logging: Support for Structured logging format

Wrapper for `gf_log` and `gf_msg` to add support for
structured logging format.

Two new wrappers available `gf_slog` and `gf_smsg`

Example 1: All static details

    gf_slog ("cli", GF_LOG_INFO, "Volume Set",
             "name=gv1",
             "option=changelog.changelog",
             "value=on",
             NULL);

    gf_smsg ("cli", GF_LOG_INFO, 0, MSGID_VOLUME_SET,
             "Volume Set",
             "name=gv1",
             "option=changelog.changelog",
             "value=on",
             NULL);

Example 2: Using Format chars in key values

    gf_slog ("cli", GF_LOG_INFO, "Volume Set",
             "name=%s", volume_name,
             "option=%s", option_name,
             "value=%s", option_value,
             NULL);

    gf_smsg ("cli", GF_LOG_INFO, 0, MSGID_VOLUME_SET,
             "Volume Set",
             "name=%s", volume_name,
             "option=%s", option_name,
             "value=%s", option_value,
             NULL);

Formats as,

    <EVENT><TAB><KEY1=VALUE1><TAB><KEY2=VALUE2>...

Example:

    Volume Set	name=gv1	option=changelog.changelog	value=on

Updates: #240
Change-Id: I871727be16a39f681d41f363daa0029b8066fb52
Signed-off-by: Aravinda VK <avishwan@redhat.com>
Reviewed-on: https://review.gluster.org/17543
Reviewed-by: MOHIT AGRAWAL <moagrawa@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Tested-by: Amar Tumballi <amarts@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>

2 files changed, 164 insertions, 0 deletions

diff --git a/libglusterfs/src/logging.c b/libglusterfs/src/logging.c
index a8e7b96a24c..9147f2782e9 100644
--- a/libglusterfs/src/logging.c
+++ b/libglusterfs/src/logging.c
@@ -35,6 +35,7 @@
 #define GF_LOG_BACKTRACE_DEPTH  5
 #define GF_LOG_BACKTRACE_SIZE   4096
 #define GF_LOG_TIMESTR_SIZE     256
+#define GF_MAX_SLOG_PAIR_COUNT  100
 
 #include "xlator.h"
 #include "logging.h"
@@ -2468,3 +2469,146 @@ out:
 
         return ret;
 }
+
+int
+_do_slog_format (const char *event, va_list inp, char **msg) {
+        va_list                    valist_tmp;
+        int                        i = 0;
+        int                        j = 0;
+        int                        k = 0;
+        int                        ret = 0;
+        char                      *fmt = NULL;
+        char                      *buffer = NULL;
+        int                        num_format_chars = 0;
+        char                       format_char = '%';
+        char                      *tmp1 = NULL;
+        char                      *tmp2 = NULL;
+
+        ret = gf_asprintf (&tmp2, "%s", event);
+        if (ret == -1)
+                goto out;
+
+        /* Hardcoded value for max key value pairs, exits early */
+        /* from loop if found NULL */
+        for (i = 0; i < GF_MAX_SLOG_PAIR_COUNT; i++) {
+                fmt = va_arg (inp, char*);
+                if (fmt == NULL) {
+                        break;
+                }
+
+                /* Get number of times % is used in input for formating, */
+                /* this count will be used to skip those many args from the */
+                /* main list and will be used to format inner format */
+                num_format_chars = 0;
+                for (k = 0; fmt[k] != '\0'; k++) {
+                        /* If %% is used then that is escaped */
+                        if (fmt[k] == format_char && fmt[k+1] == format_char) {
+                                k++;
+                        } else if (fmt[k] == format_char) {
+                                num_format_chars++;
+                        }
+                }
+
+                tmp1 = gf_strdup (tmp2);
+                if (!tmp1) {
+                        ret = -1;
+                        goto out;
+                }
+
+                GF_FREE (tmp2);
+                tmp2 = NULL;
+
+                if (num_format_chars > 0) {
+                        /* Make separate valist and format the string */
+                        va_copy (valist_tmp, inp);
+                        ret = gf_vasprintf (&buffer, fmt, valist_tmp);
+                        if (ret < 0) {
+                                va_end (valist_tmp);
+                                goto out;
+                        }
+                        va_end (valist_tmp);
+
+                        for (j = 0; j < num_format_chars; j++) {
+                                /* Skip the va_arg value since these values
+                                   are already used for internal formatting */
+                                (void) va_arg (inp, void*);
+                        }
+
+                        ret = gf_asprintf (&tmp2, "%s\t%s", tmp1, buffer);
+                        if (ret < 0)
+                                goto out;
+
+                        GF_FREE (buffer);
+                        buffer = NULL;
+                } else {
+                        ret = gf_asprintf (&tmp2, "%s\t%s", tmp1, fmt);
+                        if (ret < 0)
+                                goto out;
+                }
+
+                GF_FREE (tmp1);
+                tmp1 = NULL;
+        }
+
+        *msg = gf_strdup (tmp2);
+        if (!msg)
+                ret = -1;
+
+ out:
+        if (buffer)
+                GF_FREE (buffer);
+
+        if (tmp1)
+                GF_FREE (tmp1);
+
+        if (tmp2)
+                GF_FREE (tmp2);
+
+        return ret;
+}
+
+int
+_gf_smsg (const char *domain, const char *file, const char *function,
+          int32_t line, gf_loglevel_t level, int errnum, int trace,
+          uint64_t msgid, const char *event, ...)
+{
+        va_list     valist;
+        char       *msg = NULL;
+        int         ret = 0;
+
+        va_start (valist, event);
+        ret = _do_slog_format (event, valist, &msg);
+        if (ret == -1)
+                goto out;
+
+        ret = _gf_msg (domain, file, function, line, level, errnum, trace,
+                       msgid, "%s", msg);
+
+ out:
+        va_end (valist);
+        if (msg)
+                GF_FREE (msg);
+        return ret;
+}
+
+int
+_gf_slog (const char *domain, const char *file, const char *function, int line,
+          gf_loglevel_t level, const char *event, ...)
+{
+        va_list      valist;
+        char        *msg = NULL;
+        int          ret = 0;
+
+        va_start (valist, event);
+        ret = _do_slog_format (event, valist, &msg);
+        if (ret == -1)
+                goto out;
+
+        ret = _gf_log (domain, file, function, line, level, "%s", msg);
+
+ out:
+        va_end (valist);
+        if (msg)
+                GF_FREE (msg);
+        return ret;
+}
diff --git a/libglusterfs/src/logging.h b/libglusterfs/src/logging.h
index 78d57888f35..a7f252acf67 100644
--- a/libglusterfs/src/logging.h
+++ b/libglusterfs/src/logging.h
@@ -325,4 +325,24 @@ gf_log_disable_suppression_before_exit (struct _glusterfs_ctx *ctx);
 #define GF_ERROR(xl, format, args...)                           \
         gf_log ((xl)->name, GF_LOG_ERROR, format, ##args)
 
+int
+_gf_slog (const char *domain, const char *file, const char *function, int line,
+          gf_loglevel_t level, const char *event, ...);
+
+int
+_gf_smsg (const char *domain, const char *file, const char *function,
+          int32_t line, gf_loglevel_t level, int errnum, int trace,
+          uint64_t msgid, const char *event, ...);
+
+/* Interface to log messages with message IDs */
+#define gf_smsg(dom, levl, errnum, msgid, event...) do {              \
+                _gf_smsg (dom, __FILE__, __FUNCTION__, __LINE__,      \
+                          levl, errnum, 0, msgid, ##event);           \
+        } while (0)
+
+#define gf_slog(dom, levl, event...) do {                             \
+                _gf_slog (dom, __FILE__, __FUNCTION__, __LINE__,      \
+                          levl, ##event);                             \
+        } while (0)
+
 #endif /* __LOGGING_H__ */