75 lines
2.9 KiB
Go
75 lines
2.9 KiB
Go
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/*
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*
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* Copyright 2014, Google Inc.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following disclaimer
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* in the documentation and/or other materials provided with the
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* distribution.
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* * Neither the name of Google Inc. nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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// Package naming defines the naming API and related data structures for gRPC.
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// The interface is EXPERIMENTAL and may be suject to change.
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package naming
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// Operation defines the corresponding operations for a name resolution change.
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type Operation uint8
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const (
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// Add indicates a new address is added.
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Add Operation = iota
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// Delete indicates an exisiting address is deleted.
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Delete
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)
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// Update defines a name resolution update. Notice that it is not valid having both
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// empty string Addr and nil Metadata in an Update.
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type Update struct {
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// Op indicates the operation of the update.
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Op Operation
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// Addr is the updated address. It is empty string if there is no address update.
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Addr string
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// Metadata is the updated metadata. It is nil if there is no metadata update.
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// Metadata is not required for a custom naming implementation.
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Metadata interface{}
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}
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// Resolver creates a Watcher for a target to track its resolution changes.
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type Resolver interface {
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// Resolve creates a Watcher for target.
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Resolve(target string) (Watcher, error)
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}
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// Watcher watches for the updates on the specified target.
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type Watcher interface {
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// Next blocks until an update or error happens. It may return one or more
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// updates. The first call should get the full set of the results. It should
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// return an error if and only if Watcher cannot recover.
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Next() ([]*Update, error)
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// Close closes the Watcher.
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Close()
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}
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