hbase/hbase-protocol-shaded
stack 95c1dc93fb HBASE-15638 Shade protobuf
Which includes

    HBASE-16742 Add chapter for devs on how we do protobufs going forward

    HBASE-16741 Amend the generate protobufs out-of-band build step
    to include shade, pulling in protobuf source and a hook for patching protobuf

    Removed ByteStringer from hbase-protocol-shaded. Use the protobuf-3.1.0
    trick directly instead. Makes stuff cleaner. All under 'shaded' dir is
    now generated.

    HBASE-16567 Upgrade to protobuf-3.1.x
    Regenerate all protos in this module with protoc3.
    Redo ByteStringer to use new pb3.1.0 unsafebytesutil
    instead of HBaseZeroCopyByteString

    HBASE-16264 Figure how to deal with endpoints and shaded pb Shade our protobufs.
    Do it in a manner that makes it so we can still have in our API references to
    com.google.protobuf (and in REST). The c.g.p in API is for Coprocessor Endpoints (CPEP)

            This patch is Tactic #4 from Shading Doc attached to the referenced issue.
            Figuring an appoach took a while because we have Coprocessor Endpoints
            mixed in with the core of HBase that are tough to untangle (FIX).

            Tactic #4 (the fourth attempt at addressing this issue) is COPY all but
            the CPEP .proto files currently in hbase-protocol to a new module named
            hbase-protocol-shaded. Generate .protos again in the new location and
            then relocate/shade the generated files. Let CPEPs keep on with the
            old references at com.google.protobuf.* and
            org.apache.hadoop.hbase.protobuf.* but change the hbase core so all
            instead refer to the relocated files in their new location at
            org.apache.hadoop.hbase.shaded.com.google.protobuf.*.

            Let the new module also shade protobufs themselves and change hbase
            core to pick up this shaded protobuf rather than directly reference
            com.google.protobuf.

            This approach allows us to explicitly refer to either the shaded or
            non-shaded version of a protobuf class in any particular context (though
            usually context dictates one or the other). Core runs on shaded protobuf.
            CPEPs continue to use whatever is on the classpath with
            com.google.protobuf.* which is pb2.5.0 for the near future at least.

            See above cited doc for follow-ons and downsides. In short, IDEs will complain
            about not being able to find the shaded protobufs since shading happens at package
            time; will fix by checking in all generated classes and relocated protobuf in
            a follow-on. Also, CPEPs currently suffer an extra-copy as marshalled from
            non-shaded to shaded. To fix. Finally, our .protos are duplicated; once
            shaded, and once not. Pain, but how else to reveal our protos to CPEPs or
            C++ client that wants to talk with HBase AND shade protobuf.

            Details:

            Add a new hbase-protocol-shaded module. It is a copy of hbase-protocol
    i       with all relocated offset from o.a.h.h. to o.a.h.h.shaded. The new module
            also includes the relocated pb. It does not include CPEPs. They stay in
            their old location.

            Add another module hbase-endpoint which has in it all the endpoints
            that ship as part of hbase -- at least the ones that are not
            entangled with core such as AccessControl and Auth. Move all protos
            for these CPEPs here as well as their unit tests (mostly moving a
            bunch of stuff out of hbase-server module)

            Much of the change looks like this:

                 -import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
                 -import org.apache.hadoop.hbase.protobuf.generated.ClusterIdProtos;
                 +import org.apache.hadoop.hbase.protobuf.shaded.ProtobufUtil;
                 +import org.apache.hadoop.hbase.shaded.protobuf.generated.ClusterIdProtos;

            In HTable and in HBaseAdmin, regularize the way Callables are used and also hide
            protobuf usage as much as possible moving it up into Callable super classes or out
            to utility classes. Still TODO is adding in of retries, etc., but can wait on
            procedure which will redo all this.

            Also in HTable and HBaseAdmin as well as in HRegionServer and Server, be explicit
            when using non-shaded protobuf. Do the full-path so it is clear. This is around
            endpoint coprocessors registration of services and execution of CPEP methods.

            Shrunk ProtobufUtil by moving methods used by one CPEP only back to the CPEP either
            into Client class or as new Util class; e.g. AccessControlUtil.

            There are actually two versions of ProtobufUtil now; a shaded one and a subset
            that is used by CPEPs doing non-shaded work.

            Made it so hbase-common no longer depends on hbase-protocol (with Matteo's help)

            R*Converter classes got moved down under shaded package -- they are for internal
            use only. There are no non-shaded versions of these classes.

            D hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractRegionServerCallable
            D RetryingCallableBase
             Not used anymore and we have too many tiers of Callables so removed/cleaned-up.

            A ClientServicecallable
             Had to add this one. RegionServerCallable was made generic so it could be used
             for a few Interfaces (Client and Admin). Then added ClientServiceCallable to
             implement RegionServerCallable with the Client Interface.
2016-10-03 21:37:32 -07:00
..
src/main HBASE-15638 Shade protobuf 2016-10-03 21:37:32 -07:00
README.txt HBASE-15638 Shade protobuf 2016-10-03 21:37:32 -07:00
pom.xml HBASE-15638 Shade protobuf 2016-10-03 21:37:32 -07:00

README.txt

Please read carefully as the 'menu options' have changed.

This module has proto files used by core. These protos
overlap with protos that are used by coprocessor endpoints
(CPEP) in the module hbase-protocol. So the core versions have
a different name, the generated classes are relocated
-- i.e. shaded -- to a new location; they are moved from
org.apache.hadoop.hbase.* to org.apache.hadoop.hbase.shaded.

This module also includes the protobuf that hbase core depends
on again relocated to live at an offset of
org.apache.hadoop.hbase.shaded so as to avoid clashes with other
versions of protobuf resident on our CLASSPATH included,
transitively or otherwise, by dependencies: i.e. the shaded
protobuf Message class is at
org.apache.hadoop.hbase.shaded.com.google.protobuf.Message
rather than at com.google.protobuf.Message.

Below we describe how to generate the java files for this
module. Run this step any time you change the proto files
in this module or if you change the protobuf version. If you
add a new file, be sure to add mention of the proto in the
pom.xml (scroll till you see the listing of protos to consider).

First ensure that the appropriate protobuf protoc tool is in
your $PATH as in:

 $ export PATH=~/bin/protobuf-3.1.0/src:$PATH

.. or pass -Dprotoc.path=PATH_TO_PROTOC when running
the below mvn commands. You may need to download protobuf and
build protoc first.

Run:

 $ mvn install -Dgenerate-shaded-classes

or

 $ mvn install -Pgenerate-shaded-classes

to build and trigger the special generate-shaded-classes
profile. When finished, the content of
src/main/java/org/apache/hadoop/hbase/shaded will have
been updated. Check in the changes.

See the pom.xml under the generate-shaded-classes profile
for more info on how this step works.