source/includes/lv2/logger.h

   1 /*
   2   Copyright 2012-2016 David Robillard <http://drobilla.net>
   3
   4   Permission to use, copy, modify, and/or distribute this software for any
   5   purpose with or without fee is hereby granted, provided that the above
   6   copyright notice and this permission notice appear in all copies.
   7
   8   THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9   WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10   MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11   ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15 */
  16
  17 /**
  18    @defgroup logger Logger
  19    @ingroup log
  20
  21    Convenience API for easy logging in plugin code.  This API provides simple
  22    wrappers for logging from a plugin, which automatically fall back to
  23    printing to stderr if host support is unavailabe.
  24
  25    @{
  26 */
  27
  28 #ifndef LV2_ATOM_LOGGER_H
  29 #define LV2_ATOM_LOGGER_H
  30
  31 #include <stdio.h>
  32 #include <string.h>
  33
  34 #include "log.h"
  35
  36 #ifdef __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 /**
  41    Logger convenience API state.
  42 */
  43 typedef struct {
  44         LV2_Log_Log* log;
  45
  46         LV2_URID Error;
  47         LV2_URID Note;
  48         LV2_URID Trace;
  49         LV2_URID Warning;
  50 } LV2_Log_Logger;
  51
  52 /**
  53    Set `map` as the URI map for `logger`.
  54
  55    This affects the message type URIDs (Error, Warning, etc) which are passed
  56    to the log's print functions.
  57 */
  58 static inline void
  59 lv2_log_logger_set_map(LV2_Log_Logger* logger, LV2_URID_Map* map)
  60 {
  61         if (map) {
  62                 logger->Error   = map->map(map->handle, LV2_LOG__Error);
  63                 logger->Note    = map->map(map->handle, LV2_LOG__Note);
  64                 logger->Trace   = map->map(map->handle, LV2_LOG__Trace);
  65                 logger->Warning = map->map(map->handle, LV2_LOG__Warning);
  66         } else {
  67                 logger->Error = logger->Note = logger->Trace = logger->Warning = 0;
  68         }
  69 }
  70
  71 /**
  72    Initialise `logger`.
  73
  74    URIs will be mapped using `map` and stored, a reference to `map` itself is
  75    not held.  Both `map` and `log` may be NULL when unsupported by the host,
  76    in which case the implementation will fall back to printing to stderr.
  77 */
  78 static inline void
  79 lv2_log_logger_init(LV2_Log_Logger* logger,
  80                     LV2_URID_Map*   map,
  81                     LV2_Log_Log*    log)
  82 {
  83         logger->log = log;
  84         lv2_log_logger_set_map(logger, map);
  85 }
  86
  87 /**
  88    Log a message to the host, or stderr if support is unavailable.
  89 */
  90 LV2_LOG_FUNC(3, 0)
  91 static inline int
  92 lv2_log_vprintf(LV2_Log_Logger* logger,
  93                 LV2_URID        type,
  94                 const char*     fmt,
  95                 va_list         args)
  96 {
  97         if (logger && logger->log) {
  98                 return logger->log->vprintf(logger->log->handle, type, fmt, args);
  99         } else {
 100                 return vfprintf(stderr, fmt, args);
 101         }
 102 }
 103
 104 /** Log an error via lv2_log_vprintf(). */
 105 LV2_LOG_FUNC(2, 3)
 106 static inline int
 107 lv2_log_error(LV2_Log_Logger* logger, const char* fmt, ...)
 108 {
 109         va_list args;
 110         va_start(args, fmt);
 111         const int ret = lv2_log_vprintf(logger, logger->Error, fmt, args);
 112         va_end(args);
 113         return ret;
 114 }
 115
 116 /** Log a note via lv2_log_vprintf(). */
 117 LV2_LOG_FUNC(2, 3)
 118 static inline int
 119 lv2_log_note(LV2_Log_Logger* logger, const char* fmt, ...)
 120 {
 121         va_list args;
 122         va_start(args, fmt);
 123         const int ret = lv2_log_vprintf(logger, logger->Note, fmt, args);
 124         va_end(args);
 125         return ret;
 126 }
 127
 128 /** Log a trace via lv2_log_vprintf(). */
 129 LV2_LOG_FUNC(2, 3)
 130 static inline int
 131 lv2_log_trace(LV2_Log_Logger* logger, const char* fmt, ...)
 132 {
 133         va_list args;
 134         va_start(args, fmt);
 135         const int ret = lv2_log_vprintf(logger, logger->Trace, fmt, args);
 136         va_end(args);
 137         return ret;
 138 }
 139
 140 /** Log a warning via lv2_log_vprintf(). */
 141 LV2_LOG_FUNC(2, 3)
 142 static inline int
 143 lv2_log_warning(LV2_Log_Logger* logger, const char* fmt, ...)
 144 {
 145         va_list args;
 146         va_start(args, fmt);
 147         const int ret = lv2_log_vprintf(logger, logger->Warning, fmt, args);
 148         va_end(args);
 149         return ret;
 150 }
 151
 152 #ifdef __cplusplus
 153 }  /* extern "C" */
 154 #endif
 155
 156 #endif  /* LV2_LOG_LOGGER_H */
 157
 158 /**
 159    @}
 160 */