working commit

vendor/github.com/tetratelabs/wabin/binary/memory.go

@@ -0,0 +1,43 @@
+package binary
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/tetratelabs/wabin/wasm"
+)
+
+// decodeMemory returns the wasm.Memory decoded with the WebAssembly
+// Binary Format.
+//
+// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#binary-memory
+func decodeMemory(r *bytes.Reader) (*wasm.Memory, error) {
+	min, maxP, err := decodeLimitsType(r)
+	if err != nil {
+		return nil, err
+	}
+
+	mem := &wasm.Memory{Min: min}
+	if maxP != nil {
+		mem.Max = *maxP
+		mem.IsMaxEncoded = true
+
+		if min > mem.Max {
+			return nil, fmt.Errorf("min %d pages (%s) > max %d pages (%s)",
+				min, wasm.PagesToUnitOfBytes(min), mem.Max, wasm.PagesToUnitOfBytes(mem.Max))
+		}
+	}
+
+	return mem, nil
+}
+
+// encodeMemory returns the wasm.Memory encoded in WebAssembly Binary Format.
+//
+// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#binary-memory
+func encodeMemory(i *wasm.Memory) []byte {
+	maxPtr := &i.Max
+	if !i.IsMaxEncoded {
+		maxPtr = nil
+	}
+	return encodeLimitsType(i.Min, maxPtr)
+}