fix(memory): write memory graph atomically to prevent corruption - #4618
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Arnab758 wants to merge 2 commits into
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fix(memory): write memory graph atomically to prevent corruption#4618Arnab758 wants to merge 2 commits into
Arnab758 wants to merge 2 commits into
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saveGraph() wrote the memory file directly with fs.writeFile, so an interruption mid-write (crash, kill, power loss) could leave a truncated or corrupted memory file. Write to a unique temp file first, then rename into place — atomic on POSIX and Windows. Clean up the temp file on failure. Includes a regression test.
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What
Fixes #4614.
saveGraph()wrote the memory file directly withfs.writeFile, so an interruption mid-write (process crash, kill, power loss) could leave a truncated or corrupted memory file — permanently losing the agent's long-term memory.How
Write the graph to a unique temp file, then
rename()it into place. Rename is atomic on POSIX and Windows, so the memory file is always either the old complete version or the new complete version — never a half-written one.randomBytes(16)) prevents collisions when saves overlapTests
Added a regression test that simulates an interruption mid-write (partial bytes written, then error) and verifies:
tsc --noEmitpasses. Full suite: 51/51 tests pass.Notes
This complements (not duplicates) #4555, which serializes concurrent graph mutations. #4555 fixes concurrent writes racing each other; this fixes a single write being interrupted mid-write — two different failure modes.
Known limitation: a hard kill between write and rename can still leave a temp file behind (inherent to the temp+rename pattern). The memory file itself is never corrupted.