Re: [Quickfix-developers] Details for Solaris / SunPRO 5.3 build

[Caleb E. <cal...@gm...>]

OK, here's an optimization to Field::calculate which improves the
results from the "pt" application by a healthy amount.  When possible,
it uses a fixed-size char buffer and sprintf instead of building up a
string with operator+.  It falls back to the old behavior if the fixed
buffer is too small.

I also changed the checksum calculation to use std::accumulate, which
probably has no real impact on anything other than lines-of-code.

---8<---
  void calculate()
  {
      char buf[64];

      // If the largest possible representation of the field ID (11
      // digits) '=' value '\001' can fit in the buffer, use sprintf
      if (13 + m_string.length () < sizeof (buf))
          {
          m_length = sprintf (buf, "%d=%*.*s\001", m_field,
                              m_string.length (), m_string.length (),
                              m_string.data ());
          m_data.assign (buf, m_length);
          }
      else
          {
          m_data = IntConvertor::convert(m_field) + "=" + m_string + "\001";
          m_length = m_data.length ();
          }

    const char* iter = m_data.data ();
    m_total = std::accumulate (iter, iter + m_length, 0);
  }
---8<---

Before the change:
Converting integers to strings: 
    num: 10000, seconds: 0.006, num_per_second: 1.66667e+06
Converting strings to integers: 
    num: 10000, seconds: 0.001, num_per_second: 1e+07
Converting doubles to strings: 
    num: 10000, seconds: 0.019, num_per_second: 526316
Converting strings to doubles: 
    num: 10000, seconds: 0.028, num_per_second: 357143
Creating Heartbeat messages: 
    num: 10000, seconds: 0.113, num_per_second: 88495.6
Serializing Heartbeat messages to strings: 
    num: 10000, seconds: 0.155, num_per_second: 64516.1
Serializing Heartbeat messages from strings: 
    num: 10000, seconds: 0.275, num_per_second: 36363.6
Creating NewOrderSingle messages: 
    num: 10000, seconds: 0.415, num_per_second: 24096.4
Serializing NewOrderSingle messages to strings: 
    num: 10000, seconds: 0.41, num_per_second: 24390.2
Serializing NewOrderSingle messages from strings: 
    num: 10000, seconds: 0.585, num_per_second: 17094
Creating QuoteRequest messages: 
    num: 10000, seconds: 4.83, num_per_second: 2070.39
Serializing QuoteRequest messages to strings: 
    num: 10000, seconds: 0.646, num_per_second: 15479.9
Serializing QuoteRequest messages from strings: 
    num: 10000, seconds: 4.386, num_per_second: 2279.98
Reading fields from QuoteRequest message: 
    num: 10000, seconds: 1.374, num_per_second: 7278.02
Storing NewOrderSingle messages: 
    num: 10000, seconds: 0.576, num_per_second: 17361.1
Validating NewOrderSingle messages with no data dictionary: 
    num: 10000, seconds: 0.071, num_per_second: 140845
Validating NewOrderSingle messages with data dictionary: 
    num: 10000, seconds: 0.23, num_per_second: 43478.3

After:
Converting integers to strings: 
    num: 10000, seconds: 0.007, num_per_second: 1.42857e+06
Converting strings to integers: 
    num: 10000, seconds: 0.001, num_per_second: 1e+07
Converting doubles to strings: 
    num: 10000, seconds: 0.02, num_per_second: 500000
Converting strings to doubles: 
    num: 10000, seconds: 0.027, num_per_second: 370370
Creating Heartbeat messages: 
    num: 10000, seconds: 0.08, num_per_second: 125000
Serializing Heartbeat messages to strings: 
    num: 10000, seconds: 0.118, num_per_second: 84745.8
Serializing Heartbeat messages from strings: 
    num: 10000, seconds: 0.159, num_per_second: 62893.1
Creating NewOrderSingle messages: 
    num: 10000, seconds: 0.255, num_per_second: 39215.7
Serializing NewOrderSingle messages to strings: 
    num: 10000, seconds: 0.251, num_per_second: 39840.6
Serializing NewOrderSingle messages from strings: 
    num: 10000, seconds: 0.355, num_per_second: 28169
Creating QuoteRequest messages: 
    num: 10000, seconds: 3.131, num_per_second: 3193.87
Serializing QuoteRequest messages to strings: 
    num: 10000, seconds: 0.62, num_per_second: 16129
Serializing QuoteRequest messages from strings: 
    num: 10000, seconds: 2.846, num_per_second: 3513.7
Reading fields from QuoteRequest message: 
    num: 10000, seconds: 1.172, num_per_second: 8532.42
Storing NewOrderSingle messages: 
    num: 10000, seconds: 0.633, num_per_second: 15797.8
Validating NewOrderSingle messages with no data dictionary: 
    num: 10000, seconds: 0.042, num_per_second: 238095
Validating NewOrderSingle messages with data dictionary: 
    num: 10000, seconds: 0.189, num_per_second: 52910.1


-- 
Caleb Epstein
cal...@gm...