# Drivers¶

## Chunked storage drivers¶

json KeyValueStoreBackedChunkDriver : object

Common options supported by all chunked storage drivers.

Extends

TensorStore

Subtypes

Required members

driver : string

Driver identifier

Specifies the TensorStore driver.

kvstore : KeyValueStore

Specifies the underlying storage mechanism.

Optional members

context : Context

Specifies context resources that augment/override the parent context.

dtype : dtype

Specifies the data type.

rank : integer[0, 32]

Specifies the rank of the TensorStore.

If transform is also specified, the input rank must match. Otherwise, the rank constraint applies to the driver directly.

transform : IndexTransform

Specifies a transform.

path : string = ""

Path within the KeyValueStore specified by kvstore.

Example

"path/to/data"

open : boolean

Open an existing TensorStore. If neither open nor create is specified, defaults to true.

create : boolean = false

Create a new TensorStore. Specify true for both open and create to permit either opening an existing TensorStore or creating a new TensorStore if it does not already exist.

delete_existing : boolean = false

Delete any existing data at the specified path before creating a new TensorStore. Requires that create is true, and that open is false.

cache_pool : ContextResource = "cache_pool"

Specifies or references a previously defined Context.cache_pool. It is normally more convenient to specify a default cache_pool in the context.

data_copy_concurrency : ContextResource = "data_copy_concurrency"

Specifies or references a previously defined Context.data_copy_concurrency. It is normally more convenient to specify a default data_copy_concurrency in the context.

recheck_cached_metadata : CacheRevalidationBound = "open"

Time after which cached metadata is assumed to be fresh. Cached metadata older than the specified time is revalidated prior to use. The metadata is used to check the bounds of every read or write operation.

Specifying true means that the metadata will be revalidated prior to every read or write operation. With the default value of "open", any cached metadata is revalidated when the TensorStore is opened but is not rechecked for each read or write operation.

recheck_cached_data : CacheRevalidationBound = true

Time after which cached data is assumed to be fresh. Cached data older than the specified time is revalidated prior to being returned from a read operation. Partial chunk writes are always consistent regardless of the value of this option.

The default value of true means that cached data is revalidated on every read. To enable in-memory data caching, you must both specify a cache_pool with a non-zero total_bytes_limit and also specify false, "open", or an explicit time bound for recheck_cached_data.

json CacheRevalidationBound : true | false | "open" | number

Determines under what circumstances cached data is revalidated.

One of

true

Revalidate cached data at every operation.

false

Assume cached data is always fresh and never revalidate.

"open"

Revalidate cached data older than the time at which the TensorStore was opened.

number

Revalidate cached data older than the specified time in seconds since the unix epoch.