zck_log: allow a callback for logging

When zck is used as library, the caller has already its own LOG system.
It is nice to redirect zck's log into the main logger. ZCK can already
write into a fd specified by the user, but this add complexity in case
it cannot be mapped, for example if LOG should be sent to network or is
managed in a different way. iNot only, information like loglevel are
lost.

Signed-off-by: Stefano Babic <sbabic@denx.de>

diff --git a/include/zck.h.in b/include/zck.h.in
index a053b303c43a15d7b291362dd31bde6ee20b4db7..ed646b78271bda4d98c215762bcac653cc36ff99 100644 (file)
--- a/include/zck.h.in
+++ b/include/zck.h.in
@@ -5,6 +5,7 @@
 
 #include <stdlib.h>
 #include <stdbool.h>
+#include <stdarg.h>
 #include <sys/types.h>
 
 typedef enum zck_hash {
@@ -129,6 +130,9 @@ const char *zck_get_error(zckCtx *zck);
 /* Clear error message
  * Returns 1 if message was cleared, 0 if error is fatal and can't be cleared */
 bool zck_clear_error(zckCtx *zck);
+/* Set a callback for logs instead to write into a fd */
+typedef void (*logcallback)(const char *function, zck_log_type lt, const char *format, va_list args);
+void zck_set_log_callback(logcallback function);
 
 /*******************************************************************
  * Miscellaneous utilities

diff --git a/src/lib/log.c b/src/lib/log.c
index b6598d8d43792943ea27fe493561f67317fa72fe..a238b8709348747c8d9eb9fbdae8d0a2eb95fcfe 100644 (file)
--- a/src/lib/log.c
+++ b/src/lib/log.c
@@ -36,6 +36,8 @@
 static zck_log_type log_level = ZCK_LOG_ERROR;
 static int log_fd = STDERR_FILENO;
 
+static logcallback callback = NULL; 
+
 void PUBLIC zck_set_log_level(zck_log_type ll) {
     log_level = ll;
 }
@@ -44,14 +46,24 @@ void PUBLIC zck_set_log_fd(int fd) {
     log_fd = fd;
 }
 
+void PUBLIC zck_set_log_callback(logcallback function) {
+    if (!function)
+        return;
+    callback = function;
+}
+
 void zck_log_v(const char *function, zck_log_type lt, const char *format,
      va_list args) {
     if(lt < log_level || log_level == ZCK_LOG_ERROR)
         return;
 
-    dprintf(log_fd, "%s: ", function);
-    vdprintf(log_fd, format, args);
-    dprintf(log_fd, "\n");
+    if (callback) {
+        callback(function, lt, format, args);
+    } else {
+        dprintf(log_fd, "%s: ", function);
+        vdprintf(log_fd, format, args);
+        dprintf(log_fd, "\n");
+    }
 }
 
 void zck_log_wf(const char *function, zck_log_type lt, const char *format, ...) {