From 1f0c6a7638353d1ebbbc4ba1a8de0887d5f68e98 Mon Sep 17 00:00:00 2001 From: pacien Date: Fri, 30 Nov 2018 21:06:39 +0100 Subject: isolate blocks --- src/blocks/rawblock.nim | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 src/blocks/rawblock.nim (limited to 'src/blocks/rawblock.nim') diff --git a/src/blocks/rawblock.nim b/src/blocks/rawblock.nim new file mode 100644 index 0000000..2b32831 --- /dev/null +++ b/src/blocks/rawblock.nim @@ -0,0 +1,40 @@ +# gzip-like LZSS compressor +# Copyright (C) 2018 Pacien TRAN-GIRARD +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU Affero General Public License as +# published by the Free Software Foundation, either version 3 of the +# License, or (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU Affero General Public License for more details. +# +# You should have received a copy of the GNU Affero General Public License +# along with this program. If not, see . + +import ../bitio/integers, ../bitio/bitreader, ../bitio/bitwriter + +const maxDataBitLength = high(uint16).int +const bitLengthFieldBitLength = 2 * wordBitLength + +type RawBlock* = object + bitLength: int + data: seq[uint8] + +proc readSerialised*(bitReader: BitReader): RawBlock = + let bitLength = bitReader.readBits(bitLengthFieldBitLength, uint16).int + let data = bitReader.readSeq(bitLength, uint8) + RawBlock(bitLength: bitLength, data: data.data) + +proc writeSerialisedTo*(rawBlock: RawBlock, bitWriter: BitWriter) = + bitWriter.writeBits(bitLengthFieldBitLength, rawBlock.bitLength.uint16) + bitWriter.writeSeq(rawBlock.bitLength, rawBlock.data) + +proc readRaw*(bitReader: BitReader, bits: int = maxDataBitLength): RawBlock = + let data = bitReader.readSeq(bits, uint8) + RawBlock(bitLength: data.bitLength, data: data.data) + +proc writeRawTo*(rawBlock: RawBlock, bitWriter: BitWriter) = + bitWriter.writeSeq(rawBlock.bitLength, rawBlock.data) -- cgit v1.2.3