コード例 #1
0
ファイル: memSegmentManager.cs プロジェクト: luanzhu/OOD.NET
        public override Segment GetSegment(uint segId, Segment segFactory, object helper)
        {
            Debug.Assert(segId >= (m_bitmap.Data.Length >> m_pageBits));
            Debug.Assert(m_bitmap.PageFree(segId) == false);

            if (m_cache.Exists(segId))
            {
                //requested page is in the cache
                Segment seg = m_cache.Retrive(segId);
                //update recently used page list, move this one to the front of the list, most recently used.
                seg.BreakLinks();
                seg.BuildLinks(m_LRU, m_LRU.Next);

                return(seg);
            }
            else
            {
                //the requested page is not in the cache, read it from disk
                byte[]  content = m_diskFile.SynRead(segId * m_pageSize, m_pageSize);
                Segment seg     = segFactory.Deserialize(segId, helper, content);

                _put_in_cache(seg);

                return(seg);
            }
        }
コード例 #2
0
ファイル: memSegmentManager.cs プロジェクト: luanzhu/OOD.NET
		public override Segment GetSegment(uint segId, Segment segFactory, object helper)
		{
			Debug.Assert(segId >= (m_bitmap.Data.Length >> m_pageBits));
			Debug.Assert(m_bitmap.PageFree(segId) == false);

			if (m_cache.Exists(segId))
			{
				//requested page is in the cache
				Segment seg = m_cache.Retrive(segId);
				//update recently used page list, move this one to the front of the list, most recently used.
				seg.BreakLinks();
				seg.BuildLinks(m_LRU, m_LRU.Next);

				return seg;
			}
			else
			{
				//the requested page is not in the cache, read it from disk
				byte[] content = m_diskFile.SynRead(segId*m_pageSize, m_pageSize);
				Segment seg = segFactory.Deserialize(segId, helper, content);

				_put_in_cache(seg);
				
				return seg;
			}
 		}
コード例 #3
0
        public override Segment GetSegment(uint segId, Segment segFactory, object helper)
        {
            Segment result = null;

            //check if this segment is already in cache
            if (m_cache.Exists(segId))
            {
                result = m_cache.Retrive(segId);

                //update the least recently used list
                result.BreakLinks();
                result.BuildLinks(m_LRU, m_LRU.Next);

                return(result);
            }
            else
            {
                //if not, read that from disk
                uint offset = 0;
                int  length = 0;
                if (m_segTree.GetAddr(segId, ref offset, ref length))
                {
                    // put this segment into cache
                    byte[] content = m_diskFile.SynRead(offset, length);
                    result = segFactory.Deserialize(segId, helper, content);

                    _put_in_cache(result);
                }
                else
                {
                    throw new OOD.Exception.ProgramLogicError(
                              this,
                              "Trying to access a non-existing segment.");
                }
                return(result);
            }
        }
コード例 #4
0
ファイル: dbSegmentManager.cs プロジェクト: luanzhu/OOD.NET
		public override Segment GetSegment(uint segId, Segment segFactory, object helper)
		{
			Segment result = null;

			//check if this segment is already in cache
			if (m_cache.Exists(segId))
			{
				result = m_cache.Retrive(segId);

				//update the least recently used list
				result.BreakLinks();
				result.BuildLinks(m_LRU, m_LRU.Next);

				return result;
			}
			else
			{
				//if not, read that from disk
				uint offset = 0;
				int length = 0;
				if (m_segTree.GetAddr(segId, ref offset, ref length))
				{
					// put this segment into cache
                    byte[] content = m_diskFile.SynRead(offset, length);
					result = segFactory.Deserialize(segId, helper, content);

					_put_in_cache(result);
				}
				else
					throw new OOD.Exception.ProgramLogicError(
						this,
						"Trying to access a non-existing segment.");
				return result;	
			}
			
		}