Merge "Implement atomic refs update, if possible by database"

org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties

@@ -500,6 +500,7 @@ tagOnRepoWithoutHEADCurrentlyNotSupported=Tag on repository without HEAD current
 theFactoryMustNotBeNull=The factory must not be null
 timerAlreadyTerminated=Timer already terminated
 topologicalSortRequired=Topological sort required.
+transactionAborted=transaction aborted
 transportExceptionBadRef=Empty ref: {0}: {1}
 transportExceptionEmptyRef=Empty ref: {0}
 transportExceptionInvalid=Invalid {0} {1}:{2}

org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java

@@ -556,6 +556,7 @@ public class JGitText extends TranslationBundle {
 	/***/ public String tagAlreadyExists;
 	/***/ public String tagNameInvalid;
 	/***/ public String tagOnRepoWithoutHEADCurrentlyNotSupported;
+	/***/ public String transactionAborted;
 	/***/ public String theFactoryMustNotBeNull;
 	/***/ public String timerAlreadyTerminated;
 	/***/ public String topologicalSortRequired;

org.eclipse.jgit/src/org/eclipse/jgit/lib/RefDatabase.java

@@ -196,6 +196,14 @@ public abstract class RefDatabase {
 		return new BatchRefUpdate(this);
 	}
 
+	/**
+	 * @return if the database performs {@code newBatchUpdate()} as an atomic
+	 *         transaction.
+	 */
+	public boolean performsAtomicTransactions() {
+		return false;
+	}
+
 	/**
 	 * Read a single reference.
 	 * <p>

org.eclipse.jgit/src/org/eclipse/jgit/transport/BaseReceivePack.java

@@ -43,6 +43,7 @@
 
 package org.eclipse.jgit.transport;
 
+import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_ATOMIC;
 import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_DELETE_REFS;
 import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_OFS_DELTA;
 import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_REPORT_STATUS;
@@ -908,6 +909,8 @@ public abstract class BaseReceivePack {
 		adv.advertiseCapability(CAPABILITY_SIDE_BAND_64K);
 		adv.advertiseCapability(CAPABILITY_DELETE_REFS);
 		adv.advertiseCapability(CAPABILITY_REPORT_STATUS);
+		if (db.getRefDatabase().performsAtomicTransactions())
+			adv.advertiseCapability(CAPABILITY_ATOMIC);
 		if (allowOfsDelta)
 			adv.advertiseCapability(CAPABILITY_OFS_DELTA);
 		adv.send(getAdvertisedOrDefaultRefs());
@@ -1251,6 +1254,23 @@ public abstract class BaseReceivePack {
 		}
 	}
 
+	/** @return if any commands have been rejected so far. */
+	protected boolean anyRejects() {
+		for (ReceiveCommand cmd : commands) {
+			if (cmd.getResult() != Result.NOT_ATTEMPTED && cmd.getResult() != Result.OK)
+				return true;
+		}
+		return false;
+	}
+
+	/** Set the result to fail for any command that was not processed yet. */
+	protected void failPendingCommands() {
+		for (ReceiveCommand cmd : commands) {
+			if (cmd.getResult() == Result.NOT_ATTEMPTED)
+				cmd.setResult(Result.REJECTED_OTHER_REASON, JGitText.get().transactionAborted);
+		}
+	}
+
 	/**
 	 * Filter the list of commands according to result.
 	 *

org.eclipse.jgit/src/org/eclipse/jgit/transport/GitProtocolConstants.java

@@ -129,6 +129,14 @@ public class GitProtocolConstants {
 	 */
 	public static final String OPTION_ALLOW_TIP_SHA1_IN_WANT = "allow-tip-sha1-in-want"; //$NON-NLS-1$
 
+	/**
+	 * The client supports atomic pushes. If this option is used, the server
+	 * will update all refs within one atomic transaction.
+	 *
+	 * @since 3.6
+	 */
+	public static final String CAPABILITY_ATOMIC = "atomic-push"; //$NON-NLS-1$
+
 	/**
 	 * The client expects a status report after the server processes the pack.
 	 *

org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivePack.java

@@ -43,6 +43,7 @@
 
 package org.eclipse.jgit.transport;
 
+import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_ATOMIC;
 import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_REPORT_STATUS;
 
 import java.io.IOException;
@@ -199,8 +200,14 @@ public class ReceivePack extends BaseReceivePack {
 			}
 
 			if (unpackError == null) {
+				boolean atomic = isCapabilityEnabled(CAPABILITY_ATOMIC);
 				validateCommands();
+				if (atomic && anyRejects())
+					failPendingCommands();
+
 				preReceive.onPreReceive(this, filterCommands(Result.NOT_ATTEMPTED));
+				if (atomic && anyRejects())
+					failPendingCommands();
 				executeCommands();
 			}
 			unlockPack();