Work in progres, please take a look and give early feedback if this is the way we want to structure…

pkg/service/lib/struct.dart

Index: pkg/service/lib/struct.dart
diff --git a/pkg/service/lib/struct.dart b/pkg/service/lib/struct.dart
index 80a098315729cfdaddc40de56a8f2eed6214f686..417e60f843f67e99a7f1b84f4c8ee2346137f9c5 100644
--- a/pkg/service/lib/struct.dart
+++ b/pkg/service/lib/struct.dart
@@ -8,7 +8,7 @@ import "dart:ffi";
 
 const int HEADER_SIZE = 56;
 
-Reader getRoot(Reader reader, Foreign request) {
+Reader getRoot(Reader reader, ForeignMemory request) {
   int segments = request.getInt32(HEADER_SIZE - 8);
   if (segments == 0) {
     MessageReader messageReader = new MessageReader();
@@ -22,7 +22,7 @@ Reader getRoot(Reader reader, Foreign request) {
   }
 }
 
-Reader getSegmentedRoot(Reader reader, Foreign request, int segments) {
+Reader getSegmentedRoot(Reader reader, ForeignMemory request, int segments) {
   MessageReader messageReader = new MessageReader();
   int offset = HEADER_SIZE + 8;
   for (int i = 0; i < segments; i++) {
@@ -30,7 +30,7 @@ Reader getSegmentedRoot(Reader reader, Foreign request, int segments) {
         ? request.getUint32(offset)
         : request.getUint64(offset);
     int size = request.getInt32(offset + 8);
-    Foreign memory = new Foreign.fromAddress(address, size);
+    ForeignMemory memory = new ForeignMemory.fromAddress(address, size);
     Segment segment = new Segment(messageReader, memory);
     messageReader.segments.add(segment);
     offset += 16;
@@ -44,27 +44,27 @@ int getResultMessage(Builder builder) {
   BuilderSegment segment = builder._segment;
   if (segment._next == null) {
     // Mark result as being non-segmented.
-    Foreign memory = segment.memory;
+    ForeignMemory memory = segment.memory;
     memory.setInt32(0, 0);
     memory.setInt32(4, memory.length);
-    return memory.value;
+    return memory.address;
   }
 
   // The result is a segmented message. Build a memory block that
   // contains the addresses and sizes of all of them.
   int segments = segment._builder._segments;
   int size = 8 + (segments * 16);
-  Foreign buffer = new Foreign.allocated(size);
+  ForeignMemory buffer = new ForeignMemory.allocated(size);
   // Mark the result as being segmented.
   buffer.setInt32(0, segments);
   int offset = 8;
   do {
-    buffer.setInt64(offset, segment.memory.value);
+    buffer.setInt64(offset, segment.memory.address);
     buffer.setInt32(offset + 8, segment._used);
     segment = segment._next;
     offset += 16;
   } while (segment != null);
-  return buffer.value;
+  return buffer.address;
 }
 
 class MessageReader {
@@ -76,7 +76,7 @@ class MessageReader {
 
 class Segment {
   final MessageReader reader;
-  final Foreign memory;
+  final ForeignMemory memory;
   Segment(this.reader, this.memory);
 }
 
@@ -98,7 +98,7 @@ class Reader {
     Segment segment = _segment;
     offset += _offset;
     while (true) {
-      Foreign memory = segment.memory;
+      ForeignMemory memory = segment.memory;
       int lo = memory.getInt32(offset + 0);
       int hi = memory.getInt32(offset + 4);
       int tag = lo & 3;
@@ -119,7 +119,7 @@ class Reader {
     Segment segment = _segment;
     offset += _offset;
     while (true) {
-      Foreign memory = segment.memory;
+      ForeignMemory memory = segment.memory;
       int lo = memory.getInt32(offset + 0);
       int hi = memory.getInt32(offset + 4);
       int tag = lo & 3;
@@ -212,13 +212,13 @@ class ListReader extends Reader {
 
 class BuilderSegment {
   final MessageBuilder _builder;
-  final Foreign memory;
+  final ForeignMemory memory;
   int _id;
   int _used = 0;
   BuilderSegment _next;
 
   BuilderSegment(this._builder, this._id, int space)
-      : memory = new Foreign.allocated(space);
+      : memory = new ForeignMemory.allocated(space);
 
   bool HasSpaceForBytes(int bytes) => _used + bytes <= memory.length;
 
@@ -276,7 +276,7 @@ class Builder {
     BuilderSegment segment = _segment;
     while (true) {
       int result = segment.Allocate(size);
-      Foreign memory = segment.memory;
+      ForeignMemory memory = segment.memory;
       if (result >= 0) {
         memory.setInt32(offset + 0, (result << 2) | 1);
         memory.setInt32(offset + 4, 0);
@@ -305,7 +305,7 @@ class Builder {
     BuilderSegment segment = _segment;
     while (true) {
       int result = segment.Allocate(size);
-      Foreign memory = segment.memory;
+      ForeignMemory memory = segment.memory;
       if (result >= 0) {
         memory.setInt32(offset + 0, (result << 2) | 1);
         memory.setInt32(offset + 4, length);