* Tracing and Threads: Tracing functions are global to a process, and
* will be called in response to ICU operations performed by any
* thread. If tracing of an individual thread is desired, the
* tracing functions must themselves filter by checking that the
* current thread is the desired thread.
*
* @param context an uninterpretted pointer. Whatever is passed in
* here will in turn be passed to each of the tracing
* functions UTraceEntry, UTraceExit and UTraceData.
* ICU does not use or alter this pointer.
* @param e Callback function to be called on entry to a
* a traced ICU function.
* @param x Callback function to be called on exit from a
* traced ICU function.
* @param d Callback function to be called from within a
* traced ICU function, for the purpose of providing
* data to the trace.
*
* @stable ICU 2.8
*/
U_STABLE void U_EXPORT2
utrace_setFunctions(const void *context,
UTraceEntry *e, UTraceExit *x, UTraceData *d);
/**
* Get the currently installed ICU tracing functions. Note that a null function
* pointer will be returned if no trace function has been set.
*
* @param context The currently installed tracing context.
* @param e The currently installed UTraceEntry function.
* @param x The currently installed UTraceExit function.
* @param d The currently installed UTraceData function.
* @stable ICU 2.8
*/
U_STABLE void U_EXPORT2
utrace_getFunctions(const void **context,
UTraceEntry **e, UTraceExit **x, UTraceData **d);
/*
*
* ICU trace format string syntax
*
* Format Strings are passed to UTraceData functions, and define the
* number and types of the trace data being passed on each call.
*
* The UTraceData function, which is supplied by the application,
* not by ICU, can either forward the trace data (passed via
* varargs) and the format string back to ICU for formatting into
* a displayable string, or it can interpret the format itself,
* and do as it wishes with the trace data.
*
*
* Goals for the format string
* - basic data output
* - easy to use for trace programmer
* - sufficient provision for data types for trace output readability
* - well-defined types and binary portable APIs
*
* Non-goals
* - printf compatibility
* - fancy formatting
* - argument reordering and other internationalization features
*
* ICU trace format strings contain plain text with argument inserts,
* much like standard printf format strings.
* Each insert begins with a '%', then optionally contains a 'v',
* then exactly one type character.
* Two '%' in a row represent a '%' instead of an insert.
* The trace format strings need not have \n at the end.
*
*
* Types
* -----
*
* Type characters:
* - c A char character in the default codepage.
* - s A NUL-terminated char * string in the default codepage.
* - S A UChar * string. Requires two params, (ptr, length). Length=-1 for nul term.
* - b A byte (8-bit integer).
* - h A 16-bit integer. Also a 16 bit Unicode code unit.
* - d A 32-bit integer. Also a 20 bit Unicode code point value.
* - l A 64-bit integer.
* - p A data pointer.
*
* Vectors
* -------
*
* If the 'v' is not specified, then one item of the specified type
* is passed in.
* If the 'v' (for "vector") is specified, then a vector of items of the
* specified type is passed in, via a pointer to the first item
* and an int32_t value for the length of the vector.
* Length==-1 means zero or NUL termination. Works for vectors of all types.
*
* Note: %vS is a vector of (UChar *) strings. The strings must
* be nul terminated as there is no way to provide a
* separate length parameter for each string. The length
* parameter (required for all vectors) is the number of
* strings, not the length of the strings.
*
* Examples
* --------
*
* These examples show the parameters that will be passed to an application's
* UTraceData() function for various formats.
*
* - the precise formatting is up to the application!
* - the examples use type casts for arguments only to _show_ the types of
* arguments without needing variable declarations in the examples;
* the type casts will not be necessary in actual code
*
* UTraceDataFunc(context, fnNumber, level,
* "There is a character %c in the string %s.", // Format String
* (char)c, (const char *)s); // varargs parameters
* -> There is a character 0x42 'B' in the string "Bravo".
*
* UTraceDataFunc(context, fnNumber, level,
* "Vector of bytes %vb vector of chars %vc",
* (const uint8_t *)bytes, (int32_t)bytesLength,
* (const char *)chars, (int32_t)charsLength);
* -> Vector of bytes
* 42 63 64 3f [4]
* vector of chars
* "Bcd?"[4]
*
* UTraceDataFunc(context, fnNumber, level,
* "An int32_t %d and a whole bunch of them %vd",
* (int32_t)-5, (const int32_t *)ints, (int32_t)intsLength);
* -> An int32_t 0xfffffffb and a whole bunch of them
* fffffffb 00000005 0000010a [3]
*
*/
/**
* Trace output Formatter. An application's UTraceData tracing functions may call
* back to this function to format the trace output in a
* human readable form. Note that a UTraceData function may choose
* to not format the data; it could, for example, save it in
* in the raw form it was received (more compact), leaving
* formatting for a later trace analyis tool.
* @param outBuf pointer to a buffer to receive the formatted output. Output
* will be nul terminated if there is space in the buffer -
* if the length of the requested output < the output buffer size.
* @param capacity Length of the output buffer.
* @param indent Number of spaces to indent the output. Intended to allow
* data displayed from nested functions to be indented for readability.
* @param fmt Format specification for the data to output
* @param args Data to be formatted.
* @return Length of formatted output, including the terminating NUL.
* If buffer capacity is insufficient, the required capacity is returned.
* @stable ICU 2.8
*/
U_STABLE int32_t U_EXPORT2
utrace_vformat(char *outBuf, int32_t capacity,
int32_t indent, const char *fmt, va_list args);
/**
* Trace output Formatter. An application's UTraceData tracing functions may call
* this function to format any additional trace data, beyond that
* provided by default, in human readable form with the same
* formatting conventions used by utrace_vformat().
* @param outBuf pointer to a buffer to receive the formatted output. Output
* will be nul terminated if there is space in the buffer -
* if the length of the requested output < the output buffer size.
* @param capacity Length of the output buffer.
* @param indent Number of spaces to indent the output. Intended to allow
* data displayed from nested functions to be indented for readability.
* @param fmt Format specification for the data to output
* @param ... Data to be formatted.
* @return Length of formatted output, including the terminating NUL.
* If buffer capacity is insufficient, the required capacity is returned.
* @stable ICU 2.8
*/
U_STABLE int32_t U_EXPORT2
utrace_format(char *outBuf, int32_t capacity,
int32_t indent, const char *fmt, ...);
/* Trace function numbers --------------------------------------------------- */
/**
* Get the name of a function from its trace function number.
*
* @param fnNumber The trace number for an ICU function.
* @return The name string for the function.
*
* @see UTraceFunctionNumber
* @stable ICU 2.8
*/
U_STABLE const char * U_EXPORT2
utrace_functionName(int32_t fnNumber);
U_CDECL_END
#endif