FasterXML · cowtowncoder · Jun 20, 2022 · Mar 31, 2022
diff --git a/src/main/java/com/fasterxml/jackson/core/JsonParser.java b/src/main/java/com/fasterxml/jackson/core/JsonParser.java
@@ -325,6 +325,17 @@ public enum Feature {
           */
          INCLUDE_SOURCE_IN_LOCATION(true),
 
+         /**
+          * Feature that determines whether we use the built-in {@link Double#parseDouble(String)} code to parse
+          * doubles or if we use {@link com.fasterxml.jackson.core.io.doubleparser}
+          * instead.
+          *<p>
+          * This setting is disabled by default.
+          *
+          * @since 2.14
+          */
+         USE_FAST_DOUBLE_PARSER(false),
+
          ;
 
         /**

diff --git a/src/main/java/com/fasterxml/jackson/core/base/ParserBase.java b/src/main/java/com/fasterxml/jackson/core/base/ParserBase.java
@@ -893,11 +893,11 @@ private void _parseSlowFloat(int expType) throws IOException
                 _numberBigDecimal = _textBuffer.contentsAsDecimal();
                 _numTypesValid = NR_BIGDECIMAL;
             } else if (expType == NR_FLOAT) {
-                _numberFloat = _textBuffer.contentsAsFloat();
+                _numberFloat = _textBuffer.contentsAsFloat(isEnabled(Feature.USE_FAST_DOUBLE_PARSER));
                 _numTypesValid = NR_FLOAT;
             } else {
                 // Otherwise double has to do
-                _numberDouble = _textBuffer.contentsAsDouble();
+                _numberDouble = _textBuffer.contentsAsDouble(isEnabled(Feature.USE_FAST_DOUBLE_PARSER));
                 _numTypesValid = NR_DOUBLE;
             }
         } catch (NumberFormatException nex) {
@@ -927,7 +927,7 @@ private void _parseSlowInt(int expType) throws IOException
                     _reportTooLongIntegral(expType, numStr);
                 }
                 if ((expType == NR_DOUBLE) || (expType == NR_FLOAT)) {
-                    _numberDouble = NumberInput.parseDouble(numStr);
+                    _numberDouble = NumberInput.parseDouble(numStr, isEnabled(Feature.USE_FAST_DOUBLE_PARSER));
                     _numTypesValid = NR_DOUBLE;
                 } else {
                     // nope, need the heavy guns... (rare case)

diff --git a/src/main/java/com/fasterxml/jackson/core/io/NumberInput.java b/src/main/java/com/fasterxml/jackson/core/io/NumberInput.java
@@ -1,5 +1,8 @@
 package com.fasterxml.jackson.core.io;
 
+import com.fasterxml.jackson.core.io.doubleparser.FastDoubleParser;
+import com.fasterxml.jackson.core.io.doubleparser.FastFloatParser;
+
 import java.math.BigDecimal;
 
 public final class NumberInput
@@ -239,7 +242,9 @@ public static int parseAsInt(String s, int def)
             // if other symbols, parse as Double, coerce
             if (c > '9' || c < '0') {
                 try {
-                    return (int) parseDouble(s);
+                    //useFastParser=true is used because there is a lot less risk that small changes in result will have an affect
+                    //and performance benefit is useful
+                    return (int) parseDouble(s, true);
                 } catch (NumberFormatException e) {
                     return def;
                 }
@@ -276,7 +281,9 @@ public static long parseAsLong(String s, long def)
             // if other symbols, parse as Double, coerce
             if (c > '9' || c < '0') {
                 try {
-                    return (long) parseDouble(s);
+                    //useFastParser=true is used because there is a lot less risk that small changes in result will have an affect
+                    //and performance benefit is useful
+                    return (long) parseDouble(s, true);
                 } catch (NumberFormatException e) {
                     return def;
                 }
@@ -287,8 +294,26 @@ public static long parseAsLong(String s, long def)
         } catch (NumberFormatException e) { }
         return def;
     }
-
-    public static double parseAsDouble(String s, double def)
+
+    /**
+     * @param s a string representing a number to parse
+     * @param def the default to return if `s` is not a parseable number
+     * @return closest matching double (or `def` if there is an issue with `s`) where useFastParser=false
+     * @see #parseAsDouble(String, double, boolean)
+     */
+    public static double parseAsDouble(final String s, final double def)
+    {
+        return parseAsDouble(s, def, false);
+    }
+
+    /**
+     * @param s a string representing a number to parse
+     * @param def the default to return if `s` is not a parseable number
+     * @param useFastParser whether to use {@link com.fasterxml.jackson.core.io.doubleparser}
+     * @return closest matching double (or `def` if there is an issue with `s`)
+     * @since 2.14
+     */
+    public static double parseAsDouble(String s, final double def, final boolean useFastParser)
     {
         if (s == null) { return def; }
         s = s.trim();
@@ -297,23 +322,52 @@ public static double parseAsDouble(String s, double def)
             return def;
         }
         try {
-            return parseDouble(s);
+            return parseDouble(s, useFastParser);
         } catch (NumberFormatException e) { }
         return def;
     }
 
-    public static double parseDouble(String s) throws NumberFormatException {
-        return Double.parseDouble(s);
+    /**
+     * @param s a string representing a number to parse
+     * @return closest matching double
+     * @throws NumberFormatException if string cannot be represented by a double where useFastParser=false
+     * @see #parseDouble(String, boolean)
+     */
+    public static double parseDouble(final String s) throws NumberFormatException {
+        return parseDouble(s, false);
+    }
+
+    /**
+     * @param s a string representing a number to parse
+     * @param useFastParser whether to use {@link com.fasterxml.jackson.core.io.doubleparser}
+     * @return closest matching double
+     * @throws NumberFormatException if string cannot be represented by a double
+     * @since v2.14
+     */
+    public static double parseDouble(final String s, final boolean useFastParser) throws NumberFormatException {
+        return useFastParser ? FastDoubleParser.parseDouble(s) : Double.parseDouble(s);
+    }
+
+    /**
+     * @param s a string representing a number to parse
+     * @return closest matching float
+     * @throws NumberFormatException if string cannot be represented by a float where useFastParser=false
+     * @see #parseFloat(String, boolean)
+     * @since v2.14
+     */
+    public static float parseFloat(final String s) throws NumberFormatException {
+        return parseFloat(s, false);
     }
 
     /**
      * @param s a string representing a number to parse
+     * @param useFastParser whether to use {@link com.fasterxml.jackson.core.io.doubleparser}
      * @return closest matching float
      * @throws NumberFormatException if string cannot be represented by a float
      * @since v2.14
      */
-    public static float parseFloat(String s) throws NumberFormatException {
-        return Float.parseFloat(s);
+    public static float parseFloat(final String s, final boolean useFastParser) throws NumberFormatException {
+        return useFastParser ? FastFloatParser.parseFloat(s) : Float.parseFloat(s);
     }
 
     public static BigDecimal parseBigDecimal(String s) throws NumberFormatException {

diff --git a/src/main/java/com/fasterxml/jackson/core/json/JsonReadFeature.java b/src/main/java/com/fasterxml/jackson/core/json/JsonReadFeature.java
@@ -182,6 +182,17 @@ public enum JsonReadFeature
      */
     @SuppressWarnings("deprecation")
     ALLOW_TRAILING_COMMA(false, JsonParser.Feature.ALLOW_TRAILING_COMMA),
+
+    /**
+     * Feature that determines whether we use the built-in {@link Double#parseDouble(String)} code to parse
+     * doubles or if we use {@link com.fasterxml.jackson.core.io.doubleparser}
+     * instead.
+     *<p>
+     * This setting is disabled by default.
+     *
+     * @since 2.14
+     */
+    USE_FAST_DOUBLE_PARSER(false, JsonParser.Feature.USE_FAST_DOUBLE_PARSER)
     ;
 
     final private boolean _defaultState;

diff --git a/src/main/java/com/fasterxml/jackson/core/util/TextBuffer.java b/src/main/java/com/fasterxml/jackson/core/util/TextBuffer.java
@@ -512,9 +512,25 @@ public BigDecimal contentsAsDecimal() throws NumberFormatException
      * @return Buffered text value parsed as a {@link Double}, if possible
      *
      * @throws NumberFormatException if contents are not a valid Java number
+     * @deprecated use {@link #contentsAsDouble(boolean)}
      */
+    @Deprecated
     public double contentsAsDouble() throws NumberFormatException {
-        return NumberInput.parseDouble(contentsAsString());
+        return contentsAsDouble(false);
+    }
+
+    /**
+     * Convenience method for converting contents of the buffer
+     * into a Double value.
+     *
+     * @param useFastParser whether to use {@link com.fasterxml.jackson.core.io.doubleparser}
+     * @return Buffered text value parsed as a {@link Double}, if possible
+     *
+     * @throws NumberFormatException if contents are not a valid Java number
+     * @since 2.14
+     */
+    public double contentsAsDouble(final boolean useFastParser) throws NumberFormatException {
+        return NumberInput.parseDouble(contentsAsString(), useFastParser);
     }
 
     /**
@@ -525,9 +541,25 @@ public double contentsAsDouble() throws NumberFormatException {
      *
      * @throws NumberFormatException if contents are not a valid Java number
      * @since 2.14
+     * @deprecated use {@link #contentsAsFloat(boolean)}
      */
+    @Deprecated
     public float contentsAsFloat() throws NumberFormatException {
-        return NumberInput.parseFloat(contentsAsString());
+        return contentsAsFloat(false);
+    }
+
+    /**
+     * Convenience method for converting contents of the buffer
+     * into a Float value.
+     *
+     * @param useFastParser whether to use {@link com.fasterxml.jackson.core.io.doubleparser}
+     * @return Buffered text value parsed as a {@link Float}, if possible
+     *
+     * @throws NumberFormatException if contents are not a valid Java number
+     * @since 2.14
+     */
+    public float contentsAsFloat(final boolean useFastParser) throws NumberFormatException {
+        return NumberInput.parseFloat(contentsAsString(), useFastParser);
     }
 
     /**

diff --git a/src/test/java/com/fasterxml/jackson/core/io/TestNumberInput.java b/src/test/java/com/fasterxml/jackson/core/io/TestNumberInput.java
@@ -9,13 +9,20 @@ public void testNastySmallDouble()
         //prior to jackson v2.14, this value used to be returned as Double.MIN_VALUE
         final String nastySmallDouble = "2.2250738585072012e-308";
         assertEquals(Double.parseDouble(nastySmallDouble), NumberInput.parseDouble(nastySmallDouble));
+        assertEquals(Double.parseDouble(nastySmallDouble), NumberInput.parseDouble(nastySmallDouble, true));
     }
 
     public void testParseFloat()
     {
         final String exampleFloat = "1.199999988079071";
         assertEquals(1.1999999f, NumberInput.parseFloat(exampleFloat));
+        assertEquals(1.1999999f, NumberInput.parseFloat(exampleFloat, true));
         assertEquals(1.2f, (float)NumberInput.parseDouble(exampleFloat));
+        assertEquals(1.2f, (float)NumberInput.parseDouble(exampleFloat, true));
+
+        final String exampleFloat2 = "7.006492321624086e-46";
+        assertEquals("1.4E-45", Float.toString(NumberInput.parseFloat(exampleFloat2)));
+        assertEquals("1.4E-45", Float.toString(NumberInput.parseFloat(exampleFloat2, true)));
     }
 }
 
diff --git a/src/test/java/com/fasterxml/jackson/core/read/FastParserNonStandardNumberParsingTest.java b/src/test/java/com/fasterxml/jackson/core/read/FastParserNonStandardNumberParsingTest.java
@@ -0,0 +1,17 @@
+package com.fasterxml.jackson.core.read;
+
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.core.json.JsonReadFeature;
+
+public class FastParserNonStandardNumberParsingTest extends NonStandardNumberParsingTest {
+    private final JsonFactory fastFactory =
+            JsonFactory.builder()
+                    .enable(JsonReadFeature.ALLOW_LEADING_DECIMAL_POINT_FOR_NUMBERS)
+                    .enable(JsonReadFeature.USE_FAST_DOUBLE_PARSER)
+                    .build();
+
+    @Override
+    protected JsonFactory jsonFactory() {
+        return fastFactory;
+    }
+}
diff --git a/src/test/java/com/fasterxml/jackson/core/read/FastParserNumberParsingTest.java b/src/test/java/com/fasterxml/jackson/core/read/FastParserNumberParsingTest.java
@@ -0,0 +1,14 @@
+package com.fasterxml.jackson.core.read;
+
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.core.JsonParser;
+
+public class FastParserNumberParsingTest extends NumberParsingTest {
+
+    private final JsonFactory fastFactory = new JsonFactory().enable(JsonParser.Feature.USE_FAST_DOUBLE_PARSER);
+
+    @Override
+    protected JsonFactory jsonFactory() {
+        return fastFactory;
+    }
+}
diff --git a/src/test/java/com/fasterxml/jackson/core/read/FloatParsingTest.java b/src/test/java/com/fasterxml/jackson/core/read/FloatParsingTest.java
@@ -12,24 +12,41 @@ public class FloatParsingTest extends BaseTest
 
     public void testFloatArrayViaInputStream() throws Exception
     {
-        _testFloatArray(MODE_INPUT_STREAM);
-        _testFloatArray(MODE_INPUT_STREAM_THROTTLED);
+        _testFloatArray(MODE_INPUT_STREAM, false);
+        _testFloatArray(MODE_INPUT_STREAM_THROTTLED, false);
+    }
+
+    public void testFloatArrayViaInputStreamWithFastParser() throws Exception
+    {
+        _testFloatArray(MODE_INPUT_STREAM, true);
+        _testFloatArray(MODE_INPUT_STREAM_THROTTLED, true);
     }
 
     public void testFloatArrayViaReader() throws Exception {
-        _testFloatArray(MODE_READER);
+        _testFloatArray(MODE_READER, false);
+    }
+
+    public void testFloatArrayViaReaderWithFastParser() throws Exception {
+        _testFloatArray(MODE_READER, true);
     }
 
     public void testFloatArrayViaDataInput() throws Exception {
-       _testFloatArray(MODE_DATA_INPUT);
+       _testFloatArray(MODE_DATA_INPUT, false);
+    }
+
+    public void testFloatArrayViaDataInputWithFasrtParser() throws Exception {
+        _testFloatArray(MODE_DATA_INPUT, true);
     }
 
-    private void _testFloatArray(int mode) throws Exception
+    private void _testFloatArray(int mode, boolean useFastParser) throws Exception
     {
         // construct new instance to reduce buffer recycling etc:
         TokenStreamFactory jsonF = newStreamFactory();
 
         JsonParser p = createParser(jsonF, mode, FLOATS_DOC);
+        if (useFastParser) {
+            p.enable(JsonParser.Feature.USE_FAST_DOUBLE_PARSER);
+        }
 
         assertToken(JsonToken.START_ARRAY, p.nextToken());
 

diff --git a/src/test/java/com/fasterxml/jackson/core/read/NonStandardNumberParsingTest.java b/src/test/java/com/fasterxml/jackson/core/read/NonStandardNumberParsingTest.java
@@ -10,6 +10,10 @@ public class NonStandardNumberParsingTest
             .enable(JsonReadFeature.ALLOW_LEADING_DECIMAL_POINT_FOR_NUMBERS)
             .build();
 
+    protected JsonFactory jsonFactory() {
+        return JSON_F;
+    }
+
     /**
      * The format ".NNN" (as opposed to "0.NNN") is not valid JSON, so this should fail
      */
@@ -27,16 +31,16 @@ public void testLeadingDotInDecimal() throws Exception {
     }
 
     public void testLeadingDotInDecimalAllowedAsync() throws Exception {
-        _testLeadingDotInDecimalAllowed(JSON_F, MODE_DATA_INPUT);
+        _testLeadingDotInDecimalAllowed(jsonFactory(), MODE_DATA_INPUT);
     }
 
     public void testLeadingDotInDecimalAllowedBytes() throws Exception {
-        _testLeadingDotInDecimalAllowed(JSON_F, MODE_INPUT_STREAM);
-        _testLeadingDotInDecimalAllowed(JSON_F, MODE_INPUT_STREAM_THROTTLED);
+        _testLeadingDotInDecimalAllowed(jsonFactory(), MODE_INPUT_STREAM);
+        _testLeadingDotInDecimalAllowed(jsonFactory(), MODE_INPUT_STREAM_THROTTLED);
     }
 
     public void testLeadingDotInDecimalAllowedReader() throws Exception {
-        _testLeadingDotInDecimalAllowed(JSON_F, MODE_READER);
+        _testLeadingDotInDecimalAllowed(jsonFactory(), MODE_READER);
     }
 
     private void _testLeadingDotInDecimalAllowed(JsonFactory f, int mode) throws Exception