zarr::Store Class Reference

#include <store.hpp>

Public Member Functions
	Store (const Store &)=delete
Store &	operator= (const Store &)=delete
	Store (Store &&)=delete
Store &	operator= (Store &&)=delete
virtual std::optional< Bytes >	read (std::string_view key)=0
	Full value at key, or std::nullopt if the key is absent.
virtual std::optional< Bytes >	read_range (std::string_view key, ByteRange range)
virtual std::optional< std::uint64_t >	size (std::string_view key)
virtual std::vector< std::optional< Bytes > >	read_many (const std::vector< ReadRequest > &requests)
virtual void	write (std::string_view key, Bytes value)=0
	Create or replace the value at key.
virtual bool	exists (std::string_view key)=0
	True if key holds a value.
virtual void	erase (std::string_view key)=0
	Remove key; removing an absent key is a no-op.
virtual void	flush ()
virtual std::vector< std::string >	list_prefix (std::string_view prefix)=0
	All keys starting with prefix ("" or ending in '/'), sorted.
virtual DirListing	list_dir (std::string_view prefix)=0
	Immediate children under prefix ("" or ending in '/').

Detailed Description

Abstract key->bytes store. All array and metadata logic in libzarr is written against this interface; backends supply bytes from memory, files, ZIP archives, HTTP range requests, ...

The core is single-threaded by design; implementations are not required to be thread-safe.

Member Function Documentation

erase()

virtual void zarr::Store::erase ( std::string_view  key )

pure virtual

Remove key; removing an absent key is a no-op.

Implemented in zarr::FilesystemStore, zarr::MemoryStore, and zarr::ZipStore.

exists()

virtual bool zarr::Store::exists ( std::string_view  key )

pure virtual

True if key holds a value.

Implemented in zarr::FilesystemStore, zarr::MemoryStore, and zarr::ZipStore.

flush()

virtual void zarr::Store::flush ( )

inlinevirtual

Completes any buffered writes. Plain stores write through and need nothing; adapters that assemble objects (sharding) override.

list_dir()

virtual DirListing zarr::Store::list_dir ( std::string_view  prefix )

pure virtual

Immediate children under prefix ("" or ending in '/').

Implemented in zarr::FilesystemStore, zarr::MemoryStore, and zarr::ZipStore.

list_prefix()

virtual std::vector< std::string > zarr::Store::list_prefix ( std::string_view  prefix )

pure virtual

All keys starting with prefix ("" or ending in '/'), sorted.

Implemented in zarr::FilesystemStore, zarr::MemoryStore, and zarr::ZipStore.

read()

virtual std::optional< Bytes > zarr::Store::read ( std::string_view  key )

pure virtual

Full value at key, or std::nullopt if the key is absent.

Implemented in zarr::FilesystemStore, zarr::MemoryStore, and zarr::ZipStore.

read_many()

virtual std::vector< std::optional< Bytes > > zarr::Store::read_many ( const std::vector< ReadRequest > &  requests )

inlinevirtual

Reads several ranges in one call, order-preserving: result[i] is the value for requests[i], or std::nullopt if that key is absent. The default implementation loops over read_range; backends whose I/O has per-request latency (HTTP, object stores) should override to issue the requests concurrently or as coalesced multi-range reads, cutting round trips. Still synchronous: it returns only once every range is resolved.

read_range()

std::optional< Bytes > zarr::Store::read_range ( std::string_view  key, ByteRange  range  )

inlinevirtual

Part of the value at key: std::nullopt if the key is absent, throws zarr::error if the range lies outside the value. The default implementation reads the full value and slices it; backends with native range reads (files, HTTP) should override.

Reimplemented in zarr::FilesystemStore, and zarr::ZipStore.

size()

virtual std::optional< std::uint64_t > zarr::Store::size ( std::string_view  key )

inlinevirtual

Size in bytes of the value at key, or std::nullopt if absent. The default implementation reads the whole value; backends with cheap stat (files: fstat, HTTP: HEAD) should override.

Reimplemented in zarr::FilesystemStore, zarr::MemoryStore, and zarr::ZipStore.

write()

virtual void zarr::Store::write ( std::string_view  key, Bytes  value  )

pure virtual

Create or replace the value at key.

Implemented in zarr::FilesystemStore, zarr::MemoryStore, and zarr::ZipStore.

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The documentation for this class was generated from the following file:

• libzarr/store.hpp