimpleImmutableEntry<Value, Value>(v, value);

h2/src/main/org/h2/mvstore/db/MVSecondaryIndex.java

@@ -307,7 +307,7 @@ public final class MVSecondaryIndex extends BaseIndex implements MVIndex {
             }
             if (min == null) {
                 return new MVStoreCursor(session,
-                        Collections.<Value>emptyList().iterator(), null);
+                        Collections.<Value>emptyIterator(), null);
             }
         }
         return new MVStoreCursor(session, map.keyIterator(min), last);
@@ -394,7 +394,7 @@ public final class MVSecondaryIndex extends BaseIndex implements MVIndex {
         while (true) {
             if (key == null) {
                 return new MVStoreCursor(session,
-                        Collections.<Value>emptyList().iterator(), null);
+                        Collections.<Value>emptyIterator(), null);
             }
             if (((ValueArray) key).getList()[0] != ValueNull.INSTANCE) {
                 break;

h2/src/main/org/h2/server/TcpServer.java

@@ -21,6 +21,8 @@ import java.util.HashSet;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
 import org.h2.Driver;
 import org.h2.api.ErrorCode;
 import org.h2.engine.Constants;
@@ -49,8 +51,7 @@ public class TcpServer implements Service {
      */
     private static final String MANAGEMENT_DB_PREFIX = "management_db_";
 
-    private static final Map<Integer, TcpServer> SERVERS =
-            Collections.synchronizedMap(new HashMap<Integer, TcpServer>());
+    private static final ConcurrentHashMap<Integer, TcpServer> SERVERS = new ConcurrentHashMap<>();
 
     private int port;
     private boolean portIsSet;

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

@@ -9,10 +9,8 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.channels.FileChannel;
-import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import org.h2.util.MathUtils;
 
 /**
@@ -25,7 +23,7 @@ public abstract class FilePath {
 
     private static FilePath defaultProvider;
 
-    private static Map<String, FilePath> providers;
+    private static ConcurrentHashMap<String, FilePath> providers;
 
     /**
      * The prefix for temporary files.
@@ -66,8 +64,7 @@ public abstract class FilePath {
 
     private static void registerDefaultProviders() {
         if (providers == null || defaultProvider == null) {
-            Map<String, FilePath> map = Collections.synchronizedMap(
-                    new HashMap<String, FilePath>());
+            ConcurrentHashMap<String, FilePath> map = new ConcurrentHashMap<>();
             for (String c : new String[] {
                     "org.h2.store.fs.FilePathDisk",
                     "org.h2.store.fs.FilePathMem",

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

@@ -5,10 +5,7 @@
  */
 package org.h2.util;
 
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.IdentityHashMap;
-import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
@@ -17,10 +14,8 @@ import java.util.concurrent.atomic.AtomicBoolean;
 public class SynchronizedVerifier {
 
     private static volatile boolean enabled;
-    private static final Map<Class<?>, AtomicBoolean> DETECT =
-        Collections.synchronizedMap(new HashMap<Class<?>, AtomicBoolean>());
-    private static final Map<Object, Object> CURRENT =
-        Collections.synchronizedMap(new IdentityHashMap<>());
+    private static final ConcurrentHashMap<Class<?>, AtomicBoolean> DETECT = new ConcurrentHashMap<>();
+    private static final ConcurrentHashMap<Object, Object> CURRENT = new ConcurrentHashMap<>();
 
     /**
      * Enable or disable detection for a given class.

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

@@ -265,7 +265,7 @@ public class ToDateParser {
         while (p.hasToParseData()) {
             List<ToDateTokenizer.FormatTokenEnum> tokenList =
                     ToDateTokenizer.FormatTokenEnum.getTokensInQuestion(p.getFormatStr());
-            if (tokenList.isEmpty()) {
+            if (tokenList == null) {
                 p.removeFirstChar();
                 continue;
             }

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

@@ -9,9 +9,7 @@ import static java.lang.String.format;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 import java.util.TimeZone;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -616,10 +614,9 @@ class ToDateTokenizer {
         // where "T" and "Z" are inlined
         INLINE(PARSLET_INLINE, PATTERN_INLINE);
 
-        private static final List<FormatTokenEnum> EMPTY_LIST = Collections
-                .emptyList();
+        private static final List<FormatTokenEnum> INLINE_LIST = Collections.singletonList(INLINE);
 
-        private static final Map<Character, List<FormatTokenEnum>> CACHE = new HashMap<>(64);
+        private static List<FormatTokenEnum>[] TOKENS;
         private final ToDateParslet toDateParslet;
         private final Pattern patternToUse;
 
@@ -648,60 +645,52 @@ class ToDateTokenizer {
         /**
          * Optimization: Only return a list of {@link FormatTokenEnum} that
          * share the same 1st char using the 1st char of the 'to parse'
-         * formatStr. Or return empty list if no match.
+         * formatStr. Or return {@code null} if no match.
          *
          * @param formatStr the format string
-         * @return the list of tokens
+         * @return the list of tokens, or {@code null}
          */
         static List<FormatTokenEnum> getTokensInQuestion(String formatStr) {
-            List<FormatTokenEnum> result = EMPTY_LIST;
-            if (CACHE.size() <= 0) {
-                initCache();
-            }
             if (formatStr != null && formatStr.length() > 0) {
-                Character key = Character.toUpperCase(formatStr.charAt(0));
-                switch (key) {
-                case '"':
-                    result = new ArrayList<>();
-                    result.add(INLINE);
-                    break;
-                default:
-                    result = CACHE.get(key);
+                char key = Character.toUpperCase(formatStr.charAt(0));
+                if (key >= 'A' && key <= 'Y') {
+                    List<FormatTokenEnum>[] tokens = TOKENS;
+                    if (tokens == null) {
+                        tokens = initTokens();
                     }
+                    return tokens[key - 'A'];
+                } else if (key == '"') {
+                    return INLINE_LIST;
                 }
-            if (result == null) {
-                result = EMPTY_LIST;
             }
-            return result;
+            return null;
         }
 
-        private static synchronized void initCache() {
-            if (CACHE.size() <= 0) {
+        @SuppressWarnings("unchecked")
+        private static List<FormatTokenEnum>[] initTokens() {
+            List<FormatTokenEnum>[] tokens = new List[25];
             for (FormatTokenEnum token : FormatTokenEnum.values()) {
-
-                    List<Character> tokenKeys = new ArrayList<>();
-
-                    if (token.name().contains("_")) {
-                        String[] tokens = token.name().split("_");
-                        for (String tokenLets : tokens) {
-                            tokenKeys.add(tokenLets.toUpperCase().charAt(0));
+                String name = token.name();
+                if (name.indexOf('_') >= 0) {
+                    for (String tokenLets : name.split("_")) {
+                        putToCache(tokens, token, tokenLets);
                     }
                 } else {
-                        tokenKeys.add(token.name().toUpperCase().charAt(0));
+                    putToCache(tokens, token, name);
+                }
+            }
+            return TOKENS = tokens;
         }
 
-                    for (Character tokenKey : tokenKeys) {
-                        List<FormatTokenEnum> l = CACHE.get(tokenKey);
+        private static void putToCache(List<FormatTokenEnum>[] cache, FormatTokenEnum token, String name) {
+            int idx = Character.toUpperCase(name.charAt(0)) - 'A';
+            List<FormatTokenEnum> l = cache[idx];
             if (l == null) {
                 l = new ArrayList<>(1);
-                            CACHE.put(tokenKey, l);
+                cache[idx] = l;
             }
             l.add(token);
         }
-                }
-            }
-
-        }
 
         /**
          * Parse the format-string with passed token of {@link FormatTokenEnum}.

h2/src/test/org/h2/samples/CachedPreparedStatements.java

@@ -10,9 +10,7 @@ import java.sql.DriverManager;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.sql.Statement;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * This sample application shows how to cache prepared statements.
@@ -21,9 +19,7 @@ public class CachedPreparedStatements {
 
     private Connection conn;
     private Statement stat;
-    private final Map<String, PreparedStatement> prepared =
-        Collections.synchronizedMap(
-                new HashMap<String, PreparedStatement>());
+    private final ConcurrentHashMap<String, PreparedStatement> prepared = new ConcurrentHashMap<>();
 
     /**
      * This method is called when executing this sample application from the

h2/src/test/org/h2/samples/TriggerPassData.java

@@ -10,9 +10,8 @@ import java.sql.DriverManager;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
 import org.h2.api.Trigger;
 
 /**
@@ -21,8 +20,7 @@ import org.h2.api.Trigger;
  */
 public class TriggerPassData implements Trigger {
 
-    private static final Map<String, TriggerPassData> TRIGGERS =
-        Collections.synchronizedMap(new HashMap<String, TriggerPassData>());
+    private static final ConcurrentHashMap<String, TriggerPassData> TRIGGERS = new ConcurrentHashMap<>();
     private String triggerData;
 
     /**

h2/src/test/org/h2/test/synth/TestFuzzOptimizations.java

@@ -117,11 +117,16 @@ public class TestFuzzOptimizations extends TestBase {
                 }
                 executeAndCompare(condition, params, message);
             }
-            if (!config.mvStore) {
+            if (!config.mvStore && config.travis) {
                 /*
                  * Travis tests have problems with automatic garbage collection, so request a GC
                  * explicitly and print its results.
                  */
+                try {
+                    Thread.sleep(100);
+                } catch (InterruptedException e) {
+                    throw new RuntimeException(e);
+                }
                 println((Utils.getMemoryUsed() >> 10) + " MiB used");
             }
         }

h2/src/tools/org/h2/jaqu/SQLDialect.java

@@ -98,12 +98,12 @@ public interface SQLDialect {
             buff.append(index.indexName);
             buff.append(" ON ");
             buff.append(table);
-            buff.append("(");
+            buff.append('(');
             for (String col : index.columnNames) {
                 buff.appendExceptFirst(", ");
                 buff.append(col);
             }
-            buff.append(")");
+            buff.append(')');
             return buff.toString();
         }