Documentation
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Overview ¶
Package file is the module manifest: uploaded bytes and the rows that name them.
It is the shape every module follows, with the one asymmetry a module about bytes has: there is no rest.Spec, because a Spec's create route takes a JSON body and a file arrives as a stream. The six routes are written out in internal/handler.go.
The thing to read before the rest is where a blob write sits relative to a commit, because it is the only interesting problem here and it has two different answers.
An upload writes the bytes first and the row second: a transaction that then fails leaves bytes nobody references, which costs disk, where the other order would leave a row that references nothing, which is a download that fails forever.
A delete writes the row first and the bytes never: it publishes file.deleted and this module subscribes to its own event, so the blob goes once the transaction that removed the row has committed. Removing it inside that transaction would be a delete a rollback cannot undo — the row would come back and the bytes would be gone.
Index ¶
Constants ¶
const DefaultQuotaBytes = 1 << 30
DefaultQuotaBytes is the disk one tenant may fill when a deployment says nothing. A gigabyte is a number a person can reason about — a thousand documents, or a hundred photographs — and config.Files is where a deployment says otherwise. Zero means no quota, which is what a single-tenant installation wants and what a public sign-up must not have.
The largest one upload may be is config.DefaultFilesMaxBytes, in kit/config, which is the only place it is written: this module used to declare the same 25 << 20 beside it, and two constants for one number is one of them going stale.
Variables ¶
var Local = internal.NewLocal
Local is contracts.Storage on the filesystem. main wires it, or whatever a deployment has instead, so the choice is visible in the file that composes the application — the same way the mailer and the payment provider are.
Functions ¶
func Module ¶
Module is the manifest, and the service beside it.
It returns both, as user, notification, task and the catalogue's own modules do, because a consuming module needs the service and cannot reach into internal/ for it. Before this it returned only the manifest, and a client module that wanted to open a stored file had to call this module's own HTTP route — which meant holding file:manage to do something the interface says it may do with a transaction. contracts.Opener is the narrow half most consumers should take.
Types ¶
type Deps ¶
type Deps struct {
// Storage is where the bytes go. There is one implementation here, Local;
// the ones that speak to an object store live outside this repository.
Storage contracts.Storage
// MaxBytes is the largest upload accepted; zero means the kernel's
// config.DefaultFilesMaxBytes. It is a dependency rather than a constant
// because how much disk a deployment is willing to take from an anonymous
// mistake is a deployment's decision.
MaxBytes int64
// QuotaBytes is the disk one tenant may hold; zero means
// DefaultQuotaBytes and a negative number means no quota at all. It is
// enforced at upload, against the sum of what the tenant already holds.
QuotaBytes int64
// ReconcileEvery replaces the daily orphan sweep with an interval, for a
// test that cannot wait until four in the morning. Zero means the schedule.
ReconcileEvery time.Duration
}
Deps is what this module cannot make for itself.
Source Files
Directories
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| Path | Synopsis |
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Package contracts is everything another module, an app or a test may know about files: the entity, the events, the permissions, the storage this module needs somebody else to satisfy, and the Service interface.
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Package contracts is everything another module, an app or a test may know about files: the entity, the events, the permissions, the storage this module needs somebody else to satisfy, and the Service interface. |
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filetest
Package filetest is the conformance suite for contracts.Service, a Storage in memory that the suite runs against, and a fake Service that passes it.
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Package filetest is the conformance suite for contracts.Service, a Storage in memory that the suite runs against, and a fake Service that passes it. |
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Package internal is every implementation of the file module.
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Package internal is every implementation of the file module. |