rocksdb cache stats tool

1 files changed, 50 insertions, 0 deletions

diff --git a/kv/src/bin/rocksdb_stats.rs b/kv/src/bin/rocksdb_stats.rs
new file mode 100644
index 0000000..57724ed
--- /dev/null
+++ b/kv/src/bin/rocksdb_stats.rs
@@ -0,0 +1,50 @@
+/*
+    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2026 metamuffin <metamuffin.org>
+*/
+
+use anyhow::Result;
+use humansize::{DECIMAL, SizeFormatter};
+use rocksdb::DB;
+use std::{
+    cmp::Reverse,
+    collections::BTreeMap,
+    env::args,
+    io::{Write, stdout},
+};
+
+fn main() -> Result<()> {
+    let db = DB::open_default(args().nth(1).unwrap())?;
+    let mut dirs: BTreeMap<String, (u64, u64)> = BTreeMap::new();
+
+    let mut total = 0;
+    for r in db.prefix_iterator(&[]) {
+        let (k, v) = r?;
+        let mut k = String::from_utf8(k.to_vec()).unwrap();
+        while !k.ends_with("/") {
+            k.pop();
+        }
+        let (count, size) = dirs.entry(k).or_default();
+        total += 1;
+        *count += 1;
+        *size += v.len() as u64;
+        if total % 1234 == 0 {
+            print!("{total:>9}\r");
+            stdout().flush().unwrap();
+        }
+    }
+
+    let mut dirs = dirs.into_iter().collect::<Vec<_>>();
+    dirs.sort_by_key(|(_, (_, x))| Reverse(*x));
+
+    for (dir, (count, size)) in dirs {
+        eprintln!(
+            "{dir: <30} {count:>9} {:>12}",
+            SizeFormatter::new(size, DECIMAL).to_string()
+        )
+    }
+
+    db.flush()?;
+    Ok(())
+}