pager

Documentation

Overview

Package pager BSD 3-Clause License

Copyright (c) 2024, Alex Gaetano Padula All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Index

• Constants
• type Pager
  • func OpenPager(filename string, flag int, perm os.FileMode) (*Pager, error)
  • func (p *Pager) Close() error
  • func (p *Pager) Count() int64
  • func (p *Pager) FileName() string
  • func (p *Pager) GetPage(pageID int64) ([]byte, error)
  • func (p *Pager) Size() int64
  • func (p *Pager) Write(data []byte) (int64, error)
  • func (p *Pager) WriteTo(pageID int64, data []byte) error

Constants

const HEADER_SIZE = 16 // next (overflowed)

const PAGE_SIZE = 1024 // Page size

const SYNC_ESCALATION = 30 * time.Second // if the file is not synced 30 seconds, sync it

const SYNC_TICK_INTERVAL = 1 * time.Second // tick interval for syncing the file

const WRITE_THRESHOLD = 24576 // every 24576 writes, sync the file

Types

type Pager

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

Pager manages pages in a file

func OpenPager

func OpenPager(filename string, flag int, perm os.FileMode) (*Pager, error)

OpenPager opens a file for page management

func (*Pager) Close

func (p *Pager) Close() error

Close closes the file

func (*Pager) Count

func (p *Pager) Count() int64

Count returns the number of pages

func (*Pager) FileName

func (p *Pager) FileName() string

FileName returns the name of the file

func (*Pager) GetPage

func (p *Pager) GetPage(pageID int64) ([]byte, error)

GetPage gets a page and returns the data Will gather all the pages that are linked together

func (*Pager) Size

func (p *Pager) Size() int64

Size returns the size of the file

func (*Pager) Write

func (p *Pager) Write(data []byte) (int64, error)

Write writes data to the next available page

func (*Pager) WriteTo

func (p *Pager) WriteTo(pageID int64, data []byte) error

WriteTo writes data to a specific page