[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/).

1 files changed, 50 insertions, 0 deletions

diff --git a/vendor/github.com/tetratelabs/wazero/internal/wasm/binary/global.go b/vendor/github.com/tetratelabs/wazero/internal/wasm/binary/global.go
new file mode 100644
index 000000000..4e1c16fda
--- /dev/null
+++ b/vendor/github.com/tetratelabs/wazero/internal/wasm/binary/global.go
@@ -0,0 +1,50 @@
+package binary
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/tetratelabs/wazero/api"
+	"github.com/tetratelabs/wazero/internal/wasm"
+)
+
+// decodeGlobal returns the api.Global decoded with the WebAssembly 1.0 (20191205) Binary Format.
+//
+// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#binary-global
+func decodeGlobal(r *bytes.Reader, enabledFeatures api.CoreFeatures, ret *wasm.Global) (err error) {
+	ret.Type, err = decodeGlobalType(r)
+	if err != nil {
+		return err
+	}
+
+	err = decodeConstantExpression(r, enabledFeatures, &ret.Init)
+	return
+}
+
+// decodeGlobalType returns the wasm.GlobalType decoded with the WebAssembly 1.0 (20191205) Binary Format.
+//
+// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#binary-globaltype
+func decodeGlobalType(r *bytes.Reader) (wasm.GlobalType, error) {
+	vt, err := decodeValueTypes(r, 1)
+	if err != nil {
+		return wasm.GlobalType{}, fmt.Errorf("read value type: %w", err)
+	}
+
+	ret := wasm.GlobalType{
+		ValType: vt[0],
+	}
+
+	b, err := r.ReadByte()
+	if err != nil {
+		return wasm.GlobalType{}, fmt.Errorf("read mutablity: %w", err)
+	}
+
+	switch mut := b; mut {
+	case 0x00: // not mutable
+	case 0x01: // mutable
+		ret.Mutable = true
+	default:
+		return wasm.GlobalType{}, fmt.Errorf("%w for mutability: %#x != 0x00 or 0x01", ErrInvalidByte, mut)
+	}
+	return ret, nil
+}