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90 lines
2.8 KiB
90 lines
2.8 KiB
// Copyright 2016, 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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package gax |
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import ( |
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"time" |
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"golang.org/x/net/context" |
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) |
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// A user defined call stub. |
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type APICall func(context.Context, CallSettings) error |
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// Invoke calls the given APICall, |
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// performing retries as specified by opts, if any. |
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func Invoke(ctx context.Context, call APICall, opts ...CallOption) error { |
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var settings CallSettings |
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for _, opt := range opts { |
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opt.Resolve(&settings) |
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} |
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return invoke(ctx, call, settings, Sleep) |
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} |
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// Sleep is similar to time.Sleep, but it can be interrupted by ctx.Done() closing. |
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// If interrupted, Sleep returns ctx.Err(). |
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func Sleep(ctx context.Context, d time.Duration) error { |
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t := time.NewTimer(d) |
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select { |
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case <-ctx.Done(): |
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t.Stop() |
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return ctx.Err() |
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case <-t.C: |
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return nil |
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} |
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} |
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type sleeper func(ctx context.Context, d time.Duration) error |
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// invoke implements Invoke, taking an additional sleeper argument for testing. |
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func invoke(ctx context.Context, call APICall, settings CallSettings, sp sleeper) error { |
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var retryer Retryer |
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for { |
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err := call(ctx, settings) |
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if err == nil { |
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return nil |
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} |
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if settings.Retry == nil { |
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return err |
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} |
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if retryer == nil { |
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if r := settings.Retry(); r != nil { |
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retryer = r |
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} else { |
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return err |
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} |
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} |
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if d, ok := retryer.Retry(err); !ok { |
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return err |
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} else if err = sp(ctx, d); err != nil { |
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return err |
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} |
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} |
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}
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