* 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 uninterpreted 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 analysis 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