Polishing.

Replace String.format(…) with our own digit rendering and padding to reduce computation on hot code paths.

[resolves #558][#556]

Signed-off-by: Mark Paluch <mpaluch@vmware.com>

Author: mp911de

src/main/java/io/r2dbc/postgresql/codec/NumericDecodeUtils.java

@@ -111,18 +111,24 @@ public static BigDecimal decodeBinary(ByteBuf byteBuf) {
             digits[i] = byteBuf.readShort();
         }
 
-        StringBuilder sb = new StringBuilder();
+        StringBuilder sb = new StringBuilder((sign != 0 ? 1 : 0) + 2 + (digits.length * 4));
         if (sign != 0) {
             sb.append("-");
         }
         sb.append("0.");
         for (short digit : digits) {
-            sb.append(String.format("%04d", digit));
+            String rendered = "" + digit;
+            int padded = rendered.length();
+
+            while (padded < 4) {
+                sb.append("0");
+                padded++;
+            }
+
+            sb.append(rendered);
         }
 
-        return new BigDecimal(sb.toString())
-            .movePointRight((weight + 1) * 4)
-            .setScale(scale, RoundingMode.DOWN);
+        return new BigDecimal(sb.toString()).movePointRight((weight + 1) * 4).setScale(scale, RoundingMode.DOWN);
     }
 
 }

src/test/java/io/r2dbc/postgresql/AbstractCodecIntegrationTests.java

@@ -103,7 +103,10 @@ void bigDecimal() {
         testCodec(BigDecimal.class, new BigDecimal("-1"), "NUMERIC");
         testCodec(BigDecimal.class, new BigDecimal("10000.0000023"), "NUMERIC");
         testCodec(BigDecimal.class, new BigDecimal("10010.1200023"), "NUMERIC");
+        testCodec(BigDecimal.class, new BigDecimal("-10010.1200023"), "NUMERIC");
         testCodec(BigDecimal.class, new BigDecimal("2000010010.1200023"), "NUMERIC");
+        testCodec(BigDecimal.class, new BigDecimal("0.1200023"), "NUMERIC");
+        testCodec(BigDecimal.class, new BigDecimal("-0.1200023"), "NUMERIC");
         testCodec(BigDecimal.class, new BigDecimal("0"), "NUMERIC");
         testCodec(BigDecimal.class, new BigDecimal("100"), "INT2");
         testCodec(BigDecimal.class, new BigDecimal("100"), "INT4");

src/test/java/io/r2dbc/postgresql/codec/NumericDecodeUtilsTest.java

@@ -13,6 +13,9 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+/**
+ * Unit tests for {@link NumericDecodeUtils}.
+ */
 class NumericDecodeUtilsTest {
 
     static Stream<Object[]> bigDecimalValues() {
@@ -82,6 +85,7 @@ void decodeBinary2(BigDecimal value) {
         ByteBuf byteBuf = TestByteBufAllocator.TEST.buffer();
         byteBuf.writeBytes(ByteConverter.numeric(value));
         assertThat(NumericDecodeUtils.decodeBinary(byteBuf)).isEqualByComparingTo(value);
+        byteBuf.release();
     }
 
-}
+}