Struct FilHeader 

pub struct FilHeader {
    pub checksum: u32,
    pub page_number: u32,
    pub prev_page: u32,
    pub next_page: u32,
    pub lsn: u64,
    pub page_type: PageType,
    pub flush_lsn: u64,
    pub space_id: u32,
}

Parsed FIL header (38 bytes, present at the start of every InnoDB page).

Fields

checksum: u32

Checksum (or space id in older formats). Bytes 0-3.

page_number: u32

Page number within the tablespace. Bytes 4-7.

prev_page: u32

Previous page in the doubly-linked list. Bytes 8-11. FIL_NULL (0xFFFFFFFF) if not used.

next_page: u32

Next page in the doubly-linked list. Bytes 12-15. FIL_NULL (0xFFFFFFFF) if not used.

lsn: u64

LSN of newest modification to this page. Bytes 16-23.

page_type: PageType

Page type. Bytes 24-25.

flush_lsn: u64

Flush LSN (only meaningful for page 0 of system tablespace). Bytes 26-33.

space_id: u32

Space ID this page belongs to. Bytes 34-37.

Implementations

impl FilHeader

pub fn parse(data: &[u8]) -> Option<Self>

Parse a FIL header from a byte slice.

The slice must be at least SIZE_FIL_HEAD (38) bytes.

Examples

use idb::innodb::page::FilHeader;
use idb::innodb::page_types::PageType;
use byteorder::{BigEndian, WriteBytesExt};
use std::io::{Cursor, Write};

// Build a 38-byte FIL header with known values
let mut buf = vec![0u8; 38];
let mut c = Cursor::new(&mut buf);
c.write_u32::<BigEndian>(0xDEADBEEF).unwrap(); // checksum
c.write_u32::<BigEndian>(3).unwrap();           // page number
c.write_u32::<BigEndian>(2).unwrap();           // prev page
c.write_u32::<BigEndian>(4).unwrap();           // next page
c.write_u64::<BigEndian>(5000).unwrap();        // LSN
c.write_u16::<BigEndian>(17855).unwrap();       // page type (INDEX)
c.write_u64::<BigEndian>(4000).unwrap();        // flush LSN
c.write_u32::<BigEndian>(1).unwrap();           // space ID

let header = FilHeader::parse(&buf).unwrap();
assert_eq!(header.checksum, 0xDEADBEEF);
assert_eq!(header.page_number, 3);
assert_eq!(header.prev_page, 2);
assert_eq!(header.next_page, 4);
assert_eq!(header.lsn, 5000);
assert_eq!(header.page_type, PageType::Index);
assert_eq!(header.flush_lsn, 4000);
assert_eq!(header.space_id, 1);

pub fn has_prev(&self) -> bool

Returns true if prev_page is FIL_NULL (not used).

pub fn has_next(&self) -> bool

Returns true if next_page is FIL_NULL (not used).

Trait Implementations

impl Clone for FilHeader

fn clone(&self) -> FilHeader

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FilHeader

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Serialize for FilHeader

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.