UrlFileCacheInterface Class Reference

#include <urlfile_cache.h>

Detailed Description

UrlFileCacheInterface offers helper functions to allow to access to files with unsupported URLSCHEMEs. E.g. preset:// wont work with openexr because this lib needs a valid utf8 character path and InputStreams cannot be used to virtualize the read. In that case you would write:

maxon::Url url = MaxonConvert(name, MAXONCONVERTMODE::READ);
maxon::UrlFileCacheEntry fileCacheEntry;
 
if (!maxon::UrlFileCacheInterface::IsAccessible(url))
{
  fileCacheEntry = maxon::UrlFileCacheInterface::FindOrCreateUrl(url) iferr_return;
  url = fileCacheEntry.GetCacheUrl();
}
 
ifnoerr (maxon::BaseArray<Char> buffer = url.GetSystemPath().GetCString(maxon::StringEncodings::Utf8()))
  return exr_load(buffer.GetFirst(), &wbm);
else
  return IMAGERESULT::MISC_ERROR;

Static Public Member Functions
static MAXON_METHOD Bool	IsAccessible (const maxon::Url &url)
static MAXON_METHOD Result< UrlFileCacheEntry >	FindOrCreateUrl (const Url &sourceUrl, const TimeValue &maxCacheTime=Seconds(1.0), URLFILECACHEFLAGS flags=URLFILECACHEFLAGS::NONE)
static MAXON_METHOD Result< void >	FlushCache (const Url &url)

Private Member Functions
	MAXON_INTERFACE_NONVIRTUAL (UrlFileCacheInterface, MAXON_REFERENCE_STATIC, "net.maxon.interface.urlfilecache")

Member Function Documentation

MAXON_INTERFACE_NONVIRTUAL()

MAXON_INTERFACE_NONVIRTUAL ( UrlFileCacheInterface  , MAXON_REFERENCE_STATIC  , "net.maxon.interface.urlfilecache"    )

private

IsAccessible()

static MAXON_METHOD Bool IsAccessible ( const maxon::Url &  url )

static

Check if the url scheme is directly accessible via fopen().

Parameters

[in]

url

Url to check.

Returns

true if the url can accessed directly. false if the url needs a cached copy. in that case use UrlFileCacheInterface::FindOrCreateUrl() to create or find the cache file.

FindOrCreateUrl()

static MAXON_METHOD Result<UrlFileCacheEntry> FindOrCreateUrl ( const Url &  sourceUrl, const TimeValue &  maxCacheTime = Seconds(1.0), URLFILECACHEFLAGS  flags = URLFILECACHEFLAGS::NONE  )

static

Finds or creates a new UrlFileCacheEntry for the given source Url.

Parameters

[in]	sourceUrl	Url to be cached.
[in]	maxCacheTime	Time to wait until to delete the cache file after it's not needed anymore.
[in]	flags	See URLFILECACHEFLAGS.

Returns

A UrlFileCacheEntry which ensures the existence of the cache file as long as any reference to this handle exists.

FlushCache()

static MAXON_METHOD Result<void> FlushCache ( const Url &  url )

static

Flushes the url from the cache. Existing UrlFileCacheEntries keep alive until the last handle vanishes. Calling the FindOrCreateUrl will create a new cache file for this url.