Only generate non-constant header fields in wrapAndApply method. Fixes aeron-io#602 for java only

Author: Kyle D Kavanagh

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/java/JavaGenerator.java

@@ -2272,19 +2272,42 @@ private CharSequence generateEncoderFlyweightCode(final String className, final
  " }\n\n",
  className,
  mutableBuffer);
-
- final String wrapAndApplyHeaderMethod = String.format(
+ final String indent = " ";
+ String wrapAndApplyHeaderMethodFmtString =
  " public %1$s wrapAndApplyHeader(\n" +
  " final %2$s buffer, final int offset, final %3$s headerEncoder)\n" +
  " {\n" +
  " headerEncoder\n" +
- " .wrap(buffer, offset)\n" +
- " .blockLength(BLOCK_LENGTH)\n" +
- " .templateId(TEMPLATE_ID)\n" +
- " .schemaId(SCHEMA_ID)\n" +
- " .version(SCHEMA_VERSION);\n\n" +
+ " .wrap(buffer, offset)";
+ for (final Token headerToken : ir.headerStructure().tokens())
+ {
+ if (!headerToken.isConstantEncoding())
+ {
+ final String fieldName = headerToken.name();
+ switch (fieldName)
+ {
+ case "blockLength":
+ wrapAndApplyHeaderMethodFmtString += '\n' + indent + ".blockLength(BLOCK_LENGTH)";
+ break;
+ case "templateId":
+ wrapAndApplyHeaderMethodFmtString += '\n' + indent + ".templateId(TEMPLATE_ID)";
+ break;
+ case "schemaId":
+ wrapAndApplyHeaderMethodFmtString += '\n' + indent + ".schemaId(SCHEMA_ID)";
+ break;
+ case "version":
+ wrapAndApplyHeaderMethodFmtString += '\n' + indent + ".version(SCHEMA_VERSION)";
+ break;
+ }
+ }
+ }
+
+
+ wrapAndApplyHeaderMethodFmtString += ";\n" +
  " return wrap(buffer, offset + %3$s.ENCODED_LENGTH);\n" +
- " }\n\n",
+ " }\n\n";
+ final String wrapAndApplyHeaderMethod = String.format(
+ wrapAndApplyHeaderMethodFmtString,
  className,
  mutableBuffer,
  formatClassName(ir.headerStructure().tokens().get(0).applicableTypeName() + "Encoder"));

sbe-tool/src/test/java/uk/co/real_logic/sbe/xml/BasicSchemaFileTest.java

@@ -33,6 +33,13 @@ public void shouldHandleBasicFile()
  parse(TestUtil.getLocalResource("basic-schema.xml"), ParserOptions.DEFAULT);
  }
 
+ @Test
+ public void shouldHandleConstantHeaderField()
+ throws Exception
+ {
+ parse(TestUtil.getLocalResource("basic-schema-constant-header-field.xml"), ParserOptions.DEFAULT);
+ }
+
  @Test
  public void shouldHandleBasicFileWithGroup()
  throws Exception

sbe-tool/src/test/resources/basic-schema-constant-header-field.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<messageSchema package="SBE tests"
+ id="2"
+ semanticVersion="5.2"
+ description="Unit Test"
+ byteOrder="littleEndian">
+ <types>
+ <type name="Symbol" description="Symbol" length="20" primitiveType="char" semanticType="char"/>
+ <composite name="messageHeader" description="Message identifiers and length of message root">
+ <type name="blockLength" primitiveType="uint16"/>
+ <type name="templateId" primitiveType="uint16"/>
+ <type name="schemaId" primitiveType="uint16" presence="constant">1</type>
+ <type name="version" primitiveType="uint16"/>
+ </composite>
+ </types>
+ <message name="TestMessage50001" id="50001" description="TestMessage" blockLength="16">
+ <field name="Tag40001" id="40001" type="uint32" semanticType="int"/>
+ </message>
+</messageSchema>