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https://github.com/ceph/go-ceph
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e01eb03284
Our first operation is generating sizes for various caller-allocated buffers. The WithSizes function "suggests" sizes to an anonymous function that takes a size as an argument and returns a hint how sucessful the attempt was. If required the same function is called again with a larger size. Errors and other results of that anonymous function are "communicated" with variables of the surrounding scope in wich the function is defined. Signed-off-by: John Mulligan <jmulligan@redhat.com> Signed-off-by: Sven Anderson <sven@redhat.com>
57 lines
1.0 KiB
Go
57 lines
1.0 KiB
Go
package retry
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import (
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"fmt"
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)
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var errTooSmall = fmt.Errorf("too small")
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func fakeComplexOp(v []string) error {
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if len(v) < 30 {
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fmt.Println("too small:", len(v))
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return errTooSmall
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}
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fmt.Println("good size:", len(v))
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return nil
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}
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func ExampleWithSizes() {
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var err error
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WithSizes(1, 128, func(size int) Hint {
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buf := make([]string, size)
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// do something complex with buf
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err = fakeComplexOp(buf)
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return DoubleSize.If(err == errTooSmall)
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})
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// Output:
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// too small: 1
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// too small: 2
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// too small: 4
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// too small: 8
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// too small: 16
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// good size: 32
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}
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func fakeComplexOp2(v []string, s *int) error {
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if len(v) < 30 {
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fmt.Println("too small:", len(v))
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*s = 30
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return errTooSmall
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}
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fmt.Println("good size:", len(v))
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return nil
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}
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func ExampleWithSizes_hint() {
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var err error
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WithSizes(1, 128, func(size int) Hint {
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buf := make([]string, size)
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// do something complex with buf
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err = fakeComplexOp2(buf, &size)
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return Size(size).If(err == errTooSmall)
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})
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// Output:
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// too small: 1
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// good size: 30
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}
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