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