`queryFile` started at `var size = 0L` and only moved off it when a provider answered the
`OpenableColumns.SIZE` column, which the platform documents providers *may* omit. So "this file
is empty" and "nobody would tell me how big it is" reached `OutputPublisher.hasSpaceFor` as the
same number, and `hasSpaceFor(0)` is not a space check -- it is "is there 128 MB free", which any
phone with a working camera passes.
The reachable value is not an inference. On a Pixel 10 Pro XL, `contentResolver.query` on a
`file://` URI returns null outright, so the cursor block never runs at all and the default
survives untouched: `queryFile gave displayName='input' sizeBytes=0`. Robolectric reproduces that
exactly -- null query, and a descriptor that reports 4321 bytes for the same file -- which is why
every test here is a JVM test rather than a device one.
`InputQuery` replaces the two copies of `queryFile`, which were byte for byte identical in
`ConversionViewModel` and `JoinViewModel`, so a fix to either would have been a fix to half the
app. It asks for the size twice: what the provider says, and then what the file itself says
through `openFileDescriptor(uri, "r").statSize`. The second needs no cooperation beyond the input
being openable, which a conversion is about to require anyway, and it is what answers the device
case above. Only when both decline is the answer null, and `InputFile.sizeBytes` is `Long?` so
that null cannot be spelled the same way as zero again.
**What an unknown size does was the decision, and it is deliberately not a refusal.**
`OutputPublisher.hasSpaceForUnknownSize()` produces the same number the defect produced by
accident -- with no size to reserve for, the headroom is all there is left to check -- and that is
worth saying plainly rather than dressing up. What changed is that it is now the answer to a
question that was asked. `hasSpaceFor` means "there is room for this many bytes" and nothing else
claims it.
Refusing was the obvious alternative and would have been worse than the bug: it turns "no
provider answered the SIZE column" into "this file cannot be converted", for a user who can do
nothing about either. A fixed floor was the other, and there is no honest number for it -- a
1 GB floor refuses a 10 MB conversion on a device with 500 MB free, which is the same failure in
a costume. `SpaceCheckTest` pins the choice from both sides: an unmeasurable input must not end
the job, and a full disk must still refuse it.
That second half is why the default answers *through* `hasSpaceFor`. `FakeFailures.FullDisk` in
the instrumented suite overrides `hasSpaceFor` and nothing else, so the delegation is the only
reason it still refuses an unknown-size job. Replacing the delegation with a bare `true` leaves
the full-disk test red with `expected:<Failure {error : Not enough free space to convert.}> but
was:<Failure {error : FFmpegKit failed to start on brand: robolectric...}>` -- the job sailed past
the guard and died at the engine instead.
Both workers get the same shape. The size arrives as input `Data`, which has no null, so the
absence of the key *is* the unknown -- `getLong(key, 0L)` was the other half of the conflation.
When it is absent the worker measures the input itself, which it can do because it holds the URI:
that covers a `request(...)` built by hand and work enqueued before the size became optional, and
it costs an ordinary job nothing because it runs only on the fallback. `ConversionWorker.request`
writes neither the `Data` entry nor the `JobTags.sizeBytes` tag for a size nobody knows, since a
tag reading `size-bytes:0` would come back through `Reattachment` as a confident claim that the
user's file is empty -- and `reattach()`'s `?: 0L` is gone for the same reason.
A join's total is `InputQuery.total`, which is null the moment a *single* input cannot be sized.
Summing the ones that answered was the competing reading and is rejected: a lower bound is
indistinguishable from a real total once it reaches the space check, so the guard would reserve
for half the job and pass. Reverting it to `sumOf { it ?: 0L }` records `[1111]` for a two-file
join whose second input nothing can measure.
Work already in the queue keeps the old conflation, and there is no fixing it. The previous
`request()` always wrote `putLong(KEY_SIZE_BYTES, sizeBytes)`, so a job enqueued before this
commit for a file nothing could size carries the key *present* and set to zero -- which reads
back as a declared size of zero and is trusted, exactly as before. Its `lmc.size-bytes:0` tag
reads back the same way, so `reattach()` shows such a card "0 B" rather than "Size unknown".
Nothing can separate that from a genuinely empty file after the fact, and a rule that treated a
declared zero as suspect would only rebuild the conflation facing the other way. WorkManager
keeps finished work for about a week, so this is a bounded window that clears itself; new work
never enters it.
`hasSpaceFor`'s KDoc claimed peak usage was "roughly input + output at once" while the arithmetic
reserved `input + 128 MB`. The arithmetic is what stays and the doc now says why: `bytes` is the
input's size standing in for the output's, generous for the ordinary conversion (which is asked
for precisely because it shrinks its input) and short for a re-encode to a bulkier codec; the
128 MB absorbs that error and the transient double copy while `publish` runs. Reserving
`input + output` outright would refuse jobs that fit. This is a pre-flight check that stops an
obviously impossible job from spending minutes finding out, not a guarantee -- a conversion that
runs out of space anyway still fails through its engine.
The measurement side of that line is untouched on purpose. `StorageManager.getAllocatableBytes`
is a separate entry with its own device evidence and its own `informational += "UsableSpace"` in
the lint block; this commit is about the number going *in*. `hasSpaceFor(bytes: Long)` keeps its
signature and stays open, so nothing overriding it had to change.
The file card says "Size unknown" rather than `0 B`. Handled at the call site rather than inside
`formatBytes`, because a formatter that invented a number would be the defect on screen; the card
already degrades in words for a file nothing could read.
Five of the seven new tests were red before a line of production code moved, with the numbers
they were about: `expected:<4321> but was:<0>` for a picked file, `expected null, but was:<0>` for
one nothing can measure, `expected:<[1111, 2222]> but was:<[0, 0]>` for the join picker, and
`expected:<[4321]> but was:<[0]>` and `expected:<[3333]> but was:<[0]>` for what the two workers
asked the space check. The tests assert on the *question* rather than the verdict, which matters:
one that only checked whether the job ran would have passed against the defect, since the defect
is that the guard is vacuous rather than that it refuses.
The remaining two needed the new call to exist first, so each was proved by mutation instead.
Answering the unknown with `hasSpaceFor(0L)` inline leaves `expected:<[]> but was:<[0]>` in both
workers; refusing it instead leaves `an unknown size must not end the job; got Failure {error :
Not enough free space to convert.}`. Making the worker always measure rather than trust a declared
size leaves `expected:<[9999]> but was:<[4321]>`.
`join()`'s own use of `InputQuery.total` is tested separately from the function, because
`StagingCleanupSupport` already records what that distinction costs: a tool can be provably right
while nothing calls it. `SucceedingWorkerFactory` now keeps the input `Data` of every request that
reaches a worker -- the only place it is legible, since `WorkInfo` hands back a job's tags and its
output and never the `Data` it was built with -- and the test reads the enqueued total off it.
Restoring `inputs.sumOf { it.sizeBytes ?: 0L }` leaves every other test in the change green and
this one red with `a total that could not be worked out must not be enqueued as a number`.
`ConversionViewModelProbeFailureTest` expected `InputFile(INPUT, "input", 0L)` for an authority no
provider serves. It expects `sizeBytes = null` now, which is the behaviour change stated where a
reader will meet it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
JMR-devandClaude Opus 5
b86df47c43