BAEL-3446 (#12872)

* BAEL-3446 a simple market data streaming app for the article. * BAEL-3446 add unit tests for the article code. * BAEL-3446 increase version, activate module in the parent pom, update readme. * BAEL-3446 improve the code semantically. * BAEL-3446 remove unnecessary files * BAEL-3446 fix continuation indentation as 2 * BAEL-3446 put new module in the correct profile Co-authored-by: Yavuz Tas <[email protected]>
2022-10-22 09:45:24 +05:30
parent 2879088ee7
commit 125d9893ab
9 changed files with 519 additions and 0 deletions
@@ -0,0 +1,75 @@
+package com.baeldung.test;
+
+import java.math.BigDecimal;
+import java.nio.ByteBuffer;
+
+import org.agrona.concurrent.UnsafeBuffer;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.sbe.MarketData;
+import com.baeldung.sbe.stub.Currency;
+import com.baeldung.sbe.stub.Market;
+import com.baeldung.sbe.stub.MessageHeaderDecoder;
+import com.baeldung.sbe.stub.MessageHeaderEncoder;
+import com.baeldung.sbe.stub.TradeDataDecoder;
+import com.baeldung.sbe.stub.TradeDataEncoder;
+
+public class EncodeDecodeMarketDataUnitTest {
+
+    private MarketData marketData;
+
+    @BeforeEach
+    public void setup() {
+        marketData = new MarketData(2, 128.99, Market.NYSE, Currency.USD, "IBM");
+    }
+
+    @Test
+    public void givenMarketData_whenEncode_thenDecodedValuesMatch() {
+        // our buffer to write encoded data, initial cap. 128 bytes
+        UnsafeBuffer buffer = new UnsafeBuffer(ByteBuffer.allocate(128));
+        // necessary encoders
+        MessageHeaderEncoder headerEncoder = new MessageHeaderEncoder();
+        TradeDataEncoder dataEncoder = new TradeDataEncoder();
+        // we parse price data (double) into two parts: mantis and exponent
+        BigDecimal priceDecimal = BigDecimal.valueOf(marketData.getPrice());
+        int priceMantissa = priceDecimal.scaleByPowerOfTen(priceDecimal.scale())
+          .intValue();
+        int priceExponent = priceDecimal.scale() * -1;
+        // encode data
+        TradeDataEncoder encoder = dataEncoder.wrapAndApplyHeader(buffer, 0, headerEncoder);
+        encoder.amount(marketData.getAmount());
+        encoder.quote()
+          .market(marketData.getMarket())
+          .currency(marketData.getCurrency())
+          .symbol(marketData.getSymbol())
+          .price()
+          .mantissa(priceMantissa)
+          .exponent((byte) priceExponent);
+
+        // necessary decoders
+        MessageHeaderDecoder headerDecoder = new MessageHeaderDecoder();
+        TradeDataDecoder dataDecoder = new TradeDataDecoder();
+        // decode data
+        dataDecoder.wrapAndApplyHeader(buffer, 0, headerDecoder);
+        // decode price data (from mantissa and exponent) into a double
+        double price = BigDecimal.valueOf(dataDecoder.quote()
+            .price()
+            .mantissa())
+          .scaleByPowerOfTen(dataDecoder.quote()
+            .price()
+            .exponent())
+          .doubleValue();
+        // ensure we have the exact same values
+        Assertions.assertEquals(2, dataDecoder.amount());
+        Assertions.assertEquals("IBM", dataDecoder.quote()
+          .symbol());
+        Assertions.assertEquals(Market.NYSE, dataDecoder.quote()
+          .market());
+        Assertions.assertEquals(Currency.USD, dataDecoder.quote()
+          .currency());
+        Assertions.assertEquals(128.99, price);
+    }
+
+}