xpcom/string/src/nsPrintfCString.cpp

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  38
  39 #include "nsPrintfCString.h"
  40 #include <stdarg.h>
  41 #include "prprf.h"
  42
  43
  44 // though these classes define a fixed buffer, they do not set the F_FIXED
  45 // flag.  this is because they are not intended to be modified after they have
  46 // been constructed.  we could change this but it would require adding a new
  47 // class to the hierarchy, one that both this class and nsCAutoString would
  48 // inherit from.  for now, we populate the fixed buffer, and then let the
  49 // nsCString code treat the buffer as if it were a dependent buffer.
  50
  51 nsPrintfCString::nsPrintfCString( const char_type* format, ... )
  52   : string_type(mLocalBuffer, 0, F_TERMINATED)
  53   {
  54     va_list ap;
  55
  56     size_type logical_capacity = kLocalBufferSize;
  57     size_type physical_capacity = logical_capacity + 1;
  58
  59     va_start(ap, format);
  60     mLength = PR_vsnprintf(mData, physical_capacity, format, ap);
  61     va_end(ap);
  62   }
  63
  64 nsPrintfCString::nsPrintfCString( size_type n, const char_type* format, ... )
  65   : string_type(mLocalBuffer, 0, F_TERMINATED)
  66   {
  67     va_list ap;
  68
  69       // make sure there's at least |n| space
  70     size_type logical_capacity = kLocalBufferSize;
  71     if ( n > logical_capacity )
  72       {
  73         SetCapacity(n);
  74         if (Capacity() < n)
  75           return; // out of memory !!
  76         logical_capacity = n;
  77       }
  78     size_type physical_capacity = logical_capacity + 1;
  79
  80     va_start(ap, format);
  81     mLength = PR_vsnprintf(mData, physical_capacity, format, ap);
  82     va_end(ap);
  83   }