package hudson.scm;
import hudson.model.AbstractProject;
import hudson.model.TaskListener;
import hudson.Launcher;
import hudson.FilePath;
import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import java.io.Serializable;
/**
* Immutable object that represents the result of {@linkplain SCM#poll(AbstractProject, Launcher, FilePath, TaskListener, SCMRevisionState) SCM polling}.
*
* <p>
* This object is marked serializable just to be remoting friendly — Jenkins by itself
* doesn't persist this object.
*
* @author Kohsuke Kawaguchi
* @since 1.345
*/
public final class PollingResult implements Serializable {
/**
* Baseline of the comparison.
* (This comes from either the workspace, or from the remote repository as of the last polling.
* Can be null.
*/
public final @CheckForNull SCMRevisionState baseline;
/**
* Current state of the remote repository. To be passed to the next invocation of the polling method.
* Can be null.
*/
public final @CheckForNull SCMRevisionState remote;
/**
* Degree of the change between baseline and remote. Never null.
* <p>
* The fact that this field is independent from {@link #baseline} and {@link #remote} are
* used to (1) allow the {@linkplain Change#INCOMPARABLE incomparable} state which forces
* the immediate rebuild, and (2) allow SCM to ignore some changes in the repository to implement
* exclusion feature.
*/
public final @Nonnull Change change;
/**
* Degree of changes between the previous state and this state.
*/
public enum Change {
/**
* No change. Two {@link SCMRevisionState}s point to the same state of the same repository / the same commit.
*/
NONE,
/**
* There are some changes between states, but those changes are not significant enough to consider
* a new build. For example, some SCMs allow certain commits to be marked as excluded, and this is how
* you can do it.
*/
INSIGNIFICANT,
/**
* There are changes between states that warrant a new build. Jenkins will eventually
* schedule a new build for this change, subject to other considerations
* such as the quiet period.
*/
SIGNIFICANT,
/**
* The state as of baseline is so different from the current state that they are incomparable
* (for example, the workspace and the remote repository points to two unrelated repositories
* because the configuration has changed.) This forces Jenkins to schedule a build right away.
* <p>
* This is primarily useful in SCM implementations that require a workspace to be able
* to perform a polling. SCMs that can always compare remote revisions regardless of the local
* state should do so, and never return this constant, to let Jenkins maintain the quiet period
* behavior all the time.
* <p>
* This constant is not to be confused with the errors encountered during polling, which
* should result in an exception and eventual retry by Jenkins.
*/
INCOMPARABLE
}
public PollingResult(@CheckForNull SCMRevisionState baseline, @CheckForNull SCMRevisionState remote, @Nonnull Change change) {
if (change==null) throw new IllegalArgumentException();
this.baseline = baseline;
this.remote = remote;
this.change = change;
}
public PollingResult(@Nonnull Change change) {
this(null,null,change);
}
public boolean hasChanges() {
return change.ordinal() > Change.INSIGNIFICANT.ordinal();
}
/**
* Constant to indicate no changes in the remote repository.
*/
public static final PollingResult NO_CHANGES = new PollingResult(Change.NONE);
public static final PollingResult SIGNIFICANT = new PollingResult(Change.SIGNIFICANT);
/**
* Constant that uses {@link Change#INCOMPARABLE} which forces an immediate build.
*/
public static final PollingResult BUILD_NOW = new PollingResult(Change.INCOMPARABLE);
private static final long serialVersionUID = 1L;
}