tyiu/damus
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fix: delete stale lock.mdb during compaction to prevent SIGBUS crash

Browse Source 
Also clean up temp directory on post-replace size mismatch to match
all other error paths in compact_if_needed.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
alltheseas
2026-03-16 23:13:13 -05:00
co-authored by Claude Opus 4.6
parent cc22c1e97c
commit 9d687ce4f6
2 changed files with 71 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
nostrdb/Ndb+Compaction.swift
+29 -1
View File
@@ -109,6 +109,25 @@ extension Ndb {
let originalDataMdb = URL(fileURLWithPath: "\(path)/\(main_db_file_name)")
let compactedDataMdb = URL(fileURLWithPath: "\(tempPath)/\(main_db_file_name)")
// Validate the compacted file before replacing the original.
let originalSize = (try? FileManager.default.attributesOfItem(atPath: originalDataMdb.path)[.size] as? Int) ?? 0
let compactedSize = (try? FileManager.default.attributesOfItem(atPath: compactedDataMdb.path)[.size] as? Int) ?? 0
Log.info("compact_if_needed: original=%d bytes, compacted=%d bytes", for: .storage, originalSize, compactedSize)
guard compactedSize > 0 else {
Log.error("compact_if_needed: compacted file is missing or empty — aborting", for: .storage)
try? FileManager.default.removeItem(atPath: tempPath)
return
}
// Delete the stale lock.mdb BEFORE replacing data.mdb.
// The temp Ndb wrote reader-table / txn state into lock.mdb that references
// pages in the old data.mdb. After data.mdb is replaced with the smaller
// compacted copy, those page references become invalid and cause SIGBUS.
// LMDB will recreate a fresh lock file on the next open.
let lockPath = "\(path)/lock.mdb"
try? FileManager.default.removeItem(atPath: lockPath)
do {
_ = try FileManager.default.replaceItemAt(
originalDataMdb,
@@ -116,13 +135,22 @@ extension Ndb {
backupItemName: nil,
options: [.usingNewMetadataOnly]
)
Log.info("NostrDB compacted successfully", for: .storage)
} catch {
Log.error("compact_if_needed: failed to replace db file: %@", for: .storage, String(describing: error))
try? FileManager.default.removeItem(atPath: tempPath)
return
}
// Post-replace sanity check: verify the destination file exists with the expected size.
let finalSize = (try? FileManager.default.attributesOfItem(atPath: originalDataMdb.path)[.size] as? Int) ?? 0
if finalSize != compactedSize {
Log.error("compact_if_needed: post-replace size mismatch — expected %d, got %d", for: .storage, compactedSize, finalSize)
try? FileManager.default.removeItem(atPath: tempPath)
return
}
Log.info("NostrDB compacted successfully", for: .storage)
// Clean up the temp directory (any remaining files such as lock.mdb).
try? FileManager.default.removeItem(atPath: tempPath)