[PATCH v11 6/9] log: add hook for printing log messages

[Stephen Hemminger]

This is useful for when decorating log output for console
or journal. Provide basic version in this patch.
No functional changes in this patch, just infrastructure addition.

Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
 lib/log/log.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/lib/log/log.c b/lib/log/log.c
index 4c8666ac93..4cc871911c 100644
--- a/lib/log/log.c
+++ b/lib/log/log.c
@@ -26,16 +26,21 @@ struct rte_log_dynamic_type {
        uint32_t loglevel;
 };
 
+typedef int (*log_print_t)(FILE *f, uint32_t level, const char *fmt, va_list 
ap);
+static int log_print(FILE *f, uint32_t level, const char *format, va_list ap);
+
 /** The rte_log structure. */
 static struct rte_logs {
        uint32_t type;  /**< Bitfield with enabled logs. */
        uint32_t level; /**< Log level. */
        FILE *file;     /**< Output file set by rte_openlog_stream, or NULL. */
+       log_print_t print_func;
        size_t dynamic_types_len;
        struct rte_log_dynamic_type *dynamic_types;
 } rte_logs = {
        .type = UINT32_MAX,
        .level = RTE_LOG_DEBUG,
+       .print_func = log_print,
 };
 
 struct rte_eal_opt_loglevel {
@@ -67,8 +72,6 @@ struct log_cur_msg {
  /* per core log */
 static RTE_DEFINE_PER_LCORE(struct log_cur_msg, log_cur_msg);
 
-/* default logs */
-
 /* Change the stream that will be used by logging system */
 int
 rte_openlog_stream(FILE *f)
@@ -77,6 +80,7 @@ rte_openlog_stream(FILE *f)
                fclose(rte_logs.file);
 
        rte_logs.file = f;
+       rte_logs.print_func = log_print;
        return 0;
 }
 
@@ -473,7 +477,7 @@ rte_vlog(uint32_t level, uint32_t logtype, const char 
*format, va_list ap)
        RTE_PER_LCORE(log_cur_msg).loglevel = level;
        RTE_PER_LCORE(log_cur_msg).logtype = logtype;
 
-       ret = vfprintf(f, format, ap);
+       ret = (*rte_logs.print_func)(f, level, format, ap);
        fflush(f);
        return ret;
 }
@@ -509,6 +513,15 @@ rte_eal_log_cleanup(void)
        }
 }
 
+/* default log print function */
+__rte_format_printf(3, 0)
+static int
+log_print(FILE *f, uint32_t level __rte_unused,
+         const char *format, va_list ap)
+{
+       return vfprintf(f, format, ap);
+}
+
 /* initialize logging */
 void
 eal_log_init(const char *id __rte_unused)
-- 
2.43.0