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Diffstat (limited to 'vendor/google.golang.org/api/internal/pool.go')
-rw-r--r-- | vendor/google.golang.org/api/internal/pool.go | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/vendor/google.golang.org/api/internal/pool.go b/vendor/google.golang.org/api/internal/pool.go new file mode 100644 index 0000000..ba40624 --- /dev/null +++ b/vendor/google.golang.org/api/internal/pool.go | |||
@@ -0,0 +1,61 @@ | |||
1 | // Copyright 2016 Google LLC | ||
2 | // | ||
3 | // Licensed under the Apache License, Version 2.0 (the "License"); | ||
4 | // you may not use this file except in compliance with the License. | ||
5 | // You may obtain a copy of the License at | ||
6 | // | ||
7 | // http://www.apache.org/licenses/LICENSE-2.0 | ||
8 | // | ||
9 | // Unless required by applicable law or agreed to in writing, software | ||
10 | // distributed under the License is distributed on an "AS IS" BASIS, | ||
11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
12 | // See the License for the specific language governing permissions and | ||
13 | // limitations under the License. | ||
14 | |||
15 | package internal | ||
16 | |||
17 | import ( | ||
18 | "errors" | ||
19 | |||
20 | "google.golang.org/grpc/naming" | ||
21 | ) | ||
22 | |||
23 | // PoolResolver provides a fixed list of addresses to load balance between | ||
24 | // and does not provide further updates. | ||
25 | type PoolResolver struct { | ||
26 | poolSize int | ||
27 | dialOpt *DialSettings | ||
28 | ch chan []*naming.Update | ||
29 | } | ||
30 | |||
31 | // NewPoolResolver returns a PoolResolver | ||
32 | // This is an EXPERIMENTAL API and may be changed or removed in the future. | ||
33 | func NewPoolResolver(size int, o *DialSettings) *PoolResolver { | ||
34 | return &PoolResolver{poolSize: size, dialOpt: o} | ||
35 | } | ||
36 | |||
37 | // Resolve returns a Watcher for the endpoint defined by the DialSettings | ||
38 | // provided to NewPoolResolver. | ||
39 | func (r *PoolResolver) Resolve(target string) (naming.Watcher, error) { | ||
40 | if r.dialOpt.Endpoint == "" { | ||
41 | return nil, errors.New("No endpoint configured") | ||
42 | } | ||
43 | addrs := make([]*naming.Update, 0, r.poolSize) | ||
44 | for i := 0; i < r.poolSize; i++ { | ||
45 | addrs = append(addrs, &naming.Update{Op: naming.Add, Addr: r.dialOpt.Endpoint, Metadata: i}) | ||
46 | } | ||
47 | r.ch = make(chan []*naming.Update, 1) | ||
48 | r.ch <- addrs | ||
49 | return r, nil | ||
50 | } | ||
51 | |||
52 | // Next returns a static list of updates on the first call, | ||
53 | // and blocks indefinitely until Close is called on subsequent calls. | ||
54 | func (r *PoolResolver) Next() ([]*naming.Update, error) { | ||
55 | return <-r.ch, nil | ||
56 | } | ||
57 | |||
58 | // Close releases resources associated with the pool and causes Next to unblock. | ||
59 | func (r *PoolResolver) Close() { | ||
60 | close(r.ch) | ||
61 | } | ||