wrap index implementation, skip rss file update if the index is not changed (safes ssd life by prevent extra write operations)

src/index.rs

@@ -1,7 +1,68 @@
 use chrono::{DateTime, Utc};
+use std::collections::HashMap;
 
-pub struct Index {
+pub struct Value {
     pub time: DateTime<Utc>,
     pub node: u64,
     pub name: Option<String>,
 }
+
+/// Collect processed info hashes to skip on the next iterations (for this session)
+/// * also contains optional meta info to export index as RSS or any other format
+pub struct Index {
+    index: HashMap<String, Value>,
+    /// Track index changes to prevent extra disk write operations (safe SSD life)
+    /// * useful in the static RSS feed generation case, if enabled.
+    is_changed: bool,
+}
+
+impl Index {
+    pub fn init(capacity: usize) -> Self {
+        Self {
+            index: HashMap::with_capacity(capacity),
+            is_changed: false,
+        }
+    }
+
+    pub fn has(&self, infohash: &str) -> bool {
+        self.index.contains_key(infohash)
+    }
+
+    pub fn is_changed(&self) -> bool {
+        self.is_changed
+    }
+
+    pub fn list(&self) -> &HashMap<String, Value> {
+        &self.index
+    }
+
+    pub fn len(&self) -> usize {
+        self.index.len()
+    }
+
+    pub fn nodes(&self) -> u64 {
+        self.index.values().map(|i| i.node).sum::<u64>()
+    }
+
+    pub fn insert(&mut self, infohash: String, node: u64, name: Option<String>) {
+        if self
+            .index
+            .insert(
+                infohash,
+                Value {
+                    time: Utc::now(),
+                    node,
+                    name,
+                },
+            )
+            .is_none()
+        {
+            self.is_changed = true
+        }
+    }
+
+    pub fn refresh(&mut self) {
+        self.is_changed = false
+        // @TODO implement also index cleanup by Value timeout
+    }
+}