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// Package store is an interface for distributed data storage.
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// The design document is located at https://github.com/micro/development/blob/master/design/framework/store.md
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package store
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import (
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"context"
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"errors"
"time"
)
var (
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// ErrNotFound is returned when a key doesn't exist
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ErrNotFound = errors . New ( "not found" )
DefaultStore Store = newStore ( )
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)
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// Store is a data storage interface
type Store interface {
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// Init initialises the store. It must perform any required setup on the backing storage implementation and check that it is ready for use, returning any errors.
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Init ( ctx context . Context , opts ... Option ) error
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// Options allows you to view the current options.
Options ( ) Options
// Read takes a single key name and optional ReadOptions. It returns matching []*Record or an error.
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Read ( ctx context . Context , key string , opts ... ReadOption ) ( [ ] * Record , error )
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// Write() writes a record to the store, and returns an error if the record was not written.
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Write ( ctx context . Context , r * Record , opts ... WriteOption ) error
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// Delete removes the record with the corresponding key from the store.
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Delete ( ctx context . Context , key string , opts ... DeleteOption ) error
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// List returns any keys that match, or an empty list with no error if none matched.
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List ( ctx context . Context , opts ... ListOption ) ( [ ] string , error )
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// Close the store
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Close ( ctx context . Context ) error
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// String returns the name of the implementation.
String ( ) string
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}
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// Record is an item stored or retrieved from a Store
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type Record struct {
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// The key to store the record
Key string ` json:"key" `
// The value within the record
Value [ ] byte ` json:"value" `
// Any associated metadata for indexing
Metadata map [ string ] interface { } ` json:"metadata" `
// Time to expire a record: TODO: change to timestamp
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Expiry time . Duration ` json:"expiry,omitempty" `
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}