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// Integration tests for Chisel::counters().
//
// Goal: lock down the public-API surface and the deltas through known
// operation sequences. Same dual-backing pattern as basic_ops.rs is not
// used here — counters are an in-memory concept, so we exercise file
// and memory backings explicitly where the distinction matters
// (close/reopen test) and use memory-only where it doesn't.
use chisel::{Chisel, Options};
use tempfile::NamedTempFile;
#[test]
fn counters_after_open_in_memory_have_construction_overhead() {
let db = Chisel::open_in_memory().unwrap();
let c = db.counters().unwrap();
// Open does some work (writes initial superblock, etc.) so fsyncs are
// non-zero. Note: pages_allocated counts PageCache::new_page() calls,
// not the bootstrap superblock writes — those go through PageIo::
// write_page directly, bypassing the cache allocator. So
// pages_allocated starts at 0 even on a fresh in-memory db. We pin
// fsync_calls instead — it's the cleanest invariant the bootstrap
// path produces.
assert!(
c.fsync_calls > 0,
"open_in_memory must fsync at least once (superblock bootstrap)"
);
}
#[test]
fn counters_track_allocate_and_commit() {
let mut db = Chisel::open_in_memory().unwrap();
let baseline = db.counters().unwrap();
db.begin().unwrap();
let _h = db.allocate(b"hello").unwrap();
db.commit().unwrap();
let after = db.counters().unwrap();
// Commit calls fsync twice (data pages + superblock). Anything below
// this is a regression in the commit protocol.
assert!(
after.fsync_calls >= baseline.fsync_calls + 2,
"commit must perform at least 2 fsyncs (data + superblock); saw {} -> {}",
baseline.fsync_calls,
after.fsync_calls,
);
// Allocation grew by at least 1 (the value's data page; possibly more
// if a handle-table COW or freemap COW was needed).
assert!(after.pages_allocated > baseline.pages_allocated);
}
#[test]
fn counters_track_read_as_cache_hit_after_commit() {
let mut db = Chisel::open_in_memory().unwrap();
db.begin().unwrap();
let h = db.allocate(b"value").unwrap();
db.commit().unwrap();
let pre = db.counters().unwrap();
let _ = db.read(h).unwrap();
let post = db.counters().unwrap();
// Read must hit at least once (the data-page lookup). It may also
// hit the handle-table page. The lower bound is what we lock in.
assert!(
post.cache_hits > pre.cache_hits,
"read() must register at least one cache lookup; saw {} -> {}",
pre.cache_hits,
post.cache_hits,
);
}
#[test]
fn counters_reset_on_close_and_reopen() {
let f = NamedTempFile::new().unwrap();
let path = f.path().to_path_buf();
drop(f); // we want the path; let Chisel create the file.
{
let mut db = Chisel::open(&path, Options::default()).unwrap();
db.begin().unwrap();
let _ = db.allocate(b"first session").unwrap();
db.commit().unwrap();
let c = db.counters().unwrap();
assert!(
c.fsync_calls > 0,
"first session must have fsync'd at least once"
);
db.close().unwrap();
}
// Reopen — counters must reflect ONLY work since reopen, not the
// first session's totals.
let db2 = Chisel::open(&path, Options::default()).unwrap();
let c2 = db2.counters().unwrap();
// The reopen path does some work (reads superblocks, possibly writes
// none). We pin the upper bound: post-reopen totals must be much
// smaller than the first-session totals (which included a commit
// and therefore at least 2 fsyncs from the commit alone, plus the
// create_new bootstrap fsyncs).
assert!(
c2.fsync_calls <= 1,
"reopen path should not fsync more than once; saw {}",
c2.fsync_calls,
);
}
#[test]
fn counters_snapshot_does_not_mutate_when_engine_continues() {
let mut db = Chisel::open_in_memory().unwrap();
let snap = db.counters().unwrap();
let snap_copy = snap.clone();
// Do work after taking the snapshot.
db.begin().unwrap();
let _ = db.allocate(b"x").unwrap();
db.commit().unwrap();
// The original snapshot must not have moved.
assert_eq!(
snap, snap_copy,
"ChiselCounters is a snapshot, not a live view"
);
}