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Commit fdc2b569 authored by miloyip's avatar miloyip
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Optimize number parsing for 64-bit architecture

parent 1adeecb1
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Showing with 51 additions and 24 deletions
include/rapidjson/rapidjson.h
View file @ fdc2b569
...@@ -147,6 +147,18 @@ ...@@ -147,6 +147,18 @@
# endif # endif
#endif // RAPIDJSON_ENDIAN #endif // RAPIDJSON_ENDIAN
///////////////////////////////////////////////////////////////////////////////
// RAPIDJSON_64BIT
//! Whether using 64-bit architecture
#ifndef RAPIDJSON_64BIT
#if defined(__LP64__) || defined(_WIN64)
#define RAPIDJSON_64BIT 1
#else
#define RAPIDJSON_64BIT 0
#endif
#endif // RAPIDJSON_64BIT
/////////////////////////////////////////////////////////////////////////////// ///////////////////////////////////////////////////////////////////////////////
// RAPIDJSON_ALIGN // RAPIDJSON_ALIGN
......
include/rapidjson/reader.h
View file @ fdc2b569
...@@ -760,7 +760,8 @@ private: ...@@ -760,7 +760,8 @@ private:
// Parse int: zero / ( digit1-9 *DIGIT ) // Parse int: zero / ( digit1-9 *DIGIT )
unsigned i = 0; unsigned i = 0;
bool try64bit = false; uint64_t i64 = 0;
bool use64bit = false;
if (s.Peek() == '0') { if (s.Peek() == '0') {
i = 0; i = 0;
s.Take(); s.Take();
...@@ -772,7 +773,8 @@ private: ...@@ -772,7 +773,8 @@ private:
while (s.Peek() >= '0' && s.Peek() <= '9') { while (s.Peek() >= '0' && s.Peek() <= '9') {
if (i >= 214748364) { // 2^31 = 2147483648 if (i >= 214748364) { // 2^31 = 2147483648
if (i != 214748364 || s.Peek() > '8') { if (i != 214748364 || s.Peek() > '8') {
try64bit = true; i64 = i;
use64bit = true;
break; break;
} }
} }
...@@ -782,7 +784,8 @@ private: ...@@ -782,7 +784,8 @@ private:
while (s.Peek() >= '0' && s.Peek() <= '9') { while (s.Peek() >= '0' && s.Peek() <= '9') {
if (i >= 429496729) { // 2^32 - 1 = 4294967295 if (i >= 429496729) { // 2^32 - 1 = 4294967295
if (i != 429496729 || s.Peek() > '5') { if (i != 429496729 || s.Peek() > '5') {
try64bit = true; i64 = i;
use64bit = true;
break; break;
} }
} }
...@@ -793,14 +796,14 @@ private: ...@@ -793,14 +796,14 @@ private:
RAPIDJSON_PARSE_ERROR(kParseErrorValueInvalid, s.Tell()); RAPIDJSON_PARSE_ERROR(kParseErrorValueInvalid, s.Tell());
// Parse 64bit int // Parse 64bit int
uint64_t i64 = 0; double d = 0.0;
bool useDouble = false; bool useDouble = false;
if (try64bit) { if (use64bit) {
i64 = i;
if (minus) if (minus)
while (s.Peek() >= '0' && s.Peek() <= '9') { while (s.Peek() >= '0' && s.Peek() <= '9') {
if (i64 >= RAPIDJSON_UINT64_C2(0x0CCCCCCC, 0xCCCCCCCC)) // 2^63 = 9223372036854775808 if (i64 >= RAPIDJSON_UINT64_C2(0x0CCCCCCC, 0xCCCCCCCC)) // 2^63 = 9223372036854775808
if (i64 != RAPIDJSON_UINT64_C2(0x0CCCCCCC, 0xCCCCCCCC) || s.Peek() > '8') { if (i64 != RAPIDJSON_UINT64_C2(0x0CCCCCCC, 0xCCCCCCCC) || s.Peek() > '8') {
d = (double)i64;
useDouble = true; useDouble = true;
break; break;
} }
...@@ -810,6 +813,7 @@ private: ...@@ -810,6 +813,7 @@ private:
while (s.Peek() >= '0' && s.Peek() <= '9') { while (s.Peek() >= '0' && s.Peek() <= '9') {
if (i64 >= RAPIDJSON_UINT64_C2(0x19999999, 0x99999999)) // 2^64 - 1 = 18446744073709551615 if (i64 >= RAPIDJSON_UINT64_C2(0x19999999, 0x99999999)) // 2^64 - 1 = 18446744073709551615
if (i64 != RAPIDJSON_UINT64_C2(0x19999999, 0x99999999) || s.Peek() > '5') { if (i64 != RAPIDJSON_UINT64_C2(0x19999999, 0x99999999) || s.Peek() > '5') {
d = (double)i64;
useDouble = true; useDouble = true;
break; break;
} }
...@@ -818,9 +822,7 @@ private: ...@@ -818,9 +822,7 @@ private:
} }
// Force double for big integer // Force double for big integer
double d = 0.0;
if (useDouble) { if (useDouble) {
d = (double)i64;
while (s.Peek() >= '0' && s.Peek() <= '9') { while (s.Peek() >= '0' && s.Peek() <= '9') {
if (d >= 1.7976931348623157e307) // DBL_MAX / 10.0 if (d >= 1.7976931348623157e307) // DBL_MAX / 10.0
RAPIDJSON_PARSE_ERROR(kParseErrorNumberTooBig, s.Tell()); RAPIDJSON_PARSE_ERROR(kParseErrorNumberTooBig, s.Tell());
...@@ -831,33 +833,46 @@ private: ...@@ -831,33 +833,46 @@ private:
// Parse frac = decimal-point 1*DIGIT // Parse frac = decimal-point 1*DIGIT
int expFrac = 0; int expFrac = 0;
if (s.Peek() == '.') { if (s.Peek() == '.') {
s.Take();
#if RAPIDJSON_64BIT
// Use i64 to store significand in 64-bit architecture
if (!useDouble) { if (!useDouble) {
d = try64bit ? (double)i64 : (double)i; if (!use64bit)
useDouble = true; i64 = i;
while (s.Peek() >= '0' && s.Peek() <= '9') {
if (i64 >= RAPIDJSON_UINT64_C2(0x19999999, 0x99999999))
break;
else {
i64 = i64 * 10 + static_cast<unsigned>(s.Take() - '0');
--expFrac;
}
}
d = (double)i64;
} }
s.Take(); #else
// Use double to store significand in 32-bit architecture
if (!useDouble)
d = use64bit ? (double)i64 : (double)i;
#endif
useDouble = true;
if (s.Peek() >= '0' && s.Peek() <= '9') { while (s.Peek() >= '0' && s.Peek() <= '9') {
d = d * 10 + (s.Take() - '0'); d = d * 10 + (s.Take() - '0');
--expFrac; --expFrac;
} }
else
RAPIDJSON_PARSE_ERROR(kParseErrorNumberMissFraction, s.Tell());
while (s.Peek() >= '0' && s.Peek() <= '9') { if (expFrac == 0)
if (expFrac > -16) { RAPIDJSON_PARSE_ERROR(kParseErrorNumberMissFraction, s.Tell());
d = d * 10 + (s.Peek() - '0');
--expFrac;
}
s.Take();
}
} }
// Parse exp = e [ minus / plus ] 1*DIGIT // Parse exp = e [ minus / plus ] 1*DIGIT
int exp = 0; int exp = 0;
if (s.Peek() == 'e' || s.Peek() == 'E') { if (s.Peek() == 'e' || s.Peek() == 'E') {
if (!useDouble) { if (!useDouble) {
d = try64bit ? (double)i64 : (double)i; d = use64bit ? (double)i64 : (double)i;
useDouble = true; useDouble = true;
} }
s.Take(); s.Take();
...@@ -900,7 +915,7 @@ private: ...@@ -900,7 +915,7 @@ private:
cont = handler.Double(minus ? -d : d); cont = handler.Double(minus ? -d : d);
} }
else { else {
if (try64bit) { if (use64bit) {
if (minus) if (minus)
cont = handler.Int64(-(int64_t)i64); cont = handler.Int64(-(int64_t)i64);
else else
......
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