preallocate

README

preallocate

File preallocation library

Features

• Allocates files efficiently (via syscall) on the following platforms:
  • Linux
  • Windows
• Falls back to writing null bytes

Documentation

Docs are hosted on godoc.org.

Support

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Documentation

Overview

Package preallocate allocates disk space efficiently via syscall (on supported platforms and filesystems) or by writing null bytes.

Files opened with O_APPEND are not supported.

Index

• Constants
• func File(file *os.File, size int64) error
• func TempFile(dir string, pattern string, size int64) (*os.File, error)
• func WriteSeeker(w io.WriteSeeker, size int64) error

Constants

const NullBufferSize = 512 * 1024 // 512 KiB

NullBufferSize determines the maximum size of NULL byte blocks written to files when falling back to WriteSeeker.

Functions

func File

func File(file *os.File, size int64) error

File preallocates a file via syscall (when supported) or WriteSeeker.

func TempFile

func TempFile(dir string, pattern string, size int64) (*os.File, error)

TempFile preallocates a temporary file (see File and ioutil.TempFile).

func WriteSeeker

func WriteSeeker(w io.WriteSeeker, size int64) error

WriteSeeker preallocates an io.WriteSeeker by writing null bytes.