[OPEN-ILS-DEV] PATCH: osrf_json_object.c (jsonObjectToJSONRaw)

[Scott McKellar]

This patch affects the jsonObjectToJSONRaw function in two separate 
ways.  Summary:

1. It adds some sanity checking to prevent undefined behavior when
a floating point payload is not representable as an int.

2. It streamlines the serialization of hashes and arrays by 
eliminating a layer of allocation and deallocation.

Details:

1. A jsonObject represents a number as a double.  When we extract it
to a text representation, we test whether ( x = (int) x ) in order to
decide whether to represent a decimal point and a following decimal
fraction.

However if the integral portion of the floating point number is too
big or too small to be represented as an int, converting it to an
int results in undefined behavior.

I added some comparisons to INT_MAX and INT_MIN avoid this unhappy
circumstance.

2. In the original code, whenever we encounter a hash or an array,
we extract it into a string, append it to the buffer, and then 
deallocate the string.

The new version extracts the hash or array directly onto the end of
the original buffer, thereby eliminating a layer of allocation,
copying, and deallocation.  In my benchmarks I could demonstrate a 
modest but definite speed-up, depending on the contents of the 
jsonObject.

Scott McKellar
http://home.swbell.net/mck9/ct/

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