74 lines
2.2 KiB
Go
74 lines
2.2 KiB
Go
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package storage
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import (
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"context"
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"io"
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)
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// Storage defines a means of accessing and storing
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// data to some abstracted underlying mechanism. Whether
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// that be in-memory, an on-disk filesystem or S3 bucket.
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type Storage interface {
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// ReadBytes returns the data located at key (e.g. filepath) in storage.
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ReadBytes(ctx context.Context, key string) ([]byte, error)
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// ReadStream returns an io.ReadCloser for the data at key (e.g. filepath) in storage.
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ReadStream(ctx context.Context, key string) (io.ReadCloser, error)
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// WriteBytes writes the supplied data at key (e.g. filepath) in storage.
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WriteBytes(ctx context.Context, key string, data []byte) (int, error)
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// WriteStream writes the supplied data stream at key (e.g. filepath) in storage.
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WriteStream(ctx context.Context, key string, stream io.Reader) (int64, error)
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// Stat returns details about key (e.g. filepath) in storage, nil indicates not found.
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Stat(ctx context.Context, key string) (*Entry, error)
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// Remove will remove data at key from storage.
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Remove(ctx context.Context, key string) error
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// Clean in simple terms performs a clean of underlying
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// storage mechanism. For memory implementations this may
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// compact the underlying hashmap, for disk filesystems
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// this may remove now-unused directories.
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Clean(ctx context.Context) error
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// WalkKeys walks available keys using opts in storage.
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WalkKeys(ctx context.Context, opts WalkKeysOpts) error
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}
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// Entry represents a key in a Storage{} implementation,
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// with any associated metadata that may have been set.
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type Entry struct {
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// Key is this entry's
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// unique storage key.
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Key string
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// Size is the size of
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// this entry in storage.
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Size int64
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}
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// WalkKeysOpts are arguments provided
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// to a storage WalkKeys() implementation.
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type WalkKeysOpts struct {
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// Prefix can be used to filter entries
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// by the given key prefix, for example
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// only those under a subdirectory. This
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// is preferred over Filter() function.
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Prefix string
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// Filter can be used to filter entries
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// by any custom metric before before they
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// are passed to Step() function. E.g.
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// filter storage entries by regexp.
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Filter func(string) bool
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// Step is called for each entry during
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// WalkKeys, error triggers early return.
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Step func(Entry) error
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}
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