src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataWriter.java
changeset 50113 caf115bb98ad
child 57360 5d043a159d5c
child 58863 c16ac7a2eba4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataWriter.java	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,225 @@
+/*
+ * Copyright (c) 2016, 2018, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+package jdk.jfr.internal;
+
+import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_CONSTANT_POOL;
+import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_DEFAULT_VALUE;
+import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_DIMENSION;
+import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_GMT_OFFSET;
+import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_ID;
+import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_LOCALE;
+import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_NAME;
+import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_SIMPLE_TYPE;
+import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_SUPER_TYPE;
+import static jdk.jfr.internal.MetadataDescriptor.ATTRIBUTE_TYPE_ID;
+import static jdk.jfr.internal.MetadataDescriptor.ELEMENT_ANNOTATION;
+import static jdk.jfr.internal.MetadataDescriptor.ELEMENT_FIELD;
+import static jdk.jfr.internal.MetadataDescriptor.ELEMENT_SETTING;
+import static jdk.jfr.internal.MetadataDescriptor.ELEMENT_TYPE;
+
+import java.io.DataOutput;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Set;
+
+import jdk.jfr.AnnotationElement;
+import jdk.jfr.SettingDescriptor;
+import jdk.jfr.ValueDescriptor;
+import jdk.jfr.internal.MetadataDescriptor.Attribute;
+import jdk.jfr.internal.MetadataDescriptor.Element;
+import jdk.jfr.internal.consumer.RecordingInput;
+
+/**
+ * Class responsible for converting a list of types into a format that can be
+ * parsed by a client.
+ *
+ */
+final class MetadataWriter {
+
+    private final Element metadata = new Element("metadata");
+    private final Element root = new Element("root");
+
+    public MetadataWriter(MetadataDescriptor descriptor) {
+        descriptor.getTypes().forEach(type -> makeTypeElement(metadata, type));
+
+        root.add(metadata);
+        Element region = new Element("region");
+        region.addAttribute(ATTRIBUTE_LOCALE, descriptor.locale);
+        region.addAttribute(ATTRIBUTE_GMT_OFFSET, descriptor.gmtOffset);
+        root.add(region);
+    }
+
+    public void writeBinary(DataOutput output) throws IOException {
+        Set<String> stringPool = new HashSet<>(1000);
+        // Possible improvement, sort string by how often they occur.
+        // and assign low number to the most frequently used.
+        buildStringPool(root, stringPool);
+        HashMap<String, Integer> lookup = new LinkedHashMap<>(stringPool.size());
+        int index = 0;
+        int poolSize = stringPool.size();
+        writeInt(output, poolSize);
+        for (String s : stringPool) {
+            lookup.put(s, index);
+            writeString(output, s);
+            index++;
+        }
+        write(output, root, lookup);
+    }
+
+    private void writeString(DataOutput out, String s) throws IOException {
+        if (s == null ) {
+            out.writeByte(RecordingInput.STRING_ENCODING_NULL);
+            return;
+        }
+        out.writeByte(RecordingInput.STRING_ENCODING_CHAR_ARRAY); // encoding UTF-16
+        int length = s.length();
+        writeInt(out, length);
+            for (int i = 0; i < length; i++) {
+                writeInt(out, s.charAt(i));
+            }
+    }
+
+    private void writeInt(DataOutput out, int v) throws IOException {
+
+        long s = v & 0xffffffffL;
+        if (s < 1 << 7) {
+            out.write((byte) (s));
+            return;
+        }
+        out.write((byte) (s | 0x80)); // first byte written
+        s >>= 7;
+        if (s < 1 << 7) {
+            out.write((byte) (s));
+            return;
+        }
+        out.write((byte) (s | 0x80)); // second byte written
+        s >>= 7;
+        if (s < 1 << 7) {
+            out.write((byte) (s));
+            return;
+        }
+        out.write((byte) (s | 0x80)); // third byte written
+        s >>= 7;
+        if (s < 1 << 7) {
+            out.write((byte) (s));
+            return;
+        }
+        s >>= 7;
+        out.write((byte) (s));// fourth byte written
+    }
+
+    private void buildStringPool(Element element, Set<String> pool) {
+        pool.add(element.name);
+        for (Attribute a : element.attributes) {
+            pool.add(a.name);
+            pool.add(a.value);
+        }
+        for (Element child : element.elements) {
+            buildStringPool(child, pool);
+        }
+    }
+
+    private void write(DataOutput output,Element element, HashMap<String, Integer> lookup) throws IOException {
+        writeInt(output, lookup.get(element.name));
+        writeInt(output, element.attributes.size());
+        for (Attribute a : element.attributes) {
+            writeInt(output, lookup.get(a.name));
+            writeInt(output, lookup.get(a.value));
+        }
+        writeInt(output, element.elements.size());
+        for (Element child : element.elements) {
+            write(output, child, lookup);
+        }
+    }
+
+    private void makeTypeElement(Element root, Type type) {
+        Element element = root.newChild(ELEMENT_TYPE);
+        element.addAttribute(ATTRIBUTE_NAME, type.getName());
+        String superType = type.getSuperType();
+        if (superType != null) {
+            element.addAttribute(ATTRIBUTE_SUPER_TYPE, superType);
+        }
+        if (type.isSimpleType()) {
+            element.addAttribute(ATTRIBUTE_SIMPLE_TYPE, true);
+        }
+        element.addAttribute(ATTRIBUTE_ID, type.getId());
+        if (type instanceof PlatformEventType) {
+            for (SettingDescriptor v : ((PlatformEventType)type).getSettings()) {
+                makeSettingElement(element, v);
+            }
+        }
+        for (ValueDescriptor v : type.getFields()) {
+            makeFieldElement(element, v);
+        }
+        for (AnnotationElement a : type.getAnnotationElements()) {
+            makeAnnotation(element, a);
+        }
+    }
+
+    private void makeSettingElement(Element typeElement, SettingDescriptor s) {
+        Element element = typeElement.newChild(ELEMENT_SETTING);
+        element.addAttribute(ATTRIBUTE_NAME, s.getName());
+        element.addAttribute(ATTRIBUTE_TYPE_ID, s.getTypeId());
+        element.addAttribute(ATTRIBUTE_DEFAULT_VALUE, s.getDefaultValue());
+        for (AnnotationElement a : s.getAnnotationElements()) {
+            makeAnnotation(element, a);
+        }
+    }
+
+    private void makeFieldElement(Element typeElement, ValueDescriptor v) {
+        Element element = typeElement.newChild(ELEMENT_FIELD);
+        element.addAttribute(ATTRIBUTE_NAME, v.getName());
+        element.addAttribute(ATTRIBUTE_TYPE_ID, v.getTypeId());
+        if (v.isArray()) {
+            element.addAttribute(ATTRIBUTE_DIMENSION, 1);
+        }
+        if (PrivateAccess.getInstance().isConstantPool(v)) {
+            element.addAttribute(ATTRIBUTE_CONSTANT_POOL, true);
+        }
+        for (AnnotationElement a : v.getAnnotationElements()) {
+            makeAnnotation(element, a);
+        }
+    }
+
+    private void makeAnnotation(Element entity, AnnotationElement annotation) {
+        Element element = entity.newChild(ELEMENT_ANNOTATION);
+        element.addAttribute(ATTRIBUTE_TYPE_ID, annotation.getTypeId());
+        List<Object> values = annotation.getValues();
+        int index = 0;
+        for (ValueDescriptor v : annotation.getValueDescriptors()) {
+            Object value = values.get(index++);
+            if (v.isArray()) {
+                element.addArrayAttribute(element, v.getName(), value);
+            } else {
+                element.addAttribute(v.getName(), value);
+            }
+        }
+    }
+
+}