AccessRangeUncached() public méthode

Accesses a range of bytes within the stream, bypassing the stream cache.
public AccessRangeUncached ( long offset, uint size, MemoryMappedFileAccess access = MemoryMappedFileAccess.ReadWrite ) : StreamRange
offset long The offset within the stream, relative to the end of the stream header.
size uint The size of the range to access, in bytes.
access MemoryMappedFileAccess
Résultat StreamRange
StreamRef Class Documentation
Exemple #1
0
        private void EnsureFreelistExists()
        {
            var pHeader = (BTreeHeader *)_HeaderRange.Pointer;

            if (EnableFreelist)
            {
                long oldOffset = 0;

                if (pHeader->FreelistIndexOffset == 0)
                {
                    uint size   = FreelistIndex.Size;
                    long?offset = AllocateDataSpace(ref size);
                    if (!offset.HasValue)
                    {
                        throw new OutOfMemoryException("Unable to allocate space for freelist index in data stream.");
                    }

                    oldOffset = Interlocked.Exchange(ref pHeader->FreelistIndexOffset, offset.Value);
                }

                _FreelistIndexRange = DataStream.AccessRangeUncached(pHeader->FreelistIndexOffset, FreelistIndex.Size, MemoryMappedFileAccess.ReadWrite);
                Native.memset(_FreelistIndexRange.Pointer, 0, new UIntPtr(FreelistIndex.Size / 4));

                if (oldOffset != 0)
                {
                    FreelistPut(oldOffset, FreelistIndex.Size);
                }
            }
            else
            {
                pHeader->FreelistIndexOffset = 0;
            }
        }
Exemple #2
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        public BTree(StreamSource storage, string prefix)
        {
            Storage = storage;
            Prefix  = prefix;

            IndexStream = Storage.Open(prefix + "index");
            KeyStream   = Storage.Open(prefix + "keys");
            DataStream  = Storage.Open(prefix + "data");

            VersionCheck(IndexStream);
            VersionCheck(KeyStream);
            VersionCheck(DataStream);

            bool needInit = IndexStream.Length < BTreeHeader.Size;

            IndexStream.LengthChanging += IndexStream_LengthChanging;
            IndexStream.LengthChanged  += IndexStream_LengthChanged;

            DataStream.LengthChanging += DataStream_LengthChanging;
            DataStream.LengthChanged  += DataStream_LengthChanged;

            _GetKeyOfEntry = ReadKey;

            _HeaderRange = IndexStream.AccessRangeUncached(0, BTreeHeader.Size);

            if (needInit)
            {
                InitializeBTree();
            }

            _FreelistBucketLocks = new object[FreelistIndex.BucketCount];
            for (int i = 0; i < _FreelistBucketLocks.Length; i++)
            {
                _FreelistBucketLocks[i] = new object();
            }

            EnsureFreelistExists();
        }
Exemple #3
0
 void IndexStream_LengthChanged(object sender, EventArgs e)
 {
     _HeaderRange = IndexStream.AccessRangeUncached(0, BTreeHeader.Size);
 }