Thread: [Quickfix-developers] FieldConvertor.h optimizations

SourceForge Headquarters 225 Broadway Suite 1600 San Diego, CA 92101 +1 (858) 422-6466

I have optimized some of the field convertors in FieldConvertors.h and have=
 achieved substantial improvements in performance (generally 50% - 200% fas=
ter). I include a patch against the FieldConvertors.h file from quickfix-1.=
7.1.

The code is admittedly 'C-ish', however no interface has been changed and I=
 believe the results speak for themselves.

Replacing strtod() in the double to string conversion would probably be a s=
ignificant win, although I don't know of any efficient algorithms for this =
conversion.

Finally, time stamp conversions should probably be added to pt as well.

Cheers,

- Kris

The times were obtained from pt running on an AthlonXP 2500 running Linux k=
ernel 2.6.7 compiled with g++ 3.3.4. 'normal' builds used the existing Fiel=
dConvertors.h, 'modified' builds used the modified FieldConvertors.h.

Optimization flags for the builds were as follows:

quickfix-debug-modified/Makefile:CFLAGS =3D -g -Wall
quickfix-debug-normal/Makefile:CFLAGS =3D -g -Wall
quickfix-optimized-modified/Makefile:CFLAGS =3D -g -O3 -ffast-math -mcpu=3D=
athlon-xp -Wall
quickfix-optimized-normal/Makefile:CFLAGS =3D -g -O3 -ffast-math -mcpu=3Dat=
hlon-xp -Wall

times-debug-normal.txt      : peterson@karl src $ ./pt -c 100000
times-debug-modified.txt    : peterson@karl src $ ./pt -c 100000
times-optimized-normal.txt  : peterson@karl src $ ./pt -c 100000
times-optimized-modified.txt: peterson@karl src $ ./pt -c 100000

                            : Converting integers to strings:
times-debug-normal.txt      :     num: 100000, seconds: 0.259, num_per_seco=
nd: 386100
times-debug-modified.txt    :     num: 100000, seconds: 0.032, num_per_seco=
nd: 3.125e+06
times-optimized-normal.txt  :     num: 100000, seconds: 0.183, num_per_seco=
nd: 546448
times-optimized-modified.txt:     num: 100000, seconds: 0.026, num_per_seco=
nd: 3.84615e+06
                            : Converting strings to integers:
times-debug-normal.txt      :     num: 100000, seconds: 0.024, num_per_seco=
nd: 4.16667e+06
times-debug-modified.txt    :     num: 100000, seconds: 0.008, num_per_seco=
nd: 1.25e+07
times-optimized-normal.txt  :     num: 100000, seconds: 0.016, num_per_seco=
nd: 6.25e+06
times-optimized-modified.txt:     num: 100000, seconds: 0.004, num_per_seco=
nd: 2.5e+07
                            : Converting doubles to strings:
times-debug-normal.txt      :     num: 100000, seconds: 0.711, num_per_seco=
nd: 140647
times-debug-modified.txt    :     num: 100000, seconds: 0.243, num_per_seco=
nd: 411523
times-optimized-normal.txt  :     num: 100000, seconds: 0.531, num_per_seco=
nd: 188324
times-optimized-modified.txt:     num: 100000, seconds: 0.236, num_per_seco=
nd: 423729
                            : Converting strings to doubles:
times-debug-normal.txt      :     num: 100000, seconds: 0.987, num_per_seco=
nd: 101317
times-debug-modified.txt    :     num: 100000, seconds: 0.058, num_per_seco=
nd: 1.72414e+06
times-optimized-normal.txt  :     num: 100000, seconds: 0.725, num_per_seco=
nd: 137931
times-optimized-modified.txt:     num: 100000, seconds: 0.062, num_per_seco=
nd: 1.6129e+06
                            : Creating Heartbeat messages:
times-debug-normal.txt      :     num: 100000, seconds: 1.823, num_per_seco=
nd: 54854.6
times-debug-modified.txt    :     num: 100000, seconds: 1.166, num_per_seco=
nd: 85763.3
times-optimized-normal.txt  :     num: 100000, seconds: 1.242, num_per_seco=
nd: 80515.3
times-optimized-modified.txt:     num: 100000, seconds: 0.825, num_per_seco=
nd: 121212
                            : Serializing Heartbeat messages to strings:
times-debug-normal.txt      :     num: 100000, seconds: 2.35, num_per_secon=
d: 42553.2
times-debug-modified.txt    :     num: 100000, seconds: 1.198, num_per_seco=
nd: 83472.5
times-optimized-normal.txt  :     num: 100000, seconds: 1.425, num_per_seco=
nd: 70175.4
times-optimized-modified.txt:     num: 100000, seconds: 0.707, num_per_seco=
nd: 141443
                            : Serializing Heartbeat messages from strings:
times-debug-normal.txt      :     num: 100000, seconds: 4.749, num_per_seco=
nd: 21057.1
times-debug-modified.txt    :     num: 100000, seconds: 2.671, num_per_seco=
nd: 37439.2
times-optimized-normal.txt  :     num: 100000, seconds: 3.053, num_per_seco=
nd: 32754.7
times-optimized-modified.txt:     num: 100000, seconds: 1.782, num_per_seco=
nd: 56116.7
                            : Creating NewOrderSingle messages:
times-debug-normal.txt      :     num: 100000, seconds: 6.422, num_per_seco=
nd: 15571.5
times-debug-modified.txt    :     num: 100000, seconds: 3.937, num_per_seco=
nd: 25400.1
times-optimized-normal.txt  :     num: 100000, seconds: 4.778, num_per_seco=
nd: 20929.3
times-optimized-modified.txt:     num: 100000, seconds: 3.026, num_per_seco=
nd: 33046.9
                            : Serializing NewOrderSingle messages to string=
s:
times-debug-normal.txt      :     num: 100000, seconds: 6.429, num_per_seco=
nd: 15554.5
times-debug-modified.txt    :     num: 100000, seconds: 3.84, num_per_secon=
d: 26041.7
times-optimized-normal.txt  :     num: 100000, seconds: 4.874, num_per_seco=
nd: 20517
times-optimized-modified.txt:     num: 100000, seconds: 3.029, num_per_seco=
nd: 33014.2
                            : Serializing NewOrderSingle messages from stri=
ngs:
times-debug-normal.txt      :     num: 100000, seconds: 9.608, num_per_seco=
nd: 10408
times-debug-modified.txt    :     num: 100000, seconds: 5.385, num_per_seco=
nd: 18570.1
times-optimized-normal.txt  :     num: 100000, seconds: 7.202, num_per_seco=
nd: 13885
times-optimized-modified.txt:     num: 100000, seconds: 3.779, num_per_seco=
nd: 26462
                            : Creating QuoteRequest messages:
times-debug-normal.txt      :     num: 100000, seconds: 93.295, num_per_sec=
ond: 1071.87
times-debug-modified.txt    :     num: 100000, seconds: 46.975, num_per_sec=
ond: 2128.79
times-optimized-normal.txt  :     num: 100000, seconds: 61.148, num_per_sec=
ond: 1635.38
times-optimized-modified.txt:     num: 100000, seconds: 33.904, num_per_sec=
ond: 2949.5
                            : Serializing QuoteRequest messages to strings:
times-debug-normal.txt      :     num: 100000, seconds: 11.052, num_per_sec=
ond: 9048.14
times-debug-modified.txt    :     num: 100000, seconds: 10.691, num_per_sec=
ond: 9353.66
times-optimized-normal.txt  :     num: 100000, seconds: 5.667, num_per_seco=
nd: 17646
times-optimized-modified.txt:     num: 100000, seconds: 4.808, num_per_seco=
nd: 20798.7
                            : Serializing QuoteRequest messages from string=
s:
times-debug-normal.txt      :     num: 100000, seconds: 74.91, num_per_seco=
nd: 1334.94
times-debug-modified.txt    :     num: 100000, seconds: 48.556, num_per_sec=
ond: 2059.48
times-optimized-normal.txt  :     num: 100000, seconds: 47.944, num_per_sec=
ond: 2085.77
times-optimized-modified.txt:     num: 100000, seconds: 28.627, num_per_sec=
ond: 3493.21
                            : Reading fields from QuoteRequest message:
times-debug-normal.txt      :     num: 100000, seconds: 34.526, num_per_sec=
ond: 2896.37
times-debug-modified.txt    :     num: 100000, seconds: 12.988, num_per_sec=
ond: 7699.41
times-optimized-normal.txt  :     num: 100000, seconds: 21.891, num_per_sec=
ond: 4568.09
times-optimized-modified.txt:     num: 100000, seconds: 6.875, num_per_seco=
nd: 14545.5
                            : Storing NewOrderSingle messages:
times-debug-normal.txt      :     num: 100000, seconds: 0.765, num_per_seco=
nd: 130719
times-debug-modified.txt    :     num: 100000, seconds: 0.71, num_per_secon=
d: 140845
times-optimized-normal.txt  :     num: 100000, seconds: 0.575, num_per_seco=
nd: 173913
times-optimized-modified.txt:     num: 100000, seconds: 0.521, num_per_seco=
nd: 191939
                            : Validating NewOrderSingle messages with no da=
ta dictionary:
times-debug-normal.txt      :     num: 100000, seconds: 1.489, num_per_seco=
nd: 67159.2
times-debug-modified.txt    :     num: 100000, seconds: 0.859, num_per_seco=
nd: 116414
times-optimized-normal.txt  :     num: 100000, seconds: 0.843, num_per_seco=
nd: 118624
times-optimized-modified.txt:     num: 100000, seconds: 0.426, num_per_seco=
nd: 234742
                            : Validating NewOrderSingle messages with data =
dictionary:
times-debug-normal.txt      :     num: 100000, seconds: 7.732, num_per_seco=
nd: 12933.3
times-debug-modified.txt    :     num: 100000, seconds: 6.105, num_per_seco=
nd: 16380
times-optimized-normal.txt  :     num: 100000, seconds: 2.485, num_per_seco=
nd: 40241.4
times-optimized-modified.txt:     num: 100000, seconds: 1.717, num_per_seco=
nd: 58241.1

--- quickfix/src/C++/FieldConvertors.h  2004-04-29 20:58:20.000000000 +0100
+++ quickfix-debug-modified/src/C++/FieldConvertors.h   2004-08-12 19:13:22=
.036829060 +0100
@@ -1,3 +1,4 @@
+
 /* -*- C++ -*- */

 /*************************************************************************=
***
@@ -32,6 +33,76 @@

 namespace FIX
 {
+template<class T>
+static inline char * integer_to_string (char * buf, const size_t len, T t)
+{
+       const bool is_neg =3D t < 0;
+       char * p =3D buf + len;
+
+       *--p =3D '\0';
+
+       if (is_neg) {
+               if (t =3D=3D std::numeric_limits<T>::min()) {
+                       *--p =3D '0' + (10-t%10)%10;
+                       t/=3D10;
+               }
+               t=3D-t;
+               do {
+                       *--p =3D '0' + t % 10;
+                       t /=3D 10;
+               } while (t > 0);
+                       *--p =3D '-';
+       } else {
+               do {
+                       *--p =3D '0' + t % 10;
+                       t /=3D 10;
+               } while (t > 0);
+       }
+       return p;
+}
+
+
+
+template<class T>
+static inline char * integer_to_string_padded (char * buf,
+                                       const size_t len,
+                                       T t,
+                                       const size_t width =3D 0,
+                                       const char padding_char =3D '0')
+{
+       if (!width) return integer_to_string (buf, len, t);
+
+       const bool is_neg =3D t < 0;
+       char * p =3D buf + len;
+
+       *--p =3D '\0';
+
+       if (is_neg) {
+               if (t =3D=3D std::numeric_limits<T>::min()) {
+                       *--p =3D '0' + (10-t%10)%10;
+                       t/=3D10;
+               }
+               t=3D-t;
+               do {
+                       *--p =3D '0' + t % 10;
+                       t /=3D 10;
+               } while (t > 0);
+               if (p > buf)
+                       *--p =3D '-';
+       } else {
+               do {
+                       *--p =3D '0' + t % 10;
+                       t /=3D 10;
+               } while (t > 0);
+       }
+       const char * stop_p =3D buf + len - width - 1;
+       if (stop_p < buf) stop_p =3D buf;
+       while (p > stop_p)
+               *--p =3D padding_char;
+       return p;
+}
+
+
 /// Empty convertor is a no-op.
 struct EmptyConvertor
 {
@@ -46,21 +117,32 @@
 {
   static std::string convert( long value )
   {
-    char temp[ 12 ];
-    memset( temp, 0, 12 * sizeof( char ) );
-    sprintf( temp, "%d", ( int ) value );
-    return temp;
+    // buffer is big enough for significant digits and extra digit, minus =
and null
+    char buffer [std::numeric_limits<long>::digits10 + 3];
+    const char * const start =3D integer_to_string (buffer, sizeof (buffer=
), value);
+    return std::string (start, buffer + sizeof (buffer) - start - 1);
   }

   static bool convert( const std::string& value, long& result )
   {
     const char * str =3D value.c_str();
-    if ( *str =3D=3D '-' ) ++str;
-    for ( const char * p =3D str; *p !=3D 0; ++p )
-    {
-      if ( !isdigit( *p ) ) return false;
+    bool is_neg =3D false;
+    long x =3D 0;
+
+    if (*str =3D=3D '-') {
+      is_neg =3D true;
+      ++str;
     }
-    result =3D atol( value.c_str() );
+
+    do {
+      const int c =3D *str - '0';
+      if (c < 0 || 9 < c) return false;
+      x =3D 10 * x + c;
+    } while (*++str);
+
+    if (is_neg) x =3D -x;
+
+    result =3D x;
     return true;
   }

@@ -81,9 +163,10 @@
   throw( FieldConvertError& )
   {
     if ( value > 255 || value < 0 ) throw FieldConvertError();
-    std::stringstream stream;
-    stream << std::setw( 3 ) << std::setfill( '0' ) << value;
-    return stream.str();
+    char result [4];
+    if (integer_to_string_padded (result, sizeof(result), value, 3, '0') !=
=3D result)
+      throw FieldConvertError();
+    return std::string (result, 3);
   }

   static bool convert( const std::string& value, long& result )
@@ -104,53 +187,32 @@
   static std::string convert( double value )
   {
     char result[ 32 ];
-    memset( result, 0, 32 * sizeof( char ) );
-    sprintf( result, "%.15g", value );
-    return result;
+    return std::string (result, std::sprintf( result, "%.15g", value ));
   }

   static bool convert( const std::string& value, double& result )
   {
-    if ( !value.size() ) return false;
-    if ( value =3D=3D "." ) return false;
-
-    result =3D atof( const_cast < char* > ( value.c_str() ) );
-    std::string stripped =3D value;
-
-    // add leading zero if none exists
-    if ( *stripped.begin() =3D=3D '.' )
-      stripped =3D '0' + stripped;
-
-    // remove extra leading zeros
-    while ( stripped.size() > 1
-            && *(stripped.begin()) =3D=3D '0'
-            && isdigit(*(stripped.begin()+1)) )
-    {
-      stripped.erase( stripped.begin() );
+    const char * i =3D value.c_str();
+
+    if (!*i) return false;                             // Catch null strin=
gs
+    if (*i =3D=3D '-' && !*++i) return false;              // Eat leading =
'-' and recheck for null string
+
+    bool have_digit =3D false;
+
+    if (std::isdigit (*i)) {
+      have_digit =3D true;
+      while (std::isdigit (*++i));
     }

-    if ( stripped.find( '.' ) !=3D std::string::npos )
-    {
-      std::string::reverse_iterator r =3D stripped.rbegin();
-      while ( r !=3D stripped.rend() && ( *r =3D=3D '0' || *r =3D=3D '.' )=
 )
-      {
-        if ( *r =3D=3D '.' ) { stripped.resize( stripped.size() - 1 ); bre=
ak; }
-        stripped.resize( stripped.size() - 1 ); r++;
-      }
-    }
-    if ( *stripped.begin() =3D=3D '0' )
-    {
-      std::string::size_type i =3D stripped.find_first_not_of( '0' );
-      std::string::size_type dot =3D stripped.find( '.' );
-      if ( i !=3D dot )
-        stripped =3D stripped.substr( i );
+    if (*i =3D=3D '.' && std::isdigit (*++i)) {
+      have_digit =3D true;
+      while (std::isdigit (*++i));
     }

-    std::string converted =3D convert( result );
-    if ( stripped.size() !=3D converted.size() ) return false;
+    if (*i || !have_digit) return false;

-    // strcmp is being used because =3D=3D operator is funky under linux
-    return ( strcmp( stripped.c_str(), converted.c_str() ) =3D=3D 0 );
+    result =3D std::strtod (value.c_str(), 0);
+    return true;
   }

   static double convert( const std::string& value )
@@ -169,16 +231,13 @@
 {
   static std::string convert( char value )
   {
-    char temp[ 2 ];
-    temp[ 0 ] =3D value;
-    temp[ 1 ] =3D '\0';
-    return temp;
+    return std::string (1, value);
   }

   static bool convert( const std::string& value, char& result )
   {
-    if ( value.size() =3D=3D 0 ) return false;
-    result =3D *value.c_str();
+    if ( value.size() !=3D 1 ) return false;
+    result =3D value[0];
     return true;
   }

@@ -197,15 +256,19 @@
 struct BoolConvertor
 {
   static std::string convert( bool value )
-  { return value ? "Y" : "N"; }
+  {
+    const char ch =3D value ? 'Y' : 'N';
+    return std::string (1, ch);
+  }

   static bool convert( const std::string& value, bool& result )
   {
-    if ( value =3D=3D "Y" ) result =3D true;
-    else
-      if ( value =3D=3D "N" ) result =3D false;
-      else
-        return false;
+    if (value.size() !=3D 1) return false;
+    switch (value[0]) {
+      case 'Y': result =3D true; break;
+      case 'N': result =3D false; break;
+      default: return false;
+    }
     return true;
   }

@@ -227,13 +290,19 @@
   throw( FieldConvertError& )
   {
     char result[ 18+4 ];
-    int len =3D strftime( result, 18, "%Y%m%d-%H:%M:%S", value );
-    if ( len !=3D 17 ) throw FieldConvertError();
+
+    integer_to_string_padded (result    ,  5, static_cast<const tm*>(value=
)->tm_year + 1900, 4, '0');
+    integer_to_string_padded (result + 4,  3, static_cast<const tm*>(value=
)->tm_mon  +    1, 2, '0');
+    integer_to_string_padded (result + 6,  3, static_cast<const tm*>(value=
)->tm_mday,        2, '0'); result[8]  =3D '-';
+    integer_to_string_padded (result + 9,  3, static_cast<const tm*>(value=
)->tm_hour,        2, '0'); result[11] =3D ':';
+    integer_to_string_padded (result + 12, 3, static_cast<const tm*>(value=
)->tm_min,         2, '0'); result[14] =3D ':';
+    integer_to_string_padded (result + 15, 3, static_cast<const tm*>(value=
)->tm_sec,         2, '0');

     if(true=3D=3DshowMilliseconds)
     {
-      len =3D sprintf(result+17,".%03d",value.getMillisecond());
-      if ( len !=3D 4) throw FieldConvertError();
+      result[17] =3D '.';
+      if (integer_to_string_padded (result + 18, 4, value.getMillisecond()=
, 3, '0') !=3D result + 18)
+       throw FieldConvertError();
     }
     return result;
   }
@@ -242,19 +311,73 @@
   throw( FieldConvertError& )
   {
     UtcTimeStamp result;
-    const char* val =3D value.c_str();
-    const char* len =3D strptime( val, "%Y%m%d-%H:%M:%S", result );
-    if ( len - val !=3D 17 ) throw FieldConvertError();
-
-    // if we have milliseconds in the string, *len should be ".sss"
-    result.setMillisecond(0);
-    if(NULL !=3D len && strlen(len)=3D=3D4 && len[0] =3D=3D '.')
-    {
-      int ms =3D atoi(&len[1]);
-      if(ms < 0 || ms > 999) throw FieldConvertError();
-        result.setMillisecond(ms);
+    bool have_milliseconds =3D false;
+
+    switch (value.size()) {
+      case 21: have_milliseconds =3D true;
+      case 17: break;
+      default: throw FieldConvertError();
     }

+    int i =3D 0;
+    for (int c=3D0; c<8; ++c) if (!std::isdigit(value[i++])) throw FieldCo=
nvertError();
+                            if (value[i++] !=3D '-') throw FieldConvertErr=
or();
+    for (int c=3D0; c<2; ++c) if (!std::isdigit(value[i++])) throw FieldCo=
nvertError();
+                            if (value[i++] !=3D ':') throw FieldConvertErr=
or();
+    for (int c=3D0; c<2; ++c) if (!std::isdigit(value[i++])) throw FieldCo=
nvertError();
+                            if (value[i++] !=3D ':') throw FieldConvertErr=
or();
+    for (int c=3D0; c<2; ++c) if (!std::isdigit(value[i++])) throw FieldCo=
nvertError();
+    if (have_milliseconds) {
+      if (value[i++] !=3D '.') throw FieldConvertError();
+      for (int c=3D0; c<3; ++c) if (!std::isdigit(value[i++])) throw Field=
ConvertError();
+    }
+
+    tm & result_tm =3D *static_cast<tm*>(result);
+
+    i =3D 0;
+
+    result_tm.tm_year =3D value[i++] - '0';
+    result_tm.tm_year =3D 10 * result_tm.tm_year + value[i++] - '0';
+    result_tm.tm_year =3D 10 * result_tm.tm_year + value[i++] - '0';
+    result_tm.tm_year =3D 10 * result_tm.tm_year + value[i++] - '0';
+    result_tm.tm_year -=3D 1900;
+
+    result_tm.tm_mon =3D value[i++] - '0';
+    result_tm.tm_mon =3D 10 * result_tm.tm_mon + value[i++] - '0';
+    if (result_tm.tm_mon < 1 || 12 < result_tm.tm_mon) throw FieldConvertE=
rror();
+    --result_tm.tm_mon;
+
+    result_tm.tm_mday =3D value[i++] - '0';
+    result_tm.tm_mday =3D 10 * result_tm.tm_mday + value[i++] - '0';
+    if (result_tm.tm_mday < 1 || 31 < result_tm.tm_mday) throw FieldConver=
tError();
+
+    ++i;       // skip '-'
+
+    result_tm.tm_hour =3D value[i++] - '0';
+    result_tm.tm_hour =3D 10 * result_tm.tm_hour + value[i++] - '0';
+    if (23 < result_tm.tm_hour) throw FieldConvertError(); // No check for=
 >=3D 0 as no '-' are converted here
+
+    ++i;       // skip ':'
+
+    result_tm.tm_min =3D value[i++] - '0';
+    result_tm.tm_min =3D 10 * result_tm.tm_min + value[i++] - '0';
+    if (59 < result_tm.tm_min) throw FieldConvertError(); // No check for =
>=3D 0 as no '-' are converted here
+
+    ++i;       // skip ':'
+
+    result_tm.tm_sec =3D value[i++] - '0';
+    result_tm.tm_sec =3D 10 * result_tm.tm_sec + value[i++] - '0';
+    if (60 < result_tm.tm_sec) throw FieldConvertError(); // No check for =
>=3D 0 as no '-' are converted here
+
+    if (have_milliseconds)
+      result.setMillisecond (100 * (value[i+1] - '0') +
+                             10 * (value[i+2] - '0') +
+                                  (value[i+3] - '0'));
+    else
+      result.setMillisecond (0);
+
+    result_tm.tm_isdst =3D -1;
+
     return result;
   }
 };
@@ -266,13 +389,16 @@
   throw( FieldConvertError& )
   {
     char result[ 9+4 ];
-    int len =3D strftime( result, 9, "%H:%M:%S", value );
-    if ( len !=3D 8 ) throw FieldConvertError();
+
+    integer_to_string_padded (result    , 3, static_cast<const tm*>(value)=
->tm_hour, 2, '0'); result[2] =3D ':';
+    integer_to_string_padded (result + 3, 3, static_cast<const tm*>(value)=
->tm_min,  2, '0'); result[5] =3D ':';
+    integer_to_string_padded (result + 6, 3, static_cast<const tm*>(value)=
->tm_sec,  2, '0');

     if(true=3D=3DshowMilliseconds)
     {
-      len =3D sprintf(result+8,".%03d",value.getMillisecond());
-      if ( len !=3D 4) throw FieldConvertError();
+      result[8] =3D '.';
+      if (integer_to_string_padded (result + 9, 4, value.getMillisecond(),=
 3, '0') !=3D result + 9)
+       throw FieldConvertError();
     }

     return result;
@@ -282,19 +408,52 @@
   throw( FieldConvertError& )
   {
     UtcTimeOnly result;
-    const char* val =3D value.c_str();
-    const char* len =3D strptime( val, "%H:%M:%S", result );
-    if ( len - val !=3D 8 ) throw FieldConvertError();
-
-    // if we have milliseconds in the string, *len should be ".sss"
-    result.setMillisecond(0);
-    if(NULL !=3D len && strlen(len)=3D=3D4 && len[0] =3D=3D '.')
-    {
-      int ms =3D atoi(&len[1]);
-      if(ms < 0 || ms > 999) throw FieldConvertError();
-      result.setMillisecond(ms);
+    bool have_milliseconds =3D false;
+
+    switch (value.size()) {
+      case 12: have_milliseconds =3D true;
+      case 8: break;
+      default: throw FieldConvertError();
+    }
+
+    int i =3D 0;
+    for (int c=3D0; c<2; ++c) if (!std::isdigit(value[i++])) throw FieldCo=
nvertError();
+                            if (value[i++] !=3D ':') throw FieldConvertErr=
or();
+    for (int c=3D0; c<2; ++c) if (!std::isdigit(value[i++])) throw FieldCo=
nvertError();
+                            if (value[i++] !=3D ':') throw FieldConvertErr=
or();
+    for (int c=3D0; c<2; ++c) if (!std::isdigit(value[i++])) throw FieldCo=
nvertError();
+    if (have_milliseconds) {
+           // ++i instead of i++ skips the '.' separator
+      for (int c=3D0; c<3; ++c) if (!std::isdigit(value[++i])) throw Field=
ConvertError();
     }

+    tm & result_tm =3D *static_cast<tm*>(result);
+
+    i =3D 0;
+
+    result_tm.tm_hour =3D value[i++] - '0';
+    result_tm.tm_hour =3D 10 * result_tm.tm_hour + value[i++] - '0';
+    if (23 < result_tm.tm_hour) throw FieldConvertError(); // No check for=
 >=3D 0 as no '-' are converted here
+    ++i;       // skip ':'
+
+    result_tm.tm_min =3D value[i++] - '0';
+    result_tm.tm_min =3D 10 * result_tm.tm_min + value[i++] - '0';
+    if (59 < result_tm.tm_min) throw FieldConvertError(); // No check for =
>=3D 0 as no '-' are converted here
+    ++i;       // skip ':'
+
+    result_tm.tm_sec =3D value[i++] - '0';
+    result_tm.tm_sec =3D 10 * result_tm.tm_sec + value[i++] - '0';
+    if (60 < result_tm.tm_sec) throw FieldConvertError(); // No check for =
>=3D 0 as no '-' are converted here
+
+    if (have_milliseconds)
+      result.setMillisecond (100 * (value[i+1] - '0') +
+                             10 * (value[i+2] - '0') +
+                                  (value[i+3] - '0'));
+    else
+      result.setMillisecond (0);
+
+    result_tm.tm_isdst =3D -1;
+
     return result;
   }
 };
@@ -306,8 +465,9 @@
   throw( FieldConvertError& )
   {
     char result[ 9 ];
-    int len =3D strftime( result, 9, "%Y%m%d", value );
-    if ( len !=3D 8 ) throw FieldConvertError();
+    integer_to_string_padded (result    ,  5, static_cast<const tm*>(value=
)->tm_year + 1900, 4, '0');
+    integer_to_string_padded (result + 4,  3, static_cast<const tm*>(value=
)->tm_mon  +    1, 2, '0');
+    integer_to_string_padded (result + 6,  3, static_cast<const tm*>(value=
)->tm_mday,        2, '0');
     return result;
   }

@@ -315,9 +475,34 @@
   throw( FieldConvertError& )
   {
     UtcDate result;
-    const char* val =3D value.c_str();
-    const char* len =3D strptime( val, "%Y%m%d", result );
-    if ( len - val !=3D 8 ) throw FieldConvertError();
+
+    if (value.size() !=3D 8) throw FieldConvertError();
+
+    int i =3D 0;
+    for (int c=3D0; c<8; ++c) if (!std::isdigit(value[i++])) throw FieldCo=
nvertError();
+
+    tm & result_tm =3D *static_cast<tm*>(result);
+
+    i =3D 0;
+
+    result_tm.tm_year =3D value[i++] - '0';
+    result_tm.tm_year =3D 10 * result_tm.tm_year + value[i++] - '0';
+    result_tm.tm_year =3D 10 * result_tm.tm_year + value[i++] - '0';
+    result_tm.tm_year =3D 10 * result_tm.tm_year + value[i++] - '0';
+    result_tm.tm_year -=3D 1900;
+
+    result_tm.tm_mon =3D value[i++] - '0';
+    result_tm.tm_mon =3D 10 * result_tm.tm_mon + value[i++] - '0';
+    if (result_tm.tm_mon < 1 || 12 < result_tm.tm_mon) throw FieldConvertE=
rror();
+    --result_tm.tm_mon;
+
+    result_tm.tm_mday =3D value[i++] - '0';
+    result_tm.tm_mday =3D 10 * result_tm.tm_mday + value[i++] - '0';
+    if (result_tm.tm_mday < 1 || 31 < result_tm.tm_mday) throw FieldConver=
tError();
+    ++i;       // skip '-'
+
+    result_tm.tm_isdst =3D -1;
+
     return result;
   }
 };


<font face=3D"Times New Roman" size=3D"3">
<p>------------------------------------------------------------------------=
------</p>
<p> This email is intended only for the use of the individual(s) to whom it=
 is addressed and may be privileged and confidential. Unauthorised use or d=
isclosure is prohibited. If you receive this e-mail in error, please advise=
 immediately and delete the original message. This message may have been al=
tered without your or our knowledge and the sender does not accept any liab=
ility for any errors or omissions in the message.</p>
<p>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D</p>
</font>





Thread: [Quickfix-developers] FieldConvertor.h optimizations

quickfix-developers