Crate flatdata[−][src]

Implementation of heremaps/flatdata in Rust.

Flatdata is a library providing data structures for convenient creation, storage and access of packed memory-mappable structures with minimal overhead.

The idea is, that the user defines a schema of the data format using flatdata's very simple schema language supporting plain structs, vectors and multivectors. The schema is then used to generate builders and readers for serialization and deserialization of the data. The data is serialized in a portable way which allows zero-overhead random access to it by using memory mapped storage. Memory mapped approach makes it possible to use the operating system facilities for loading, caching and paging of the data, and most important, accessing it as if it were in memory. Read more in "Why flatdata?".

This create provides:

macros for generated code (prefixed with create_),
macros for zero-cost serialization read_bytes and deserialization write_bytes, * in-memory MemoryResourceStorage and memory-mapped FileResourceStorage storages, * data structures for writing data: StructBuf, Vector, ExternalVector, MultiVector,
data structures for reading data: ArrayView, MultiArrayView.

The generator is part of the main heremaps/flatdata repository.

For a comprehensive example, cf. coappearances generated code and the corresponding usage.

Modules

helper

Module containing helper traits and macros.

Macros

define_archive	Macro used by generator to define a flatdata archive and corresponding archive builder.
define_index	Macro used by generator to define a flatdata index.
define_struct	Macro used by generator to define a flatdata struct.
define_variadic_struct	Macro used by generator to define a flatdata variant used in `MultiVector` and `MultiArrayView`.
read_bytes	Reads specified number of bits from data at specified offset in portable way.
write_bytes	Writes specified number of bits of a given value to a slice at a specified offset in portable way.

Structs

ArrayView	A read-only view on a contiguous sequence of flatdata structs of the same type `T`.
ExternalVector	Vector which flushes its content when growing.
FileResourceStorage	Resource storage on disk using memory mapped files.
Handle	Handle to a flatdata struct for read-only fields access.
HandleMut	Mutable handle to a flatdata struct for reading and writing fields.
MemoryDescriptor	Describes a chunk of memory
MemoryResourceStorage	Resource storage in memory.
MultiArrayView	A read-only view on a multivector.
MultiVector	A container for writing an indexed sequence of heterogeneous data items.
StructBuf	A container holding a single flatdata struct in memory, and providing read and write access to it.
Vector	A container holding a contiguous sequence of flatdata structs of the same type `T` in memory, and providing read and write access to it.

Enums

ResourceStorageError

Error indicating failures when reading and writing data from/to a Storage.

Traits

Archive	A flatdata archive representing serialized data.
ArchiveBuilder	A flatdata archive builder for serializing data.
Index	A type in archive used as index of a `MultiArrayView`.
IndexMut	A type in archive used as mutable index of a `MultiVector`.
ResourceStorage	Hierarchical Resource Storage
Struct	A type in flatdata used for reading data.
StructMut	A mutable type in flatdata used for writing data.
VariadicStruct	A type used as element of `MultiArrayView`.

Functions

create_archive	Creates a new archive in resource storage.
create_external_vector	Helper for creating an external vector in the given resource storage.
create_multi_vector	Helper for creating a multivector in the given resource storage.

Type Definitions

TypeIndex

Index specifying a variadic type of MultiArrayView.