03bfa31928
This removes tedium in our examples and docs by using `Runtime.Close` instead of tracking everything. Internal tests still track too much, but anyway at least this stops suggesting others should do it. This also changes our examples to use log.PanicXX so that the line number goes into the console output. Signed-off-by: Adrian Cole <adrian@tetrate.io>
72 lines
1.8 KiB
Go
72 lines
1.8 KiB
Go
package experimental_test
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import (
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"context"
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"encoding/hex"
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"fmt"
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"log"
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"math/rand"
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"os"
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"github.com/tetratelabs/wazero"
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"github.com/tetratelabs/wazero/experimental"
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"github.com/tetratelabs/wazero/wasi"
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)
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type fakeSys struct{}
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const (
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epochNanos = uint64(1640995200000000000) // midnight UTC 2022-01-01
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seed = int64(42) // fixed seed value
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)
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func (d fakeSys) TimeNowUnixNano() uint64 {
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return epochNanos
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}
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func (d fakeSys) RandSource(p []byte) error {
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s := rand.NewSource(seed)
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rng := rand.New(s)
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_, err := rng.Read(p)
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return err
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}
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// This is a very basic integration of sys config. The main goal is to show how it is configured.
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func Example_sys() {
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// Set context to one that has experimental sys config
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ctx := context.WithValue(context.Background(), experimental.SysKey{}, &fakeSys{})
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r := wazero.NewRuntimeWithConfig(wazero.NewRuntimeConfigInterpreter())
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defer r.Close(ctx) // This closes everything this Runtime created.
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if _, err := wasi.InstantiateSnapshotPreview1(ctx, r); err != nil {
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log.Panicln(err)
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}
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code, err := r.CompileModule(ctx, []byte(`(module
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(import "wasi_snapshot_preview1" "random_get"
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(func $wasi.random_get (param $buf i32) (param $buf_len i32) (result (;errno;) i32)))
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(func i32.const 0 i32.const 4 call 0 drop) ;; write 4 bytes of random data
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(memory 1 1)
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(start 1) ;; call the second function
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)`), wazero.NewCompileConfig())
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if err != nil {
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log.Panicln(err)
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}
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mod, err := r.InstantiateModule(ctx, code, wazero.NewModuleConfig().WithStdout(os.Stdout))
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if err != nil {
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log.Panicln(err)
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}
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// Try to read 4 bytes of random data.
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if bytes, ok := mod.Memory().Read(ctx, 0, 4); !ok {
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log.Panicf("Memory.Read(0, 4) out of range of memory size %d", mod.Memory().Size(ctx))
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} else {
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fmt.Println(hex.EncodeToString(bytes))
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}
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// Output:
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// 538c7f96
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}
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