ltrans_file_cache Class Reference

#include <lto-ltrans-cache.h>

Collaboration diagram for ltrans_file_cache:

Data Structures
struct	item

Public Member Functions
	ltrans_file_cache (const char *dir, const char *prefix, const char *suffix, size_t soft_cache_size)
	~ltrans_file_cache ()
void	load_cache ()
void	save_cache ()
bool	add_to_cache (const char *filename, item *&_item)
item *	get_item (const char *input)
void	try_prune ()
void	cleanup ()
	operator bool ()

Data Fields
lockfile	creation_lock
lockfile	deletion_lock
const char *	dir

Private Member Functions
void	add_item (item *item)
item *	create_item (checksum_t checksum)
void	prune ()
std::string	filename_cachedata ()

Private Attributes
std::vector< item * >	items
std::map< checksum_t, item * >	map_checksum
std::map< std::string, item * >	map_input
const char *	prefix
const char *	suffix
size_t	soft_cache_size
uint32_t	usage_counter
std::string	cache_prefix
uint32_t	cache_free_idx
char *	str_buffer

Constructor & Destructor Documentation

ltrans_file_cache()

ltrans_file_cache::ltrans_file_cache	(	const char *	dir,
		const char *	prefix,
		const char *	suffix,
		size_t	soft_cache_size )

Constructor.  Resulting cache item filenames will be
in format `prefix%d[.ltrans]suffix`.   

References cache_free_idx, cache_prefix, creation_lock, deletion_lock, dir, prefix, str_buffer, and suffix.

~ltrans_file_cache()

ltrans_file_cache::~ltrans_file_cache

(

)

Destructor.   

References cleanup(), free(), and str_buffer.

Member Function Documentation

add_item()

void ltrans_file_cache::add_item ( ltrans_file_cache::item * item )

private

Adds given cache item to all relevant datastructures.   

References ltrans_file_cache::item::input, ltrans_file_cache::item::input_checksum, items, ltrans_file_cache::item::last_used, map_checksum, map_input, and usage_counter.

Referenced by add_to_cache(), load_cache(), and prune().

add_to_cache()

bool ltrans_file_cache::add_to_cache	(	const char *	filename,
		item *&	_item )

Adds input file into cache.  Cache item with input file identical to
added input file will be returned as _item.
If the file was already cached, `true` is returned, `false` otherwise.
The added input file is deleted (or moved).

Must be called with creation_lock held to prevent data race.   

References add_item(), create_item(), file_checksum(), files_identical(), ltrans_file_cache::item::input, ltrans_file_cache::item::last_used, map_checksum, and usage_counter.

Referenced by run_gcc().

cleanup()

void ltrans_file_cache::cleanup

(

)

Clears cache class, as if only constructor was called.   

References items, map_checksum, map_input, and usage_counter.

Referenced by load_cache(), prune(), and ~ltrans_file_cache().

create_item()

ltrans_file_cache::item * ltrans_file_cache::create_item ( checksum_t checksum )

private

Creates new cache item with given checksum.
New input/output files are chosen to not collide with other items.

Must be called with creation_lock held to prevent data race.   

References cache_free_idx, cache_prefix, map_input, str_buffer, suffix, and usage_counter.

Referenced by add_to_cache().

filename_cachedata()

std::string ltrans_file_cache::filename_cachedata ( )

private

Creates cachedata filename for save/load.   

References dir.

Referenced by load_cache(), and save_cache().

get_item()

ltrans_file_cache::item * ltrans_file_cache::get_item

(

const char *

input

)

If exists, returns cache item corresponding to cached input file.   

References map_input, and NULL.

Referenced by run_gcc().

load_cache()

void ltrans_file_cache::load_cache

(

)

Loads data about previously cached items from cachedata file.
Sorts items by last_used and remaps last_used to small integers.

Must be called with creation_lock or deletion_lock held to
prevent data race.   

References a, add_item(), b, cleanup(), dir, filename_cachedata(), fopen, i, items, read_cache_item(), and usage_counter.

Referenced by prune(), and run_gcc().

operator bool()

ltrans_file_cache::operator bool ( )

inline

References dir.

prune()

void ltrans_file_cache::prune ( )

private

Prunes oldest unused cache items over limit.
Must be called with deletion_lock held to prevent data race.   

References add_item(), cleanup(), file_exists(), i, ltrans_file_cache::item::input, items, load_cache(), ltrans_file_cache::item::output, save_cache(), and soft_cache_size.

Referenced by try_prune().

save_cache()

void ltrans_file_cache::save_cache

(

)

Rewrites data about cache items into cachedata file.

Must be only called when creation_lock or deletion_lock was held since last
call to load_cache.   

References dir, filename_cachedata(), fopen, items, and write_cache_item().

Referenced by prune(), and run_gcc().

try_prune()

void ltrans_file_cache::try_prune

(

)

If no other process holds the deletion_lock, prunes oldest unused cache
items over limit.   

References deletion_lock, prune(), lockfile::try_lock_write(), and lockfile::unlock().

Referenced by run_gcc().

Field Documentation

cache_free_idx

uint32_t ltrans_file_cache::cache_free_idx

private

Referenced by create_item(), and ltrans_file_cache().

cache_prefix

std::string ltrans_file_cache::cache_prefix

private

Referenced by create_item(), and ltrans_file_cache().

creation_lock

lockfile ltrans_file_cache::creation_lock

Referenced by ltrans_file_cache(), and run_gcc().

deletion_lock

lockfile ltrans_file_cache::deletion_lock

Referenced by ltrans_file_cache(), run_gcc(), and try_prune().

dir

const char* ltrans_file_cache::dir

Referenced by filename_cachedata(), load_cache(), ltrans_file_cache(), operator bool(), read_cache_item(), save_cache(), and write_cache_item().

items

std::vector<item*> ltrans_file_cache::items

private

Referenced by add_item(), cleanup(), load_cache(), prune(), and save_cache().

map_checksum

std::map<checksum_t, item*> ltrans_file_cache::map_checksum

private

Referenced by add_item(), add_to_cache(), and cleanup().

map_input

std::map<std::string, item*> ltrans_file_cache::map_input

private

Referenced by add_item(), cleanup(), create_item(), and get_item().

prefix

const char* ltrans_file_cache::prefix

private

Referenced by ltrans_file_cache().

soft_cache_size

size_t ltrans_file_cache::soft_cache_size

private

Referenced by prune().

str_buffer

char* ltrans_file_cache::str_buffer

private

Referenced by create_item(), ltrans_file_cache(), and ~ltrans_file_cache().

suffix

const char* ltrans_file_cache::suffix

private

Referenced by create_item(), and ltrans_file_cache().

usage_counter

uint32_t ltrans_file_cache::usage_counter

private

Referenced by add_item(), add_to_cache(), cleanup(), create_item(), and load_cache().

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The documentation for this class was generated from the following files:

• lto-ltrans-cache.h
• lto-ltrans-cache.cc