Function DropRelFileNodeLocalBuffers

src/backend/storage/buffer/localbuf.c:346–390

* DropRelFileNodeLocalBuffers * This function removes from the buffer pool all the pages of the * specified relation that have block numbers >= firstDelBlock. * (In particular, with firstDelBlock = 0, all pages are removed.) * Dirty pages are simply dropped, without bothering to write them * out first. Therefore, this is NOT rollback-able, and so should be * used only with extreme cau

 *		See DropRelFileNodeBuffers in bufmgr.c for more notes.
 */
void
DropRelFileNodeLocalBuffers(RelFileNode rnode, ForkNumber forkNum,
							BlockNumber firstDelBlock)
{
	int			i;

	/*
	 * Local buffers are used for temp tables in PostgreSQL.  As temp tables
	 * use shared buffers in Cloudberry, we shouldn't be useing local buffers
	 * for anything.
	 */
	Assert(false);
	for (i = 0; i < NLocBuffer; i++)
	{
		BufferDesc *bufHdr = GetLocalBufferDescriptor(i);
		LocalBufferLookupEnt *hresult;
		uint32		buf_state;

		buf_state = pg_atomic_read_u32(&bufHdr->state);

		if ((buf_state & BM_TAG_VALID) &&
			RelFileNodeEquals(bufHdr->tag.rnode, rnode) &&
			bufHdr->tag.forkNum == forkNum &&
			bufHdr->tag.blockNum >= firstDelBlock)
		{
			if (LocalRefCount[i] != 0)
				elog(ERROR, "block %u of %s is still referenced (local %u)",
					 bufHdr->tag.blockNum,
					 relpathbackend(bufHdr->tag.rnode, MyBackendId,
									bufHdr->tag.forkNum),
					 LocalRefCount[i]);
			/* Remove entry from hashtable */
			hresult = (LocalBufferLookupEnt *)
				hash_search(LocalBufHash, (void *) &bufHdr->tag,
							HASH_REMOVE, NULL);
			if (!hresult)		/* shouldn't happen */
				elog(ERROR, "local buffer hash table corrupted");
			/* Mark buffer invalid */
			CLEAR_BUFFERTAG(bufHdr->tag);
			buf_state &= ~BUF_FLAG_MASK;
			buf_state &= ~BUF_USAGECOUNT_MASK;
			pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
		}
	}
}

/*
 * DropRelFileNodeAllLocalBuffers