Refactor ParseNumber for two modes (incomplete)

1 files changed, 44 insertions, 21 deletions

diff --git a/include/rapidjson/reader.h b/include/rapidjson/reader.h
index 92deeab7..60d1f0a3 100644
--- a/include/rapidjson/reader.h
+++ b/include/rapidjson/reader.h
@@ -132,7 +132,8 @@ enum ParseFlag {
     kParseInsituFlag = 1,           //!< In-situ(destructive) parsing.

     kParseValidateEncodingFlag = 2, //!< Validate encoding of JSON strings.

     kParseIterativeFlag = 4,        //!< Iterative(constant complexity in terms of function call stack size) parsing.

-    kParseStopWhenDoneFlag = 8      //!< After parsing a complete JSON root from stream, stop further processing the rest of stream. When this flag is used, parser will not generate kParseErrorDocumentRootNotSingular error.

+    kParseStopWhenDoneFlag = 8,     //!< After parsing a complete JSON root from stream, stop further processing the rest of stream. When this flag is used, parser will not generate kParseErrorDocumentRootNotSingular error.

+    kParseFullPrecisionFlag = 16    //!< Parse number in full precision (but slower).

 };

 

 ///////////////////////////////////////////////////////////////////////////////

@@ -644,7 +645,7 @@ private:
             ParseStringToStream<parseFlags, SourceEncoding, TargetEncoding>(s, stackStream);

             RAPIDJSON_PARSE_ERROR_EARLY_RETURN_VOID;

             size_t length = stackStream.Length();

-            if (!handler.String(stackStream.Pop(), length - 1, true))

+            if (!handler.String(stackStream.Pop(), SizeType(length - 1), true))

                 RAPIDJSON_PARSE_ERROR(kParseErrorTermination, s.Tell());

         }

     }

@@ -710,17 +711,52 @@ private:
         }

     }

 

+    template<typename InputStream, bool backup>

+    class NumberStream {

+    public:

+        NumberStream(GenericReader& reader, InputStream& is) : reader(reader), is(is) {}

+        Ch Peek() { return is.Peek(); }

+        Ch Take() { return is.Take(); }

+        size_t Tell() { return is.Tell(); }

+        const char* Pop() { return 0; }

+

+    private:

+        NumberStream& operator=(const NumberStream&);

+

+        GenericReader& reader;

+        InputStream& is;

+    };

+

+    template<typename InputStream>

+    struct NumberStream<InputStream, true> {

+    public:

+        NumberStream(GenericReader& reader, InputStream& is) : reader(reader), is(is), stackStream(reader.stack_) {}

+

+        Ch Take() {

+            stackStream.Put((char)is.Peek());

+            return is.Take();

+        }

+

+        const char* Pop() {

+            stackStream.Put('\0');

+            return stackStream.Pop();

+        }

+

+    private:

+        GenericReader& reader;

+        InputStream& is;

+        StackStream<char> stackStream;

+    };

+

     template<unsigned parseFlags, typename InputStream, typename Handler>

     void ParseNumber(InputStream& is, Handler& handler) {

         internal::StreamLocalCopy<InputStream> copy(is);

-        InputStream& s(copy.s);

-        StackStream<char> stackStream(stack_);    // Backup string for slow path double conversion.

+        NumberStream<InputStream, parseFlags & kParseFullPrecisionFlag> s(*this, copy.s);

 

         // Parse minus

         bool minus = false;

         if (s.Peek() == '-') {

             minus = true;

-            stackStream.Put(s.Peek());

             s.Take();

         }

 

@@ -730,11 +766,9 @@ private:
         bool use64bit = false;

         if (s.Peek() == '0') {

             i = 0;

-            stackStream.Put(s.Peek());

             s.Take();

         }

         else if (s.Peek() >= '1' && s.Peek() <= '9') {

-            stackStream.Put(s.Peek());

             i = static_cast<unsigned>(s.Take() - '0');

 

             if (minus)

@@ -746,7 +780,6 @@ private:
                             break;

                         }

                     }

-                    stackStream.Put(s.Peek());

                     i = i * 10 + static_cast<unsigned>(s.Take() - '0');

                 }

             else

@@ -758,7 +791,6 @@ private:
                             break;

                         }

                     }

-                    stackStream.Put(s.Peek());

                     i = i * 10 + static_cast<unsigned>(s.Take() - '0');

                 }

         }

@@ -776,7 +808,6 @@ private:
                             useDouble = true;

                             break;

                         }

-                    stackStream.Put(s.Peek());

                     i64 = i64 * 10 + static_cast<unsigned>(s.Take() - '0');

                 }

             else

@@ -786,7 +817,6 @@ private:
                             useDouble = true;

                             break;

                         }

-                    stackStream.Put(s.Peek());

                     i64 = i64 * 10 + static_cast<unsigned>(s.Take() - '0');

                 }

         }

@@ -794,14 +824,13 @@ private:
         // Force double for big integer

         if (useDouble) {

             while (s.Peek() >= '0' && s.Peek() <= '9')

-                stackStream.Put(s.Take());

+                s.Take();

             useStrtod = true;

         }

 

         // Parse frac = decimal-point 1*DIGIT

         int expFrac = 0;

         if (s.Peek() == '.') {

-            stackStream.Put(s.Peek());

             s.Take();

 

             if (!useDouble) {

@@ -816,7 +845,6 @@ private:
                         break;

                     }

                     else {

-                        stackStream.Put(s.Peek());

                         i64 = i64 * 10 + static_cast<unsigned>(s.Take() - '0');

                         --expFrac;

                     }

@@ -826,7 +854,7 @@ private:
             useDouble = true;

 

             while (s.Peek() >= '0' && s.Peek() <= '9') {

-                stackStream.Put(s.Take());

+                s.Take();

                 --expFrac;

             }

 

@@ -838,23 +866,19 @@ private:
         int exp = 0;

         if (s.Peek() == 'e' || s.Peek() == 'E') {

             useDouble = true;

-            stackStream.Put(s.Peek());

             s.Take();

 

             bool expMinus = false;

             if (s.Peek() == '+')

                 s.Take();

             else if (s.Peek() == '-') {

-                stackStream.Put(s.Peek());

                 s.Take();

                 expMinus = true;

             }

 

             if (s.Peek() >= '0' && s.Peek() <= '9') {

-                stackStream.Put(s.Peek());

                 exp = s.Take() - '0';

                 while (s.Peek() >= '0' && s.Peek() <= '9') {

-                    stackStream.Put(s.Peek());

                     exp = exp * 10 + (s.Take() - '0');

                     if (exp > 308 && !expMinus) // exp > 308 should be rare, so it should be checked first.

                         RAPIDJSON_PARSE_ERROR(kParseErrorNumberTooBig, s.Tell());

@@ -871,8 +895,7 @@ private:
         bool cont = true;

 

         // Pop stack no matter if it will be used or not.

-        stackStream.Put('\0');

-        const char* str = stackStream.Pop();

+        const char* str = s.Pop();

 

         if (useDouble) {

             int p = exp + expFrac;