Fetch web resources caching them in the local filesystem following XDG specifications. More...

#include <WebCache.h>

Inheritance diagram for rose::WebCache:

Collaboration diagram for rose::WebCache:

Public Types
using	key_t = uint32_t

using	local_id_t = std::string

using	result_t = std::tuple< long, key_t >

using	item_map_t = std::map< key_t, local_id_t >

using	AsyncList = std::vector< std::future< result_t > >

Public Member Functions
	WebCache (const std::string &rootUri, const path &xdgDir, const std::string &storeRoot, std::chrono::system_clock::duration duration)
	Constructor. More...

template<typename It >
	WebCache (const std::string &rootUri, const path &xdgDir, const std::string &storeRoot, std::chrono::system_clock::duration duration, It first, It last)

void	setCacheItem (key_t key, local_id_t localId)
	Add or change a cache item. More...

template<typename It >
void	setCacheItem (It first, It last)
	Add or change cache items from a container. More...

bool	storeExists () const
	Test to see if the store exists. More...

virtual std::string	translateItemLocalId (local_id_t localId)
	Translate a local id. More...

path	itemLocalPath (key_t key)
	Get the filesystem path of a local item by key. More...

std::optional< path >	localItemExists (key_t key)
	Get the local path to an item if it is known and exists in the local store. More...

std::optional< time_t >	cacheTime (const path &itemPath)
	Get the time the item was cached if the cache time has expired. More...

virtual std::string	constructUrl (const local_id_t &localId)
	Construct the appropriate URL for the item. More...

bool	itemKnown (key_t key)

bool	fetchAll ()
	Fetch all cache items which have not been previously cached or have expired cache times.

bool	fetchItem (key_t key)

bool	pendingFutures () const

bool	processFutures ()

Static Public Member Functions
template<typename T >
static std::chrono::system_clock::time_point	fileClockToSystemClock (T fileTimePoint)
	Convert a filesystem time to a system clock time point. More...

static std::chrono::system_clock::time_point	fileClockToSystemClock (const path &filePath)
	Convert a filesystem time to a system clock time point. More...

static WebCache::result_t	fetch (WebCache::key_t key, const std::string &itemUrl, const path &itemPath, const path &tempPath, std::optional< time_t > cacheFileTime)
	Fetch a cache item. More...

Public Attributes
WebCacheProtocol::signal_type	cacheLoaded {}

Protected Member Functions
void	asyncFetchItem (item_map_t::value_type &item)

Protected Attributes
std::error_code	mEc {}
	The last error code returned from a std::filesystem operation.

std::string	mRootURI {}
	The root URI for items in the cache.

path	mStoreRoot {}
	The root of the filesystem backing store.

file_status	mStoreStatus {}
	File status of the filesystem backing store root.

std::mutex	mMutex
	Mutex for locking the WebFileCache.

item_map_t	mItemMap {}
	The map of keys to local cache items.

AsyncList	mAsyncList {}
	The list of asynchronous fetches active.

std::chrono::system_clock::duration	mCacheValidDuration {}
	The duration local files are considered valid. The interval between cache refresh checks.

Detailed Description

Fetch web resources caching them in the local filesystem following XDG specifications.

Constructor & Destructor Documentation

◆ WebCache()

rose::WebCache::WebCache	(	const std::string &	rootUri,
		const path &	xdgDir,
		const std::string &	storeRoot,
		std::chrono::system_clock::duration	duration
	)

Constructor.

Parameters

rootUri	The base URI locating all the items manage by the cache.
xdgDir	The XDG compliant specification for the user caching directory. See rose::Environment.
storeRoot	A relative path from xdgDir that this cache will use.
duration	The period of time cache items should be considered valid before being reloaded.

Member Function Documentation

◆ cacheTime()

std::optional<time_t> rose::WebCache::cacheTime ( const path & itemPath )

inline

Get the time the item was cached if the cache time has expired.

Parameters

itemPath The item path (returned by itemLocalPath()).

Returns: A time_t expressing the last write time of the local file if cache time has expired, an empty std::optional otherwise.

◆ constructUrl()

virtual std::string rose::WebCache::constructUrl ( const local_id_t & localId )

inlinevirtual

Construct the appropriate URL for the item.

Default procedure is to append the local id to the rout URI.

Parameters

localId The local id.

Returns: The constructed URL.

Reimplemented in rose::ClearSkyEphemeris, and ClearSkyEphemeris.

◆ fetch()

WebCache::result_t rose::WebCache::fetch	(	WebCache::key_t	key,
		const std::string &	itemUrl,
		const path &	itemPath,
		const path &	tempPath,
		std::optional< time_t >	cacheFileTime
	)

static

Fetch a cache item.

Parameters

key	The item key.
itemUrl	The item url (returned by constructUrl()).
itemPath	The full item path.
cacheFileTime	The std::optional returned by cacheTime().

Returns: A tuple containing the returned HTTP status code and the item key.

◆ fileClockToSystemClock() [1/2]

template<typename T >

static std::chrono::system_clock::time_point rose::WebCache::fileClockToSystemClock ( T fileTimePoint )

inlinestatic

Convert a filesystem time to a system clock time point.

Template Parameters

T	The type of the file time point.

Parameters

fileTimePoint The value of the file time point.

Returns: std::chrono::system_clock::time_point.

◆ fileClockToSystemClock() [2/2]

static std::chrono::system_clock::time_point rose::WebCache::fileClockToSystemClock ( const path & filePath )

inlinestatic

Convert a filesystem time to a system clock time point.

Parameters

filePath The filesystem path to get the last write time from.

Returns: std::chrono::system_clock::time_point.

◆ itemLocalPath()

path rose::WebCache::itemLocalPath ( key_t key )

inline

Get the filesystem path of a local item by key.

Parameters

key	The key to search for.

Returns: The translated local id. See translateItemLocalId().

◆ localItemExists()

std::optional<path> rose::WebCache::localItemExists ( key_t key )

inline

Get the local path to an item if it is known and exists in the local store.

Parameters

key	The item key.

Returns: std::optional<path> with the file path if it exists.

◆ setCacheItem() [1/2]

void rose::WebCache::setCacheItem	(	key_t	key,
		local_id_t	localId
	)

inline

Add or change a cache item.

Parameters

key	The key to identify the cache item.
localId	The local identity in the filesystem cache, the file name.

◆ setCacheItem() [2/2]

template<typename It >

void rose::WebCache::setCacheItem	(	It	first,
		It	last
	)

inline

Add or change cache items from a container.

Template Parameters

It	The iterator type.

Parameters

first	The first item iterator.
last	The last item iterator.

◆ storeExists()

bool rose::WebCache::storeExists ( ) const

inline

Test to see if the store exists.

Returns: True if it exits and is a directory.

◆ translateItemLocalId()

virtual std::string rose::WebCache::translateItemLocalId ( local_id_t localId )

inlinevirtual

Translate a local id.

This provides a method for derived cache types to modify the local name to something more suitable to the backing filesystem including prepending a relative path. The default is to do nothing.

Parameters

localId The local id to translate.

Returns: The translated local id.

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

src/WebCache.h
src/WebCache.cpp

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ WebCache()

Member Function Documentation

◆ cacheTime()

◆ constructUrl()

◆ fetch()

◆ fileClockToSystemClock() [1/2]

◆ fileClockToSystemClock() [2/2]

◆ itemLocalPath()

◆ localItemExists()

◆ setCacheItem() [1/2]

◆ setCacheItem() [2/2]

◆ storeExists()

◆ translateItemLocalId()