log UPDATE new thread-specific logger callback

Author: michalvasko

src/log.c

@@ -4,7 +4,7 @@
  * @author Michal Vasko <mvasko@cesnet.cz>
  * @brief Logger routines implementations
  *
- * Copyright (c) 2015 - 2023 CESNET, z.s.p.o.
+ * Copyright (c) 2015 - 2026 CESNET, z.s.p.o.
  *
  * This source code is licensed under BSD 3-Clause License (the "License").
  * You may not use this file except in compliance with the License.
@@ -41,6 +41,7 @@ ATOMIC_T ly_ll = (uint_fast32_t)LY_LLWRN;
 ATOMIC_T ly_log_opts = (uint_fast32_t)(LY_LOLOG | LY_LOSTORE_LAST);
 THREAD_LOCAL uint32_t *temp_ly_log_opts;
 static ly_log_clb log_clb;
+THREAD_LOCAL ly_log_clb temp_log_clb;
 THREAD_LOCAL char last_msg[LY_LAST_MSG_SIZE];
 #ifndef NDEBUG
 ATOMIC_T ly_ldbg_groups = 0;
@@ -300,6 +301,16 @@ ly_get_log_clb(void)
     return log_clb;
 }
 
+LIBYANG_API_DEF ly_log_clb
+ly_temp_log_clb(ly_log_clb clb)
+{
+    ly_log_clb prev_cb = temp_log_clb;
+
+    temp_log_clb = clb;
+
+    return prev_cb;
+}
+
 void
 ly_log_location(const struct lysc_node *scnode, const struct lyd_node *dnode, const char *path, const struct ly_in *in)
 {
@@ -582,7 +593,9 @@ log_vprintf(const struct ly_ctx *ctx, LY_LOG_LEVEL level, LY_ERR err, LY_VECODE
 
     /* if we are only storing errors internally, never print the message (yet) */
     if (lolog) {
-        if (log_clb) {
+        if (temp_log_clb) {
+            temp_log_clb(level, msg, data_path, schema_path, line);
+        } else if (log_clb) {
             log_clb(level, msg, data_path, schema_path, line);
         } else if (level <= ATOMIC_LOAD_RELAXED(ly_ll)) {
             fprintf(stderr, "libyang[%d]: ", level);

src/log.h

@@ -4,7 +4,7 @@
  * @author Michal Vasko <mvasko@cesnet.cz>
  * @brief Logger manipulation routines and error definitions.
  *
- * Copyright (c) 2015 - 2022 CESNET, z.s.p.o.
+ * Copyright (c) 2015 - 2026 CESNET, z.s.p.o.
  *
  * This source code is licensed under BSD 3-Clause License (the "License").
  * You may not use this file except in compliance with the License.
@@ -127,7 +127,7 @@ LIBYANG_API_DECL LY_LOG_LEVEL ly_log_level(LY_LOG_LEVEL level);
  */
 
 /**
- * @brief Set logger options. Default is #LY_LOLOG | #LY_LOSTORE_LAST.
+ * @brief Set global logger options. Default is #LY_LOLOG | #LY_LOSTORE_LAST.
  *
  * To get the current value, the function must be called twice resetting the level by the received value.
  *
@@ -137,7 +137,7 @@ LIBYANG_API_DECL LY_LOG_LEVEL ly_log_level(LY_LOG_LEVEL level);
 LIBYANG_API_DECL uint32_t ly_log_options(uint32_t opts);
 
 /**
- * @brief Set temporary thread-safe logger options overwriting those set by ::ly_log_options().
+ * @brief Set temporary thread-safe (thread-specific) logger options overwriting those set by ::ly_log_options().
  *
  * @param[in] opts Pointer to the temporary @ref logopts. If NULL, restores the effect of global logger options.
  * @return Previous temporary options.
@@ -187,7 +187,7 @@ typedef void (*ly_log_clb)(LY_LOG_LEVEL level, const char *msg, const char *data
         uint64_t line);
 
 /**
- * @brief Set logger callback.
+ * @brief Set global logger callback.
  *
  * Is not affected by global log level.
  *
@@ -196,12 +196,22 @@ typedef void (*ly_log_clb)(LY_LOG_LEVEL level, const char *msg, const char *data
 LIBYANG_API_DECL void ly_set_log_clb(ly_log_clb clb);
 
 /**
- * @brief Get logger callback.
+ * @brief Get global logger callback.
  *
  * @return Logger callback (can be NULL).
  */
 LIBYANG_API_DECL ly_log_clb ly_get_log_clb(void);
 
+/**
+ * @brief Set temporary thread-safe (thread-specific) logger callback ovewriting that set by ::ly_set_log_clb.
+ *
+ * Is not affected by global log level.
+ *
+ * @param[in] clb Logging callback.
+ * @return Previous temporary logging callback.
+ */
+LIBYANG_API_DECL ly_log_clb ly_temp_log_clb(ly_log_clb clb);
+
 /** @} log */
 
 /**