cache_example_test.go

Documentation: github.com/tetratelabs/wazero

     1  package wazero_test
     2  
     3  import (
     4  	"context"
     5  	_ "embed"
     6  	"log"
     7  	"os"
     8  
     9  	"github.com/tetratelabs/wazero"
    10  )
    11  
    12  // This is a basic example of using the file system compilation cache via wazero.NewCompilationCacheWithDir.
    13  // The main goal is to show how it is configured.
    14  func Example_compileCache() {
    15  	// Prepare a cache directory.
    16  	cacheDir, err := os.MkdirTemp("", "example")
    17  	if err != nil {
    18  		log.Panicln(err)
    19  	}
    20  	defer os.RemoveAll(cacheDir)
    21  
    22  	ctx := context.Background()
    23  
    24  	// Create a runtime config which shares a compilation cache directory.
    25  	cache := newCompilationCacheWithDir(cacheDir)
    26  	defer cache.Close(ctx)
    27  	config := wazero.NewRuntimeConfig().WithCompilationCache(cache)
    28  
    29  	// Using the same wazero.CompilationCache instance allows the in-memory cache sharing.
    30  	newRuntimeCompileClose(ctx, config)
    31  	newRuntimeCompileClose(ctx, config)
    32  
    33  	// Since the above stored compiled functions to disk as well, below won't compile from scratch.
    34  	// Instead, compilation result stored in the directory is re-used.
    35  	newRuntimeCompileClose(ctx, config.WithCompilationCache(newCompilationCacheWithDir(cacheDir)))
    36  	newRuntimeCompileClose(ctx, config.WithCompilationCache(newCompilationCacheWithDir(cacheDir)))
    37  
    38  	// Output:
    39  	//
    40  }
    41  
    42  func newCompilationCacheWithDir(cacheDir string) wazero.CompilationCache {
    43  	cache, err := wazero.NewCompilationCacheWithDir(cacheDir)
    44  	if err != nil {
    45  		log.Panicln(err)
    46  	}
    47  	return cache
    48  }
    49  
    50  // newRuntimeCompileDestroy creates a new wazero.Runtime, compile a binary, and then delete the runtime.
    51  func newRuntimeCompileClose(ctx context.Context, config wazero.RuntimeConfig) {
    52  	r := wazero.NewRuntimeWithConfig(ctx, config)
    53  	defer r.Close(ctx) // This closes everything this Runtime created except the file system cache.
    54  
    55  	_, err := r.CompileModule(ctx, addWasm)
    56  	if err != nil {
    57  		log.Panicln(err)
    58  	}
    59  }
    60
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