Improve caching of artifacts using new Transport#downloadArtifact

p2-maven-plugin/src/main/java/org/eclipse/tycho/p2maven/transport/TychoRepositoryTransport.java

@@ -43,6 +43,9 @@
 import org.eclipse.equinox.internal.provisional.p2.repository.IStateful;
 import org.eclipse.equinox.p2.core.IProvisioningAgent;
 import org.eclipse.equinox.p2.core.spi.IAgentServiceFactory;
+import org.eclipse.equinox.p2.metadata.IArtifactKey;
+import org.eclipse.equinox.p2.metadata.Version;
+import org.eclipse.equinox.p2.repository.artifact.IArtifactDescriptor;
 
 @Component(role = org.eclipse.equinox.internal.p2.repository.Transport.class, hint = "tycho")
 public class TychoRepositoryTransport extends org.eclipse.equinox.internal.p2.repository.Transport
@@ -94,35 +97,81 @@ public IStatus download(URI toDownload, OutputStream target, long startPos, IPro
 
  @Override
  public IStatus download(URI toDownload, OutputStream target, IProgressMonitor monitor) {
+ return downloadArtifact(toDownload, target, null, monitor);
+ }
+
+ private IStatus reportStatus(IStatus status, OutputStream target) {
+ if (target instanceof IStateful stateful) {
+ stateful.setStatus(status);
+ }
+ return status;
+ }
+
+ @Override
+ public IStatus downloadArtifact(URI source, OutputStream target, IArtifactDescriptor descriptor,
+ IProgressMonitor monitor) {
+ if (descriptor != null) {
+ // TODO query the p2 pools!
+ Path cacheLocation = getCacheLocation(descriptor);
+ if (Files.isRegularFile(cacheLocation)) {
+ // TODO need to check local properties!
+ try {
+ Files.copy(cacheLocation, target);
+ } catch (IOException e) {
+ return reportStatus(Status.error("download from " + source + " failed", e), target);
+ }
+ return reportStatus(Status.OK_STATUS, target);
+ } else {
+ // TODO need to download to cache!
+ }
+ }
  String id = "p2"; // TODO we might compute the id from the IRepositoryIdManager based on the URI?
- if (cacheConfig.isInteractive()) {
- logger.info("Downloading from " + id + ": " + toDownload);
+ boolean printMessage = cacheConfig.isInteractive() && !cacheConfig.isOffline();
+ if (printMessage) {
+ logger.info("Downloading from " + id + ": " + source);
  }
  try {
  DownloadStatusOutputStream statusOutputStream = new DownloadStatusOutputStream(target,
- "Download of " + toDownload);
- stream(toDownload, monitor).transferTo(statusOutputStream);
+ "Download of " + source);
+ stream(source, monitor).transferTo(statusOutputStream);
  DownloadStatus downloadStatus = statusOutputStream.getStatus();
- if (cacheConfig.isInteractive()) {
- logger.info("Downloaded from " + id + ": " + toDownload + " ("
+ if (printMessage) {
+ logger.info("Downloaded from " + id + ": " + source + " ("
  + FileUtils.byteCountToDisplaySize(downloadStatus.getFileSize()) + " at "
  + FileUtils.byteCountToDisplaySize(downloadStatus.getTransferRate()) + "/s)");
  }
  return reportStatus(downloadStatus, target);
  } catch (AuthenticationFailedException e) {
- return Status.error("authentication failed for " + toDownload, e);
+ return Status.error("authentication failed for " + source, e);
  } catch (IOException e) {
- return reportStatus(Status.error("download from " + toDownload + " failed", e), target);
+ return reportStatus(Status.error("download from " + source + " failed", e), target);
  } catch (CoreException e) {
  return reportStatus(e.getStatus(), target);
  }
  }
 
- private IStatus reportStatus(IStatus status, OutputStream target) {
- if (target instanceof IStateful stateful) {
- stateful.setStatus(status);
+ private Path getCacheLocation(IArtifactDescriptor descriptor) {
+ Path location = cacheConfig.getCacheLocation().toPath();
+ IArtifactKey artifactKey = descriptor.getArtifactKey();
+ // TODO check the maven properties and construct a path to the local repo!
+ return location.resolve(getClassifier(artifactKey)).resolve(artifactKey.getId())
+ .resolve(getVersion(artifactKey));
+ }
+
+ private String getVersion(IArtifactKey artifactKey) {
+ Version version = artifactKey.getVersion();
+ if (version == null) {
+ return "0.0.0";
  }
- return status;
+ return version.toString();
+ }
+
+ private String getClassifier(IArtifactKey artifactKey) {
+ String classifier = artifactKey.getClassifier();
+ if (classifier == null || classifier.isBlank()) {
+ return "artifacts";
+ }
+ return classifier;
  }
 
  @Override