Class Transport

  • All Implemented Interfaces:
    AutoCloseable
    Direct Known Subclasses:
    HttpTransport, TcpTransport, TransportBundleStream

    public abstract class Transport
    extends Object
    implements AutoCloseable
    Connects two Git repositories together and copies objects between them.

    A transport can be used for either fetching (copying objects into the caller's repository from the remote repository) or pushing (copying objects into the remote repository from the caller's repository). Each transport implementation is responsible for the details associated with establishing the network connection(s) necessary for the copy, as well as actually shuffling data back and forth.

    Transport instances and the connections they create are not thread-safe. Callers must ensure a transport is accessed by only one thread at a time.

    • Field Detail

      • REFSPEC_TAGS

        public static final RefSpec REFSPEC_TAGS
        Specification for fetch or push operations, to fetch or push all tags. Acts as --tags.
      • REFSPEC_PUSH_ALL

        public static final RefSpec REFSPEC_PUSH_ALL
        Specification for push operation, to push all refs under refs/heads. Acts as --all.
      • local

        protected final Repository local
        The repository this transport fetches into, or pushes out of.
      • uri

        protected final URIish uri
        The URI used to create this transport.
    • Constructor Detail

      • Transport

        protected Transport​(Repository local,
                            URIish uri)
        Create a new transport instance.
        Parameters:
        local - the repository this instance will fetch into, or push out of. This must be the repository passed to open(Repository, URIish).
        uri - the URI used to access the remote repository. This must be the URI passed to open(Repository, URIish).
      • Transport

        protected Transport​(URIish uri)
        Create a minimal transport instance not tied to a single repository.
        Parameters:
        uri - a URIish object.
    • Method Detail

      • register

        public static void register​(TransportProtocol proto)
        Register a TransportProtocol instance for use during open.

        Protocol definitions are held by WeakReference, allowing them to be garbage collected when the calling application drops all strongly held references to the TransportProtocol. Therefore applications should use a singleton pattern as described in TransportProtocol's class documentation to ensure their protocol does not get disabled by garbage collection earlier than expected.

        The new protocol is registered in front of all earlier protocols, giving it higher priority than the built-in protocol definitions.

        Parameters:
        proto - the protocol definition. Must not be null.
      • unregister

        public static void unregister​(TransportProtocol proto)
        Unregister a TransportProtocol instance.

        Unregistering a protocol usually isn't necessary, as protocols are held by weak references and will automatically clear when they are garbage collected by the JVM. Matching is handled by reference equality, so the exact reference given to register(TransportProtocol) must be used.

        Parameters:
        proto - the exact object previously given to register.
      • getTransportProtocols

        public static List<TransportProtocol> getTransportProtocols()
        Obtain a copy of the registered protocols.
        Returns:
        an immutable copy of the currently registered protocols.
      • open

        public static Transport open​(Repository local,
                                     String remote,
                                     Transport.Operation op)
                              throws NotSupportedException,
                                     URISyntaxException,
                                     TransportException
        Open a new transport instance to connect two repositories.
        Parameters:
        local - existing local repository.
        remote - location of the remote repository - may be URI or remote configuration name.
        op - planned use of the returned Transport; the URI may differ based on the type of connection desired.
        Returns:
        the new transport instance. Never null. In case of multiple URIs in remote configuration, only the first is chosen.
        Throws:
        URISyntaxException - the location is not a remote defined in the configuration file and is not a well-formed URL.
        NotSupportedException - the protocol specified is not supported.
        TransportException - the transport cannot open this URI.
      • open

        public static Transport open​(Repository local,
                                     RemoteConfig cfg,
                                     Transport.Operation op)
                              throws NotSupportedException,
                                     TransportException
        Open a new transport instance to connect two repositories.
        Parameters:
        local - existing local repository.
        cfg - configuration describing how to connect to the remote repository.
        op - planned use of the returned Transport; the URI may differ based on the type of connection desired.
        Returns:
        the new transport instance. Never null. In case of multiple URIs in remote configuration, only the first is chosen.
        Throws:
        NotSupportedException - the protocol specified is not supported.
        TransportException - the transport cannot open this URI.
        IllegalArgumentException - if provided remote configuration doesn't have any URI associated.
      • open

        public static Transport open​(Repository local,
                                     URIish uri,
                                     String remoteName)
                              throws NotSupportedException,
                                     TransportException
        Open a new transport instance to connect two repositories.
        Parameters:
        local - existing local repository.
        uri - location of the remote repository.
        remoteName - name of the remote, if the remote as configured in local; otherwise null.
        Returns:
        the new transport instance. Never null.
        Throws:
        NotSupportedException - the protocol specified is not supported.
        TransportException - the transport cannot open this URI.
      • findRemoteRefUpdatesFor

        public static Collection<RemoteRefUpdate> findRemoteRefUpdatesFor​(Repository db,
                                                                          Collection<RefSpec> specs,
                                                                          Map<String,​RefLeaseSpec> leases,
                                                                          Collection<RefSpec> fetchSpecs)
                                                                   throws IOException
        Convert push remote refs update specification from RefSpec form to RemoteRefUpdate. Conversion expands wildcards by matching source part to local refs. expectedOldObjectId in RemoteRefUpdate is set when specified in leases. Tracking branch is configured if RefSpec destination matches source of any fetch ref spec for this transport remote configuration.
        Parameters:
        db - local database.
        specs - collection of RefSpec to convert.
        leases - map from ref to lease (containing expected old object id)
        fetchSpecs - fetch specifications used for finding localtracking refs. May be null or empty collection.
        Returns:
        collection of set up RemoteRefUpdate.
        Throws:
        IOException - when problem occurred during conversion or specification set up: most probably, missing objects or refs.
        Since:
        4.7
      • findRemoteRefUpdatesFor

        public static Collection<RemoteRefUpdate> findRemoteRefUpdatesFor​(Repository db,
                                                                          Collection<RefSpec> specs,
                                                                          Collection<RefSpec> fetchSpecs)
                                                                   throws IOException
        Convert push remote refs update specification from RefSpec form to RemoteRefUpdate. Conversion expands wildcards by matching source part to local refs. expectedOldObjectId in RemoteRefUpdate is always set as null. Tracking branch is configured if RefSpec destination matches source of any fetch ref spec for this transport remote configuration.
        Parameters:
        db - local database.
        specs - collection of RefSpec to convert.
        fetchSpecs - fetch specifications used for finding localtracking refs. May be null or empty collection.
        Returns:
        collection of set up RemoteRefUpdate.
        Throws:
        IOException - when problem occurred during conversion or specification set up: most probably, missing objects or refs.
      • getURI

        public URIish getURI()
        Get the URI this transport connects to.

        Each transport instance connects to at most one URI at any point in time.

        Returns:
        the URI describing the location of the remote repository.
      • getOptionUploadPack

        public String getOptionUploadPack()
        Get the name of the remote executable providing upload-pack service.
        Returns:
        typically "git-upload-pack".
      • setOptionUploadPack

        public void setOptionUploadPack​(String where)
        Set the name of the remote executable providing upload-pack services.
        Parameters:
        where - name of the executable.
      • getTagOpt

        public TagOpt getTagOpt()
        Get the description of how annotated tags should be treated during fetch.
        Returns:
        option indicating the behavior of annotated tags in fetch.
      • setTagOpt

        public void setTagOpt​(TagOpt option)
        Set the description of how annotated tags should be treated on fetch.
        Parameters:
        option - method to use when handling annotated tags.
      • isFetchThin

        public boolean isFetchThin()
        Default setting is: DEFAULT_FETCH_THIN
        Returns:
        true if fetch should request thin-pack when possible; false otherwise
        See Also:
        PackTransport
      • setFetchThin

        public void setFetchThin​(boolean fetchThin)
        Set the thin-pack preference for fetch operation. Default setting is: DEFAULT_FETCH_THIN
        Parameters:
        fetchThin - true when fetch should request thin-pack when possible; false when it shouldn't
        See Also:
        PackTransport
      • isCheckFetchedObjects

        public boolean isCheckFetchedObjects()
        Whether fetch will verify if received objects are formatted correctly.
        Returns:
        true if fetch will verify received objects are formatted correctly. Validating objects requires more CPU time on the client side of the connection.
      • setCheckFetchedObjects

        public void setCheckFetchedObjects​(boolean check)
        Configure if checking received objects is enabled
        Parameters:
        check - true to enable checking received objects; false to assume all received objects are valid.
        See Also:
        setObjectChecker(ObjectChecker)
      • getObjectChecker

        public ObjectChecker getObjectChecker()
        Get configured object checker for received objects
        Returns:
        configured object checker for received objects, or null.
        Since:
        3.6
      • setObjectChecker

        public void setObjectChecker​(ObjectChecker impl)
        Set the object checker to verify each received object with
        Parameters:
        impl - if non-null the object checking instance to verify each received object with; null to disable object checking.
        Since:
        3.6
      • setOptionReceivePack

        public void setOptionReceivePack​(String optionReceivePack)
        Set remote executable providing receive-pack service for pack transports. Default setting is: RemoteConfig.DEFAULT_RECEIVE_PACK
        Parameters:
        optionReceivePack - remote executable, if null or empty default one is set;
      • isPushThin

        public boolean isPushThin()
        Default setting is: false
        Returns:
        true if push should produce thin-pack in pack transports
        See Also:
        PackTransport
      • setPushThin

        public void setPushThin​(boolean pushThin)
        Set thin-pack preference for push operation. Default setting is: false
        Parameters:
        pushThin - true when push should produce thin-pack in pack transports; false when it shouldn't
        See Also:
        PackTransport
      • isPushAtomic

        public boolean isPushAtomic()
        Default setting is false.
        Returns:
        true if push requires all-or-nothing atomic behavior.
        Since:
        4.2
      • setPushAtomic

        public void setPushAtomic​(boolean atomic)
        Request atomic push (all references succeed, or none do).

        Server must also support atomic push. If the server does not support the feature the push will abort without making changes.

        Parameters:
        atomic - true when push should be an all-or-nothing operation.
        Since:
        4.2
        See Also:
        PackTransport
      • isRemoveDeletedRefs

        public boolean isRemoveDeletedRefs()
        Whether destination refs should be removed if they no longer exist at the source repository.
        Returns:
        true if destination refs should be removed if they no longer exist at the source repository.
      • setRemoveDeletedRefs

        public void setRemoveDeletedRefs​(boolean remove)
        Set whether or not to remove refs which no longer exist in the source.

        If true, refs at the destination repository (local for fetch, remote for push) are deleted if they no longer exist on the source side (remote for fetch, local for push).

        False by default, as this may cause data to become unreachable, and eventually be deleted on the next GC.

        Parameters:
        remove - true to remove refs that no longer exist.
      • setFilterBlobLimit

        @Deprecated
        public final void setFilterBlobLimit​(long bytes)
        Deprecated.
        Parameters:
        bytes - exclude blobs of size greater than this
        Since:
        5.0
      • setFilterSpec

        public final void setFilterSpec​(@NonNull
                                        FilterSpec filter)
        Parameters:
        filter - a new filter to use for this transport
        Since:
        5.4
      • getDepth

        public final Integer getDepth()
        Retrieves the depth for a shallow clone.
        Returns:
        the depth, or null if none set
        Since:
        6.3
      • setDepth

        public final void setDepth​(int depth)
        Limits fetching to the specified number of commits from the tip of each remote branch history.
        Parameters:
        depth - the depth
        Since:
        6.3
      • setDepth

        public final void setDepth​(Integer depth)
        Limits fetching to the specified number of commits from the tip of each remote branch history.
        Parameters:
        depth - the depth, or null to unset the depth
        Since:
        6.3
      • getDeepenSince

        public final Instant getDeepenSince()
        Returns:
        the deepen-since for a shallow clone
        Since:
        6.3
      • setDeepenSince

        public final void setDeepenSince​(@NonNull
                                         Instant deepenSince)
        Deepen or shorten the history of a shallow repository to include all reachable commits after a specified time.
        Parameters:
        deepenSince - the deepen-since. Must not be null
        Since:
        6.3
      • getDeepenNots

        public final List<String> getDeepenNots()
        Returns:
        the deepen-not for a shallow clone
        Since:
        6.3
      • setDeepenNots

        public final void setDeepenNots​(@NonNull
                                        List<String> deepenNots)
        Deepen or shorten the history of a shallow repository to exclude commits reachable from a specified remote branch or tag.
        Parameters:
        deepenNots - the deepen-not. Must not be null
        Since:
        6.3
      • applyConfig

        public void applyConfig​(RemoteConfig cfg)
        Apply provided remote configuration on this transport.
        Parameters:
        cfg - configuration to apply on this transport.
      • isDryRun

        public boolean isDryRun()
        Whether push operation should just check for possible result and not really update remote refs
        Returns:
        true if push operation should just check for possible result and not really update remote refs, false otherwise - when push should act normally.
      • setDryRun

        public void setDryRun​(boolean dryRun)
        Set dry run option for push operation.
        Parameters:
        dryRun - true if push operation should just check for possible result and not really update remote refs, false otherwise - when push should act normally.
      • getTimeout

        public int getTimeout()
        Get timeout (in seconds) before aborting an IO operation.
        Returns:
        timeout (in seconds) before aborting an IO operation.
      • setTimeout

        public void setTimeout​(int seconds)
        Set the timeout before willing to abort an IO call.
        Parameters:
        seconds - number of seconds to wait (with no data transfer occurring) before aborting an IO read or write operation with this remote.
      • getPackConfig

        public PackConfig getPackConfig()
        Get the configuration used by the pack generator to make packs. If setPackConfig(PackConfig) was previously given null a new PackConfig is created on demand by this method using the source repository's settings.
        Returns:
        the pack configuration. Never null.
      • setPackConfig

        public void setPackConfig​(PackConfig pc)
        Set the configuration used by the pack generator.
        Parameters:
        pc - configuration controlling packing parameters. If null the source repository's settings will be used.
      • setCredentialsProvider

        public void setCredentialsProvider​(CredentialsProvider credentialsProvider)
        A credentials provider to assist with authentication connections..
        Parameters:
        credentialsProvider - the credentials provider, or null if there is none
      • getCredentialsProvider

        public CredentialsProvider getCredentialsProvider()
        The configured credentials provider.
        Returns:
        the credentials provider, or null if no credentials provider is associated with this transport.
      • getPushOptions

        public List<String> getPushOptions()
        Get the option strings associated with the push operation
        Returns:
        the option strings associated with the push operation
        Since:
        4.5
      • setPushOptions

        public void setPushOptions​(List<String> pushOptions)
        Sets the option strings associated with the push operation.
        Parameters:
        pushOptions - null if push options are unsupported
        Since:
        4.5
      • fetch

        public FetchResult fetch​(ProgressMonitor monitor,
                                 Collection<RefSpec> toFetch)
                          throws NotSupportedException,
                                 TransportException
        Fetch objects and refs from the remote repository to the local one.

        This is a utility function providing standard fetch behavior. Local tracking refs associated with the remote repository are automatically updated if this transport was created from a RemoteConfig with fetch RefSpecs defined.

        Parameters:
        monitor - progress monitor to inform the user about our processing activity. Must not be null. Use NullProgressMonitor if progress updates are not interesting or necessary.
        toFetch - specification of refs to fetch locally. May be null or the empty collection to use the specifications from the RemoteConfig. May contains regular and negative RefSpecs. Source for each regular RefSpec can't be null.
        Returns:
        information describing the tracking refs updated.
        Throws:
        NotSupportedException - this transport implementation does not support fetching objects.
        TransportException - the remote connection could not be established or object copying (if necessary) failed or update specification was incorrect.
        Since:
        5.11
      • fetch

        public FetchResult fetch​(ProgressMonitor monitor,
                                 Collection<RefSpec> toFetch,
                                 String branch)
                          throws NotSupportedException,
                                 TransportException
        Fetch objects and refs from the remote repository to the local one.

        This is a utility function providing standard fetch behavior. Local tracking refs associated with the remote repository are automatically updated if this transport was created from a RemoteConfig with fetch RefSpecs defined.

        Parameters:
        monitor - progress monitor to inform the user about our processing activity. Must not be null. Use NullProgressMonitor if progress updates are not interesting or necessary.
        toFetch - specification of refs to fetch locally. May be null or the empty collection to use the specifications from the RemoteConfig. May contain regular and negative RefSpecs. Source for each regular RefSpec can't be null.
        branch - the initial branch to check out when cloning the repository. Can be specified as ref name (refs/heads/master), branch name (master) or tag name (v1.2.3). The default is to use the branch pointed to by the cloned repository's HEAD and can be requested by passing null or HEAD.
        Returns:
        information describing the tracking refs updated.
        Throws:
        NotSupportedException - this transport implementation does not support fetching objects.
        TransportException - the remote connection could not be established or object copying (if necessary) failed or update specification was incorrect.
        Since:
        5.11
      • push

        public PushResult push​(ProgressMonitor monitor,
                               Collection<RemoteRefUpdate> toPush,
                               OutputStream out)
                        throws NotSupportedException,
                               TransportException
        Push objects and refs from the local repository to the remote one.

        This is a utility function providing standard push behavior. It updates remote refs and send there necessary objects according to remote ref update specification. After successful remote ref update, associated locally stored tracking branch is updated if set up accordingly. Detailed operation result is provided after execution.

        For setting up remote ref update specification from ref spec, see helper method findRemoteRefUpdatesFor(Collection), predefined refspecs (REFSPEC_TAGS, REFSPEC_PUSH_ALL) or consider using directly RemoteRefUpdate for more possibilities.

        When isDryRun() is true, result of this operation is just estimation of real operation result, no real action is performed.

        Parameters:
        monitor - progress monitor to inform the user about our processing activity. Must not be null. Use NullProgressMonitor if progress updates are not interesting or necessary.
        toPush - specification of refs to push. May be null or the empty collection to use the specifications from the RemoteConfig converted by findRemoteRefUpdatesFor(Collection). No more than 1 RemoteRefUpdate with the same remoteName is allowed. These objects are modified during this call.
        out - output stream to write messages to
        Returns:
        information about results of remote refs updates, tracking refs updates and refs advertised by remote repository.
        Throws:
        NotSupportedException - this transport implementation does not support pushing objects.
        TransportException - the remote connection could not be established or object copying (if necessary) failed at I/O or protocol level or update specification was incorrect.
        Since:
        3.0
        See Also:
        RemoteRefUpdate
      • push

        public PushResult push​(ProgressMonitor monitor,
                               Collection<RemoteRefUpdate> toPush)
                        throws NotSupportedException,
                               TransportException
        Push objects and refs from the local repository to the remote one.

        This is a utility function providing standard push behavior. It updates remote refs and sends necessary objects according to remote ref update specification. After successful remote ref update, associated locally stored tracking branch is updated if set up accordingly. Detailed operation result is provided after execution.

        For setting up remote ref update specification from ref spec, see helper method findRemoteRefUpdatesFor(Collection), predefined refspecs (REFSPEC_TAGS, REFSPEC_PUSH_ALL) or consider using directly RemoteRefUpdate for more possibilities.

        When isDryRun() is true, result of this operation is just estimation of real operation result, no real action is performed.

        Parameters:
        monitor - progress monitor to inform the user about our processing activity. Must not be null. Use NullProgressMonitor if progress updates are not interesting or necessary.
        toPush - specification of refs to push. May be null or the empty collection to use the specifications from the RemoteConfig converted by findRemoteRefUpdatesFor(Collection). No more than 1 RemoteRefUpdate with the same remoteName is allowed. These objects are modified during this call.
        Returns:
        information about results of remote refs updates, tracking refs updates and refs advertised by remote repository.
        Throws:
        NotSupportedException - this transport implementation does not support pushing objects.
        TransportException - the remote connection could not be established or object copying (if necessary) failed at I/O or protocol level or update specification was incorrect.
        See Also:
        RemoteRefUpdate
      • findRemoteRefUpdatesFor

        public Collection<RemoteRefUpdate> findRemoteRefUpdatesFor​(Collection<RefSpec> specs)
                                                            throws IOException
        Convert push remote refs update specification from RefSpec form to RemoteRefUpdate. Conversion expands wildcards by matching source part to local refs. expectedOldObjectId in RemoteRefUpdate is always set as null. Tracking branch is configured if RefSpec destination matches source of any fetch ref spec for this transport remote configuration.

        Conversion is performed for context of this transport (database, fetch specifications).

        Parameters:
        specs - collection of RefSpec to convert.
        Returns:
        collection of set up RemoteRefUpdate.
        Throws:
        IOException - when problem occurred during conversion or specification set up: most probably, missing objects or refs.
      • findRemoteRefUpdatesFor

        public Collection<RemoteRefUpdate> findRemoteRefUpdatesFor​(Collection<RefSpec> specs,
                                                                   Map<String,​RefLeaseSpec> leases)
                                                            throws IOException
        Convert push remote refs update specification from RefSpec form to RemoteRefUpdate. Conversion expands wildcards by matching source part to local refs. expectedOldObjectId in RemoteRefUpdate is set according to leases. Tracking branch is configured if RefSpec destination matches source of any fetch ref spec for this transport remote configuration.

        Conversion is performed for context of this transport (database, fetch specifications).

        Parameters:
        specs - collection of RefSpec to convert.
        leases - map from ref to lease (containing expected old object id)
        Returns:
        collection of set up RemoteRefUpdate.
        Throws:
        IOException - when problem occurred during conversion or specification set up: most probably, missing objects or refs.
        Since:
        4.7
      • openFetch

        public abstract FetchConnection openFetch()
                                           throws NotSupportedException,
                                                  TransportException
        Begins a new connection for fetching from the remote repository.

        If the transport has no local repository, the fetch connection can only be used for reading remote refs.

        Returns:
        a fresh connection to fetch from the remote repository.
        Throws:
        NotSupportedException - the implementation does not support fetching.
        TransportException - the remote connection could not be established.
      • openFetch

        public FetchConnection openFetch​(Collection<RefSpec> refSpecs,
                                         String... additionalPatterns)
                                  throws NotSupportedException,
                                         TransportException
        Begins a new connection for fetching from the remote repository.

        If the transport has no local repository, the fetch connection can only be used for reading remote refs.

        If the server supports git protocol V2, the RefSpecs and the additional patterns, if any, are used to restrict the server's ref advertisement to matching refs only.

        Transports that want to support git protocol V2 must override this; the default implementation ignores its arguments and calls openFetch().

        Parameters:
        refSpecs - that will be fetched via FetchConnection.fetch(ProgressMonitor, Collection, java.util.Set, OutputStream) later
        additionalPatterns - that will be set as ref prefixes if the server supports git protocol V2; null values are ignored
        Returns:
        a fresh connection to fetch from the remote repository.
        Throws:
        NotSupportedException - the implementation does not support fetching.
        TransportException - the remote connection could not be established.
        Since:
        5.11
      • close

        public abstract void close()

        Close any resources used by this transport.

        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.

        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 AutoCloseable