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1 /*
2 *******************************************************************************
3 *
4 *   Copyright (C) 2003-2013, 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_UCOL_STRCOLLUTF8, /**< @stable ICU 50 */
90     UTRACE_COLLATION_LIMIT
91 } UTraceFunctionNumber;
92 
93 /**
94  * Setter for the trace level.
95  * @param traceLevel A UTraceLevel value.
96  * @stable ICU 2.8
97  */
98 U_STABLE void U_EXPORT2
99 utrace_setLevel(int32_t traceLevel);
100 
101 /**
102  * Getter for the trace level.
103  * @return The UTraceLevel value being used by ICU.
104  * @stable ICU 2.8
105  */
106 U_STABLE int32_t U_EXPORT2
107 utrace_getLevel(void);
108 
109 /* Trace function pointers types  ----------------------------- */
110 
111 /**
112   *  Type signature for the trace function to be called when entering a function.
113   *  @param context value supplied at the time the trace functions are set.
114   *  @param fnNumber Enum value indicating the ICU function being entered.
115   *  @stable ICU 2.8
116   */
117 typedef void U_CALLCONV
118 UTraceEntry(const void *context, int32_t fnNumber);
119 
120 /**
121   *  Type signature for the trace function to be called when exiting from a function.
122   *  @param context value supplied at the time the trace functions are set.
123   *  @param fnNumber Enum value indicating the ICU function being exited.
124   *  @param fmt     A formatting string that describes the number and types
125   *                 of arguments included with the variable args.  The fmt
126   *                 string has the same form as the utrace_vformat format
127   *                 string.
128   *  @param args    A variable arguments list.  Contents are described by
129   *                 the fmt parameter.
130   *  @see   utrace_vformat
131   *  @stable ICU 2.8
132   */
133 typedef void U_CALLCONV
134 UTraceExit(const void *context, int32_t fnNumber,
135            const char *fmt, va_list args);
136 
137 /**
138   *  Type signature for the trace function to be called from within an ICU function
139   *  to display data or messages.
140   *  @param context  value supplied at the time the trace functions are set.
141   *  @param fnNumber Enum value indicating the ICU function being exited.
142   *  @param level    The current tracing level
143   *  @param fmt      A format string describing the tracing data that is supplied
144   *                  as variable args
145   *  @param args     The data being traced, passed as variable args.
146   *  @stable ICU 2.8
147   */
148 typedef void U_CALLCONV
149 UTraceData(const void *context, int32_t fnNumber, int32_t level,
150            const char *fmt, va_list args);
151 
152 /**
153   *  Set ICU Tracing functions.  Installs application-provided tracing
154   *  functions into ICU.  After doing this, subsequent ICU operations
155   *  will call back to the installed functions, providing a trace
156   *  of the use of ICU.  Passing a NULL pointer for a tracing function
157   *  is allowed, and inhibits tracing action at points where that function
158   *  would be called.
159   *  <p>
160   *  Tracing and Threads:  Tracing functions are global to a process, and
161   *  will be called in response to ICU operations performed by any
162   *  thread.  If tracing of an individual thread is desired, the
163   *  tracing functions must themselves filter by checking that the
164   *  current thread is the desired thread.
165   *
166   *  @param context an uninterpretted pointer.  Whatever is passed in
167   *                 here will in turn be passed to each of the tracing
168   *                 functions UTraceEntry, UTraceExit and UTraceData.
169   *                 ICU does not use or alter this pointer.
170   *  @param e       Callback function to be called on entry to a
171   *                 a traced ICU function.
172   *  @param x       Callback function to be called on exit from a
173   *                 traced ICU function.
174   *  @param d       Callback function to be called from within a
175   *                 traced ICU function, for the purpose of providing
176   *                 data to the trace.
177   *
178   *  @stable ICU 2.8
179   */
180 U_STABLE void U_EXPORT2
181 utrace_setFunctions(const void *context,
182                     UTraceEntry *e, UTraceExit *x, UTraceData *d);
183 
184 /**
185   * Get the currently installed ICU tracing functions.   Note that a null function
186   *   pointer will be returned if no trace function has been set.
187   *
188   * @param context  The currently installed tracing context.
189   * @param e        The currently installed UTraceEntry function.
190   * @param x        The currently installed UTraceExit function.
191   * @param d        The currently installed UTraceData function.
192   * @stable ICU 2.8
193   */
194 U_STABLE void U_EXPORT2
195 utrace_getFunctions(const void **context,
196                     UTraceEntry **e, UTraceExit **x, UTraceData **d);
197 
198 
199 
200 /*
201  *
202  * ICU trace format string syntax
203  *
204  * Format Strings are passed to UTraceData functions, and define the
205  * number and types of the trace data being passed on each call.
206  *
207  * The UTraceData function, which is supplied by the application,
208  * not by ICU, can either forward the trace data (passed via
209  * varargs) and the format string back to ICU for formatting into
210  * a displayable string, or it can interpret the format itself,
211  * and do as it wishes with the trace data.
212  *
213  *
214  * Goals for the format string
215  * - basic data output
216  * - easy to use for trace programmer
217  * - sufficient provision for data types for trace output readability
218  * - well-defined types and binary portable APIs
219  *
220  * Non-goals
221  * - printf compatibility
222  * - fancy formatting
223  * - argument reordering and other internationalization features
224  *
225  * ICU trace format strings contain plain text with argument inserts,
226  * much like standard printf format strings.
227  * Each insert begins with a '%', then optionally contains a 'v',
228  * then exactly one type character.
229  * Two '%' in a row represent a '%' instead of an insert.
230  * The trace format strings need not have \n at the end.
231  *
232  *
233  * Types
234  * -----
235  *
236  * Type characters:
237  * - c A char character in the default codepage.
238  * - s A NUL-terminated char * string in the default codepage.
239  * - S A UChar * string.  Requires two params, (ptr, length).  Length=-1 for nul term.
240  * - b A byte (8-bit integer).
241  * - h A 16-bit integer.  Also a 16 bit Unicode code unit.
242  * - d A 32-bit integer.  Also a 20 bit Unicode code point value.
243  * - l A 64-bit integer.
244  * - p A data pointer.
245  *
246  * Vectors
247  * -------
248  *
249  * If the 'v' is not specified, then one item of the specified type
250  * is passed in.
251  * If the 'v' (for "vector") is specified, then a vector of items of the
252  * specified type is passed in, via a pointer to the first item
253  * and an int32_t value for the length of the vector.
254  * Length==-1 means zero or NUL termination.  Works for vectors of all types.
255  *
256  * Note:  %vS is a vector of (UChar *) strings.  The strings must
257  *        be nul terminated as there is no way to provide a
258  *        separate length parameter for each string.  The length
259  *        parameter (required for all vectors) is the number of
260  *        strings, not the length of the strings.
261  *
262  * Examples
263  * --------
264  *
265  * These examples show the parameters that will be passed to an application's
266  *   UTraceData() function for various formats.
267  *
268  * - the precise formatting is up to the application!
269  * - the examples use type casts for arguments only to _show_ the types of
270  *   arguments without needing variable declarations in the examples;
271  *   the type casts will not be necessary in actual code
272  *
273  * UTraceDataFunc(context, fnNumber, level,
274  *              "There is a character %c in the string %s.",   // Format String
275  *              (char)c, (const char *)s);                     // varargs parameters
276  * ->   There is a character 0x42 'B' in the string "Bravo".
277  *
278  * UTraceDataFunc(context, fnNumber, level,
279  *              "Vector of bytes %vb vector of chars %vc",
280  *              (const uint8_t *)bytes, (int32_t)bytesLength,
281  *              (const char *)chars, (int32_t)charsLength);
282  * ->  Vector of bytes
283  *      42 63 64 3f [4]
284  *     vector of chars
285  *      "Bcd?"[4]
286  *
287  * UTraceDataFunc(context, fnNumber, level,
288  *              "An int32_t %d and a whole bunch of them %vd",
289  *              (int32_t)-5, (const int32_t *)ints, (int32_t)intsLength);
290  * ->   An int32_t 0xfffffffb and a whole bunch of them
291  *      fffffffb 00000005 0000010a [3]
292  *
293  */
294 
295 
296 
297 /**
298   *  Trace output Formatter.  An application's UTraceData tracing functions may call
299   *                 back to this function to format the trace output in a
300   *                 human readable form.  Note that a UTraceData function may choose
301   *                 to not format the data;  it could, for example, save it in
302   *                 in the raw form it was received (more compact), leaving
303   *                 formatting for a later trace analyis tool.
304   *  @param outBuf  pointer to a buffer to receive the formatted output.  Output
305   *                 will be nul terminated if there is space in the buffer -
306   *                 if the length of the requested output < the output buffer size.
307   *  @param capacity  Length of the output buffer.
308   *  @param indent  Number of spaces to indent the output.  Intended to allow
309   *                 data displayed from nested functions to be indented for readability.
310   *  @param fmt     Format specification for the data to output
311   *  @param args    Data to be formatted.
312   *  @return        Length of formatted output, including the terminating NUL.
313   *                 If buffer capacity is insufficient, the required capacity is returned.
314   *  @stable ICU 2.8
315   */
316 U_STABLE int32_t U_EXPORT2
317 utrace_vformat(char *outBuf, int32_t capacity,
318               int32_t indent, const char *fmt,  va_list args);
319 
320 /**
321   *  Trace output Formatter.  An application's UTraceData tracing functions may call
322   *                 this function to format any additional trace data, beyond that
323   *                 provided by default, in human readable form with the same
324   *                 formatting conventions used by utrace_vformat().
325   *  @param outBuf  pointer to a buffer to receive the formatted output.  Output
326   *                 will be nul terminated if there is space in the buffer -
327   *                 if the length of the requested output < the output buffer size.
328   *  @param capacity  Length of the output buffer.
329   *  @param indent  Number of spaces to indent the output.  Intended to allow
330   *                 data displayed from nested functions to be indented for readability.
331   *  @param fmt     Format specification for the data to output
332   *  @param ...     Data to be formatted.
333   *  @return        Length of formatted output, including the terminating NUL.
334   *                 If buffer capacity is insufficient, the required capacity is returned.
335   *  @stable ICU 2.8
336   */
337 U_STABLE int32_t U_EXPORT2
338 utrace_format(char *outBuf, int32_t capacity,
339               int32_t indent, const char *fmt,  ...);
340 
341 
342 
343 /* Trace function numbers --------------------------------------------------- */
344 
345 /**
346  * Get the name of a function from its trace function number.
347  *
348  * @param fnNumber The trace number for an ICU function.
349  * @return The name string for the function.
350  *
351  * @see UTraceFunctionNumber
352  * @stable ICU 2.8
353  */
354 U_STABLE const char * U_EXPORT2
355 utrace_functionName(int32_t fnNumber);
356 
357 U_CDECL_END
358 
359 #endif
360