icuSources/common/unicode/utrace.h

   1 /*
   2 *******************************************************************************
   3 *
   4 *   Copyright (C) 2003-2006, International Business Machines
   5 *   Corporation and others.  All Rights Reserved.
   6 *
   7 *******************************************************************************
   8 *   file name:  utrace.h
   9 *   encoding:   US-ASCII
  10 *   tab size:   8 (not used)
  11 *   indentation:4
  12 *
  13 *   created on: 2003aug06
  14 *   created by: Markus W. Scherer
  15 *
  16 *   Definitions for ICU tracing/logging.
  17 *
  18 */
  19
  20 #ifndef __UTRACE_H__
  21 #define __UTRACE_H__
  22
  23 #include <stdarg.h>
  24 #include "unicode/utypes.h"
  25
  26 /**
  27  * \file
  28  * \brief C API:  Definitions for ICU tracing/logging.
  29  */
  30
  31 U_CDECL_BEGIN
  32
  33 /**
  34  * Trace severity levels.  Higher levels increase the verbosity of the trace output.
  35  * @see utrace_setLevel
  36  * @stable ICU 2.8
  37  */
  38 typedef enum UTraceLevel {
  39     /** Disable all tracing  @stable ICU 2.8*/
  40     UTRACE_OFF=-1,
  41     /** Trace error conditions only  @stable ICU 2.8*/
  42     UTRACE_ERROR=0,
  43     /** Trace errors and warnings  @stable ICU 2.8*/
  44     UTRACE_WARNING=3,
  45     /** Trace opens and closes of ICU services  @stable ICU 2.8*/
  46     UTRACE_OPEN_CLOSE=5,
  47     /** Trace an intermediate number of ICU operations  @stable ICU 2.8*/
  48     UTRACE_INFO=7,
  49     /** Trace the maximum number of ICU operations  @stable ICU 2.8*/
  50     UTRACE_VERBOSE=9
  51 } UTraceLevel;
  52
  53 /**
  54  *  These are the ICU functions that will be traced when tracing is enabled.
  55  *  @stable ICU 2.8
  56  */
  57 typedef enum UTraceFunctionNumber {
  58     UTRACE_FUNCTION_START=0,
  59     UTRACE_U_INIT=UTRACE_FUNCTION_START,
  60     UTRACE_U_CLEANUP,
  61     UTRACE_FUNCTION_LIMIT,
  62
  63     UTRACE_CONVERSION_START=0x1000,
  64     UTRACE_UCNV_OPEN=UTRACE_CONVERSION_START,
  65     UTRACE_UCNV_OPEN_PACKAGE,
  66     UTRACE_UCNV_OPEN_ALGORITHMIC,
  67     UTRACE_UCNV_CLONE,
  68     UTRACE_UCNV_CLOSE,
  69     UTRACE_UCNV_FLUSH_CACHE,
  70     UTRACE_UCNV_LOAD,
  71     UTRACE_UCNV_UNLOAD,
  72     UTRACE_CONVERSION_LIMIT,
  73
  74     UTRACE_COLLATION_START=0x2000,
  75     UTRACE_UCOL_OPEN=UTRACE_COLLATION_START,
  76     UTRACE_UCOL_CLOSE,
  77     UTRACE_UCOL_STRCOLL,
  78     UTRACE_UCOL_GET_SORTKEY,
  79     UTRACE_UCOL_GETLOCALE,
  80     UTRACE_UCOL_NEXTSORTKEYPART,
  81     UTRACE_UCOL_STRCOLLITER,
  82     UTRACE_UCOL_OPEN_FROM_SHORT_STRING,
  83     UTRACE_COLLATION_LIMIT
  84 } UTraceFunctionNumber;
  85
  86 /**
  87  * Setter for the trace level.
  88  * @param traceLevel A UTraceLevel value.
  89  * @stable ICU 2.8
  90  */
  91 U_STABLE void U_EXPORT2
  92 utrace_setLevel(int32_t traceLevel);
  93
  94 /**
  95  * Getter for the trace level.
  96  * @return The UTraceLevel value being used by ICU.
  97  * @stable ICU 2.8
  98  */
  99 U_STABLE int32_t U_EXPORT2
 100 utrace_getLevel(void);
 101
 102 /* Trace function pointers types  ----------------------------- */
 103
 104 /**
 105   *  Type signature for the trace function to be called when entering a function.
 106   *  @param context value supplied at the time the trace functions are set.
 107   *  @param fnNumber Enum value indicating the ICU function being entered.
 108   *  @stable ICU 2.8
 109   */
 110 typedef void U_CALLCONV
 111 UTraceEntry(const void *context, int32_t fnNumber);
 112
 113 /**
 114   *  Type signature for the trace function to be called when exiting from a function.
 115   *  @param context value supplied at the time the trace functions are set.
 116   *  @param fnNumber Enum value indicating the ICU function being exited.
 117   *  @param fmt     A formatting string that describes the number and types
 118   *                 of arguments included with the variable args.  The fmt
 119   *                 string has the same form as the utrace_vformat format
 120   *                 string.
 121   *  @param args    A variable arguments list.  Contents are described by
 122   *                 the fmt parameter.
 123   *  @see   utrace_vformat
 124   *  @stable ICU 2.8
 125   */
 126 typedef void U_CALLCONV
 127 UTraceExit(const void *context, int32_t fnNumber,
 128            const char *fmt, va_list args);
 129
 130 /**
 131   *  Type signature for the trace function to be called from within an ICU function
 132   *  to display data or messages.
 133   *  @param context  value supplied at the time the trace functions are set.
 134   *  @param fnNumber Enum value indicating the ICU function being exited.
 135   *  @param level    The current tracing level
 136   *  @param fmt      A format string describing the tracing data that is supplied
 137   *                  as variable args
 138   *  @param args     The data being traced, passed as variable args.
 139   *  @stable ICU 2.8
 140   */
 141 typedef void U_CALLCONV
 142 UTraceData(const void *context, int32_t fnNumber, int32_t level,
 143            const char *fmt, va_list args);
 144
 145 /**
 146   *  Set ICU Tracing functions.  Installs application-provided tracing
 147   *  functions into ICU.  After doing this, subsequent ICU operations
 148   *  will call back to the installed functions, providing a trace
 149   *  of the use of ICU.  Passing a NULL pointer for a tracing function
 150   *  is allowed, and inhibits tracing action at points where that function
 151   *  would be called.
 152   *  <p>
 153   *  Tracing and Threads:  Tracing functions are global to a process, and
 154   *  will be called in response to ICU operations performed by any
 155   *  thread.  If tracing of an individual thread is desired, the
 156   *  tracing functions must themselves filter by checking that the
 157   *  current thread is the desired thread.
 158   *
 159   *  @param context an uninterpretted pointer.  Whatever is passed in
 160   *                 here will in turn be passed to each of the tracing
 161   *                 functions UTraceEntry, UTraceExit and UTraceData.
 162   *                 ICU does not use or alter this pointer.
 163   *  @param e       Callback function to be called on entry to a
 164   *                 a traced ICU function.
 165   *  @param x       Callback function to be called on exit from a
 166   *                 traced ICU function.
 167   *  @param d       Callback function to be called from within a
 168   *                 traced ICU function, for the purpose of providing
 169   *                 data to the trace.
 170   *
 171   *  @stable ICU 2.8
 172   */
 173 U_STABLE void U_EXPORT2
 174 utrace_setFunctions(const void *context,
 175                     UTraceEntry *e, UTraceExit *x, UTraceData *d);
 176
 177 /**
 178   * Get the currently installed ICU tracing functions.   Note that a null function
 179   *   pointer will be returned if no trace function has been set.
 180   *
 181   * @param context  The currently installed tracing context.
 182   * @param e        The currently installed UTraceEntry function.
 183   * @param x        The currently installed UTraceExit function.
 184   * @param d        The currently installed UTraceData function.
 185   * @stable ICU 2.8
 186   */
 187 U_STABLE void U_EXPORT2
 188 utrace_getFunctions(const void **context,
 189                     UTraceEntry **e, UTraceExit **x, UTraceData **d);
 190
 191
 192
 193 /*
 194  *
 195  * ICU trace format string syntax
 196  *
 197  * Format Strings are passed to UTraceData functions, and define the
 198  * number and types of the trace data being passed on each call.
 199  *
 200  * The UTraceData function, which is supplied by the application,
 201  * not by ICU, can either forward the trace data (passed via
 202  * varargs) and the format string back to ICU for formatting into
 203  * a displayable string, or it can interpret the format itself,
 204  * and do as it wishes with the trace data.
 205  *
 206  *
 207  * Goals for the format string
 208  * - basic data output
 209  * - easy to use for trace programmer
 210  * - sufficient provision for data types for trace output readability
 211  * - well-defined types and binary portable APIs
 212  *
 213  * Non-goals
 214  * - printf compatibility
 215  * - fancy formatting
 216  * - argument reordering and other internationalization features
 217  *
 218  * ICU trace format strings contain plain text with argument inserts,
 219  * much like standard printf format strings.
 220  * Each insert begins with a '%', then optionally contains a 'v',
 221  * then exactly one type character.
 222  * Two '%' in a row represent a '%' instead of an insert.
 223  * The trace format strings need not have \n at the end.
 224  *
 225  *
 226  * Types
 227  * -----
 228  *
 229  * Type characters:
 230  * - c A char character in the default codepage.
 231  * - s A NUL-terminated char * string in the default codepage.
 232  * - S A UChar * string.  Requires two params, (ptr, length).  Length=-1 for nul term.
 233  * - b A byte (8-bit integer).
 234  * - h A 16-bit integer.  Also a 16 bit Unicode code unit.
 235  * - d A 32-bit integer.  Also a 20 bit Unicode code point value.
 236  * - l A 64-bit integer.
 237  * - p A data pointer.
 238  *
 239  * Vectors
 240  * -------
 241  *
 242  * If the 'v' is not specified, then one item of the specified type
 243  * is passed in.
 244  * If the 'v' (for "vector") is specified, then a vector of items of the
 245  * specified type is passed in, via a pointer to the first item
 246  * and an int32_t value for the length of the vector.
 247  * Length==-1 means zero or NUL termination.  Works for vectors of all types.
 248  *
 249  * Note:  %vS is a vector of (UChar *) strings.  The strings must
 250  *        be nul terminated as there is no way to provide a
 251  *        separate length parameter for each string.  The length
 252  *        parameter (required for all vectors) is the number of
 253  *        strings, not the length of the strings.
 254  *
 255  * Examples
 256  * --------
 257  *
 258  * These examples show the parameters that will be passed to an application's
 259  *   UTraceData() function for various formats.
 260  *
 261  * - the precise formatting is up to the application!
 262  * - the examples use type casts for arguments only to _show_ the types of
 263  *   arguments without needing variable declarations in the examples;
 264  *   the type casts will not be necessary in actual code
 265  *
 266  * UTraceDataFunc(context, fnNumber, level,
 267  *              "There is a character %c in the string %s.",   // Format String
 268  *              (char)c, (const char *)s);                     // varargs parameters
 269  * ->   There is a character 0x42 'B' in the string "Bravo".
 270  *
 271  * UTraceDataFunc(context, fnNumber, level,
 272  *              "Vector of bytes %vb vector of chars %vc",
 273  *              (const uint8_t *)bytes, (int32_t)bytesLength,
 274  *              (const char *)chars, (int32_t)charsLength);
 275  * ->  Vector of bytes
 276  *      42 63 64 3f [4]
 277  *     vector of chars
 278  *      "Bcd?"[4]
 279  *
 280  * UTraceDataFunc(context, fnNumber, level,
 281  *              "An int32_t %d and a whole bunch of them %vd",
 282  *              (int32_t)-5, (const int32_t *)ints, (int32_t)intsLength);
 283  * ->   An int32_t 0xfffffffb and a whole bunch of them
 284  *      fffffffb 00000005 0000010a [3]
 285  *
 286  */
 287
 288
 289
 290 /**
 291   *  Trace output Formatter.  An application's UTraceData tracing functions may call
 292   *                 back to this function to format the trace output in a
 293   *                 human readable form.  Note that a UTraceData function may choose
 294   *                 to not format the data;  it could, for example, save it in
 295   *                 in the raw form it was received (more compact), leaving
 296   *                 formatting for a later trace analyis tool.
 297   *  @param outBuf  pointer to a buffer to receive the formatted output.  Output
 298   *                 will be nul terminated if there is space in the buffer -
 299   *                 if the length of the requested output < the output buffer size.
 300   *  @param capacity  Length of the output buffer.
 301   *  @param indent  Number of spaces to indent the output.  Intended to allow
 302   *                 data displayed from nested functions to be indented for readability.
 303   *  @param fmt     Format specification for the data to output
 304   *  @param args    Data to be formatted.
 305   *  @return        Length of formatted output, including the terminating NUL.
 306   *                 If buffer capacity is insufficient, the required capacity is returned.
 307   *  @stable ICU 2.8
 308   */
 309 U_STABLE int32_t U_EXPORT2
 310 utrace_vformat(char *outBuf, int32_t capacity,
 311               int32_t indent, const char *fmt,  va_list args);
 312
 313 /**
 314   *  Trace output Formatter.  An application's UTraceData tracing functions may call
 315   *                 this function to format any additional trace data, beyond that
 316   *                 provided by default, in human readable form with the same
 317   *                 formatting conventions used by utrace_vformat().
 318   *  @param outBuf  pointer to a buffer to receive the formatted output.  Output
 319   *                 will be nul terminated if there is space in the buffer -
 320   *                 if the length of the requested output < the output buffer size.
 321   *  @param capacity  Length of the output buffer.
 322   *  @param indent  Number of spaces to indent the output.  Intended to allow
 323   *                 data displayed from nested functions to be indented for readability.
 324   *  @param fmt     Format specification for the data to output
 325   *  @param ...     Data to be formatted.
 326   *  @return        Length of formatted output, including the terminating NUL.
 327   *                 If buffer capacity is insufficient, the required capacity is returned.
 328   *  @stable ICU 2.8
 329   */
 330 U_STABLE int32_t U_EXPORT2
 331 utrace_format(char *outBuf, int32_t capacity,
 332               int32_t indent, const char *fmt,  ...);
 333
 334
 335
 336 /* Trace function numbers --------------------------------------------------- */
 337
 338 /**
 339  * Get the name of a function from its trace function number.
 340  *
 341  * @param fnNumber The trace number for an ICU function.
 342  * @return The name string for the function.
 343  *
 344  * @see UTraceFunctionNumber
 345  * @stable ICU 2.8
 346  */
 347 U_STABLE const char * U_EXPORT2
 348 utrace_functionName(int32_t fnNumber);
 349
 350 U_CDECL_END
 351
 352 #endif