Add the ability to reply asynchronously to a ResendRequest

.editorconfig

@@ -0,0 +1,15 @@
+# Helps IDEA users apply some of the formatting rules enforced by checkstyle
+
+root = true
+
+[*.java]
+indent_size = 4
+max_line_length = 120
+ij_java_method_brace_style = next_line
+ij_java_block_brace_style = next_line
+ij_java_else_on_new_line = true
+ij_java_class_brace_style = next_line
+ij_java_space_after_type_cast = false
+ij_any_catch_on_new_line = true
+ij_any_spaces_around_equality_operators = true
+ij_java_continuation_indent_size = 4

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

@@ -31,6 +31,7 @@ public abstract class CommonDecoderImpl
     protected int invalidTagId = Decoder.NO_ERROR;
     protected int rejectReason = Decoder.NO_ERROR;
     protected AsciiBuffer buffer;
+    protected UnknownTagVisitor unknownTagVisitor;
 
     public int invalidTagId()
     {
@@ -42,6 +43,11 @@ public int rejectReason()
         return rejectReason;
     }
 
+    public void setUnknownTagVisitor(final UnknownTagVisitor unknownTagVisitor)
+    {
+        this.unknownTagVisitor = unknownTagVisitor;
+    }
+
     public int getInt(
         final AsciiBuffer buffer,
         final int startInclusive, final int endExclusive, final int tag, final boolean validation)

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

@@ -0,0 +1,95 @@
+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
+{
+    protected MutableAsciiBuffer customTagsBuffer = new MutableAsciiBuffer(new byte[128]);
+
+    public void setCustomTagsBuffer(final MutableAsciiBuffer customTagsBuffer)
+    {
+        this.customTagsBuffer = customTagsBuffer;
+    }
+
+    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 boolean value)
+    {
+        int pos = putTagHeader(tag);
+        pos += customTagsBuffer.putCharAscii(pos, value ? 'Y' : 'N');
+        customTagsBuffer.putSeparator(pos++);
+        customTagsLength = pos;
+        return this;
+    }
+
+    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 customTag(final int tag, final char value)
+    {
+        int pos = putTagHeader(tag);
+        pos += customTagsBuffer.putCharAscii(pos, value);
+        customTagsBuffer.putSeparator(pos++);
+        customTagsLength = pos;
+        return this;
+    }
+
+    public CommonEncoderImpl customTag(final int tag, final long value)
+    {
+        int pos = putTagHeader(tag);
+        pos += customTagsBuffer.putLongAscii(pos, value);
+        customTagsBuffer.putSeparator(pos++);
+        customTagsLength = pos;
+        return this;
+    }
+
+    public CommonEncoderImpl customTag(final int tag, final double value)
+    {
+        int pos = putTagHeader(tag);
+        pos += customTagsBuffer.putAscii(pos, String.valueOf(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 CommonEncoderImpl customTagAscii(final int tag, final byte[] value)
+    {
+        int pos = putTagHeader(tag);
+        customTagsBuffer.putBytes(pos, value);
+        pos += value.length;
+        customTagsBuffer.putSeparator(pos++);
+        customTagsLength = pos;
+        return this;
+    }
+
+    public void resetCustomTags()
+    {
+        customTagsLength = 0;
+    }
+}

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

@@ -91,4 +91,11 @@ public interface Decoder extends CharAppender
      * @return the encoder passed as an argument.
      */
     Encoder toEncoder(Encoder encoder);
+
+    /**
+     * Sets a visitor to be called when an unknown tag is encountered while decoding a message.
+     *
+     * @param visitor the visitor to invoke
+     */
+    void setUnknownTagVisitor(UnknownTagVisitor visitor);
 }

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

@@ -0,0 +1,26 @@
+package uk.co.real_logic.artio.builder;
+
+import uk.co.real_logic.artio.util.AsciiBuffer;
+
+/**
+ * Interface for visiting unknown tags.
+ *
+ * @see CommonDecoderImpl#setUnknownTagVisitor(UnknownTagVisitor)
+ */
+public interface UnknownTagVisitor
+{
+    /**
+     * Called when an unknown tag is encountered while decoding a message.
+     *
+     * @param tag    The tag number of the unknown tag
+     * @param buffer The buffer containing the unknown tag
+     * @param offset The offset at which the unknown tag starts
+     * @param length The length of the unknown tag
+     */
+    void onUnknownTag(
+        int tag,
+        AsciiBuffer buffer,
+        int offset,
+        int length
+    );
+}

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

@@ -1691,24 +1691,28 @@ private String decodeMethod(final List<Entry> entries, final Aggregate aggregate
 
         final String suffix =
             "            default:\n" +
+            "                boolean isTrailer = " + unknownFieldPredicate(type) + ";\n" +
             "                if (!" + CODEC_REJECT_UNKNOWN_FIELD_ENABLED + ")\n" +
             "                {\n" +
             (isGroup ?
             "                    seenFields.remove(tag);\n" :
             "                    alreadyVisitedFields.remove(tag);\n") +
+            "                    if (unknownTagVisitor != null && !isTrailer)\n" +
+            "                    {\n" +
+            "                        unknownTagVisitor.onUnknownTag(tag, buffer, valueOffset, valueLength);\n" +
+            "                    }\n" +
             "                }\n" +
             (isGroup ? "" :
             "                else\n" +
             "                {\n" +
-            "                    if (!" + unknownFieldPredicate(type) + ")\n" +
+            "                    if (!isTrailer)\n" +
             "                    {\n" +
             "                        unknownFields.add(tag);\n" +
             "                    }\n" +
             "                }\n") +
-
             // Skip the thing if it's a completely unknown field and you aren't validating messages
             "                if (" + CODEC_REJECT_UNKNOWN_FIELD_ENABLED +
-            " || " + unknownFieldPredicate(type) + ")\n" +
+            " || isTrailer)\n" +
             "                {\n" +
             decodeTrailerOrReturn(hasCommonCompounds, 5) +
             "                }\n" +

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.FieldBagEncoder;
 import uk.co.real_logic.artio.builder.SessionHeaderEncoder;
@@ -210,6 +211,7 @@ protected void generateAggregateFile(final Aggregate aggregate, final AggregateT
                     MutableDirectBuffer.class,
                     UnsafeBuffer.class,
                     AsciiSequenceView.class,
+                    CommonEncoderImpl.class,
                     FieldBagEncoder.class);
                 generateAggregateClass(aggregate, aggregateType, className, out);
             });
@@ -342,7 +344,7 @@ private String classDeclaration(
         }
         else
         {
-            extendsClause = "";
+            extendsClause = " extends CommonEncoderImpl";
         }
         return String.format(
             "\n" +
@@ -368,6 +370,9 @@ 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 = "";
         }
@@ -994,6 +999,13 @@ 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

@@ -244,6 +244,10 @@ public final class ExampleDictionary
         "8=FIX.4.4\0019=53\00135=0\001115=abc\001116=2\001117=A\001127=19700101-00:00:00.001" +
         "\00110=043\001";
 
+    public static final String UNKNOWN_TAG_MESSAGE =
+        "8=FIX.4.4\0019=53\00135=0\001115=abc\00110100=FOO\001116=2\001117=A\00110101=BAR" +
+        "\001127=19700101-00:00:00.001\00110=043\001";
+
     public static final String OUT_OF_RANGE_FLOAT_VALUE_MESSAGE =
         "8=FIX.4.4\0019=53\00135=0\001115=abc\001116=2\001117=10000000000000000000000\001" +
         "127=19700101-00:00:00.001\00110=043\001";
@@ -423,6 +427,13 @@ 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/DecoderGeneratorFlyweightTest.java

@@ -20,6 +20,8 @@
 import org.junit.Test;
 import uk.co.real_logic.artio.builder.Decoder;
 
+import java.util.HashMap;
+
 import static org.junit.Assert.assertEquals;
 import static uk.co.real_logic.artio.dictionary.ExampleDictionary.*;
 import static uk.co.real_logic.artio.util.CustomMatchers.assertTargetThrows;
@@ -65,4 +67,15 @@ public void shouldNotThrowWhenAccessingUnsetString() throws Exception
         assertTargetThrows(() -> getAsciiSequenceView(decoder, "testReqID"), IllegalArgumentException.class,
             "No value for optional field: TestReqID");
     }
+
+    @Test
+    public void shouldVisitUnknownTags() throws Exception
+    {
+        final Decoder decoder = newHeartbeat();
+        final HashMap<Integer, String> map = new HashMap<>();
+        decoder.setUnknownTagVisitor((tag, buffer, offset, length) -> map.put(tag, buffer.getAscii(offset, length)));
+        decode(UNKNOWN_TAG_MESSAGE, decoder);
+        assertEquals("FOO", map.get(10100));
+        assertEquals("BAR", map.get(10101));
+    }
 }

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.builder.FieldBagEncoder;
 import uk.co.real_logic.artio.fields.DecimalFloat;
@@ -737,6 +738,19 @@ 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
     {

artio-core/src/main/java/uk/co/real_logic/artio/session/ResendRequestController.java

@@ -16,6 +16,7 @@
 package uk.co.real_logic.artio.session;
 
 import uk.co.real_logic.artio.decoder.AbstractResendRequestDecoder;
+import uk.co.real_logic.artio.util.AsciiBuffer;
 
 /**
  * Customer interface to control whether resend requests are responded to or not.
@@ -33,11 +34,16 @@ public interface ResendRequestController
      * (eg: begin sequence number > end sequence number or begin sequence number > last sent sequence number)
      * then this callback won't be invoked.
      *
+     * SessionProxy is now also notified immediately after this method is called, with additional parameters that
+     * allow to delay the processing of the ResendRequest. The SessionProxy can thus override the decision made by
+     * ResendRequestController.
+     *
      * @param session the session that has received the resend request.
      * @param resendRequest the decoded resend request in question.
      * @param correctedEndSeqNo the end sequence number that Artio will reply with. This is useful if, for example, the
      *                          resend request uses 0 for its endSeqNo parameter.
      * @param response respond to the resend request by calling methods on this object.
+     * @see SessionProxy#onResend(Session, AbstractResendRequestDecoder, int, ResendRequestResponse, AsciiBuffer, int, int)
      */
     void onResend(
         Session session,