debug info page for db kv and cache kv

2 files changed, 38 insertions, 3 deletions

diff --git a/kv/src/lib.rs b/kv/src/lib.rs
index 83f2635..dd30460 100644
--- a/kv/src/lib.rs
+++ b/kv/src/lib.rs
@@ -20,6 +20,9 @@ use anyhow::Result;
 
 pub trait Store: Send + Sync + 'static {
     fn transaction(&self, f: &mut dyn FnMut(&mut dyn Transaction) -> Result<()>) -> Result<()>;
+    fn debug_info(&self) -> Result<String> {
+        Ok(String::new())
+    }
 }
 pub trait Transaction {
     fn set(&mut self, key: &[u8], value: &[u8]) -> Result<()>;
@@ -35,4 +38,7 @@ pub trait Transaction {
 pub trait BlobStorage: Send + Sync + 'static {
     fn store(&self, key: &str, value: &[u8]) -> Result<()>;
     fn read(&self, key: &str) -> Result<Option<Vec<u8>>>;
+    fn debug_info(&self) -> Result<String> {
+        Ok(String::new())
+    }
 }
diff --git a/kv/src/rocksdb.rs b/kv/src/rocksdb.rs
index 683e399..04d7437 100644
--- a/kv/src/rocksdb.rs
+++ b/kv/src/rocksdb.rs
@@ -4,11 +4,17 @@
     Copyright (C) 2026 metamuffin <metamuffin.org>
 */
 
+use crate::{BlobStorage, Store, Transaction};
 use anyhow::Result;
+use humansize::{DECIMAL, SizeFormatter};
 use rocksdb::{Direction, ErrorKind, IteratorMode, OptimisticTransactionDB};
-use std::path::Path;
+use std::{
+    path::Path,
+    sync::atomic::{AtomicU64, Ordering},
+};
 
-use crate::{BlobStorage, Store, Transaction};
+pub static NUM_TXN_COMMIT: AtomicU64 = AtomicU64::new(0);
+pub static NUM_TXN_ATTEMPT: AtomicU64 = AtomicU64::new(0);
 
 pub fn new(path: &Path) -> Result<OptimisticTransactionDB> {
     Ok(OptimisticTransactionDB::open_default(path)?)
@@ -18,13 +24,29 @@ impl Store for OptimisticTransactionDB {
     fn transaction(&self, f: &mut dyn FnMut(&mut dyn Transaction) -> Result<()>) -> Result<()> {
         loop {
             let mut txn = self.transaction();
+            NUM_TXN_ATTEMPT.fetch_add(1, Ordering::Relaxed);
             f(&mut txn)?;
             match txn.commit() {
-                Ok(()) => break Ok(()),
+                Ok(()) => break,
                 Err(e) if e.kind() == ErrorKind::Busy => continue,
                 Err(e) => return Err(e.into()),
             }
         }
+        NUM_TXN_COMMIT.fetch_add(1, Ordering::Relaxed);
+        Ok(())
+    }
+    fn debug_info(&self) -> Result<String> {
+        let size = self.get_approximate_sizes(&[rocksdb::Range::new(&[0x00], &[0xff])])[0];
+        let attempts = NUM_TXN_ATTEMPT.load(Ordering::Relaxed);
+        let commits = NUM_TXN_COMMIT.load(Ordering::Relaxed);
+        let retry_factor = attempts as f64 / commits as f64;
+        Ok(format!(
+            "transactions attempted:    {attempts:>12}\n\
+             transactions commited:     {commits:>12}\n\
+             transactions retry factor: {retry_factor:>12.03}\n\
+             approximate size on disk:  {:>12}\n",
+            SizeFormatter::new(size, DECIMAL).to_string()
+        ))
     }
 }
 
@@ -67,4 +89,11 @@ impl BlobStorage for OptimisticTransactionDB {
     fn read(&self, key: &str) -> Result<Option<Vec<u8>>> {
         Ok(self.get(key)?)
     }
+    fn debug_info(&self) -> Result<String> {
+        let size = self.get_approximate_sizes(&[rocksdb::Range::new(&[0x00], &[0xff])])[0];
+        Ok(format!(
+            "approximate size on disk:  {:>12}\n",
+            SizeFormatter::new(size, DECIMAL).to_string()
+        ))
+    }
 }