MMappedUUIDHashTable::table_t Struct Reference

On-disk layout of the hash table stored in the mmap file. More...

Collaboration diagram for MMappedUUIDHashTable::table_t:

Public Member Functions
constexpr unsigned long	capacity ()
	Maximum number of slots in the table (2^log_size).

Static Public Member Functions
static constexpr std::size_t	sizeForLogSize (unsigned ls)
	Compute the file size required for a table with 2^ls slots.
static constexpr unsigned	logSizeForSize (std::size_t size)
	Compute the log2 of the slot count from the file size.

Public Attributes
uint64_t	magic
	File-type identifier.
uint16_t	version
	Format version (currently 1).
uint16_t	elem_size
	sizeof(value_t) at write time
uint32_t	_reserved
	Padding, must be 0.
unsigned	log_size
	log2 of the number of slots
unsigned long	nb_elements
	Current number of stored key-value pairs.
unsigned long	next_value
	Next integer value to assign to a new UUID.
value_t	t []
	Flexible array of hash-table slots.

Detailed Description

On-disk layout of the hash table stored in the mmap file.

The header fields are followed by a flexible array of value_t slots.

Definition at line 51 of file MMappedUUIDHashTable.h.

Member Function Documentation

capacity()

unsigned long MMappedUUIDHashTable::table_t::capacity ( )

inlineconstexpr

Maximum number of slots in the table (2^log_size).

Returns

Current capacity (number of available hash-table slots).

Definition at line 80 of file MMappedUUIDHashTable.h.

logSizeForSize()

constexpr unsigned MMappedUUIDHashTable::table_t::logSizeForSize ( std::size_t size )

inlinestaticconstexpr

Compute the log2 of the slot count from the file size.

Parameters

size	File size in bytes.

Returns

Log2 of the number of slots that fit in size.

Definition at line 65 of file MMappedUUIDHashTable.h.

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sizeForLogSize()

constexpr std::size_t MMappedUUIDHashTable::table_t::sizeForLogSize ( unsigned ls )

inlinestaticconstexpr

Compute the file size required for a table with 2^ls slots.

Parameters

ls	Log2 of the desired slot count.

Returns

Required file size in bytes.

Definition at line 57 of file MMappedUUIDHashTable.h.

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Member Data Documentation

_reserved

uint32_t MMappedUUIDHashTable::table_t::_reserved

Padding, must be 0.

Definition at line 87 of file MMappedUUIDHashTable.h.

elem_size

uint16_t MMappedUUIDHashTable::table_t::elem_size

sizeof(value_t) at write time

Definition at line 86 of file MMappedUUIDHashTable.h.

log_size

unsigned MMappedUUIDHashTable::table_t::log_size

log2 of the number of slots

Definition at line 88 of file MMappedUUIDHashTable.h.

magic

uint64_t MMappedUUIDHashTable::table_t::magic

File-type identifier.

Definition at line 84 of file MMappedUUIDHashTable.h.

nb_elements

unsigned long MMappedUUIDHashTable::table_t::nb_elements

Current number of stored key-value pairs.

Definition at line 89 of file MMappedUUIDHashTable.h.

next_value

unsigned long MMappedUUIDHashTable::table_t::next_value

Next integer value to assign to a new UUID.

Definition at line 90 of file MMappedUUIDHashTable.h.

t

value_t MMappedUUIDHashTable::table_t::t[]

Flexible array of hash-table slots.

Definition at line 91 of file MMappedUUIDHashTable.h.

version

uint16_t MMappedUUIDHashTable::table_t::version

Format version (currently 1).

Definition at line 85 of file MMappedUUIDHashTable.h.

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The documentation for this struct was generated from the following file:

• /home/pierre/git/software/provsql/src/MMappedUUIDHashTable.h