gotosocial/vendor/github.com/tetratelabs/wazero/internal/filecache/compilationcache.go
kim 1e7b32490d
[experiment] add alternative wasm sqlite3 implementation available via build-tag (#2863)
This allows for building GoToSocial with [SQLite transpiled to WASM](https://github.com/ncruces/go-sqlite3) and accessed through [Wazero](https://wazero.io/).
2024-05-27 17:46:15 +02:00

43 lines
1.9 KiB
Go

package filecache
import (
"crypto/sha256"
"io"
)
// Cache allows the compiler engine to skip compilation of wasm to machine code
// where doing so is redundant for the same wasm binary and version of wazero.
//
// This augments the default in-memory cache of compiled functions, by
// decoupling it from a wazero.Runtime instance. Concretely, a runtime loses
// its cache once closed. This cache allows the runtime to rebuild its
// in-memory cache quicker, significantly reducing first-hit penalty on a hit.
//
// See New for the example implementation.
type Cache interface {
// Get is called when the runtime is trying to get the cached compiled functions.
// Implementations are supposed to return compiled function in io.Reader with ok=true
// if the key exists on the cache. In the case of not-found, this should return
// ok=false with err=nil. content.Close() is automatically called by
// the caller of this Get.
//
// Note: the returned content won't go through the validation pass of Wasm binary
// which is applied when the binary is compiled from scratch without cache hit.
Get(key Key) (content io.ReadCloser, ok bool, err error)
//
// Add is called when the runtime is trying to add the new cache entry.
// The given `content` must be un-modified, and returned as-is in Get method.
//
// Note: the `content` is ensured to be safe through the validation phase applied on the Wasm binary.
Add(key Key, content io.Reader) (err error)
//
// Delete is called when the cache on the `key` returned by Get is no longer usable, and
// must be purged. Specifically, this is called happens when the wazero's version has been changed.
// For example, that is when there's a difference between the version of compiling wazero and the
// version of the currently used wazero.
Delete(key Key) (err error)
}
// Key represents the 256-bit unique identifier assigned to each cache entry.
type Key = [sha256.Size]byte