Garbage collect expired history files

REQUIREMENTS.md

@@ -2,6 +2,8 @@
 This tool has some additional compilation requirements besides the Rust
 toolchain.
 
+- Rust 1.20 or above (verify this)
+
 ## Requirements
 - OpenSSL development files
   - Ubuntu package: `libssl-dev`

api/src/file/remote_file.rs

@@ -157,6 +157,17 @@ impl RemoteFile {
         &self.id
     }
 
+    /// Check whether this file has expired, based on it's expiry property.
+    ///
+    /// If no expiry time is set (known) for this file,
+    /// the `def` value is returned instead.
+    pub fn has_expired(&self, def: bool) -> bool {
+        match self.expire_at {
+            Some(time) => time < Utc::now(),
+            None => def,
+        }
+    }
+
     /// Get the file URL, provided by the server.
     pub fn url(&self) -> &Url {
         &self.url

cli/src/history.rs

@@ -50,6 +50,9 @@ impl History {
         let mut history: Self = toml::from_str(&data)?;
         history.autosave = Some(path);
 
+        // Garbage collect
+        history.gc();
+
         Ok(history)
     }
 
@@ -67,6 +70,9 @@ impl History {
 
     /// Save the history to the internal autosave file.
     pub fn save(&mut self) -> Result<(), SaveError> {
+        // Garbage collect
+        self.gc();
+
         // Get the path
         let path = self.autosave
             .as_ref()
@@ -123,6 +129,34 @@ impl History {
     pub fn files(&self) -> &Vec<RemoteFile> {
         &self.files
     }
+
+    /// Garbage collect (remove) all files that have been expired,
+    /// as defined by their `expire_at` property.
+    ///
+    /// If the expiry property is None (thus unknown), the file will be kept.
+    ///
+    /// The number of exired files is returned.
+    pub fn gc(&mut self) -> usize {
+        // Get the indices of files that have expired
+        let expired_indices: Vec<usize> = self.files.iter()
+            .enumerate()
+            .filter(|(_, f)| f.has_expired(false))
+            .map(|(i, _)| i)
+            .collect();
+
+        // Remove these specific files
+        for i in &expired_indices {
+            self.files.remove(*i);
+        }
+
+        // Set the changed flag
+        if !expired_indices.is_empty() {
+            self.changed = true;
+        }
+
+        // Return the number of expired files
+        expired_indices.len()
+    }
 }
 
 impl Drop for History {