Configurable storage engine for Netdata agents: step 1 (#12776)

* rrd: move API structures out of rrddim_volatile

In C, unlike C++, it's not possible to reference a nested structure
from outside this structure.

Since we later want to use rrddim_query_ops and rrddim_collect_ops
separately from rrddim_volatile, move these nested structures out.

* rrd: use opaque handle types for different memory modes

1 files changed, 16 insertions, 0 deletions

diff --git a/database/engine/rrdengine.h b/database/engine/rrdengine.h
index 7aba98e451..fae911e747 100644
--- a/database/engine/rrdengine.h
+++ b/database/engine/rrdengine.h
@@ -34,6 +34,22 @@ struct rrdengine_instance;
 #define RRDENG_FILE_NUMBER_SCAN_TMPL "%1u-%10u"
 #define RRDENG_FILE_NUMBER_PRINT_TMPL "%1.1u-%10.10u"
 
+struct rrdeng_collect_handle {
+    struct rrdeng_page_descr *descr, *prev_descr;
+    unsigned long page_correlation_id;
+    struct rrdengine_instance *ctx;
+    // set to 1 when this dimension is not page aligned with the other dimensions in the chart
+    uint8_t unaligned_page;
+};
+
+struct rrdeng_query_handle {
+    struct rrdeng_page_descr *descr;
+    struct rrdengine_instance *ctx;
+    struct pg_cache_page_index *page_index;
+    time_t next_page_time;
+    time_t now;
+    unsigned position;
+};
 
 typedef enum {
     RRDENGINE_STATUS_UNINITIALIZED = 0,