fix for issue 2099 (#2100)

* fix for issue 2099

* avoid exceptions.

* fix for exception-less code

include/simdjson/generic/numberparsing.h

@@ -446,11 +446,8 @@ simdjson_inline size_t significant_digits(const uint8_t * start_digits, size_t d
 } // unnamed namespace
 
 /** @private */
-template<typename W>
-error_code slow_float_parsing(simdjson_unused const uint8_t * src, W writer) {
-  double d;
-  if (parse_float_fallback(src, &d)) {
-    writer.append_double(d);
+static error_code slow_float_parsing(simdjson_unused const uint8_t * src, double* answer) {
+  if (parse_float_fallback(src, answer)) {
     return SUCCESS;
   }
   return INVALID_NUMBER(src);
@@ -474,13 +471,13 @@ simdjson_inline error_code write_float(const uint8_t *const src, bool negative,
     // 10000000000000000000000000000000000000000000e+308
     // 3.1415926535897932384626433832795028841971693993751
     //
-    // NOTE: This makes a *copy* of the writer and passes it to slow_float_parsing. This happens
-    // because slow_float_parsing is a non-inlined function. If we passed our writer reference to
-    // it, it would force it to be stored in memory, preventing the compiler from picking it apart
-    // and putting into registers. i.e. if we pass it as reference, it gets slow.
-    // This is what forces the skip_double, as well.
-    error_code error = slow_float_parsing(src, writer);
-    writer.skip_double();
+    // NOTE: We do not pass a reference to the to slow_float_parsing. If we passed our writer
+    // reference to it, it would force it to be stored in memory, preventing the compiler from
+    // picking it apart and putting into registers. i.e. if we pass it as reference,
+    // it gets slow.
+    double d;
+    error_code error = slow_float_parsing(src, &d);
+    writer.append_double(d);
     return error;
   }
   // NOTE: it's weird that the simdjson_unlikely() only wraps half the if, but it seems to get slower any other

include/simdjson/generic/ondemand/json_type.h

@@ -92,8 +92,6 @@ protected:
    */
   friend class value_iterator;
   template<typename W>
-  friend error_code numberparsing::slow_float_parsing(simdjson_unused const uint8_t * src, W writer);
-  template<typename W>
   friend error_code numberparsing::write_float(const uint8_t *const src, bool negative, uint64_t i, const uint8_t * start_digits, size_t digit_count, int64_t exponent, W &writer);
   template<typename W>
   friend error_code numberparsing::parse_number(const uint8_t *const src, W &writer);

tests/ondemand/ondemand_number_tests.cpp

@@ -278,6 +278,19 @@ namespace number_tests {
     TEST_SUCCEED();
   }
 
+  bool issue2099() {
+    TEST_START();
+    ondemand::parser parser;
+    auto json = "1000000000.000000001"_padded;
+    ondemand::document doc;
+    ASSERT_SUCCESS(parser.iterate(json).get(doc));
+    ondemand::number number;
+    ASSERT_SUCCESS(doc.get_number().get(number));
+    ASSERT_EQUAL(number.get_number_type(), ondemand::number_type::floating_point_number);
+    ASSERT_EQUAL(number.get_double(), 1e9);
+    TEST_SUCCEED();
+}
+
   bool issue1878() {
     TEST_START();
     ondemand::parser parser;
@@ -429,7 +442,8 @@ namespace number_tests {
   }
 
   bool run() {
-    return issue2093() &&
+    return issue2099() &&
+           issue2093() &&
            issue2045() &&
            issue2017() &&
            issue_1898() &&