btrace blog initial changes

Author: jbachorik

_includes/header.html

@@ -29,8 +29,9 @@
                 <ul class="nav navbar-nav">
                     <li class="active"><a href="{{ site.baseurl }}/">Home</a></li>
                     <li class="active visible-xs-block"><a href="{{ site.baseurl }}/links.html">Links</a></li>
+                    <li class="active"><a href="{{ site.baseurl }}/downloads.html">Downloads</a></li>
+                    <!--<li class="active"><a href="{{ site.baseurl }}/about.html">About</a></li>-->
                     <li class="active"><a href="{{ site.baseurl }}/archive.html">Archive</a></li>
-                    <li class="active"><a href="{{ site.baseurl }}/about.html">About</a></li>
                     <li class="active"><a href="{{ site.baseurl }}/feed.xml">RSS</a></li>
                     {% if site.github != '' %}
                       <li class="active"><a href="https://github.com/{{ site.github }}">Github</a></li>

_includes/links-list.html

@@ -1,7 +1,4 @@
 <h1>Links</h1>
 <ul>
-  <li><a href="#">One</a></li>
-  <li><a href="#">Two</a></li>
-  <li><a href="#">Three</a></li>
-  <li><a href="#">Four</a></li>
+  <li><a href="#">None yet</a></li>
 </ul>

_layouts/default.html

@@ -2,12 +2,12 @@
 
 <div class="container container-left">
     <div class="row">
-        <div class="col-md-3 hidden-xs">
-            {% include sidebar.html %}
-        </div>
         <div class="col-md-9">
             {{ content }}
         </div>
+        <div class="col-md-3 hidden-xs">
+            {% include sidebar.html %}
+        </div>
     </div>
 </div>
 

_posts/2012-05-22-Vivamus-porttitor-porta-tortor.md

@@ -0,0 +1,67 @@
+---
+layout: post
+title: "Extensible Services for BTrace"
+date: 2014-09-10 20:00:00 +0100
+comments: false
+---
+
+# History
+
+The ability to extend **BTrace** with plugins to overcome the limits imposed by its safety guarantees while still not allowing to inject any arbitrary code was requested a long time ago and is tracked as [BTRACE-64](https://github.com/jbachorik/btrace/issues/29)
+
+# Solution, round 1
+
+The first attempt to address this problem brought many problems that were supposed to be solved by a more-or-less complete engine rewrite in **BTrace 2.0**. In order to make the system really extensible the modularity was baked-in to all its parts - it was possible to even extend the internal communication protocol with custom messages. 
+
+All of this came at a price, though. It was paid by extra nano- and micro-seconds spent in the BTrace runtime jumping through all those indirection levels.
+
+Despite the availability of the [**BTrace 2.0 Preview** builds](https://kenai.com/projects/btrace/forums/forum/topics/523919-BTrace-2) for quite a long time there was almost no reaction from the community. This would indicate that the *“rewrite from scratch”* approach is a deal-breaker for the majority of the users.
+
+# Rewind, Round 2
+
+## Sketchup
+
+Instead of rewriting the engine from scratch it seems to be possible to go the way of gradual changes and improvements.
+
+The main goal is to allow the users to write application specific extensions for **BTrace** which can be easily used just by having them on the classpath.
+
+Eg. the following invocation will allow to use any **BTrace** extensions available in the *path_to_my_extension.jar* archive. A class is considered to be an extension if it extends a **BTrace** extension base class (eg. *com.sun.btrace.services.spi.SimpleService*)
+
+## How to Use
+
+The following command would instruct **BTrace** to pickup the extensions jar.
+
+`btrace -cp ...:<path_to_my_extension.jar> <pid> <tracing script>`
+
+In order to use an extension one would do 
+
+
+``` java
+@OnMethod(....)
+public static void handler(...) {  
+  // the following statement will inject the runtime  
+  // aware service "Printer"  
+  @Injected Printer p = Service.runtime(Printer.class);    
+  p.println("hello");
+}
+
+```
+
+
+As one can see it is not that different to what one was used to do before. 
+
+## Why All This Fuzz
+
+### DSL(?) Mess Cleanup
+
+Let’s face it. **BTraceUtils** is a dump right now. It contains any and all functions one might think as being useful when writing BTrace scripts. As the result it is rather difficult to locate the method one actually wants to use.
+
+The extensions will allow for off-loading specific features of **BTraceUtils** leaving there only methods comprising the actual **DSL** (well, I might even rename the class to something more meaningful)
+
+### Integration with External Systems
+
+Right now **BTrace** is pretty limited in how it can export the collected data - it can either write it to file or stdout. While this is sufficient for one-off scripts it is not the first choice when one wants to include **BTrace** in more complex systems (eg. acting as a data provider for [Riemann](http://riemann.io/)).
+
+### Performance
+
+This implementation, in addition to not causing any performance regression, can even provide slight improvements for the runtime aware services like **Printer**. Each invocation of *print*/*println* will use the cached runtime as opposed to looking it up when using **BTraceUtils** (not using services). 

_posts/2013-05-22-Nulla-vel-risus-dapibus.md

@@ -0,0 +1,82 @@
+---
+layout: post
+title: "BTrace Services (Final Proposal)"
+date: 2014-11-13 20:00:00 +0100
+comments: false
+---
+
+In my previous [blog post](2014/09/extensible-services) I was sketching up a possible solution to **BTrace** extensibility.
+
+A few experiments with AST and bytecode verifiers later I came up with a relatively easy way to provide the extensibility of the core **BTrace** functionality by the means of external plugins. Very importantly, introducing external plugins doesn’t incur any additional overhead on top of the one caused by the extension functionality itself.
+
+# Creating a New Service
+
+Creating a new service is just a matter of extending one of the following two classes
+
+* com.sun.btrace.services.spi.SimpleService
+* com.sun.btrace.services.spi.RuntimeService
+
+
+## SimpleService
+
+A stateless service which can even be a singleton. It has no access to the **BTrace** runtime and can rely on the provided values.
+
+## RuntimeService
+
+For each **BTraceRuntime** a new service instance will be created. The service can use **BTrace** features exposed via **BTraceRuntime** - eg. send messages over the wire channel.
+
+## Using Services
+
+Services become available by adding the jars containing them to the bootclasspath. (eg. via [agent options](https://github.com/jbachorik/btrace/wiki#starting-application-with-btrace))
+
+The recommended way to use services in the script is to create fields of the appropriate service type and annotate them by the **@Injected** annotation.
+
+
+```java
+@BTrace public class MyTrace {
+    // a simple service instantiated via the default noarg constructor
+    @Injected private static MyService svc;
+
+    // a simple service instantiated via the given static method
+    @Injected(factoryMethod = "singleton") private static MyService svc1;
+
+    // a runtime-aware service instantiated via the default single arg (*BTraceRuntime*) constructor
+    @Injected(ServiceType.RUNTIME) private static RtService svc2;
+
+    @OnMethod(....)
+    public static void interceptMethod(...) {
+        svc.process(...);
+        svc1.process(...);
+        svc2.process(...);
+    }
+}
+
+```
+
+There is an alternative approach valid only for locally accessible services.
+
+```java
+@OnMethod(...)
+public void handler(...) {
+    // a simple service instantiated via the default noarg constructor
+    MyService svc = Service.simple(MyService.class);
+    
+    // a simple service instantiated via the given static method
+    MyService svc1 = Service.simple("singleton", MyService.class)
+
+    // a runtime-aware service instantiated via the default single arg (*BTraceRuntime*) constructor
+    RtService svc2 = Service.runtime(RtService.classs);
+
+    svc.process(...);
+    svc1.process(...);
+    svc2.process(...);
+}
+```
+
+These two approaches are functionally equivalent - it really depends on the script author which one she should choose.
+
+# Planning
+
+This functionality is planned for the upcoming version 1.3 of **BTrace**.
+
+Integration is tracked by this [pull request](https://github.com/jbachorik/btrace/pull/98)

_posts/2013-06-22-Cum-sociis-natoque-penatibus.md

@@ -24,8 +24,13 @@ body {
     color: #428bca;
 }
 
+.sidebar ul {
+    margin-top: -0.5em;
+}
+
 .sidebar li {
     margin-top: .7em;
+    margin-left: -1em;
     line-height: 1em;
 }
 
@@ -38,8 +43,27 @@ body {
 }
 
 .well h1 {
-    color: #ee4444;
-    font-size: 1.3em;
+    margin-top: -0.1em;
+    color: #7891b3;
+    font-size: 1.6em;
+}
+
+.well h2 {
+    margin-top: -0.1em;
+    color: #7891b3;
+    font-size: 1.4em;
+}
+
+.well h3 {
+    margin-top: -0.1em;
+    color: #7891b3;
+    font-size: 1.2em;
+}
+
+.well h4 {
+    margin-top: -0.1em;
+    color: #7891b3;
+    font-size: 1.0em;
 }
 
 .author {

_posts/2014-06-22-Maecenas-feugiat-fringilla-nibh.md

@@ -0,0 +1,14 @@
+---
+layout: default
+---
+
+<div class="article">
+    <h1>Downloads</h1>
+    <div class="well">
+        <h1>1.3-snapshot</h1>
+        <ul>
+            <li><a href="http://dl.bintray.com/jbachorik/snapshots/btrace/1.3/btrace-bin.zip">btrace-bin.zip</a></li>
+            <li><a href="http://dl.bintray.com/jbachorik/snapshots/btrace/1.3/btrace-bin.tar.gz">btrace-bin.tar.gz</a></li>
+        </ul>
+    </div>
+</div>

_posts/2014-07-22-Lorem-ipsum-dolor-sit-amet.md

@@ -1,22 +1,22 @@
 ---
-layout: none
+layout: null
 ---
 
 <?xml version="1.0" encoding="UTF-8"?>
 <rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
-	<channel>
-		<title>{{ site.name }}</title>
-		<description>{{ site.description }}</description>
-		<link>{{ site.baseurl}}{{ site.url }}</link>
-		<atom:link href="{{ site.baseurl}}{{ site.url }}/feed.xml" rel="self" type="application/rss+xml" />
-		{% for post in site.posts limit:10 %}
-			<item>
-				<title>{{ post.title }}</title>
-				<description>{{ post.content | xml_escape }}</description>
-				<pubDate>{{ post.date | date: "%a, %d %b %Y %H:%M:%S %z" }}</pubDate>
-				<link>{{ site.url }}{{ site.baseurl}}{{ post.url }}</link>
-				<guid isPermaLink="true">{{ site.url }}{{ site.baseurl}}{{ post.url }}</guid>
-			</item>
-		{% endfor %}
-	</channel>
+    <channel>
+        <title>{{ site.name }}</title>
+        <description>{{ site.description }}</description>
+        <link>{{ site.baseurl}}{{ site.url }}</link>
+        <atom:link href="{{ site.baseurl}}{{ site.url }}/feed.xml" rel="self" type="application/rss+xml" />
+        {% for post in site.posts limit:10 %}
+                <item>
+                        <title>{{ post.title }}</title>
+                        <description>{{ post.content | xml_escape }}</description>
+                        <pubDate>{{ post.date | date: "%a, %d %b %Y %H:%M:%S %z" }}</pubDate>
+                        <link>{{ site.url }}{{ site.baseurl}}{{ post.url }}</link>
+                        <guid isPermaLink="true">{{ site.url }}{{ site.baseurl}}{{ post.url }}</guid>
+                </item>
+        {% endfor %}
+    </channel>
 </rss>

_posts/2014-08-22-jekyll-clean-theme.md

@@ -2,12 +2,27 @@
 layout: default
 ---
 
+<div class="article">
+    <div class="well">
+        <h1>BTrace - a safe, dynamic tracing tool for the Java platform</h1>
+        <div style="font-size: larger">BTrace is a safe, dynamic tracing tool for the Java platform.</div>
+
+        BTrace can be used to dynamically trace a running Java program 
+        (similar to DTrace for OpenSolaris applications and OS). 
+        BTrace dynamically instruments the classes of the target 
+        application to inject tracing code ("bytecode tracing").
+        {% if site.github != '' %}
+            <a href="https://github.com/{{ site.github }}/wiki">[more]</a>
+        {% endif %}
+    </div>
+</div>
+
 {% for post in paginator.posts %}
 <div class="article">
     <div class="well">
         <h1><a href="{{ site.baseurl}}{{ post.url }}">{{ post.date | date: "%b %-d, %Y" }} - {{ post.title }}</a></h1>
         {% if site.comments == true and post.comments == true and site.disqus != '' %}
-          <p class="author"><a href="{{ site.baseurl }}{{ post.url }}/#disqus_thread">Comments</a></p>
+        <p class="author"><a href="{{ site.baseurl }}{{ post.url }}/#disqus_thread">Comments</a></p>
         {% endif %}
         <div class="content">
             {{ post.content }}
@@ -17,15 +32,15 @@ <h1><a href="{{ site.baseurl}}{{ post.url }}">{{ post.date | date: "%b %-d, %Y"
 {% endfor %}
 
 <div class="pagination">
-  {% if paginator.previous_page %}
-      {% if paginator.previous_page == 1 %}
-        <a class="btn btn-default" href="{{ site.baseurl}}/index.html" class="previous">Newer</a>
-      {% else %}
-        <a class="btn btn-default" href="{{ site.baseurl}}/page{{ paginator.previous_page }}" class="previous">Newer</a>
-      {% endif %}
-  {% endif %}
-  <span class="page_number ">Page: {{ paginator.page }} of {{ paginator.total_pages }}</span>
-  {% if paginator.next_page %}
+    {% if paginator.previous_page %}
+    {% if paginator.previous_page == 1 %}
+    <a class="btn btn-default" href="{{ site.baseurl}}/index.html" class="previous">Newer</a>
+    {% else %}
+    <a class="btn btn-default" href="{{ site.baseurl}}/page{{ paginator.previous_page }}" class="previous">Newer</a>
+    {% endif %}
+    {% endif %}
+    <span class="page_number ">Page: {{ paginator.page }} of {{ paginator.total_pages }}</span>
+    {% if paginator.next_page %}
     <a class="btn btn-default" href="{{ site.baseurl}}/page{{ paginator.next_page }}" class="next">Older</a>
-  {% endif %}
+    {% endif %}
 </div>