libsigrok  0.5.0
sigrok hardware access and backend library
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log.c
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1 /*
2  * This file is part of the libsigrok project.
3  *
4  * Copyright (C) 2011-2012 Uwe Hermann <uwe@hermann-uwe.de>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <config.h>
21 #include <stdarg.h>
22 #include <stdio.h>
23 #include <glib/gprintf.h>
24 #include <libsigrok/libsigrok.h>
25 #include "libsigrok-internal.h"
26 
27 /** @cond PRIVATE */
28 #define LOG_PREFIX "log"
29 /** @endcond */
30 
31 /**
32  * @file
33  *
34  * Controlling the libsigrok message logging functionality.
35  */
36 
37 /**
38  * @defgroup grp_logging Logging
39  *
40  * Controlling the libsigrok message logging functionality.
41  *
42  * @{
43  */
44 
45 /* Currently selected libsigrok loglevel. Default: SR_LOG_WARN. */
46 static int cur_loglevel = SR_LOG_WARN; /* Show errors+warnings per default. */
47 
48 /* Function prototype. */
49 static int sr_logv(void *cb_data, int loglevel, const char *format,
50  va_list args);
51 
52 /* Pointer to the currently selected log callback. Default: sr_logv(). */
53 static sr_log_callback sr_log_cb = sr_logv;
54 
55 /*
56  * Pointer to private data that can be passed to the log callback.
57  * This can be used (for example) by C++ GUIs to pass a "this" pointer.
58  */
59 static void *sr_log_cb_data = NULL;
60 
61 /** @cond PRIVATE */
62 #define LOGLEVEL_TIMESTAMP SR_LOG_DBG
63 /** @endcond */
64 static int64_t sr_log_start_time = 0;
65 
66 /**
67  * Set the libsigrok loglevel.
68  *
69  * This influences the amount of log messages (debug messages, error messages,
70  * and so on) libsigrok will output. Using SR_LOG_NONE disables all messages.
71  *
72  * Note that this function itself will also output log messages. After the
73  * loglevel has changed, it will output a debug message with SR_LOG_DBG for
74  * example. Whether this message is shown depends on the (new) loglevel.
75  *
76  * @param loglevel The loglevel to set (SR_LOG_NONE, SR_LOG_ERR, SR_LOG_WARN,
77  * SR_LOG_INFO, SR_LOG_DBG, or SR_LOG_SPEW).
78  *
79  * @return SR_OK upon success, SR_ERR_ARG upon invalid loglevel.
80  *
81  * @since 0.1.0
82  */
83 SR_API int sr_log_loglevel_set(int loglevel)
84 {
85  if (loglevel < SR_LOG_NONE || loglevel > SR_LOG_SPEW) {
86  sr_err("Invalid loglevel %d.", loglevel);
87  return SR_ERR_ARG;
88  }
89  /* Output time stamps relative to time at startup */
90  if (loglevel >= LOGLEVEL_TIMESTAMP && sr_log_start_time == 0)
91  sr_log_start_time = g_get_monotonic_time();
92 
93  cur_loglevel = loglevel;
94 
95  sr_dbg("libsigrok loglevel set to %d.", loglevel);
96 
97  return SR_OK;
98 }
99 
100 /**
101  * Get the libsigrok loglevel.
102  *
103  * @return The currently configured libsigrok loglevel.
104  *
105  * @since 0.1.0
106  */
108 {
109  return cur_loglevel;
110 }
111 
112 /**
113  * Set the libsigrok log callback to the specified function.
114  *
115  * @param cb Function pointer to the log callback function to use.
116  * Must not be NULL.
117  * @param cb_data Pointer to private data to be passed on. This can be used by
118  * the caller to pass arbitrary data to the log functions. This
119  * pointer is only stored or passed on by libsigrok, and is
120  * never used or interpreted in any way. The pointer is allowed
121  * to be NULL if the caller doesn't need/want to pass any data.
122  *
123  * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
124  *
125  * @since 0.3.0
126  */
128 {
129  if (!cb) {
130  sr_err("%s: cb was NULL", __func__);
131  return SR_ERR_ARG;
132  }
133 
134  /* Note: 'cb_data' is allowed to be NULL. */
135 
136  sr_log_cb = cb;
137  sr_log_cb_data = cb_data;
138 
139  return SR_OK;
140 }
141 
142 /**
143  * Set the libsigrok log callback to the default built-in one.
144  *
145  * Additionally, the internal 'sr_log_cb_data' pointer is set to NULL.
146  *
147  * @return SR_OK upon success, a negative error code otherwise.
148  *
149  * @since 0.1.0
150  */
152 {
153  /*
154  * Note: No log output in this function, as it should safely work
155  * even if the currently set log callback is buggy/broken.
156  */
157  sr_log_cb = sr_logv;
158  sr_log_cb_data = NULL;
159 
160  return SR_OK;
161 }
162 
163 static int sr_logv(void *cb_data, int loglevel, const char *format, va_list args)
164 {
165  uint64_t elapsed_us, minutes;
166  unsigned int rest_us, seconds, microseconds;
167  char *raw_output, *output;
168  int raw_len, raw_idx, idx, ret;
169 
170  /* This specific log callback doesn't need the void pointer data. */
171  (void)cb_data;
172 
173  /* Only output messages of at least the selected loglevel(s). */
174  if (loglevel > cur_loglevel)
175  return SR_OK;
176 
177  if (cur_loglevel >= LOGLEVEL_TIMESTAMP) {
178  elapsed_us = g_get_monotonic_time() - sr_log_start_time;
179 
180  minutes = elapsed_us / G_TIME_SPAN_MINUTE;
181  rest_us = elapsed_us % G_TIME_SPAN_MINUTE;
182  seconds = rest_us / G_TIME_SPAN_SECOND;
183  microseconds = rest_us % G_TIME_SPAN_SECOND;
184 
185  ret = g_fprintf(stderr, "sr: [%.2" PRIu64 ":%.2u.%.6u] ",
186  minutes, seconds, microseconds);
187  } else {
188  ret = fputs("sr: ", stderr);
189  }
190 
191  if (ret < 0 || (raw_len = g_vasprintf(&raw_output, format, args)) < 0)
192  return SR_ERR;
193 
194  output = g_malloc0(raw_len + 1);
195 
196  /* Copy the string without any unwanted newlines. */
197  raw_idx = idx = 0;
198  while (raw_idx < raw_len) {
199  if (raw_output[raw_idx] != '\n') {
200  output[idx] = raw_output[raw_idx];
201  idx++;
202  }
203  raw_idx++;
204  }
205 
206  g_fprintf(stderr, "%s\n", output);
207  g_free(raw_output);
208  g_free(output);
209 
210  return SR_OK;
211 }
212 
213 /** @private */
214 SR_PRIV int sr_log(int loglevel, const char *format, ...)
215 {
216  int ret;
217  va_list args;
218 
219  va_start(args, format);
220  ret = sr_log_cb(sr_log_cb_data, loglevel, format, args);
221  va_end(args);
222 
223  return ret;
224 }
225 
226 /** @} */
Generic/unspecified error.
Definition: libsigrok.h:68
Output very noisy debug messages.
Definition: libsigrok.h:100
No error.
Definition: libsigrok.h:67
The public libsigrok header file to be used by frontends.
Output warnings.
Definition: libsigrok.h:97
int sr_log_loglevel_get(void)
Get the libsigrok loglevel.
Definition: log.c:107
int sr_log_loglevel_set(int loglevel)
Set the libsigrok loglevel.
Definition: log.c:83
#define SR_PRIV
Definition: libsigrok.h:128
int sr_log_callback_set_default(void)
Set the libsigrok log callback to the default built-in one.
Definition: log.c:151
int(* sr_log_callback)(void *cb_data, int loglevel, const char *format, va_list args)
Definition: proto.h:55
Function argument error.
Definition: libsigrok.h:70
int sr_log_callback_set(sr_log_callback cb, void *cb_data)
Set the libsigrok log callback to the specified function.
Definition: log.c:127
#define SR_API
Definition: libsigrok.h:121