A block of bytes that holds one or more
VertexDataBlocks. The entire page may be paged out, in the form of in-memory compression or to an on-disk cache file, if necessary.
These are used to indicate the current residency state of the page, which may or may not have been temporarily evicted to satisfy memory requirements.
enumerator RC_resident = 0
enumerator RC_compressed = 1
enumerator RC_disk = 2
enumerator RC_end_of_list = 3
list marker; do not use
- enumerator RC_resident = 0
VertexDataBlock *alloc(std::size_t size)
Allocates a new block. Returns NULL if a block of the requested size cannot be allocated.
To free the allocated block, call block->free(), or simply delete the block pointer.
static void flush_threads(void)
Waits for all of the pending thread tasks to finish before returning.
VertexDataBlock *get_first_block(void) const
Returns a pointer to the first allocated block, or NULL if there are no allocated blocks.
SimpleLru *get_global_lru(VertexDataPage::RamClass rclass)
Returns a pointer to the global LRU object that manages the VertexDataPage’s with the indicated
Returns the number of read requests that are waiting to be serviced by a thread.
Returns the number of write requests that are waiting to be serviced by a thread.
Returns the number of threads that have been spawned to service vertex paging requests, or 0 if no threads have been spawned (which may mean either that all paging requests will be handled by the main thread, or simply that no paging requests have yet been issued).
Returns a pointer to the global LRU object that manages the VertexDataPage’s that are pending processing by the thread.
RamClass get_pending_ram_class(void) const
Returns the pending ram class of the array. If this is different from
get_ram_class(), this page has been queued to be processed by the thread. Eventually the page will be set to this ram class.
RamClass get_ram_class(void) const
Returns the current ram class of the array. If this is other than RC_resident, the array data is not resident in memory.
Returns the global
VertexDataSaveFilethat will be used to save vertex data buffers to disk when necessary.
virtual void output(std::ostream &out) const
Ensures that the page will become resident soon. Future calls to get_page_data() will eventually return non-NULL.
Writes the page to disk, but does not evict it from memory or affect its LRU status. If it gets evicted later without having been modified, it will not need to write itself to disk again.
static void stop_threads(void)
Call this to stop the paging threads, if they were started. This may block until all of the pending tasks have been completed.
virtual void write(std::ostream &out, int indent_level) const
- enum RamClass