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package org.eclipse.jgit.transport;

import java.util.Collection;

Hook invoked by ReceivePack before any updates are executed. 

The hook is called with any commands that are deemed valid after parsing them
from the client and applying the standard receive configuration options to
them:

receive.denyDenyDeletes
receive.denyNonFastForwards
 This means the hook will not receive a non-fast-forward update command if denyNonFastForwards is set to true in the configuration file. To get all commands within the hook, see BaseReceivePack.getAllCommands(). 
 As the hook is invoked prior to the commands being executed, the hook may choose to block any command by setting its result status with ReceiveCommand.setResult(Result). 
 The hook may also choose to perform the command itself (or merely pretend that it has performed the command), by setting the result status to Result.OK. 

Hooks should run quickly, as they block the caller thread and the client
process from completing.
 Hooks may send optional messages back to the client via methods on ReceivePack. Implementors should be aware that not all network transports support this output, so some (or all) messages may simply be discarded. These messages should be advisory only. /**
 * Hook invoked by {@link org.eclipse.jgit.transport.ReceivePack} before any
 * updates are executed.
 * <p>
 * The hook is called with any commands that are deemed valid after parsing them
 * from the client and applying the standard receive configuration options to
 * them:
 * <ul>
 * <li><code>receive.denyDenyDeletes</code></li>
 * <li><code>receive.denyNonFastForwards</code></li>
 * </ul>
 * This means the hook will not receive a non-fast-forward update command if
 * denyNonFastForwards is set to true in the configuration file. To get all
 * commands within the hook, see
 * {@link org.eclipse.jgit.transport.ReceivePack#getAllCommands()}.
 * <p>
 * As the hook is invoked prior to the commands being executed, the hook may
 * choose to block any command by setting its result status with
 * {@link org.eclipse.jgit.transport.ReceiveCommand#setResult(ReceiveCommand.Result)}.
 * <p>
 * The hook may also choose to perform the command itself (or merely pretend
 * that it has performed the command), by setting the result status to
 * {@link org.eclipse.jgit.transport.ReceiveCommand.Result#OK}.
 * <p>
 * Hooks should run quickly, as they block the caller thread and the client
 * process from completing.
 * <p>
 * Hooks may send optional messages back to the client via methods on
 * {@link org.eclipse.jgit.transport.ReceivePack}. Implementors should be aware
 * that not all network transports support this output, so some (or all)
 * messages may simply be discarded. These messages should be advisory only.
 */
public interface PreReceiveHook {
	
A simple no-op hook. /** A simple no-op hook. */
	PreReceiveHook NULL = (final ReceivePack rp,
			final Collection<ReceiveCommand> commands) -> {
		// Do nothing.
	};

	
Invoked just before commands are executed.

See the class description for how this method can impact execution.
Params:
rp – 
           the process handling the current receive. Hooks may obtain
           details about the destination repository through this handle.
commands – 
           unmodifiable set of valid commands still pending execution.
           May be the empty set./**
	 * Invoked just before commands are executed.
	 * <p>
	 * See the class description for how this method can impact execution.
	 *
	 * @param rp
	 *            the process handling the current receive. Hooks may obtain
	 *            details about the destination repository through this handle.
	 * @param commands
	 *            unmodifiable set of valid commands still pending execution.
	 *            May be the empty set.
	 */
	void onPreReceive(ReceivePack rp, Collection<ReceiveCommand> commands);
}