Class WalkPushConnection

  • All Implemented Interfaces:
    java.lang.AutoCloseable, Connection, PushConnection

    class WalkPushConnection
    extends BaseConnection
    implements PushConnection
    Generic push support for dumb transport protocols.

    Since there are no Git-specific smarts on the remote side of the connection the client side must handle everything on its own. The generic push support requires being able to delete, create and overwrite files on the remote side, as well as create any missing directories (if necessary). Typically this can be handled through an FTP style protocol.

    Objects not on the remote side are uploaded as pack files, using one pack file per invocation. This simplifies the implementation as only two data files need to be written to the remote repository.

    Push support supplied by this class is not multiuser safe. Concurrent pushes to the same repository may yield an inconsistent reference database which may confuse fetch clients.

    A single push is concurrently safe with multiple fetch requests, due to the careful order of operations used to update the repository. Clients fetching may receive transient failures due to short reads on certain files if the protocol does not support atomic file replacement.

    See Also:
    WalkRemoteObjectDatabase
    • Field Detail

      • local

        private final Repository local
        The repository this transport pushes out of.
      • uri

        private final URIish uri
        Location of the remote repository we are writing to.
      • transport

        private final Transport transport
        The configured transport we were constructed by.
      • packNames

        private java.util.LinkedHashMap<java.lang.String,​java.lang.String> packNames
        Packs already known to reside in the remote repository.

        This is a LinkedHashMap to maintain the original order.

      • newRefs

        private java.util.Map<java.lang.String,​Ref> newRefs
        Complete listing of refs the remote will have after our push.
      • packedRefUpdates

        private java.util.Collection<RemoteRefUpdate> packedRefUpdates
        Updates which require altering the packed-refs file to complete.

        If this collection is non-empty then any refs listed in newRefs with a storage class of Ref.Storage.PACKED will be written.

    • Method Detail

      • push

        public void push​(ProgressMonitor monitor,
                         java.util.Map<java.lang.String,​RemoteRefUpdate> refUpdates)
                  throws TransportException
        Pushes to the remote repository basing on provided specification. This possibly result in update/creation/deletion of refs on remote repository and sending objects that remote repository need to have a consistent objects graph from new refs.

        Only one call per connection is allowed. Subsequent calls will result in TransportException.

        Implementation may use local repository to send a minimum set of objects needed by remote repository in efficient way. Transport.isPushThin() should be honored if applicable. refUpdates should be filled with information about status of each update.

        Specified by:
        push in interface PushConnection
        Parameters:
        monitor - progress monitor to update the end-user about the amount of work completed, or to indicate cancellation. Implementors should poll the monitor at regular intervals to look for cancellation requests from the user.
        refUpdates - map of remote refnames to remote refs update specifications/statuses. Can't be empty. This indicate what refs caller want to update on remote side. Only refs updates with RemoteRefUpdate.Status.NOT_ATTEMPTED should passed. Implementation must ensure that and appropriate status with optional message should be set during call. No refUpdate with RemoteRefUpdate.Status.AWAITING_REPORT or RemoteRefUpdate.Status.NOT_ATTEMPTED can be leaved by implementation after return from this call.
        Throws:
        TransportException - objects could not be copied due to a network failure, critical protocol error, or error on remote side, or connection was already used for push - new connection must be created. Non-critical errors concerning only isolated refs should be placed in refUpdates.
      • push

        public void push​(ProgressMonitor monitor,
                         java.util.Map<java.lang.String,​RemoteRefUpdate> refUpdates,
                         java.io.OutputStream out)
                  throws TransportException
        Pushes to the remote repository basing on provided specification. This possibly result in update/creation/deletion of refs on remote repository and sending objects that remote repository need to have a consistent objects graph from new refs.

        Only one call per connection is allowed. Subsequent calls will result in TransportException.

        Implementation may use local repository to send a minimum set of objects needed by remote repository in efficient way. Transport.isPushThin() should be honored if applicable. refUpdates should be filled with information about status of each update.

        Specified by:
        push in interface PushConnection
        Parameters:
        monitor - progress monitor to update the end-user about the amount of work completed, or to indicate cancellation. Implementors should poll the monitor at regular intervals to look for cancellation requests from the user.
        refUpdates - map of remote refnames to remote refs update specifications/statuses. Can't be empty. This indicate what refs caller want to update on remote side. Only refs updates with RemoteRefUpdate.Status.NOT_ATTEMPTED should passed. Implementation must ensure that and appropriate status with optional message should be set during call. No refUpdate with RemoteRefUpdate.Status.AWAITING_REPORT or RemoteRefUpdate.Status.NOT_ATTEMPTED can be leaved by implementation after return from this call.
        out - output stream to write sideband messages to
        Throws:
        TransportException - objects could not be copied due to a network failure, critical protocol error, or error on remote side, or connection was already used for push - new connection must be created. Non-critical errors concerning only isolated refs should be placed in refUpdates.
      • close

        public void close()

        Close any resources used by this connection.

        If the remote repository is contacted by a network socket this method must close that network socket, disconnecting the two peers. If the remote repository is actually local (same system) this method must close any open file handles used to read the "remote" repository.

        If additional messages were produced by the remote peer, these should still be retained in the connection instance for Connection.getMessages().

        AutoClosable.close() declares that it throws Exception. Implementers shouldn't throw checked exceptions. This override narrows the signature to prevent them from doing so.

        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface Connection
        Specified by:
        close in class BaseConnection
      • safeDelete

        private void safeDelete​(java.io.File path)
      • isNewRepository

        private boolean isNewRepository()
      • pickHEAD

        private static java.lang.String pickHEAD​(java.util.List<RemoteRefUpdate> updates)