Add WasmInterpreter.heap()

shareup · Aug 13, 2020 · 9f07c12 · 9f07c12
1 parent 6dc932e
commit 9f07c12
Show file tree

Hide file tree

Showing 2 changed files with 15 additions and 3 deletions.
diff --git a/Sources/WasmInterpreter/Heap.swift b/Sources/WasmInterpreter/Heap.swift
@@ -0,0 +1,6 @@
+import Foundation
+
+public struct Heap {
+    public let pointer: UnsafeMutablePointer<UInt8>
+    public let size: Int
+}
diff --git a/Sources/WasmInterpreter/WasmInterpreter.swift b/Sources/WasmInterpreter/WasmInterpreter.swift
@@ -50,16 +50,22 @@ public final class WasmInterpreter {
         removeImportedFunctions(for: _importedFunctionContexts)
     }
 
-    public func dataFromHeap(offset: Int, length: Int) throws -> Data {
+    public func heap() throws -> Heap {
         let totalBytes = UnsafeMutablePointer<UInt32>.allocate(capacity: 1)
         defer { totalBytes.deallocate() }
 
         guard let bytesPointer = m3_GetMemory(_runtime, totalBytes, 0) else {
             throw WasmInterpreterError.invalidMemoryAccess
         }
-        guard offset + length < totalBytes.pointee else { throw WasmInterpreterError.invalidMemoryAccess }
 
-        return Data(bytes: bytesPointer.advanced(by: offset), count: length)
+        return Heap(pointer: bytesPointer, size: Int(totalBytes.pointee))
+    }
+
+    public func dataFromHeap(offset: Int, length: Int) throws -> Data {
+        let heap = try self.heap()
+        guard offset + length < heap.size else { throw WasmInterpreterError.invalidMemoryAccess }
+
+        return Data(bytes: heap.pointer.advanced(by: offset), count: length)
     }
 
     public func stringFromHeap(offset: Int, length: Int) throws -> String {