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Hi Ant developers-in-charge,
I sent this to the list two weeks ago and didn't
get any reply.
Can you please give me an indication whether this
patch is at all useful? Or if you think it isn't, then tell me why. I would
really like to know that.
I have a couple of ideas for other patches to
submit; but I don't want to go through the hassle to prepare them if there is no
interest. So I'm using this patch as a kind of test balloon ;-)
Best,
-Stefan
----- Original Message -----
Sent: Saturday, July 21, 2001 7:25
PM
Subject: [PATCH] Lazy task class
loading
Hi,
currently Ant loads all taskdef classes (as
defined in defaults.properties) on startup. This mechanism has at least 3
drawbacks:
-It can take up to one second or longer (if you
use ant for everyday development, you will notice the difference)
-It wastes memory
-It completely lacks descriptive error messages.
For example, if you use <junit>, but junit.jar isn't in your classpath,
you only get a default message telling you something about optional.jar. I've
been puzzled as to why tasks couldn't be loaded more than once.
I would like to submit a patch that solves all
three problems. I also took care to ensure
that the public interface of org.apache.tools.ant.Project is backward
compatible.
-Stefan
Here is the patch against recent CVS (I already
added @author tags for your convenience ;-):
Index:
main/org/apache/tools/ant/Project.java
===================================================================
RCS
file:
/home/cvspublic/jakarta-ant/src/main/org/apache/tools/ant/Project.java,v
retrieving
revision 1.64
diff -u -r1.64 Project.java
---
main/org/apache/tools/ant/Project.java 2001/07/17
12:12:39 1.64
+++
main/org/apache/tools/ant/Project.java 2001/07/21 17:03:14
@@ -68,6
+68,7 @@
* file paths at runtime as well as defining various project
properties.
*
* @author [EMAIL PROTECTED]
+ * @author Stefan Reich
<a href="">[EMAIL PROTECTED]</a>
*/
public class Project {
@@ -101,7 +102,8
@@
private Hashtable references = new
Hashtable();
private String
defaultTarget;
private Hashtable
dataClassDefinitions = new Hashtable();
- private
Hashtable taskClassDefinitions = new Hashtable();
+
private TaskDefinitionHashtable taskClassDefinitions = new
TaskDefinitionHashtable();
+
private Hashtable targets = new Hashtable();
private Hashtable filters = new Hashtable();
private File baseDir;
@@ -114,6 +116,27 @@
/**
The system classloader - may be null */
private ClassLoader systemLoader =
null;
+ public static class
TaskDefinitionHashtable extends Hashtable {
+
/** lazily call Class.forName */
+ public
Object get(Object key) {
+ Object
value = super.get(key);
+ if
(value instanceof String)
{
+ try
{
+ value
= Class.forName((String)
value);
+ } catch
(ClassNotFoundException e)
{
+ throw
new
RuntimeException(e.toString());
+
} catch (NoClassDefFoundError e)
{
+ throw
new
RuntimeException(e.toString());
+
}
+
}
+ return
value;
+ }
+
+ public String getClassName(Object key)
{
+ return (String)
super.get(key);
+ }
+
}
+
static
{
// Determine
the Java version by looking at available classes
@@ -161,19 +184,23
@@
props.load(in);
in.close();
+ long startTime =
System.currentTimeMillis();
Enumeration enum =
props.propertyNames();
while (enum.hasMoreElements())
{
String key = (String)
enum.nextElement();
String value =
props.getProperty(key);
-
try
{
+
/*try
{
Class taskClass =
Class.forName(value);
addTaskDefinition(key,
taskClass);
} catch (NoClassDefFoundError ncdfe)
{
//
ignore...
} catch (ClassNotFoundException cnfe)
{
//
ignore...
-
}
+
}*/
+
addTaskDefinition(key,
value);
}
+ long endTime =
System.currentTimeMillis();
+
System.out.println("Class loading took
"+(endTime-startTime)+"
ms");
} catch (IOException
ioe)
{
throw new BuildException("Can't load default task
list");
}
@@ -367,13
+394,19 @@
log("Detected
OS: " + System.getProperty("os.name"),
MSG_VERBOSE);
}
+
public void addTaskDefinition(String taskName, String taskClass)
{
+ String msg = " +User task: "
+ taskName + " " +
taskClass;
+ log(msg,
MSG_DEBUG);
+
taskClassDefinitions.put(taskName, taskClass);
+
}
+
public void addTaskDefinition(String
taskName, Class taskClass)
{
String msg = " +User
task: " + taskName + " " +
taskClass.getName();
log(msg, MSG_DEBUG);
taskClassDefinitions.put(taskName, taskClass);
}
- public Hashtable getTaskDefinitions()
{
+ public TaskDefinitionHashtable getTaskDefinitions()
{
return
taskClassDefinitions;
}
@@ -445,7
+478,12 @@
}
public Task createTask(String taskType) throws BuildException
{
- Class c = (Class)
taskClassDefinitions.get(taskType);
+
Class c;
+ try
{
+ c = (Class)
taskClassDefinitions.get(taskType);
+
} catch (RuntimeException e)
{
+ throw new
BuildException(e.getMessage());
+
}
if (c ==
null)
return null;
Index:
main/org/apache/tools/ant/taskdefs/Ant.java
===================================================================
RCS
file:
/home/cvspublic/jakarta-ant/src/main/org/apache/tools/ant/taskdefs/Ant.java,v
retrieving
revision 1.23
diff -u -r1.23 Ant.java
---
main/org/apache/tools/ant/taskdefs/Ant.java 2001/07/06
11:57:29 1.23
+++
main/org/apache/tools/ant/taskdefs/Ant.java 2001/07/21 17:03:15
@@
-76,6 +76,7 @@
*
*
* @author [EMAIL PROTECTED]
+ * @author Stefan Reich
<a href="">[EMAIL PROTECTED]</a>
*/
public class Ant extends Task {
@@ -143,11 +144,11
@@
}
}
- Hashtable taskdefs
= project.getTaskDefinitions();
+
Project.TaskDefinitionHashtable taskdefs =
project.getTaskDefinitions();
Enumeration et =
taskdefs.keys();
while
(et.hasMoreElements())
{
String taskName = (String)
et.nextElement();
-
Class taskClass = (Class)
taskdefs.get(taskName);
+
String taskClass =
taskdefs.getClassName(taskName);
p1.addTaskDefinition(taskName,
taskClass);
}
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