icuSources/common/unicode/utrace.h

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4 *******************************************************************************
   5 *
   6 *   Copyright (C) 2003-2013, International Business Machines
   7 *   Corporation and others.  All Rights Reserved.
   8 *
   9 *******************************************************************************
  10 *   file name:  utrace.h
  11 *   encoding:   UTF-8
  12 *   tab size:   8 (not used)
  13 *   indentation:4
  14 *
  15 *   created on: 2003aug06
  16 *   created by: Markus W. Scherer
  17 *
  18 *   Definitions for ICU tracing/logging.
  19 *
  20 */
  21
  22 #ifndef __UTRACE_H__
  23 #define __UTRACE_H__
  24
  25 #include <stdarg.h>
  26 #include "unicode/utypes.h"
  27
  28 /**
  29  * \file
  30  * \brief C API:  Definitions for ICU tracing/logging.
  31  *
  32  * This provides API for debugging the internals of ICU without the use of
  33  * a traditional debugger.
  34  *
  35  * By default, tracing is disabled in ICU. If you need to debug ICU with
  36  * tracing, please compile ICU with the --enable-tracing configure option.
  37  */
  38
  39 U_CDECL_BEGIN
  40
  41 /**
  42  * Trace severity levels.  Higher levels increase the verbosity of the trace output.
  43  * @see utrace_setLevel
  44  * @stable ICU 2.8
  45  */
  46 typedef enum UTraceLevel {
  47     /** Disable all tracing  @stable ICU 2.8*/
  48     UTRACE_OFF=-1,
  49     /** Trace error conditions only  @stable ICU 2.8*/
  50     UTRACE_ERROR=0,
  51     /** Trace errors and warnings  @stable ICU 2.8*/
  52     UTRACE_WARNING=3,
  53     /** Trace opens and closes of ICU services  @stable ICU 2.8*/
  54     UTRACE_OPEN_CLOSE=5,
  55     /** Trace an intermediate number of ICU operations  @stable ICU 2.8*/
  56     UTRACE_INFO=7,
  57     /** Trace the maximum number of ICU operations  @stable ICU 2.8*/
  58     UTRACE_VERBOSE=9
  59 } UTraceLevel;
  60
  61 /**
  62  *  These are the ICU functions that will be traced when tracing is enabled.
  63  *  @stable ICU 2.8
  64  */
  65 typedef enum UTraceFunctionNumber {
  66     UTRACE_FUNCTION_START=0,
  67     UTRACE_U_INIT=UTRACE_FUNCTION_START,
  68     UTRACE_U_CLEANUP,
  69 #ifndef U_HIDE_DEPRECATED_API
  70     /**
  71      * One more than the highest normal collation trace location.
  72      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
  73      */
  74     UTRACE_FUNCTION_LIMIT,
  75 #endif  // U_HIDE_DEPRECATED_API
  76
  77     UTRACE_CONVERSION_START=0x1000,
  78     UTRACE_UCNV_OPEN=UTRACE_CONVERSION_START,
  79     UTRACE_UCNV_OPEN_PACKAGE,
  80     UTRACE_UCNV_OPEN_ALGORITHMIC,
  81     UTRACE_UCNV_CLONE,
  82     UTRACE_UCNV_CLOSE,
  83     UTRACE_UCNV_FLUSH_CACHE,
  84     UTRACE_UCNV_LOAD,
  85     UTRACE_UCNV_UNLOAD,
  86 #ifndef U_HIDE_DEPRECATED_API
  87     /**
  88      * One more than the highest normal collation trace location.
  89      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
  90      */
  91     UTRACE_CONVERSION_LIMIT,
  92 #endif  // U_HIDE_DEPRECATED_API
  93
  94     UTRACE_COLLATION_START=0x2000,
  95     UTRACE_UCOL_OPEN=UTRACE_COLLATION_START,
  96     UTRACE_UCOL_CLOSE,
  97     UTRACE_UCOL_STRCOLL,
  98     UTRACE_UCOL_GET_SORTKEY,
  99     UTRACE_UCOL_GETLOCALE,
 100     UTRACE_UCOL_NEXTSORTKEYPART,
 101     UTRACE_UCOL_STRCOLLITER,
 102     UTRACE_UCOL_OPEN_FROM_SHORT_STRING,
 103     UTRACE_UCOL_STRCOLLUTF8, /**< @stable ICU 50 */
 104 #ifndef U_HIDE_DEPRECATED_API
 105     /**
 106      * One more than the highest normal collation trace location.
 107      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
 108      */
 109     UTRACE_COLLATION_LIMIT
 110 #endif  // U_HIDE_DEPRECATED_API
 111 } UTraceFunctionNumber;
 112
 113 /**
 114  * Setter for the trace level.
 115  * @param traceLevel A UTraceLevel value.
 116  * @stable ICU 2.8
 117  */
 118 U_STABLE void U_EXPORT2
 119 utrace_setLevel(int32_t traceLevel);
 120
 121 /**
 122  * Getter for the trace level.
 123  * @return The UTraceLevel value being used by ICU.
 124  * @stable ICU 2.8
 125  */
 126 U_STABLE int32_t U_EXPORT2
 127 utrace_getLevel(void);
 128
 129 /* Trace function pointers types  ----------------------------- */
 130
 131 /**
 132   *  Type signature for the trace function to be called when entering a function.
 133   *  @param context value supplied at the time the trace functions are set.
 134   *  @param fnNumber Enum value indicating the ICU function being entered.
 135   *  @stable ICU 2.8
 136   */
 137 typedef void U_CALLCONV
 138 UTraceEntry(const void *context, int32_t fnNumber);
 139
 140 /**
 141   *  Type signature for the trace function to be called when exiting from a function.
 142   *  @param context value supplied at the time the trace functions are set.
 143   *  @param fnNumber Enum value indicating the ICU function being exited.
 144   *  @param fmt     A formatting string that describes the number and types
 145   *                 of arguments included with the variable args.  The fmt
 146   *                 string has the same form as the utrace_vformat format
 147   *                 string.
 148   *  @param args    A variable arguments list.  Contents are described by
 149   *                 the fmt parameter.
 150   *  @see   utrace_vformat
 151   *  @stable ICU 2.8
 152   */
 153 typedef void U_CALLCONV
 154 UTraceExit(const void *context, int32_t fnNumber,
 155            const char *fmt, va_list args);
 156
 157 /**
 158   *  Type signature for the trace function to be called from within an ICU function
 159   *  to display data or messages.
 160   *  @param context  value supplied at the time the trace functions are set.
 161   *  @param fnNumber Enum value indicating the ICU function being exited.
 162   *  @param level    The current tracing level
 163   *  @param fmt      A format string describing the tracing data that is supplied
 164   *                  as variable args
 165   *  @param args     The data being traced, passed as variable args.
 166   *  @stable ICU 2.8
 167   */
 168 typedef void U_CALLCONV
 169 UTraceData(const void *context, int32_t fnNumber, int32_t level,
 170            const char *fmt, va_list args);
 171
 172 /**
 173   *  Set ICU Tracing functions.  Installs application-provided tracing
 174   *  functions into ICU.  After doing this, subsequent ICU operations
 175   *  will call back to the installed functions, providing a trace
 176   *  of the use of ICU.  Passing a NULL pointer for a tracing function
 177   *  is allowed, and inhibits tracing action at points where that function
 178   *  would be called.
 179   *  <p>
 180   *  Tracing and Threads:  Tracing functions are global to a process, and
 181   *  will be called in response to ICU operations performed by any
 182   *  thread.  If tracing of an individual thread is desired, the
 183   *  tracing functions must themselves filter by checking that the
 184   *  current thread is the desired thread.
 185   *
 186   *  @param context an uninterpreted pointer.  Whatever is passed in
 187   *                 here will in turn be passed to each of the tracing
 188   *                 functions UTraceEntry, UTraceExit and UTraceData.
 189   *                 ICU does not use or alter this pointer.
 190   *  @param e       Callback function to be called on entry to a
 191   *                 a traced ICU function.
 192   *  @param x       Callback function to be called on exit from a
 193   *                 traced ICU function.
 194   *  @param d       Callback function to be called from within a
 195   *                 traced ICU function, for the purpose of providing
 196   *                 data to the trace.
 197   *
 198   *  @stable ICU 2.8
 199   */
 200 U_STABLE void U_EXPORT2
 201 utrace_setFunctions(const void *context,
 202                     UTraceEntry *e, UTraceExit *x, UTraceData *d);
 203
 204 /**
 205   * Get the currently installed ICU tracing functions.   Note that a null function
 206   *   pointer will be returned if no trace function has been set.
 207   *
 208   * @param context  The currently installed tracing context.
 209   * @param e        The currently installed UTraceEntry function.
 210   * @param x        The currently installed UTraceExit function.
 211   * @param d        The currently installed UTraceData function.
 212   * @stable ICU 2.8
 213   */
 214 U_STABLE void U_EXPORT2
 215 utrace_getFunctions(const void **context,
 216                     UTraceEntry **e, UTraceExit **x, UTraceData **d);
 217
 218
 219
 220 /*
 221  *
 222  * ICU trace format string syntax
 223  *
 224  * Format Strings are passed to UTraceData functions, and define the
 225  * number and types of the trace data being passed on each call.
 226  *
 227  * The UTraceData function, which is supplied by the application,
 228  * not by ICU, can either forward the trace data (passed via
 229  * varargs) and the format string back to ICU for formatting into
 230  * a displayable string, or it can interpret the format itself,
 231  * and do as it wishes with the trace data.
 232  *
 233  *
 234  * Goals for the format string
 235  * - basic data output
 236  * - easy to use for trace programmer
 237  * - sufficient provision for data types for trace output readability
 238  * - well-defined types and binary portable APIs
 239  *
 240  * Non-goals
 241  * - printf compatibility
 242  * - fancy formatting
 243  * - argument reordering and other internationalization features
 244  *
 245  * ICU trace format strings contain plain text with argument inserts,
 246  * much like standard printf format strings.
 247  * Each insert begins with a '%', then optionally contains a 'v',
 248  * then exactly one type character.
 249  * Two '%' in a row represent a '%' instead of an insert.
 250  * The trace format strings need not have \n at the end.
 251  *
 252  *
 253  * Types
 254  * -----
 255  *
 256  * Type characters:
 257  * - c A char character in the default codepage.
 258  * - s A NUL-terminated char * string in the default codepage.
 259  * - S A UChar * string.  Requires two params, (ptr, length).  Length=-1 for nul term.
 260  * - b A byte (8-bit integer).
 261  * - h A 16-bit integer.  Also a 16 bit Unicode code unit.
 262  * - d A 32-bit integer.  Also a 20 bit Unicode code point value.
 263  * - l A 64-bit integer.
 264  * - p A data pointer.
 265  *
 266  * Vectors
 267  * -------
 268  *
 269  * If the 'v' is not specified, then one item of the specified type
 270  * is passed in.
 271  * If the 'v' (for "vector") is specified, then a vector of items of the
 272  * specified type is passed in, via a pointer to the first item
 273  * and an int32_t value for the length of the vector.
 274  * Length==-1 means zero or NUL termination.  Works for vectors of all types.
 275  *
 276  * Note:  %vS is a vector of (UChar *) strings.  The strings must
 277  *        be nul terminated as there is no way to provide a
 278  *        separate length parameter for each string.  The length
 279  *        parameter (required for all vectors) is the number of
 280  *        strings, not the length of the strings.
 281  *
 282  * Examples
 283  * --------
 284  *
 285  * These examples show the parameters that will be passed to an application's
 286  *   UTraceData() function for various formats.
 287  *
 288  * - the precise formatting is up to the application!
 289  * - the examples use type casts for arguments only to _show_ the types of
 290  *   arguments without needing variable declarations in the examples;
 291  *   the type casts will not be necessary in actual code
 292  *
 293  * UTraceDataFunc(context, fnNumber, level,
 294  *              "There is a character %c in the string %s.",   // Format String
 295  *              (char)c, (const char *)s);                     // varargs parameters
 296  * ->   There is a character 0x42 'B' in the string "Bravo".
 297  *
 298  * UTraceDataFunc(context, fnNumber, level,
 299  *              "Vector of bytes %vb vector of chars %vc",
 300  *              (const uint8_t *)bytes, (int32_t)bytesLength,
 301  *              (const char *)chars, (int32_t)charsLength);
 302  * ->  Vector of bytes
 303  *      42 63 64 3f [4]
 304  *     vector of chars
 305  *      "Bcd?"[4]
 306  *
 307  * UTraceDataFunc(context, fnNumber, level,
 308  *              "An int32_t %d and a whole bunch of them %vd",
 309  *              (int32_t)-5, (const int32_t *)ints, (int32_t)intsLength);
 310  * ->   An int32_t 0xfffffffb and a whole bunch of them
 311  *      fffffffb 00000005 0000010a [3]
 312  *
 313  */
 314
 315
 316
 317 /**
 318   *  Trace output Formatter.  An application's UTraceData tracing functions may call
 319   *                 back to this function to format the trace output in a
 320   *                 human readable form.  Note that a UTraceData function may choose
 321   *                 to not format the data;  it could, for example, save it in
 322   *                 in the raw form it was received (more compact), leaving
 323   *                 formatting for a later trace analysis tool.
 324   *  @param outBuf  pointer to a buffer to receive the formatted output.  Output
 325   *                 will be nul terminated if there is space in the buffer -
 326   *                 if the length of the requested output < the output buffer size.
 327   *  @param capacity  Length of the output buffer.
 328   *  @param indent  Number of spaces to indent the output.  Intended to allow
 329   *                 data displayed from nested functions to be indented for readability.
 330   *  @param fmt     Format specification for the data to output
 331   *  @param args    Data to be formatted.
 332   *  @return        Length of formatted output, including the terminating NUL.
 333   *                 If buffer capacity is insufficient, the required capacity is returned.
 334   *  @stable ICU 2.8
 335   */
 336 U_STABLE int32_t U_EXPORT2
 337 utrace_vformat(char *outBuf, int32_t capacity,
 338               int32_t indent, const char *fmt,  va_list args);
 339
 340 /**
 341   *  Trace output Formatter.  An application's UTraceData tracing functions may call
 342   *                 this function to format any additional trace data, beyond that
 343   *                 provided by default, in human readable form with the same
 344   *                 formatting conventions used by utrace_vformat().
 345   *  @param outBuf  pointer to a buffer to receive the formatted output.  Output
 346   *                 will be nul terminated if there is space in the buffer -
 347   *                 if the length of the requested output < the output buffer size.
 348   *  @param capacity  Length of the output buffer.
 349   *  @param indent  Number of spaces to indent the output.  Intended to allow
 350   *                 data displayed from nested functions to be indented for readability.
 351   *  @param fmt     Format specification for the data to output
 352   *  @param ...     Data to be formatted.
 353   *  @return        Length of formatted output, including the terminating NUL.
 354   *                 If buffer capacity is insufficient, the required capacity is returned.
 355   *  @stable ICU 2.8
 356   */
 357 U_STABLE int32_t U_EXPORT2
 358 utrace_format(char *outBuf, int32_t capacity,
 359               int32_t indent, const char *fmt,  ...);
 360
 361
 362
 363 /* Trace function numbers --------------------------------------------------- */
 364
 365 /**
 366  * Get the name of a function from its trace function number.
 367  *
 368  * @param fnNumber The trace number for an ICU function.
 369  * @return The name string for the function.
 370  *
 371  * @see UTraceFunctionNumber
 372  * @stable ICU 2.8
 373  */
 374 U_STABLE const char * U_EXPORT2
 375 utrace_functionName(int32_t fnNumber);
 376
 377 U_CDECL_END
 378
 379 #endif