Documentation
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Overview ¶
Package ndjson stores each record stream as a local file: one line per row in <dir>/<kind>/<stream>.ndjson, written {"seq":N,"row":{…}}, beside a <stream>.meta.json sidecar holding the stream's recordstore.Meta. A trimmed stream's rows move to <stream>@<low seq>.ndjson, which the sidecar names.
It is the durable backend a CLI run writes when no shared store is configured. Two bounds keep it from filling a disk nobody watches: a per stream byte cap, which refuses an append loudly rather than dropping it, and a per kind count of streams kept, which removes the oldest when a new one opens.
Index ¶
- type Backend
- func (b *Backend) Append(ctx context.Context, stream, kind string, rows []recordstore.Row) (recordstore.AppendResult, error)
- func (b *Backend) Close() error
- func (b *Backend) Expire(_ context.Context, stream string, ttl time.Duration) error
- func (b *Backend) Meta(_ context.Context, stream string) (recordstore.Meta, error)
- func (b *Backend) Scan(_ context.Context, stream string, afterSeq int64, ...) error
- func (b *Backend) Trim(_ context.Context, stream string, before time.Time) (recordstore.Meta, error)
- type Options
Constants ¶
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Variables ¶
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Functions ¶
This section is empty.
Types ¶
type Backend ¶
type Backend struct {
// contains filtered or unexported fields
}
Backend is a recordstore.Backend over a directory of files.
func (*Backend) Append ¶
func (b *Backend) Append(ctx context.Context, stream, kind string, rows []recordstore.Row) (recordstore.AppendResult, error)
Append encodes the rows it keeps as lines after the stream's high seq and appends them.
type Options ¶
type Options struct {
// Dir holds a directory per kind.
Dir string
// Schema resolves a kind to its key and retention. A kind it refuses
// cannot be written.
Schema recordstore.SchemaResolver
// MaxBytes caps one stream's file. An append that would take it past the
// cap is refused whole with recordstore.ErrCapacity and the stream is
// marked capped.
MaxBytes int64
// KeepStreams is how many streams of one kind the directory keeps. Opening
// a new stream removes the least recently written beyond it; a stream
// being written at that moment is left alone.
KeepStreams int
// TTL is how long a stream lives from its first append unless Expire moves
// it, or how long a row of a kind retaining rows lives from its own append.
// Zero keeps a stream until it is expired or rotated out, and refuses a
// kind retaining rows.
TTL time.Duration
// Now is the clock streams are stamped and expired by. Nil is time.Now.
Now func() time.Time
}
Options configure an ndjson backend.
Source Files