Allow setting custom FIX tags in encoders (WIP) real-logic#462

.editorconfig

@@ -0,0 +1,12 @@
+# Helps IDEA users apply some of the formatting rules enforced by checkstyle
+
+root = true
+
+[*]
+
+[*.java]
+indent_size = 4
+ij_java_method_brace_style = next_line
+ij_java_block_brace_style = next_line
+ij_java_class_brace_style = next_line
+ij_java_space_after_type_cast = false

artio-codecs/src/main/java/uk/co/real_logic/artio/builder/CommonEncoderImpl.java

@@ -0,0 +1,45 @@
+package uk.co.real_logic.artio.builder;
+
+import uk.co.real_logic.artio.util.MutableAsciiBuffer;
+
+/**
+ * Class provides common implementation methods used by encoders.
+ */
+public class CommonEncoderImpl
+{
+    // TODO resizable buffer or way to set a size
+    protected MutableAsciiBuffer customTagsBuffer = new MutableAsciiBuffer(new byte[64]);
+
+    protected int customTagsLength = 0;
+
+    private int putTagHeader(final int tag)
+    {
+        int pos = customTagsLength;
+        pos += customTagsBuffer.putIntAscii(pos, tag);
+        customTagsBuffer.putByte(pos++, (byte)'=');
+        return pos;
+    }
+
+    public CommonEncoderImpl customTag(final int tag, final int value)
+    {
+        int pos = putTagHeader(tag);
+        pos += customTagsBuffer.putIntAscii(pos, value);
+        customTagsBuffer.putSeparator(pos++);
+        customTagsLength = pos;
+        return this;
+    }
+
+    public CommonEncoderImpl customTagAscii(final int tag, final CharSequence value)
+    {
+        int pos = putTagHeader(tag);
+        pos += customTagsBuffer.putStringWithoutLengthAscii(pos, value);
+        customTagsBuffer.putSeparator(pos++);
+        customTagsLength = pos;
+        return this;
+    }
+
+    public void resetCustomTags()
+    {
+        customTagsLength = 0;
+    }
+}

artio-codecs/src/main/java/uk/co/real_logic/artio/dictionary/generation/EncoderGenerator.java

@@ -20,6 +20,7 @@
 import org.agrona.MutableDirectBuffer;
 import org.agrona.concurrent.UnsafeBuffer;
 import org.agrona.generation.OutputManager;
+import uk.co.real_logic.artio.builder.CommonEncoderImpl;
 import uk.co.real_logic.artio.builder.Encoder;
 import uk.co.real_logic.artio.builder.SessionHeaderEncoder;
 import uk.co.real_logic.artio.dictionary.Generated;
@@ -207,7 +208,8 @@ protected void generateAggregateFile(final Aggregate aggregate, final AggregateT
                     DirectBuffer.class,
                     MutableDirectBuffer.class,
                     UnsafeBuffer.class,
-                    AsciiSequenceView.class);
+                    AsciiSequenceView.class,
+                    CommonEncoderImpl.class);
                 generateAggregateClass(aggregate, aggregateType, className, out);
             });
     }
@@ -339,7 +341,7 @@ private String classDeclaration(
         }
         else
         {
-            extendsClause = "";
+            extendsClause = " extends CommonEncoderImpl";
         }
         return String.format(
             "\n" +
@@ -365,6 +367,9 @@ private String completeResetMethod(
             case HEADER:
                 additionalReset = "        beginStringAsCopy(DEFAULT_BEGIN_STRING, 0, DEFAULT_BEGIN_STRING.length);\n";
                 break;
+            case MESSAGE:
+                additionalReset = "        resetCustomTags();\n";
+                break;
             default:
                 additionalReset = "";
         }
@@ -968,6 +973,13 @@ private String encodeMethod(final List<Entry> entries, final AggregateType aggre
         if (aggregateType == AggregateType.MESSAGE)
         {
             suffix =
+                "\n" +
+                "        if (customTagsLength > 0)\n" +
+                "        {\n" +
+                "            buffer.putBytes(position, customTagsBuffer, 0, customTagsLength);\n" +
+                "            position += customTagsLength;\n" +
+                "        }\n" +
+                "\n" +
                 "        position += trailer.startTrailer(buffer, position);\n" +
                 "\n" +
                 "        final int messageStart = header.finishHeader(buffer, bodyStart, position - bodyStart);\n" +

artio-codecs/src/test/java/uk/co/real_logic/artio/dictionary/ExampleDictionary.java

@@ -412,6 +412,13 @@ public final class ExampleDictionary
         "8=FIX.4.4\0019=91\00135=0\001115=abc\001116=2\001117=1.1\001127=19700101-00:00:00.001" +
         "\001124=2\001130=2\001131=1\001404=10\001131=2\001404=20\00110=176\001";
 
+    public static final String WITH_CUSTOM_TAGS =
+        "8=FIX.4.4\0019=110\00135=0\001115=abc\001116=2\001117=1.1\001127=19700101-00:00:00.001" +
+        "\001124=2\001130=2\001131=1\001404=10\001131=2\001404=20" +
+        "\00110100=42" +
+        "\00110101=foo" +
+        "\00110=227\001";
+
     public static final String NESTED_COMPONENT_MESSAGE =
         "8=FIX.4.4\0019=120\00135=0\001115=abc\001116=2\001117=1.1\001127=19700101-00:00:00.001" +
         "\001124=2\001130=2\001131=1\001404=10\001131=2\001404=20\001141=180\001142=2\001143=99\001143=100\001" +

artio-codecs/src/test/java/uk/co/real_logic/artio/dictionary/generation/EncoderGeneratorTest.java

@@ -23,6 +23,7 @@
 import org.junit.BeforeClass;
 import org.junit.Test;
 import uk.co.real_logic.artio.EncodingException;
+import uk.co.real_logic.artio.builder.CommonEncoderImpl;
 import uk.co.real_logic.artio.builder.Encoder;
 import uk.co.real_logic.artio.fields.DecimalFloat;
 import uk.co.real_logic.artio.fields.UtcTimestampEncoder;
@@ -698,6 +699,19 @@ public void shouldValidateMissingRequiredFloatFields() throws Exception
         encoder.encode(buffer, 1);
     }
 
+    @Test
+    public void shouldSetCustomTags() throws Exception
+    {
+        final Encoder encoder = newHeartbeat();
+        setRequiredFields(encoder);
+        setupComponent(encoder);
+
+        ((CommonEncoderImpl)encoder).customTag(10100, 42);
+        ((CommonEncoderImpl)encoder).customTagAscii(10101, "foo");
+
+        assertEncodesTo(encoder, WITH_CUSTOM_TAGS);
+    }
+
     @Test(expected = EncodingException.class)
     public void shouldValidateMissingRequiredIntFields() throws Exception
     {