rrd: pack multiple rrd values into th estat list

src/rrd/cache.rs

@@ -82,3 +82,30 @@ pub fn extract_data(
         Ok(RRD::new().extract_data(now, timeframe, mode))
     }
 }
+
+
+pub fn extract_data_list(
+    base: &str,
+    items: &[&str],
+    timeframe: RRDTimeFrameResolution,
+    mode: RRDMode,
+) -> Result<Value, Error> {
+
+    let now = now()?;
+
+    let map = RRD_CACHE.read().unwrap();
+
+    let mut list: Vec<(&str, &RRD)> = Vec::new();
+
+    let empty_rrd = RRD::new();
+
+    for name in items.iter() {
+        if let Some(rrd) = map.get(&format!("{}/{}", base, name)) {
+            list.push((name, rrd));
+        } else {
+            list.push((name, &empty_rrd));
+        }
+    }
+
+    Ok(extract_rrd_data(&list, now, timeframe, mode))
+}

src/rrd/rrd.rs

@@ -6,8 +6,7 @@ use serde_json::{json, Value};
 
 use crate::api2::types::{RRDMode, RRDTimeFrameResolution};
 
-const RRD_DATA_ENTRIES: usize = 70;
+pub const RRD_DATA_ENTRIES: usize = 70;
-
 
 #[repr(C)]
 #[derive(Default, Copy, Clone)]
@@ -209,3 +208,54 @@ impl RRD {
         self.last_update = epoch;
     }
 }
+
+pub fn extract_rrd_data(
+    rrd_list: &[(&str, &RRD)],
+    epoch: u64,
+    timeframe: RRDTimeFrameResolution,
+    mode: RRDMode,
+) -> Value {
+
+    let reso = timeframe as u64;
+
+    let end = reso*(epoch/reso);
+    let start = end - reso*(RRD_DATA_ENTRIES as u64);
+
+    let mut list = Vec::new();
+
+    let mut t = start;
+    let mut index = ((t/reso) % (RRD_DATA_ENTRIES as u64)) as usize;
+    for _ in 0..RRD_DATA_ENTRIES {
+        let mut item = json!({ "time": t });
+        for (name, rrd) in rrd_list.iter() {
+            let rrd_end = reso*(rrd.last_update/reso);
+            let rrd_start = rrd_end - reso*(RRD_DATA_ENTRIES as u64);
+
+            if t < rrd_start || t > rrd_end {
+                continue;
+            } else {
+                let data = match timeframe {
+                    RRDTimeFrameResolution::Hour => &rrd.hour,
+                    RRDTimeFrameResolution::Day => &rrd.day,
+                    RRDTimeFrameResolution::Week => &rrd.week,
+                    RRDTimeFrameResolution::Month => &rrd.month,
+                    RRDTimeFrameResolution::Year => &rrd.year,
+                };
+                let entry = data[index];
+                if entry.count == 0 {
+                    continue;
+                } else {
+                    let value = match mode {
+                        RRDMode::Max => entry.max,
+                        RRDMode::Average => entry.average,
+                    };
+                    item[name] = value.into();
+                }
+            }
+        }
+        list.push(item);
+        t += reso; index = (index + 1) % RRD_DATA_ENTRIES;
+    }
+
+    list.into()
+}