1 /*! \file exif-log.h
2  *  \brief Log message infrastructure
3  */
4 /*
5  * Copyright (c) 2004 Lutz Mueller <lutz@users.sourceforge.net>
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, write to the
19  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20  * Boston, MA  02110-1301  USA.
21  */
22 
23 #ifndef __EXIF_LOG_H__
24 #define __EXIF_LOG_H__
25 
26 #ifdef __cplusplus
27 extern "C" {
28 #endif /* __cplusplus */
29 
30 #include <libexif/exif-mem.h>
31 #include <stdarg.h>
32 
33 /*! State maintained by the logging interface */
34 typedef struct _ExifLog        ExifLog;
35 
36 /*! Create a new logging instance.
37  * \see exif_log_free
38  *
39  * \return new instance of #ExifLog
40  */
41 ExifLog *exif_log_new     (void);
42 ExifLog *exif_log_new_mem (ExifMem *);
43 void     exif_log_ref     (ExifLog *log);
44 void     exif_log_unref   (ExifLog *log);
45 
46 /*! Delete instance of #ExifLog.
47  * \see exif_log_new
48  *
49  * \param[in] log #ExifLog
50  * \return new instance of #ExifLog
51  */
52 void     exif_log_free    (ExifLog *log);
53 
54 typedef enum {
55 	EXIF_LOG_CODE_NONE,
56 	EXIF_LOG_CODE_DEBUG,
57 	EXIF_LOG_CODE_NO_MEMORY,
58 	EXIF_LOG_CODE_CORRUPT_DATA
59 } ExifLogCode;
60 
61 /*! Return a textual description of the given class of error log.
62  *
63  * \param[in] code logging message class
64  * \return textual description of the log class
65  */
66 const char *exif_log_code_get_title   (ExifLogCode code);
67 
68 /*! Return a verbose description of the given class of error log.
69  *
70  * \param[in] code logging message class
71  * \return verbose description of the log class
72  */
73 const char *exif_log_code_get_message (ExifLogCode code);
74 
75 /*! Log callback function prototype.
76  */
77 typedef void (* ExifLogFunc) (ExifLog *log, ExifLogCode, const char *domain,
78 			      const char *format, va_list args, void *data);
79 
80 /*! Register log callback function.
81  * Calls to the log callback function are purely for diagnostic purposes.
82  *
83  * \param[in] log logging state variable
84  * \param[in] func callback function to set
85  * \param[in] data data to pass into callback function
86  */
87 void     exif_log_set_func (ExifLog *log, ExifLogFunc func, void *data);
88 
89 #ifndef NO_VERBOSE_TAG_STRINGS
90 void     exif_log  (ExifLog *log, ExifLogCode, const char *domain,
91 		    const char *format, ...)
92 #ifdef __GNUC__
93 			__attribute__((__format__(printf,4,5)))
94 #endif
95 ;
96 #else
97 #if defined(__STDC_VERSION__) &&  __STDC_VERSION__ >= 199901L
98 #define exif_log(...) do { } while (0)
99 #elif defined(__GNUC__)
100 #define exif_log(x...) do { } while (0)
101 #else
102 #define exif_log (void)
103 #endif
104 #endif
105 
106 void     exif_logv (ExifLog *log, ExifLogCode, const char *domain,
107 		    const char *format, va_list args);
108 
109 /* For your convenience */
110 #define EXIF_LOG_NO_MEMORY(l,d,s) exif_log ((l), EXIF_LOG_CODE_NO_MEMORY, (d), "Could not allocate %lu byte(s).", (unsigned long)(s))
111 
112 #ifdef __cplusplus
113 }
114 #endif /* __cplusplus */
115 
116 #endif /* __EXIF_LOG_H__ */
117