cache

Documentation

Overview

Package mmap allows mapping files into memory. It tries to provide a simple, reasonably portable interface, but doesn't go out of its way to abstract away every little platform detail. This specifically means:

• forked processes may or may not inherit mappings
• a file's timestamp may or may not be updated by writes through mappings
• specifying a size larger than the file's actual size can increase the file's size
• If the mapped file is being modified by another process while your program's running, don't expect consistent results between platforms

Index

• Constants
• func ToSlices[E any](cache *Cache) []E
• type Cache
  • func OpenCache(name string, size int64) (*Cache, error)
  • func (c *Cache) Close()
  • func (c *Cache) Flush() error
• type Map
  • func (this *Map[K, V]) Get(k K) (V, bool)
  • func (this *Map[K, V]) Put(k K, v V)
• type MemObject
  • func FileMap(f *os.File, prot, flags int) (MemObject, error)
  • func MapRegion(f *os.File, length int, prot, flags int, offset int64) (MemObject, error)
  • func (m MemObject) Flush() error
  • func (m MemObject) Lock() error
  • func (m MemObject) Unlock() error
  • func (m *MemObject) Unmap() error
• type Pool
  • func (this *Pool[E]) Acquire() *E
  • func (this *Pool[E]) Release(obj *E)

Constants

const (
	// RDONLY maps the memory read-only.
	// Attempts to write to the MemObject object will result in undefined behavior.
	RDONLY = 0
	// RDWR maps the memory as read-write. Writes to the MemObject object will update the
	// underlying file.
	RDWR = 1 << iota
	// COPY maps the memory as copy-on-write. Writes to the MemObject object will affect
	// memory, but the underlying file will remain unchanged.
	COPY
	// If EXEC is set, the mapped memory is marked as executable.
	EXEC
)

const (
	// If the ANON flag is set, the mapped memory will not be backed by a file.
	ANON = 1 << iota
)

Functions

func ToSlices

func ToSlices[E any](cache *Cache) []E

ToSlices 内存转切片

Types

type Cache

type Cache struct {
	// contains filtered or unexported fields
}

Cache 使用跨平台的mmap构建的快速缓存

func OpenCache

func OpenCache(name string, size int64) (*Cache, error)

OpenCache 打开本地缓存

func (*Cache) Close

func (c *Cache) Close()

Close 关闭缓存

func (*Cache) Flush

func (c *Cache) Flush() error

Flush 同步数据到磁盘

type Map

type Map[K any, V any] struct {
	// contains filtered or unexported fields
}

Map 二次封装的泛型sync.Map

func (*Map[K, V]) Get

func (this *Map[K, V]) Get(k K) (V, bool)

func (*Map[K, V]) Put

func (this *Map[K, V]) Put(k K, v V)

type MemObject

type MemObject []byte

MemObject represents a file mapped into memory.

func FileMap

func FileMap(f *os.File, prot, flags int) (MemObject, error)

FileMap maps an entire file into memory. If ANON is set in flags, f is ignored.

func MapRegion

func MapRegion(f *os.File, length int, prot, flags int, offset int64) (MemObject, error)

MapRegion maps part of a file into memory. The offset parameter must be a multiple of the system's page size. If length < 0, the entire file will be mapped. If ANON is set in flags, f is ignored.

func (MemObject) Flush

func (m MemObject) Flush() error

Flush synchronizes the mapping's contents to the file's contents on disk.

func (MemObject) Lock

func (m MemObject) Lock() error

Lock keeps the mapped region in physical memory, ensuring that it will not be swapped out.

func (MemObject) Unlock

func (m MemObject) Unlock() error

Unlock reverses the effect of Lock, allowing the mapped region to potentially be swapped out. If m is already unlocked, aan error will result.

func (*MemObject) Unmap

func (m *MemObject) Unmap() error

Unmap deletes the memory mapped region, flushes any remaining changes, and sets m to nil. Trying to read or write any remaining references to m after Unmap is called will result in undefined behavior. Unmap should only be called on the slice value that was originally returned from a call to FileMap. Calling Unmap on a derived slice may cause errors.

type Pool

type Pool[E any] struct {
	// contains filtered or unexported fields
}

Pool 二次封装的泛型sync.Pool

func (*Pool[E]) Acquire

func (this *Pool[E]) Acquire() *E

Acquire 申请内存

func (*Pool[E]) Release

func (this *Pool[E]) Release(obj *E)

Release 释放内存