Class Innodb::Space
In: lib/innodb/space.rb
Parent: Object

An InnoDB space file, which can be either a multi-table ibdataN file or a single-table "innodb_file_per_table" .ibd file.

Methods

data_dictionary_page   data_file_for_offset   doublewrite_page?   each_doublewrite_page_number   each_index   each_index_root_page_number   each_inode   each_inode_list   each_page   each_page_status   each_page_type_region   each_xdes   each_xdes_list   each_xdes_page   each_xdes_page_number   extent_size   fsp   fsp_flags   ibuf_bitmap_page_for_page   index   inode_lists   inspect   list   name   new   page   page_data   page_fsp_hdr   page_sys_data_dictionary   page_trx_sys   pages_per_bookkeeping_page   pages_per_extent   raw_fsp_header_flags   read_at_offset   rseg_page?   space_id   system_space?   trx_sys   type_for_page   xdes_entry_for_page   xdes_for_page   xdes_lists   xdes_page_for_page  

Classes and Modules

Class Innodb::Space::DataFile

Constants

DEFAULT_PAGE_SIZE = 16384   InnoDB‘s default page size is 16KiB.
SYSTEM_SPACE_PAGE_MAP = { 0 => :FSP_HDR, 1 => :IBUF_BITMAP, 2 => :INODE, 3 => :SYS, 4 => :INDEX, 5 => :TRX_SYS, 6 => :SYS, 7 => :SYS, }   A map of InnoDB system space fixed-allocation pages. This can be used to check whether a space is a system space or not, as non-system spaces will not match this pattern.

Attributes

innodb_system  [RW]  The Innodb::System to which this space belongs, if any.
page_size  [R]  The size (in bytes) of each page in the space.
pages  [R]  The number of pages in the space.
record_describer  [RW]  An object which can be used to describe records found in pages within this space.
size  [R]  The size (in bytes) of the space
system_page_size  [R]  The system default page size (in bytes), equivalent to UNIV_PAGE_SIZE.

Public Class methods

new(filenames)

Open a space file, optionally providing the page size to use. Pages that aren‘t 16 KiB may not be supported well.

Public Instance methods

doublewrite_page?(page_number)

Return true if a page is in the doublewrite buffer.

each_doublewrite_page_number() {|page_number| ...}

Iterate through the page numbers in the doublewrite buffer.

each_index() {|index(page_number)| ...}

Iterate through all indexes in the space.

each_index_root_page_number() {|record["PAGE_NO"]| ...}

Iterate through all root page numbers for indexes in the space.

each_inode() {|inode| ...}

Iterate through Innodb::Inode objects in the space.

each_page(start_page=0) {|page_number, current_page if current_page| ...}

Iterate through all pages in a space, returning the page number and an Innodb::Page object for each one.

each_page_status(start_page=0) {|page_number, this_page, page_status| ...}

Iterate through all pages, yielding the page number, page object, and page status.

each_page_type_region(start_page=0) {|region if region| ...}

Iterate through unique regions in the space by page type. This is useful to achieve an overall view of the space.

each_xdes() {|xdes if xdes.xdes[:state]| ...}

Iterate through all extent descriptors for the space, returning an Innodb::Xdes object for each one.

each_xdes_list() {|name, list(name)| ...}

Iterate through Innodb::Xdes lists in the space.

each_xdes_page_number() {|n| ...}

An array of all FSP/XDES page numbers for the space.

extent_size()

The size (in bytes) of an extent.

fsp()

Get (and cache) the FSP header from the FSP_HDR page.

fsp_flags()

The FSP header flags, decoded. If the page size has not been initialized, reach into the raw bytes of the FSP_HDR page and attempt to decode the flags field that way.

ibuf_bitmap_page_for_page(page_number)

The IBUF_BITMAP page which will contain the bitmap entry for a given page.

index(root_page_number, record_describer=nil)

Get an Innodb::Index object for a specific index by root page number.

list(name)

Get an Innodb::List object for a specific list by list name.

name()

Return a string which can uniquely identify this space. Be careful not to do anything which could instantiate a BufferCursor so that we can use this method in cursor initialization.

page(page_number)

Get an Innodb::Page object for a specific page by page number.

page_data(page_number)

Get the raw byte buffer for a specific page by page number.

page_fsp_hdr()

Return the page number for the space‘s FSP_HDR page.

page_sys_data_dictionary()

Return the page number for the space‘s SYS data dictionary header.

page_trx_sys()

Return the page number for the space‘s TRX_SYS page.

pages_per_bookkeeping_page()

The number of pages per FSP_HDR/XDES/IBUF_BITMAP page. This is crudely mapped to the page size, and works for pages down to 1KiB.

pages_per_extent()

The number of pages per extent.

raw_fsp_header_flags()

Read the FSP header "flags" field by byte offset within the space file. This is useful in order to initialize the page size, as we can‘t properly read the FSP_HDR page before we know its size.

read_at_offset(offset, size)

Get the raw byte buffer of size bytes at offset in the file.

system_space?()

Determine whether this space looks like a system space. If the initial pages in the space match the SYSTEM_SPACE_PAGE_MAP, it is likely to be a system space.

trx_sys()

Get the Innodb::Page::TrxSys page for a system space.

type_for_page(page, page_status)

A helper to produce a printable page type.

xdes_entry_for_page(page_number)

The XDES entry offset for a given page within its FSP_HDR/XDES page‘s XDES array.

xdes_for_page(page_number)

Return the Innodb::Xdes entry which represents a given page.

xdes_lists()

An array of Innodb::Xdes list names.

xdes_page_for_page(page_number)

The FSP_HDR/XDES page which will contain the XDES entry for a given page.

[Validate]