default text fields

compiler/src/main/cpp/capnpc-java.c++

@@ -942,6 +942,10 @@ private:
 
     } else if (kind == FieldKind::BLOB && typeBody.which() == schema::Type::TEXT ) {
 
+      uint64_t typeId = field.getContainingStruct().getProto().getId();
+      kj::String defaultParams = defaultOffset == 0 ? kj::str() : kj::str(
+        "Schemas.b_", kj::hex(typeId), ", ", defaultOffset * 8, ", ", defaultSize);
+
       kj::String blobKind =  kj::str("Text");
 
       return FieldText {
@@ -955,7 +959,7 @@ private:
           spaces(indent), "  public ", type, ".Reader",
           " get", titleCase, "() {\n",
           spaces(indent), "    return _reader.getPointerField(",
-          offset, ").get", blobKind, " ();\n", // XXX
+          offset, ").getText(", defaultParams, ");\n",
           spaces(indent), "  }\n", "\n"),
 
         kj::strTree(
@@ -966,7 +970,7 @@ private:
           spaces(indent), "  }\n",
           spaces(indent), "  public final ", type, ".Builder get", titleCase, "() {\n",
           spaces(indent), "    return _builder.getPointerField(",
-          offset, ").get", blobKind, " ();\n", // XXX
+          offset, ").get", blobKind, "(", defaultParams, ");\n",
           spaces(indent), "  }\n",
           spaces(indent), "  public final void set", titleCase, "(", type, ".Reader value) {\n",
           unionDiscrim.set,

compiler/src/test/scala/org/capnproto/TestUtil.scala

@@ -237,6 +237,7 @@ object TestUtil {
     assert(builder.getUInt64Field() == 0xab54a98ceb1f0ad2L);
     assert(builder.getFloat32Field() == 1234.5f);
     assert(builder.getFloat64Field() == -123e45);
+    (builder.getTextField().toString()) should equal ("foo");
   }
 
   def checkDefaultMessage(reader : TestDefaults.Reader) {
@@ -252,6 +253,7 @@ object TestUtil {
     assert(reader.getUInt64Field() == 0xab54a98ceb1f0ad2L);
     assert(reader.getFloat32Field() == 1234.5f);
     assert(reader.getFloat64Field() == -123e45);
+    (reader.getTextField().toString()) should equal ("foo");
   }
 
 

compiler/src/test/schema/test.capnp

@@ -66,6 +66,7 @@ struct TestDefaults {
   uInt64Field    @9  : UInt64  = 12345678901234567890;
   float32Field   @10 : Float32 = 1234.5;
   float64Field   @11 : Float64 = -123e45;
+  textField      @12 : Text    = "foo";
 }
 
 struct TestAnyPointer {

runtime/src/main/java/org/capnproto/PointerBuilder.java

@@ -31,7 +31,15 @@ public final class PointerBuilder {
 
     public final Text.Builder getText() {
         return WireHelpers.getWritableTextPointer(
-            this.pointer, this.segment);
+            this.pointer, this.segment, null, 0, 0);
+    }
+
+    public Text.Builder getText(java.nio.ByteBuffer defaultBuffer, int defaultOffset, int defaultSize) {
+        return WireHelpers.getWritableTextPointer(this.pointer,
+                                                  this.segment,
+                                                  defaultBuffer,
+                                                  defaultOffset,
+                                                  defaultSize);
     }
 
     public final Data.Builder getData() {

runtime/src/main/java/org/capnproto/PointerReader.java

@@ -53,8 +53,11 @@ public final class PointerReader {
     }
 
     public Text.Reader getText() {
-        return WireHelpers.readTextPointer(this.segment,
+        return WireHelpers.readTextPointer(this.segment, this.pointer, null, 0, 0);
-                                           this.pointer);
+    }
+
+    public Text.Reader getText(java.nio.ByteBuffer defaultBuffer, int defaultOffset, int defaultSize) {
+        return WireHelpers.readTextPointer(this.segment, this.pointer, defaultBuffer, defaultOffset, defaultSize);
     }
 
     public Data.Reader getData() {

runtime/src/main/java/org/capnproto/WireHelpers.java

@@ -1,5 +1,7 @@
 package org.capnproto;
 
+import java.nio.ByteBuffer;
+
 final class WireHelpers {
 
     public static int roundBytesUpToWords(int bytes) {
@@ -310,12 +312,23 @@ final class WireHelpers {
     }
 
     public static Text.Builder getWritableTextPointer(int refOffset,
-                                                      SegmentBuilder segment) {
+                                                      SegmentBuilder segment,
+                                                      ByteBuffer defaultBuffer,
+                                                      int defaultOffset,
+                                                      int defaultSize) {
         long ref = WirePointer.get(segment.buffer, refOffset);
 
         if (WirePointer.isNull(ref)) {
-            // TODO default values
+            if (defaultBuffer == null) {
-            return new Text.Builder(null, 0, 0);
+                return new Text.Builder(null, 0, 0);
+            } else {
+                Text.Builder builder = initTextPointer(refOffset, segment, defaultSize);
+                // TODO is there a way to do this with bulk methods?
+                for (int i = 0; i < builder.size; ++i) {
+                    builder.buffer.put(builder.offset + i, defaultBuffer.get(defaultOffset + i));
+                }
+                return builder;
+            }
         }
 
         int refTarget = WirePointer.target(refOffset, ref);
@@ -454,12 +467,19 @@ final class WireHelpers {
     }
 
     public static Text.Reader readTextPointer(SegmentReader segment,
-                                              int refOffset) {
+                                              int refOffset,
+                                              ByteBuffer defaultBuffer,
+                                              int defaultOffset,
+                                              int defaultSize) {
         long ref = WirePointer.get(segment.buffer, refOffset);
 
         if (WirePointer.isNull(ref)) {
-            // XXX should use the default value
+            if (defaultBuffer == null) {
-            return new Text.Reader(java.nio.ByteBuffer.wrap(new byte[0]), 0, 0);
+                // XXX -- what about null terminator?
+                return new Text.Reader(ByteBuffer.wrap(new byte[0]), 0, 0);
+            } else {
+                return new Text.Reader(defaultBuffer, defaultOffset, defaultSize);
+            }
         }
 
         int refTarget = WirePointer.target(refOffset, ref);