Allocator for an owned mapped file region that supports thread-safe and process-safe bump pointer allocation. More...

#include "llvm/CAS/MappedFileRegionArena.h"

Classes
struct	Header
	Header for MappedFileRegionArena. More...

Public Types
using	RegionT = sys::fs::mapped_file_region

Public Member Functions
Expected< char * >	allocate (uint64_t AllocSize)
	Allocate at least `AllocSize`. Rounds up to getAlign().
LLVM_ABI_FOR_TEST Expected< int64_t >	allocateOffset (uint64_t AllocSize)
	Allocate, returning the offset from data() instead of a pointer.
char *	data () const
uint64_t	size () const
uint64_t	capacity () const
RegionT &	getRegion ()
	~MappedFileRegionArena ()
	MappedFileRegionArena ()=default
	MappedFileRegionArena (MappedFileRegionArena &&RHS)
MappedFileRegionArena &	operator= (MappedFileRegionArena &&RHS)
	MappedFileRegionArena (const MappedFileRegionArena &)=delete
MappedFileRegionArena &	operator= (const MappedFileRegionArena &)=delete

Static Public Member Functions
static LLVM_ABI_FOR_TEST Expected< MappedFileRegionArena >	create (const Twine &Path, uint64_t Capacity, uint64_t HeaderOffset, std::shared_ptr< ondisk::OnDiskCASLogger > Logger, function_ref< Error(MappedFileRegionArena &)> NewFileConstructor)
	Create a `MappedFileRegionArena`.
static constexpr Align	getAlign ()
	Minimum alignment for allocations, currently hardcoded to 8B.

Detailed Description

Allocator for an owned mapped file region that supports thread-safe and process-safe bump pointer allocation.

This allocator is designed to create a sparse file when supported by the filesystem's ftruncate so that it can be used with a large maximum size. It will also attempt to shrink the underlying file down to its current allocation size when the last concurrent mapping is closed.

Process-safe. Uses file locks when resizing the file during initialization and destruction.

Thread-safe. Requires OS support thread-safe file lock.

Provides 8-byte alignment for all allocations.

Definition at line 42 of file MappedFileRegionArena.h.

Member Typedef Documentation

◆ RegionT

using llvm::cas::MappedFileRegionArena::RegionT = sys::fs::mapped_file_region

Definition at line 44 of file MappedFileRegionArena.h.

Constructor & Destructor Documentation

◆ ~MappedFileRegionArena()

llvm::cas::MappedFileRegionArena::~MappedFileRegionArena ( )

inline

Definition at line 97 of file MappedFileRegionArena.h.

◆ MappedFileRegionArena() [1/3]

llvm::cas::MappedFileRegionArena::MappedFileRegionArena ( )

default

Referenced by create(), MappedFileRegionArena(), MappedFileRegionArena(), operator=(), and operator=().

◆ MappedFileRegionArena() [2/3]

llvm::cas::MappedFileRegionArena::MappedFileRegionArena ( MappedFileRegionArena && RHS )

inline

Definition at line 100 of file MappedFileRegionArena.h.

References MappedFileRegionArena(), and RHS.

◆ MappedFileRegionArena() [3/3]

llvm::cas::MappedFileRegionArena::MappedFileRegionArena ( const MappedFileRegionArena & )

delete

References MappedFileRegionArena().

Member Function Documentation

◆ allocate()

Expected< char * > llvm::cas::MappedFileRegionArena::allocate ( uint64_t AllocSize )

inline

Allocate at least AllocSize. Rounds up to getAlign().

Definition at line 82 of file MappedFileRegionArena.h.

References allocateOffset(), data(), LLVM_UNLIKELY, and llvm::Offset.

◆ allocateOffset()

Expected< int64_t > MappedFileRegionArena::allocateOffset ( uint64_t AllocSize )

Allocate, returning the offset from data() instead of a pointer.

Definition at line 352 of file MappedFileRegionArena.cpp.

References llvm::alignTo(), assert(), capacity(), createAllocatorOutOfSpaceError(), data(), getAlign(), llvm::Increment, LLVM_UNLIKELY, and llvm::cas::ondisk::preallocateFileTail().

Referenced by allocate().

◆ capacity()

uint64_t llvm::cas::MappedFileRegionArena::capacity ( ) const

inline

Definition at line 93 of file MappedFileRegionArena.h.

Referenced by allocateOffset().

◆ create()

Expected< MappedFileRegionArena > MappedFileRegionArena::create	(	const Twine &	Path,
		uint64_t	Capacity,
		uint64_t	HeaderOffset,
		std::shared_ptr< ondisk::OnDiskCASLogger >	Logger,
		function_ref< Error(MappedFileRegionArena &)>	NewFileConstructor )

static

Create a MappedFileRegionArena.

Parameters

Path	the path to open the mapped region.
Capacity	the maximum size for the mapped file region.
HeaderOffset	the offset at which to store the header. This is so that information can be stored before the header, like a file magic.
NewFileConstructor	is for constructing new files. It has exclusive access to the file. Must call `initializeBumpPtr`.

Definition at line 161 of file MappedFileRegionArena.cpp.

References llvm::SmallString< InternalLen >::append(), assert(), llvm::sys::fs::convertFDToNativeFile(), llvm::createFileError(), llvm::createStringError(), llvm::sys::fs::Exclusive, MappedFileRegionArena(), llvm::sys::fs::readNativeFileSlice(), llvm::sys::fs::mapped_file_region::readwrite, llvm::sys::fs::resize_file_sparse(), llvm::sys::fs::Shared, Size, and llvm::utostr().

Referenced by llvm::cas::ondisk::DatabaseFile::create().

◆ data()

char * llvm::cas::MappedFileRegionArena::data ( ) const

inline

Definition at line 91 of file MappedFileRegionArena.h.

Referenced by allocate(), and allocateOffset().

◆ getAlign()

constexpr Align llvm::cas::MappedFileRegionArena::getAlign ( )

inlinestaticconstexpr

Minimum alignment for allocations, currently hardcoded to 8B.

Definition at line 74 of file MappedFileRegionArena.h.

References llvm::Align::Of(), and T.

Referenced by allocateOffset().

◆ getRegion()

RegionT & llvm::cas::MappedFileRegionArena::getRegion ( )

inline

Definition at line 95 of file MappedFileRegionArena.h.

◆ operator=() [1/2]

MappedFileRegionArena & llvm::cas::MappedFileRegionArena::operator= ( const MappedFileRegionArena & )

delete

References LLVM_ABI_FOR_TEST, MappedFileRegionArena(), and RHS.

◆ operator=() [2/2]

MappedFileRegionArena & llvm::cas::MappedFileRegionArena::operator= ( MappedFileRegionArena && RHS )

inline

Definition at line 101 of file MappedFileRegionArena.h.

References MappedFileRegionArena(), and RHS.

◆ size()

uint64_t llvm::cas::MappedFileRegionArena::size ( ) const

inline

Definition at line 92 of file MappedFileRegionArena.h.

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

include/llvm/CAS/MappedFileRegionArena.h
lib/CAS/MappedFileRegionArena.cpp

Classes

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Typedef Documentation

◆ RegionT

Constructor & Destructor Documentation

◆ ~MappedFileRegionArena()

◆ MappedFileRegionArena() [1/3]

◆ MappedFileRegionArena() [2/3]

◆ MappedFileRegionArena() [3/3]

Member Function Documentation

◆ allocate()

◆ allocateOffset()

◆ capacity()

◆ create()

◆ data()

◆ getAlign()

◆ getRegion()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ size()