isolate blocks

1 files changed, 40 insertions, 0 deletions

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 <https://www.gnu.org/licenses/>.
+
+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)