Extract writeSize() function

2 files changed, 33 insertions, 11 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatModules.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatModules.java
index f03cdd32..cddfb026 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatModules.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatModules.java
@@ -11,6 +11,7 @@ import java.util.HexFormat;
 
 import static org.shedlang.compiler.backends.wasm.structure.binary.WasmBinaryFormatConventions.writeVec;
 import static org.shedlang.compiler.backends.wasm.structure.binary.WasmBinaryFormatNameSection.writeNameSection;
+import static org.shedlang.compiler.backends.wasm.structure.binary.WasmBinaryFormatSize.writeSize;
 import static org.shedlang.compiler.backends.wasm.structure.binary.WasmBinaryFormatTypes.*;
 import static org.shedlang.compiler.backends.wasm.structure.binary.WasmBinaryFormatValues.writeString;
 
@@ -49,17 +50,7 @@ public class WasmBinaryFormatModules {
         // * the actual contents
         writer.writeByte(sectionId.id);
 
-        var sizePosition = writer.position();
-        Leb128Encoding.encodePaddedUnsignedInt32(0, writer);
-
-        var contentStartPosition = writer.position();
-        writeContent.write();
-        var contentEndPosition = writer.position();
-
-        var size = contentEndPosition - contentStartPosition;
-        writer.seek(sizePosition);
-        Leb128Encoding.encodePaddedUnsignedInt32(size, writer);
-        writer.seek(contentEndPosition);
+        writeSize(writer, writeContent::write);
     }
 
     enum SectionId {
diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatSize.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatSize.java
new file mode 100644
index 00000000..7a90bdb0
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatSize.java
@@ -0,0 +1,31 @@
+package org.shedlang.compiler.backends.wasm.structure.binary;
+
+import org.shedlang.compiler.backends.wasm.structure.BinaryWriter;
+
+import java.io.IOException;
+
+public class WasmBinaryFormatSize {
+    private WasmBinaryFormatSize() {
+    }
+
+    public interface Write {
+        void write() throws IOException;
+    }
+
+    public static void writeSize(
+        BinaryWriter writer,
+        Write writeContent
+    ) throws IOException {
+        var sizePosition = writer.position();
+        Leb128Encoding.encodePaddedUnsignedInt32(0, writer);
+
+        var contentStartPosition = writer.position();
+        writeContent.write();
+        var contentEndPosition = writer.position();
+
+        var size = contentEndPosition - contentStartPosition;
+        writer.seek(sizePosition);
+        Leb128Encoding.encodePaddedUnsignedInt32(size, writer);
+        writer.seek(contentEndPosition);
+    }
+}