Exemple #1
0
        internal static List <DiskRange> getStreamBuffers(DiskRangeList range, long offset, long length)
        {
            // This assumes sorted ranges (as do many other parts of ORC code.
            List <DiskRange> buffers = new List <DiskRange>();

            if (length == 0)
            {
                return(buffers);
            }
            long streamEnd = offset + length;
            bool inRange   = false;

            while (range != null)
            {
                if (!inRange)
                {
                    if (range.getEnd() <= offset)
                    {
                        range = range.next;
                        continue; // Skip until we are in range.
                    }
                    inRange = true;
                    if (range.getOffset() < offset)
                    {
                        // Partial first buffer, add a slice of it.
                        buffers.Add(range.sliceAndShift(offset, Math.Min(streamEnd, range.getEnd()), -offset));
                        if (range.getEnd() >= streamEnd)
                        {
                            break;                              // Partial first buffer is also partial last buffer.
                        }
                        range = range.next;
                        continue;
                    }
                }
                else if (range.getOffset() >= streamEnd)
                {
                    break;
                }
                if (range.getEnd() > streamEnd)
                {
                    // Partial last buffer (may also be the first buffer), add a slice of it.
                    buffers.Add(range.sliceAndShift(range.getOffset(), streamEnd, -offset));
                    break;
                }
                // Buffer that belongs entirely to one stream.
                // TODO: ideally we would want to reuse the object and remove it from the list, but we cannot
                //       because bufferChunks is also used by clearStreams for zcr. Create a useless dup.
                buffers.Add(range.sliceAndShift(range.getOffset(), range.getEnd(), -offset));
                if (range.getEnd() == streamEnd)
                {
                    break;
                }
                range = range.next;
            }
            return(buffers);
        }
Exemple #2
0
        /**
         * Read the list of ranges from the file.
         * @param file the file to read
         * @param base the base of the stripe
         * @param ranges the disk ranges within the stripe to read
         * @return the bytes read for each disk range, which is the same length as
         *    ranges
         * @
         */
        static DiskRangeList readDiskRanges(Stream file,
                                            long @base,
                                            DiskRangeList range,
                                            bool doForceDirect)
        {
            if (range == null)
            {
                return(null);
            }
            DiskRangeList prev = range.prev;

            if (prev == null)
            {
                prev = new DiskRangeList.MutateHelper(range);
            }
            while (range != null)
            {
                if (range.hasData())
                {
                    range = range.next;
                    continue;
                }
                int  len = (int)(range.getEnd() - range.getOffset());
                long off = range.getOffset();
                if (doForceDirect)
                {
                    file.Seek(@base + off, SeekOrigin.Current);
                    ByteBuffer directBuf = ByteBuffer.allocateDirect(len);
                    readDirect(file, len, directBuf);
                    range = range.replaceSelfWith(new RecordReaderImpl.BufferChunk(directBuf, range.getOffset()));
                }
                else
                {
                    byte[] buffer = new byte[len];
                    file.readFully((@base + off), buffer, 0, buffer.Length);
                    range = range.replaceSelfWith(new RecordReaderImpl.BufferChunk(ByteBuffer.wrap(buffer), range.getOffset()));
                }
                range = range.next;
            }
            return(prev.next);
        }