ELAPI Event resolver

Started working on the async processing
and realised that I need to have a good
copy of the event with all the fields resolved
so this patch has some foundation for the async
functions (module elapi_async.c) but they
are mostly stubbed out.
The actual code will be added down the road.
Instead the patch focuses on the code
introduced in elapi_resolve.c module
and the use of the functions from it.
It also adds the implementation of the
high level calls that initialize ELAPI
with the external callbacks to be used
during async processing (elapi_log.c).

1 files changed, 66 insertions, 41 deletions

diff --git a/common/elapi/elapi_priv.h b/common/elapi/elapi_priv.h
index fb8cd3e85..27b0079ff 100644
--- a/common/elapi/elapi_priv.h
+++ b/common/elapi/elapi_priv.h
@@ -21,6 +21,7 @@
 #define ELAPI_PRIV_H
 
 #include <stdint.h>
+#include <stdarg.h>
 
 #include "collection.h"
 #include "elapi_async.h"
@@ -33,6 +34,7 @@
 #define COL_CLASS_ELAPI_SINK        COL_CLASS_ELAPI_BASE + 2
 #define COL_CLASS_ELAPI_TARGET      COL_CLASS_ELAPI_BASE + 3
 #define COL_CLASS_ELAPI_SINK_REF    COL_CLASS_ELAPI_BASE + 4
+#define COL_CLASS_ELAPI_RES_ITEM    COL_CLASS_ELAPI_BASE + 5
 
 /* Names for the collections */
 #define E_TEMPLATE_NAME "template"
@@ -51,6 +53,7 @@
 #define ELAPI_SINK_ONERROR  "onerror"
 #define ELAPI_SINK_TIMEOUT  "timeout"
 #define ELAPI_SINK_SYNCH    "synch"
+#define ELAPI_RESOLVE_ITEM  "res_item"
 
 /* Default timout before dispatcher tries to revive sink.
  * The actual value is configurable on per sink basis
@@ -73,6 +76,22 @@
 #define ELAPI_ONERROR_REVIVE        0
 #define ELAPI_ONERROR_DISABLE       1
 
+/* Structure that contains the pointer to functions
+ * that needed to be provided to enable async processing.
+ */
+struct elapi_async_ctx {
+    /* Callbacks related to file descriptor. */
+    elapi_add_fd add_fd_cb;
+    elapi_rem_fd rem_fd_cb;
+    elapi_set_fd set_fd_cb;
+    /* File descriptor callback external data. */
+    void *ext_fd_data;
+    /* Callbacks for timer */
+    elapi_add_tm add_tm_cb;
+    elapi_rem_tm rem_tm_cb;
+    /* Timer's external data */
+    void *ext_tm_data;
+};
 
 struct elapi_dispatcher {
     /* Application name */
@@ -87,24 +106,14 @@ struct elapi_dispatcher {
     struct collection_item *sink_list;
     /* Configuration */
     struct collection_item *ini_config;
+    /* Items to resolve */
+    struct collection_iterator *resolve_list;
     /* Default event template */
     struct collection_item *default_template;
     /* Async processing related data */
     struct elapi_async_ctx *async_ctx;
-    /* Indicator of our synch mode
-     * FIXME: Do we need it?
-     */
-    uint32_t async_mode;
-    /* Time offset */
-    int32_t offset;
 };
 
-/* Structure to pass data from logging function to targets */
-struct elapi_tgt_data {
-    struct collection_item *event;
-    struct elapi_dispatcher *handle;
-    uint32_t target_mask;
-};
 
 /* This is a structure that holds the information
  *  about the target.
@@ -165,41 +174,32 @@ struct elapi_sink_ctx {
 
 };
 
-/* The structure to hold the event and its context */
-/* FIXME The event should be turned into this object
- * on the high level before going
- * into any target.
- * and then this should be passed around
- * instead of the actual event.
+/* A helper structure that holds data
+ * needed to resolve the event.
  */
-struct elapi_event_ctx {
-    /* This is a copy of the event */
-    /* We have to copy it for two reasons:
-     * a) It needs to be flattened so
-     * that we do not get unnecesary naming
-     * collisions if same key appears on different
-     * levels
-     * b) In case of async logging we need
-     * the original event until we are sure
-     * it is actually logged. If we do not
-     * keep it around the application can modify
-     * it or delete it before we figured out
-     * that sink is broken and we need to fail over.
-     * If in this case we go to another sink
-     * and if we do not have the original event
-     * we are screwed.
-     */
+struct elapi_resolve_data {
+    /* Reference to the event */
     struct collection_item *event;
-    /* Reference count */
-    int refcount;
-    /* Event time */
+    /* Reference back to dispatcher */
+    struct elapi_dispatcher *handle;
+    /* Time related data */
     time_t tm;
-    /* Resolved message */
-    char *message;
+    /* Structured UTC time */
+    struct tm utc_time;
+    /* Structured local time */
+    struct tm local_time;
     /* Time offset */
-    int32_t offset;
+    int offset;
 };
 
+/* Structure to pass data from logging function to targets */
+struct elapi_tgt_data {
+    struct collection_item *event;
+    struct elapi_dispatcher *handle;
+    uint32_t target_mask;
+};
+
+
 /* Lookup structure for searching for providers */
 struct elapi_prvdr_lookup {
     const char *name;
@@ -213,6 +213,26 @@ struct elapi_get_sink {
     int found;
 };
 
+/* Signature of the item resolution function */
+typedef int (*elapi_rslv_cb)(struct elapi_resolve_data *resolver,
+                             struct collection_item *item,
+                             int *skip);
+
+/* Structure to hold type-callback tuples */
+struct elapi_rslv_item_data {
+    int type;
+    elapi_rslv_cb resolve_cb;
+};
+
+/* Structure to hold name-data tuples */
+struct elapi_resolve_list {
+    const char *name;
+    struct elapi_rslv_item_data resolve_item;
+};
+
+/* Function to initialize resolution list */
+int elapi_init_resolve_list(struct collection_iterator **list);
+
 /* Function to create event using arg list */
 int elapi_create_event_with_vargs(struct collection_item **event,
                                   struct collection_item *template,
@@ -296,6 +316,11 @@ int elapi_tgt_submit(struct elapi_dispatcher *handle,
 /* Create list of targets for a dispatcher */
 int elapi_tgt_mklist(struct elapi_dispatcher *handle);
 
+/* Create event context */
+int elapi_resolve_event(struct collection_item **final_event,
+                        struct collection_item *event,
+                        struct elapi_dispatcher *handle);
+
 /* Send ELAPI config errors into a file */
 void elapi_dump_ini_err(struct collection_item *error_list);