hashPhase returned the moment recordRun failed and left the pool
running: the feeder parked forever on a full jobs channel and every
worker on a full results channel. Until #4 landed the process exited
before that mattered; now that runScan returns an error and unwinds,
the goroutines are a real leak.
The pool is now an owned hashPool. Its context is derived from the
scan's, every blocking send in the feeder and the workers selects on
ctx.Done(), the feeder closes jobs on every path out so the workers'
range always terminates, and hashPhase defers pool.stop(), which
cancels and then drains results until the last goroutine has exited.
Draining is the half that matters: a worker already parked on a send
cannot observe the cancellation until a receiver frees it.
ctx comes from cmd.Context() and is threaded through runScan,
syncScan, both worker pools and the database layer as the first
parameter throughout, so graceful interrupt handling has a path to
hook into rather than a pool to rewrite.
The walk pool never leaked, because walkPhase always drains its
events to close, but it has the same unbounded-send shape and gets
the same treatment, together with a ctx.Err() guard after the walk: a
cancelled walk leaves a partial size census, and the update phase
would read every file it never reached as vanished and delete its
record.
Tests drive the scan entry point against a database whose insert
trigger aborts, with a fixture large enough that the failure lands
partway through the hash phase with more runs queued than either pool
channel can hold, and assert that the scan fails instead of hanging
and that runtime.NumGoroutine polls back to its pre-scan baseline.
fatalf called os.Exit(1), which does not run deferred functions, so
every defer db.Close() was dead on the fatal path: the SQLite WAL was
left uncheckpointed and the -wal/-shm sidecars were left for the next
process to recover. It also made those paths impossible to exercise
in-process.
fatalf is gone. runScan, runReport, runTrees, loadRecords and
resolveRoots return their errors, so the deferred close always runs,
and the only exit point is run() in main.go.
Mapping errors to exit codes needs care: cobra prints the error and
the command's usage text for anything RunE returns, and main mapped
every Execute() error to exit 2. A runtime failure is not a usage
problem, so the runE adapter silences both for the subcommands and
marks their errors fatalError; run() reports a fatalError as
"sfdupes: ..." on stderr and exits 1, and leaves everything else --
cobra's own argument, flag and unknown-command errors, which cobra has
already reported with its usage text -- on exit 2. The bare
"sfdupes" invocation still prints usage and exits 2.
Exit codes and message text are unchanged: 0 on success even with
per-file warnings, 1 fatal, 2 usage, per README section "Error
handling and exit codes". Everything on stdout is still data only.
main_test.go drives the CLI in-process and covers all three: a fatal
error raised after the database is open (a database with no files
table) closes it and leaves no -wal or -shm behind for scan, report
and trees; a nonexistent PATH operand is fatal, not usage, and prints
no usage text; the usage errors still exit 2; and a scan that skipped
an unreadable file still exits 0.
Restructure scan into three phases: walk+stat, hash, update.
The stat pass is folded into the walk workers: each regular file is
lstatted as its directory is read, while the metadata is hot. The
walk builds a scan-wide size census (walked files plus records
outside the scan roots), and unchanged already-hashed files resolve
during the walk without further work.
Only files whose size at least one other file shares are ever read:
a size-unique file cannot be a duplicate, so it is recorded without
hashes (head and tail empty). When a later scan makes its size
shared, the file is hashed then, even if otherwise unchanged. report
excludes unhashed records; trees gives them a never-matching
signature so a tree containing one never compares equal to another.
Hashed records are committed in batched transactions while the hash
phase runs, so an interrupted scan keeps everything hashed so far
and the next run resumes cheaply. The hash phase total is exact,
giving a meaningful ETA.
Memory drops accordingly: the existing-record index holds only path,
size, mtime, and a hashed flag (no hash values); the walk carries one
small record per candidate file; overlapping operands are pruned up
front instead of deduplicating every walked path in a scan-wide set.
Files no bigger than one chunk are hashed with a single read.
scan now synchronizes a database that survives between runs
(SFDUPES_DATABASE, default /var/lib/sfdupes/db.sqlite) instead of
emitting a stream: operands are resolved to absolute paths, unchanged
files (same size, mtime not newer than recorded) are never re-read, new
and changed files are hashed, and records under the scanned operands
that were not verified this run are deleted; records outside the
operands are untouched. All changes commit in a single transaction, and
WAL journaling with a busy timeout keeps a report run during a cron
scan safe.
report and trees read the database (no positional arguments); the
NUL-terminated stream format, its parser, and the malformed-record
handling are gone. The driver is modernc.org/sqlite (pure Go), so
builds keep cgo disabled.
150 findings fixed: linter autofixes for whitespace style (wsl_v5,
nlreturn, noinlineerr), named returns removed, magic numbers replaced
with named constants, static errNotRegular error, explicit Close/Parse
error handling, unused cobra params renamed to _, and runReport/
runTrees/hashPass split into helpers to satisfy cyclop, gocognit, and
funlen. Behavior verified unchanged against the README smoke test.
