Checking and Recovery

Classes
struct	MDBX_chk_line_t
	A virtual row of the report generated during a database integrity check. More...
struct	MDBX_chk_issue_t
	An issue problem was discovered during a database integrity check. More...
struct	MDBX_chk_scope_t
	A hierarchical context during a database integrity check. More...
struct	MDBX_chk_histogram
	A histogram with some statistical information collected during a database integrity check. More...
struct	MDBX_chk_table_t
	Information about a certain key-value table during a database integrity check. More...
struct	MDBX_chk_context_t
	The context for checking the integrity of a database. More...
struct	MDBX_chk_callbacks_t
	A set of callback functions used for checking the integrity of a database. More...
union	MDBX_chk_scope_t.usr_z
union	MDBX_chk_scope_t.usr_v
union	MDBX_chk_scope_t.usr_o
struct	MDBX_chk_histogram.ranges
struct	MDBX_chk_table_t.pages
struct	MDBX_chk_table_t.histogram
struct	MDBX_chk_context_t.result

Macros
#define	mdbx_env_open_for_recoveryT(env, pathname, target_mets, writeable)
#define	mdbx_preopen_snapinfoT(pathname, info, bytes)

Functions
LIBMDBX_API int	mdbx_env_turn_for_recovery (MDBX_env *env, unsigned target_meta)
	Turn database to the specified meta-page.

Detailed Description

Basically this is internal API for mdbx_chk tool, etc. You should avoid to use it, except some extremal special cases.

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Class Documentation

MDBX_chk_line_t

struct MDBX_chk_line_t

A virtual row of the report generated during a database integrity check.

See also

mdbx_env_chk()

Class Members
char *	begin
struct MDBX_chk_context *	ctx
uint8_t	empty
char *	end
char *	out
uint8_t	scope_depth
uint8_t	severity

MDBX_chk_issue_t

struct MDBX_chk_issue_t

An issue problem was discovered during a database integrity check.

See also

mdbx_env_chk()

Class Members
const char *	caption
size_t	count
struct MDBX_chk_issue *	next

MDBX_chk_scope_t

struct MDBX_chk_scope_t

A hierarchical context during a database integrity check.

See also

mdbx_env_chk()

Public Attributes
MDBX_chk_issue_t *	issues
struct MDBX_chk_internal *	internal
const void *	object
MDBX_chk_stage_t	stage
MDBX_chk_severity_t	verbosity
size_t	subtotal_issues
union {
void *	ptr
size_t	number
}	usr_z
union {
void *	ptr
size_t	number
}	usr_v
union {
void *	ptr
size_t	number
}	usr_o

Member Data Documentation

internal

struct MDBX_chk_internal* MDBX_chk_scope_t::internal

issues

MDBX_chk_issue_t* MDBX_chk_scope_t::issues

object

const void* MDBX_chk_scope_t::object

stage

MDBX_chk_stage_t MDBX_chk_scope_t::stage

subtotal_issues

size_t MDBX_chk_scope_t::subtotal_issues

[union]

union { ... } MDBX_chk_scope_t::usr_o

[union]

union { ... } MDBX_chk_scope_t::usr_v

[union]

union { ... } MDBX_chk_scope_t::usr_z

verbosity

MDBX_chk_severity_t MDBX_chk_scope_t::verbosity

MDBX_chk_histogram

struct MDBX_chk_histogram

A histogram with some statistical information collected during a database integrity check.

See also

mdbx_env_chk()

Public Attributes
size_t	amount
size_t	count
size_t	le1_amount
size_t	le1_count
struct {
size_t	begin
size_t	end
size_t	amount
size_t	count
}	ranges [9]

Member Data Documentation

amount

size_t MDBX_chk_histogram::amount

count

size_t MDBX_chk_histogram::count

le1_amount

size_t MDBX_chk_histogram::le1_amount

le1_count

size_t MDBX_chk_histogram::le1_count

[struct]

struct { ... } MDBX_chk_histogram::ranges[9]

MDBX_chk_table_t

struct MDBX_chk_table_t

Information about a certain key-value table during a database integrity check.

See also

mdbx_env_chk()

Public Attributes
MDBX_chk_user_table_cookie_t *	cookie
MDBX_val	name
MDBX_db_flags_t	flags
int	id
size_t	payload_bytes
size_t	lost_bytes
struct {
size_t	all
size_t	empty
size_t	broken
size_t	branch
size_t	leaf
size_t	nested_branch
size_t	nested_leaf
size_t	nested_subleaf
}	pages
struct {
struct MDBX_chk_histogram	height
struct MDBX_chk_histogram	large_pages
struct MDBX_chk_histogram	nested_height_or_gc_span_length
struct MDBX_chk_histogram	key_len
struct MDBX_chk_histogram	val_len
struct MDBX_chk_histogram	multival
struct MDBX_chk_histogram	tree_density
struct MDBX_chk_histogram	large_or_nested_density
struct MDBX_chk_histogram	page_age
struct MDBX_chk_histogram	pgno
}	histogram

Member Data Documentation

cookie

MDBX_chk_user_table_cookie_t* MDBX_chk_table_t::cookie

flags

MDBX_db_flags_t MDBX_chk_table_t::flags

[struct]

struct { ... } MDBX_chk_table_t::histogram

id

int MDBX_chk_table_t::id

lost_bytes

size_t MDBX_chk_table_t::lost_bytes

name

MDBX_val MDBX_chk_table_t::name

[struct]

struct { ... } MDBX_chk_table_t::pages

payload_bytes

size_t MDBX_chk_table_t::payload_bytes

MDBX_chk_context_t

struct MDBX_chk_context_t

The context for checking the integrity of a database.

See also

mdbx_env_chk()

Public Attributes
struct MDBX_chk_internal *	internal
MDBX_env *	env
MDBX_txn *	txn
MDBX_chk_scope_t *	scope
uint8_t	scope_nesting
struct {
size_t	total_payload_bytes
size_t	table_total
size_t	table_processed
size_t	total_unused_bytes
size_t	unused_pages
size_t	processed_pages
size_t	reclaimable_pages
size_t	gc_pages
size_t	alloc_pages
size_t	backed_pages
size_t	problems_meta
size_t	tree_problems
size_t	gc_tree_problems
size_t	kv_tree_problems
size_t	problems_gc
size_t	problems_kv
size_t	total_problems
uint64_t	steady_txnid
uint64_t	recent_txnid
struct MDBX_chk_histogram	histogram_page_age
struct MDBX_chk_histogram	histogram_pgno_payload
struct MDBX_chk_histogram	histogram_pgno_retained
const MDBX_chk_table_t *const *	tables
}	result

Member Data Documentation

env

MDBX_env* MDBX_chk_context_t::env

internal

struct MDBX_chk_internal* MDBX_chk_context_t::internal

[struct]

struct { ... } MDBX_chk_context_t::result

scope

MDBX_chk_scope_t* MDBX_chk_context_t::scope

scope_nesting

uint8_t MDBX_chk_context_t::scope_nesting

txn

MDBX_txn* MDBX_chk_context_t::txn

MDBX_chk_callbacks_t

struct MDBX_chk_callbacks_t

A set of callback functions used for checking the integrity of a database.

The callback functions are designed to organize interaction with the application code. This includes the integration of application logic that verifies the integrity of a data structure above the key-value level, the preparation and structured output of information about both the progress and the results of verification.

All callback functions are optional, unused ones must be set to nullptr.

Note

This API has not been frozen yet, and there may be improvements and changes in subsequent versions.

See also

mdbx_env_chk()

Public Attributes
bool(*	check_break )(MDBX_chk_context_t *ctx)
int(*	scope_push )(MDBX_chk_context_t *ctx, MDBX_chk_scope_t *outer, MDBX_chk_scope_t *inner, const char *fmt, va_list args)
int(*	scope_conclude )(MDBX_chk_context_t *ctx, MDBX_chk_scope_t *outer, MDBX_chk_scope_t *inner, int err)
void(*	scope_pop )(MDBX_chk_context_t *ctx, MDBX_chk_scope_t *outer, MDBX_chk_scope_t *inner)
void(*	issue )(MDBX_chk_context_t *ctx, const char *object, uint64_t entry_number, const char *issue, const char *extra_fmt, va_list extra_args)
MDBX_chk_user_table_cookie_t *(*	table_filter )(MDBX_chk_context_t *ctx, const MDBX_val *name, MDBX_db_flags_t flags)
int(*	table_conclude )(MDBX_chk_context_t *ctx, const MDBX_chk_table_t *table, MDBX_cursor *cursor, int err)
void(*	table_dispose )(MDBX_chk_context_t *ctx, const MDBX_chk_table_t *table)
int(*	table_handle_kv )(MDBX_chk_context_t *ctx, const MDBX_chk_table_t *table, size_t entry_number, const MDBX_val *key, const MDBX_val *value)
int(*	stage_begin )(MDBX_chk_context_t *ctx, MDBX_chk_stage_t)
int(*	stage_end )(MDBX_chk_context_t *ctx, MDBX_chk_stage_t, int err)
MDBX_chk_line_t *(*	print_begin )(MDBX_chk_context_t *ctx, MDBX_chk_severity_t severity)
void(*	print_flush )(MDBX_chk_line_t *)
void(*	print_done )(MDBX_chk_line_t *)
void(*	print_chars )(MDBX_chk_line_t *, const char *str, size_t len)
void(*	print_format )(MDBX_chk_line_t *, const char *fmt, va_list args)
void(*	print_size )(MDBX_chk_line_t *, const char *prefix, const uint64_t value, const char *suffix)

Member Data Documentation

check_break

bool(* MDBX_chk_callbacks_t::check_break) (MDBX_chk_context_t *ctx)

issue

void(* MDBX_chk_callbacks_t::issue) (MDBX_chk_context_t *ctx, const char *object, uint64_t entry_number, const char *issue, const char *extra_fmt, va_list extra_args)

print_begin

MDBX_chk_line_t *(* MDBX_chk_callbacks_t::print_begin) (MDBX_chk_context_t *ctx, MDBX_chk_severity_t severity)

print_chars

void(* MDBX_chk_callbacks_t::print_chars) (MDBX_chk_line_t *, const char *str, size_t len)

print_done

void(* MDBX_chk_callbacks_t::print_done) (MDBX_chk_line_t *)

print_flush

void(* MDBX_chk_callbacks_t::print_flush) (MDBX_chk_line_t *)

print_format

void(* MDBX_chk_callbacks_t::print_format) (MDBX_chk_line_t *, const char *fmt, va_list args)

print_size

void(* MDBX_chk_callbacks_t::print_size) (MDBX_chk_line_t *, const char *prefix, const uint64_t value, const char *suffix)

scope_conclude

int(* MDBX_chk_callbacks_t::scope_conclude) (MDBX_chk_context_t *ctx, MDBX_chk_scope_t *outer, MDBX_chk_scope_t *inner, int err)

scope_pop

void(* MDBX_chk_callbacks_t::scope_pop) (MDBX_chk_context_t *ctx, MDBX_chk_scope_t *outer, MDBX_chk_scope_t *inner)

scope_push

int(* MDBX_chk_callbacks_t::scope_push) (MDBX_chk_context_t *ctx, MDBX_chk_scope_t *outer, MDBX_chk_scope_t *inner, const char *fmt, va_list args)

stage_begin

int(* MDBX_chk_callbacks_t::stage_begin) (MDBX_chk_context_t *ctx, MDBX_chk_stage_t)

stage_end

int(* MDBX_chk_callbacks_t::stage_end) (MDBX_chk_context_t *ctx, MDBX_chk_stage_t, int err)

table_conclude

int(* MDBX_chk_callbacks_t::table_conclude) (MDBX_chk_context_t *ctx, const MDBX_chk_table_t *table, MDBX_cursor *cursor, int err)

table_dispose

void(* MDBX_chk_callbacks_t::table_dispose) (MDBX_chk_context_t *ctx, const MDBX_chk_table_t *table)

table_filter

MDBX_chk_user_table_cookie_t *(* MDBX_chk_callbacks_t::table_filter) (MDBX_chk_context_t *ctx, const MDBX_val *name, MDBX_db_flags_t flags)

table_handle_kv

int(* MDBX_chk_callbacks_t::table_handle_kv) (MDBX_chk_context_t *ctx, const MDBX_chk_table_t *table, size_t entry_number, const MDBX_val *key, const MDBX_val *value)

MDBX_chk_scope_t.usr_z

union MDBX_chk_scope_t.usr_z

Class Members
size_t	number
void *	ptr

MDBX_chk_scope_t.usr_v

union MDBX_chk_scope_t.usr_v

Class Members
size_t	number
void *	ptr

MDBX_chk_scope_t.usr_o

union MDBX_chk_scope_t.usr_o

Class Members
size_t	number
void *	ptr

MDBX_chk_histogram.ranges

struct MDBX_chk_histogram.ranges

Class Members
size_t	amount
size_t	begin
size_t	count
size_t	end

MDBX_chk_table_t.pages

struct MDBX_chk_table_t.pages

Class Members
size_t	all
size_t	branch
size_t	broken
size_t	empty
size_t	leaf
size_t	nested_branch
size_t	nested_leaf
size_t	nested_subleaf

MDBX_chk_table_t.histogram

struct MDBX_chk_table_t.histogram

Class Members
struct MDBX_chk_histogram	height	Tree deep histogram
struct MDBX_chk_histogram	key_len	Keys length histogram
struct MDBX_chk_histogram	large_or_nested_density	Histogram of nested tree(s) branch and leaf pages filling in percents
struct MDBX_chk_histogram	large_pages	Histogram of large/overflow pages length
struct MDBX_chk_histogram	multival	Number of multi-values (aka duplicates) histogram
struct MDBX_chk_histogram	nested_height_or_gc_span_length	Histogram of nested trees height, span length for GC
struct MDBX_chk_histogram	page_age	Histogram of pages age
struct MDBX_chk_histogram	pgno	Histogram of used pgno
struct MDBX_chk_histogram	tree_density	Histogram of branch and leaf pages filling in percents
struct MDBX_chk_histogram	val_len	Values length histogram

MDBX_chk_context_t.result

struct MDBX_chk_context_t.result

Class Members
size_t	alloc_pages
size_t	backed_pages
size_t	gc_pages
size_t	gc_tree_problems
struct MDBX_chk_histogram	histogram_page_age	Histogram of pages age
struct MDBX_chk_histogram	histogram_pgno_payload	Histogram of pgno retained by readers
struct MDBX_chk_histogram	histogram_pgno_retained	Histogram of pgno used by all payload
size_t	kv_tree_problems
size_t	problems_gc
size_t	problems_kv
size_t	problems_meta
size_t	processed_pages
uint64_t	recent_txnid
size_t	reclaimable_pages
uint64_t	steady_txnid
size_t	table_processed
size_t	table_total
const MDBX_chk_table_t *const *	tables	A pointer to the array of table_total pointers to instances of MDBX_chk_table_t structures with information about all key-value tables, including MainDB and GC.
size_t	total_payload_bytes
size_t	total_problems
size_t	total_unused_bytes
size_t	tree_problems
size_t	unused_pages

Macro Definition Documentation

mdbx_env_open_for_recoveryT

#define mdbx_env_open_for_recoveryT	(		env,
			pathname,
			target_mets,
			writeable )

Value:

mdbx_env_open_for_recoveryW(env, pathname, target_mets, writeable)

mdbx_preopen_snapinfoT

#define mdbx_preopen_snapinfoT	(		pathname,
			info,
			bytes )

Value:

mdbx_preopen_snapinfoW(pathname, info, bytes)

Function Documentation

mdbx_env_turn_for_recovery()

LIBMDBX_API int mdbx_env_turn_for_recovery	(	MDBX_env *	env,
		unsigned	target_meta )

Turn database to the specified meta-page.

This function mostly of internal API for mdbx_chk utility and subject to change at any time. Do not use this function to avoid shooting your own leg(s).