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, or NULL if unknown 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, or NULL if unknown 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