refactor database engine/options; add column descriptors

Signed-off-by: Jason Volk <jason@zemos.net>

src/database/engine/files.rs

@@ -0,0 +1,32 @@
+use std::fmt::Write;
+
+use conduwuit::{implement, Result};
+
+use super::Engine;
+
+#[implement(Engine)]
+pub fn file_list(&self) -> Result<String> {
+	match self.db.live_files() {
+		| Err(e) => Ok(String::from(e)),
+		| Ok(mut files) => {
+			files.sort_by_key(|f| f.name.clone());
+			let mut res = String::new();
+			writeln!(res, "| lev  | sst  | keys | dels | size | column |")?;
+			writeln!(res, "| ---: | :--- | ---: | ---: | ---: | :---   |")?;
+			for file in files {
+				writeln!(
+					res,
+					"| {} | {:<13} | {:7}+ | {:4}- | {:9} | {} |",
+					file.level,
+					file.name,
+					file.num_entries,
+					file.num_deletions,
+					file.size,
+					file.column_family_name,
+				)?;
+			}
+
+			Ok(res)
+		},
+	}
+}