Holder of temporary data to read files from cache: More...
Inherited by DD::Image::FileStreamRead, ImageCacheRead, and ImageCacheWriteRead.
Public Member Functions | |
| virtual size_t | read (void *to, size_t n)=0 |
| bool | tryRead (void *t, size_t n) |
| virtual void | seek (size_t to)=0 |
| virtual void | seekRelative (off_t offset)=0 |
| virtual void | close ()=0 |
| virtual int | uniqueID () const =0 |
Holder of temporary data to read files from cache:
| virtual size_t DD::Image::ImageCacheReadI::read | ( | void * | to, |
| size_t | n | ||
| ) | [pure virtual] |
Read a block of data from a file opened with Image_Cache::open(). Returns number of bytes read.
Referenced by DD::Image::ViewerCache::read_from_cache().
| bool DD::Image::ImageCacheReadI::tryRead | ( | void * | t, |
| size_t | n | ||
| ) | [inline] |
Try to read a certain number of bytes. If it fails to read that number, return false.
| virtual void DD::Image::ImageCacheReadI::seek | ( | size_t | to | ) | [pure virtual] |
Move the file pointer to an absolute position in the file.
| virtual void DD::Image::ImageCacheReadI::seekRelative | ( | off_t | offset | ) | [pure virtual] |
Move the file pointer by n bytes.
Referenced by DD::Image::ViewerCache::read_from_cache().
| virtual void DD::Image::ImageCacheReadI::close | ( | ) | [pure virtual] |
Close the file and delete the r data structure.
Referenced by DD::Image::ViewerCache::BoxPresent(), and DD::Image::ViewerCache::read_from_cache().
| virtual int DD::Image::ImageCacheReadI::uniqueID | ( | ) | const [pure virtual] |
get a unique ID for the memory-cached data, or 0 if the data was not in the memory cache. if the contents of the memory-cached data change (or if the data is removed from the memory cache and then reloaded) this number will increase.
Referenced by DD::Image::ViewerCache::BoxPresent().