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Converting to UTF-8
If you have installed a string converter, the Ice run time calls the converter's toUTF8 function whenever it needs to convert a native string into UTF-8 representation for transmission. The sourceStart and sourceEnd pointers point at the first byte and one-beyond-the-last byte of the source string, respectively. The implementation of toUTF8 must return a pointer to the first unused byte following the converted string.
Your implementation of toUTF8 must allocate the returned string by calling the getMoreBytes member function of the UTF8Buffer class that is passed as the third argument. (getMoreBytes throws a std::bad_alloc if it cannot allocate enough memory.) The firstUnused parameter must point at the first unused byte of the allocated memory region. You can make several calls to getMoreBytes to incrementally allocate memory for the converted string. If you do, getMoreBytes may relocate the buffer in memory. (If it does, it copies the part of the string that was converted so far into the new memory region.) The function returns a pointer to the first unused byte of the (possibly relocated) memory.
Conversion with toUTF8 during marshaling can fail because getMoreBytes can cause the message size to exceed Ice.MessageSizeMax. In this case, you should let the MemoryLimitException thrown by getMoreBytes propagate to the caller.
Conversion can also fail because the encoding of the source string is internally incorrect. In that case, you should throw a StringConversionFailed exception from toUTF8.
After it has marshaled the returned string into an internal marshaling buffer, the Ice run time deallocates the string.
Converting from UTF-8
During unmarshaling, the Ice run time calls the fromUTF8 member function on the corresponding string converter. The function converts a UTF-8 string into its native form as a std::string. (The string into which the function must place the converted characters is passed to fromUTF8 as the target parameter.)
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