Applied patch (FELIX-285) to improve OBR dependency resolution by searching
resolving bundles before local bundles and to search through all available
candidates to find one that can resolve instead of picking one and failing
if it cannot be resolved.
git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@539599 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/bundlerepository/src/main/java/org/apache/felix/bundlerepository/ResolverImpl.java b/bundlerepository/src/main/java/org/apache/felix/bundlerepository/ResolverImpl.java
index c096097..1b02c27 100644
--- a/bundlerepository/src/main/java/org/apache/felix/bundlerepository/ResolverImpl.java
+++ b/bundlerepository/src/main/java/org/apache/felix/bundlerepository/ResolverImpl.java
@@ -155,7 +155,7 @@
{
boolean result = true;
- // Check for a cycle.
+ // Check for cycles.
if (m_resolveSet.contains(resource))
{
return result;
@@ -165,7 +165,8 @@
m_resolveSet.add(resource);
// Resolve the requirements for the resource according to the
- // search order of: added, local, resolving, and remote resources.
+ // search order of: added, resolving, local and finally remote
+ // resources.
Requirement[] reqs = resource.getRequirements();
if (reqs != null)
{
@@ -175,13 +176,31 @@
candidate = searchAddedResources(reqs[reqIdx]);
if (candidate == null)
{
- candidate = searchLocalResources(reqs[reqIdx]);
+ candidate = searchResolvingResources(reqs[reqIdx]);
if (candidate == null)
- {
- candidate = searchResolvingResources(reqs[reqIdx]);
- if (candidate == null)
+ {
+ // TODO: OBR - We need a nicer way to make sure that
+ // the local resources are preferred over the remote
+ // resources. Currently, we are just putting them at
+ // the beginning of the candidate list.
+ List possibleCandidates = searchLocalResources(reqs[reqIdx]);
+ possibleCandidates.addAll(searchRemoteResources(reqs[reqIdx]));
+
+ // Determine the best candidate available that
+ // can resolve.
+ while ((candidate == null) && !possibleCandidates.isEmpty())
{
- candidate = searchRemoteResources(reqs[reqIdx]);
+ Resource bestResource = (Resource) getBestResource(possibleCandidates);
+
+ // Try to resolve the best resource.
+ if (resolve(bestResource))
+ {
+ candidate = bestResource;
+ }
+ else
+ {
+ possibleCandidates.remove(bestResource);
+ }
}
}
}
@@ -231,6 +250,15 @@
}
}
+ // If the resource did not resolve, then remove it from
+ // the resolve set, since to keep it consistent for iterative
+ // resolving, such as what happens when determining the best
+ // available candidate.
+ if (!result)
+ {
+ m_resolveSet.remove(resource);
+ }
+
return result;
}
@@ -254,24 +282,6 @@
return null;
}
- private Resource searchLocalResources(Requirement req)
- {
- Resource[] resources = m_local.getResources();
- for (int resIdx = 0; (resources != null) && (resIdx < resources.length); resIdx++)
- {
- Capability[] caps = resources[resIdx].getCapabilities();
- for (int capIdx = 0; (caps != null) && (capIdx < caps.length); capIdx++)
- {
- if (req.isSatisfied(caps[capIdx]))
- {
- return resources[resIdx];
- }
- }
- }
-
- return null;
- }
-
private Resource searchResolvingResources(Requirement req)
{
Resource[] resources = (Resource[])
@@ -291,15 +301,39 @@
return null;
}
- private Resource searchRemoteResources(Requirement req)
+ /**
+ * Returns a local resource meeting the given requirement
+ * @param req The requirement that the local resource must meet
+ * @return Returns the found local resource if available
+ */
+ private List searchLocalResources(Requirement req)
{
- // For now, guess that if there is a version associated with
- // the candidate capability that we should choose the highest
- // version; otherwise, choose the resource with the greatest
- // number of capabilities.
- // TODO: OBR - This could probably be improved.
- Resource best = null;
- Version bestVersion = null;
+ List matchingCandidates = new ArrayList();
+ Resource[] resources = m_local.getResources();
+ for (int resIdx = 0; (resources != null) && (resIdx < resources.length); resIdx++)
+ {
+ Capability[] caps = resources[resIdx].getCapabilities();
+ for (int capIdx = 0; (caps != null) && (capIdx < caps.length); capIdx++)
+ {
+ if (req.isSatisfied(caps[capIdx]))
+ {
+ matchingCandidates.add(resources[resIdx]);
+ }
+ }
+ }
+
+ return matchingCandidates;
+ }
+
+ /**
+ * Searches for remote resources that do meet the given requirement
+ * @param req
+ * @return all remote resources meeting the given requirement
+ */
+ private List searchRemoteResources(Requirement req)
+ {
+ List matchingCandidates = new ArrayList();
+
Repository[] repos = m_admin.listRepositories();
for (int repoIdx = 0; (repos != null) && (repoIdx < repos.length); repoIdx++)
{
@@ -311,52 +345,72 @@
{
if (req.isSatisfied(caps[capIdx]))
{
- if (best == null)
- {
- best = resources[resIdx];
- Object v = caps[capIdx].getProperties().get(Resource.VERSION);
- if ((v != null) && (v instanceof Version))
- {
- bestVersion = (Version) v;
- }
- }
- else
- {
- Object v = caps[capIdx].getProperties().get(Resource.VERSION);
-
- // If there is no version, then select the resource
- // with the greatest number of capabilities.
- if ((v == null) && (bestVersion == null)
- && (best.getCapabilities().length < caps.length))
- {
- best = resources[resIdx];
- bestVersion = (Version) v;
- }
- else if ((v != null) && (v instanceof Version))
- {
- // If there is no best version or if the current
- // resource's version is lower, then select it.
- if ((bestVersion == null) || (bestVersion.compareTo(v) < 0))
- {
- best = resources[resIdx];
- bestVersion = (Version) v;
- }
- // If the current resource version is equal to the
- // best, then select the one with the greatest
- // number of capabilities.
- else if ((bestVersion != null) && (bestVersion.compareTo(v) == 0)
- && (best.getCapabilities().length < caps.length))
- {
- best = resources[resIdx];
- bestVersion = (Version) v;
- }
- }
- }
+ matchingCandidates.add(resources[resIdx]);
}
}
}
}
+ return matchingCandidates;
+ }
+
+ /**
+ * Determines which resource is preferred to deliver the required capability.
+ * This implementation will select the resource with the newest version. If two resources have
+ * the same version will the one with the largest number of cabailities be preferred
+ * @param resources
+ * @return
+ */
+ private Resource getBestResource(List resources) {
+ Version bestVersion = null;
+ Resource best = null;
+
+ for(int resIdx = 0; resIdx < resources.size(); resIdx++)
+ {
+ Resource currentResource = (Resource) resources.get(resIdx);
+
+ if (best == null)
+ {
+ best = currentResource;
+ Object v = currentResource.getProperties().get(Resource.VERSION);
+ if ((v != null) && (v instanceof Version))
+ {
+ bestVersion = (Version) v;
+ }
+ }
+ else
+ {
+ Object v = currentResource.getProperties().get(Resource.VERSION);
+
+ // If there is no version, then select the resource
+ // with the greatest number of capabilities.
+ if ((v == null) && (bestVersion == null) && (best.getCapabilities().length < currentResource.getCapabilities().length))
+ {
+ best = currentResource;
+ bestVersion = (Version) v;
+ }
+ else if ((v != null) && (v instanceof Version))
+ {
+ // If there is no best version or if the current
+ // resource's version is lower, then select it.
+ if ((bestVersion == null) || (bestVersion.compareTo(v) < 0))
+ {
+ best = currentResource;
+ bestVersion = (Version) v;
+ }
+ // If the current resource version is equal to the
+ // best, then select the one with the greatest
+ // number of capabilities.
+ else if ((bestVersion != null) && (bestVersion.compareTo(v) == 0)
+ && (best.getCapabilities().length < currentResource.getCapabilities().length))
+ {
+ best = currentResource;
+ bestVersion = (Version) v;
+ }
+ }
+ }
+ }
+
return best;
}
@@ -427,7 +481,7 @@
try
{
localResource.getBundle().update(deployResources[i].getURL().openStream());
-
+
// If necessary, save the updated bundle to be
// started later.
if (start)
@@ -461,7 +515,7 @@
+ deployResources[i].getSymbolicName()
+ "/" + System.currentTimeMillis(),
url.openStream());
-
+
// If necessary, save the installed bundle to be
// started later.
if (start)
@@ -538,6 +592,11 @@
return null;
}
+ /**
+ * Returns all local resources with the given symbolic name.
+ * @param symName The symbolic name of the wanted local resources.
+ * @return The local resources with the specified symbolic name.
+ */
private Resource[] findLocalResources(String symName)
{
Resource[] localResources = m_local.getResources();
@@ -594,7 +653,7 @@
return true;
}
-
+
private Requirement[] getResolvableRequirements(Resource resource, Resource[] resources)
{
// For the specified resource, find all requirements that are