Re: [p2-dev] Planner explanation question

["Todorova, Katya" <katya.todorova@xxxxxxx>]

The Slicer returns all missing requirements properly but if there's an attempt to calculate the minimal explanation, some of these reqirements are cut off and only the first one is returned to the end user.

 

Here's the part of code that calculates the explanation:

 

if (s.getCode() != UNSATISFIABLE || (context != null && !(context.getProperty(EXPLANATION) == null || Boolean.TRUE.toString().equalsIgnoreCase(context.getProperty(EXPLANATION))))) {

    ...

    return plan;                          //that plan status contains all problematic requirements though all substatus codes are "Warning"

}

//Extract the explanation

Set<Explanation> explanation = projector.getExplanation(sub.newChild(ExpandWork / 4));     //here some of missing requirements are removed and the only one remaining is marked as Error.

Test case attached.

 

What is the minimal explanation supposed to contain?

 

Thanks,

Katya

---

From: p2-dev-bounces@xxxxxxxxxxx [mailto:p2-dev-bounces@xxxxxxxxxxx] On Behalf Of Pascal Rapicault
Sent: Thursday, May 12, 2011 8:56 PM
To: P2 developer discussions
Subject: Re: [p2-dev] Planner explanation question

From a quick code inspection to SimplePlanner, setting explanation to false will completely disable the explanation support (this is used in the case of the dropins to avoid computing the explanation since there is no one to read it).

Some of the missing requirements are filtered as part of the Slicer (but this is expected and filter out the noise), but after that the explanation is constructed by the solver and it tries to return the minimal explanation between what you have installed and what you are trying to install.

However if you have several missing requirements I think it will stop at the first one. Is that the pb you are seeing?

If you can provide an automated test case, we could see what can be done.

On 2011-05-12, at 1:40 PM, Todorova, Katya wrote:

Hi guys,

 

I came across a strange behavior of p2 planner - it hides information when trying to resolve an IU and resolution fails (due to missing requirements for example).

If there are more than one missing requirements the final explanation (and corresponding MultiStatus) will contain only the first one found. This default behavior

could be avoided if "org.eclipse.equinox.p2.director.explain" property is set to "false" in the provisioning context used by the planner.

 

I thought that the explanation is supposed to contain more details than the "ordinary" status but it turned out it's not the case and it contains even less. Is that expected?

If yes, any idea why?

 

Thanks in advance,

Katya

 

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### Eclipse Workspace Patch 1.0
#P org.eclipse.equinox.p2.tests
Index: src/org/eclipse/equinox/p2/tests/planner/ExplanationTest.java
===================================================================
RCS file: src/org/eclipse/equinox/p2/tests/planner/ExplanationTest.java
diff -N src/org/eclipse/equinox/p2/tests/planner/ExplanationTest.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/equinox/p2/tests/planner/ExplanationTest.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,37 @@
+package org.eclipse.equinox.p2.tests.planner;
+
+import org.eclipse.equinox.internal.p2.director.ProfileChangeRequest;
+import org.eclipse.equinox.p2.engine.*;
+import org.eclipse.equinox.p2.metadata.*;
+import org.eclipse.equinox.p2.planner.IPlanner;
+import org.eclipse.equinox.p2.tests.AbstractProvisioningTest;
+
+public class ExplanationTest extends AbstractProvisioningTest {
+	IInstallableUnit root;
+	IInstallableUnit b;
+	IInstallableUnit c;
+	IPlanner planner;
+
+	protected void setUp() throws Exception {
+		super.setUp();
+		root = createIU("root", Version.create("1.0.0"), new IRequirement[] {MetadataFactory.createRequirement(IInstallableUnit.NAMESPACE_IU_ID, "B", new VersionRange("[1.0.0, 1.0.0]"), null, false, false, true), MetadataFactory.createRequirement(IInstallableUnit.NAMESPACE_IU_ID, "missing", new VersionRange("[1.0.0, 1.0.0]"), null, false, false, true), MetadataFactory.createRequirement(IInstallableUnit.NAMESPACE_IU_ID, "C", new VersionRange("[1.0.0, 1.0.0]"), null, false, false, true)}, NO_PROPERTIES, true);
+
+		b = createIU("B", Version.create("1.0.0"), true);
+
+		c = createIU("C", Version.create("1.0.0"), new IRequirement[] {MetadataFactory.createRequirement("java.package", "a.b.c", new VersionRange("[1.0.0, 1.0.0]"), null, false, false, true)}, NO_PROPERTIES, true);
+
+		createTestMetdataRepository(new IInstallableUnit[] {root, b, c});
+
+		planner = createPlanner();
+	}
+
+	public void testExplanation() {
+		IProfile profile1 = createProfile("TestProfile." + getName());
+		ProfileChangeRequest req = new ProfileChangeRequest(profile1);
+		req.addInstallableUnits(new IInstallableUnit[] {root});
+		ProvisioningContext context = new ProvisioningContext(getAgent());
+		//context.setProperty("org.eclipse.equinox.p2.director.explain", "false");
+		IProvisioningPlan plan = planner.getProvisioningPlan(req, context, null);
+		assertEquals("Explanation contains " + plan.getStatus().getChildren().length + " instead of 4", true, plan.getStatus().getChildren().length == 4);
+	}
+}