Add a reader for Single Queues

src/main/java/net/openhft/chronicle/queue/ChronicleReader.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2014 Higher Frequency Trading
+ *
+ * http://www.higherfrequencytrading.com
+ *
+ * Licensed 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 net.openhft.chronicle.queue;
+
+import net.openhft.chronicle.bytes.Bytes;
+import net.openhft.chronicle.queue.impl.single.SingleChronicleQueueBuilder;
+import net.openhft.chronicle.wire.DocumentContext;
+
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * Display records in a Chronicle in a text form.
+ *
+ * @author peter.lawrey
+ */
+public enum ChronicleReader {
+    ;
+
+    public static void main(String... args) throws IOException, InterruptedException {
+        if (args.length < 1) {
+            System.err.println("Usage: java " + ChronicleReader.class.getName() + " {chronicle-base-path} [from-index]");
+            System.exit(-1);
+        }
+
+        String basePath = args[0];
+        ChronicleQueue ic = SingleChronicleQueueBuilder.binary(new File(basePath)).build();
+        ExcerptTailer tailer = ic.createTailer();
+        if (args.length > 1) {
+            long index = Long.parseLong(args[1]);
+            while (!tailer.moveToIndex(index))
+                Thread.sleep(50);
+        }
+
+        //noinspection InfiniteLoopStatement
+        while (true) {
+            try (DocumentContext dc = tailer.readingDocument()) {
+                if (!dc.isPresent()) {
+                    Thread.sleep(50);
+                    continue;
+                }
+                System.out.print(Long.toHexString(dc.index()) + ": ");
+                Bytes<?> bytes = dc.wire().bytes();
+                byte b0 = bytes.readByte(0);
+                if (b0 < 0) {
+                    System.out.println(bytes.toHexString());
+                } else {
+                    System.out.println(bytes.toString());
+                }
+            }
+            System.out.println();
+        }
+    }
+}

src/main/java/net/openhft/chronicle/queue/impl/single/SingleChronicleQueueExcerpts.java

@@ -35,12 +35,15 @@
 
 public class SingleChronicleQueueExcerpts {
 
+    private static final Logger LOG = LoggerFactory.getLogger(SingleChronicleQueueExcerpts.class);
+    private static final String ROLL_STRING = "roll";
+    private static final int ROLL_KEY = BytesUtil.asInt(ROLL_STRING);
+    private static final int SPB_HEADER_SIZE = 4;
     @FunctionalInterface
     public interface BytesConsumer {
         boolean accept(Bytes<?> bytes)
                 throws InterruptedException;
     }
-
     @FunctionalInterface
     public interface WireWriter<T> {
         long writeOrAdvanceIfNotEmpty(
@@ -50,12 +53,6 @@ long writeOrAdvanceIfNotEmpty(
     }
 
 
-    private static final Logger LOG = LoggerFactory.getLogger(SingleChronicleQueueExcerpts.class);
-    private static final String ROLL_STRING = "roll";
-    private static final int ROLL_KEY = BytesUtil.asInt(ROLL_STRING);
-    private static final int SPB_HEADER_SIZE = 4;
-
-
     // *************************************************************************
     //
     // APPENDERS
@@ -278,6 +275,11 @@ public Wire wire() {
             return wire;
         }
 
+        @Override
+        public long index() {
+            throw new UnsupportedOperationException("todo");
+        }
+
         @Override
         public void close() {
             storeAppender.index++;
@@ -299,8 +301,13 @@ private static class TailerDocumentContext implements DocumentContext {
             this.wire = wire;
         }
 
-        public void start() {
-            dc.start();
+        public void start(boolean next, long index) {
+            dc.start(next, index);
+        }
+
+        @Override
+        public long index() {
+            return dc.index();
         }
 
         @Override
@@ -381,8 +388,7 @@ public boolean readBytes(@NotNull final Bytes using) {
 
         @Override
         public DocumentContext readingDocument() {
-            next();
-            dc.start();
+            dc.start(next(), index);
             return dc;
         }