From 8af38da097b8358cb273baa37c748120461c718e Mon Sep 17 00:00:00 2001
From: pacien
Date: Fri, 30 Nov 2018 16:57:32 +0100
Subject: isolate bit IO

---
 src/bitreader.nim | 57 -------------------------------------------------------
 1 file changed, 57 deletions(-)
 delete mode 100644 src/bitreader.nim

(limited to 'src/bitreader.nim')

diff --git a/src/bitreader.nim b/src/bitreader.nim
deleted file mode 100644
index baa8bf8..0000000
--- a/src/bitreader.nim
+++ /dev/null
@@ -1,57 +0,0 @@
-# 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 streams
-import integers
-
-type BitReader* = ref object
-  stream: Stream
-  bitOffset: int
-  overflowBuffer: uint8
-
-proc bitReader*(stream: Stream): BitReader =
-  BitReader(stream: stream, bitOffset: 0, overflowBuffer: 0)
-
-proc atEnd*(bitReader: BitReader): bool =
-  bitReader.bitOffset == 0 and bitReader.stream.atEnd()
-
-proc readBits*[T: SomeUnsignedInt](bitReader: BitReader, bits: int, to: typedesc[T]): T =
-  if bits < 0 or bits > sizeof(T) * wordBitLength: raise newException(RangeError, "invalid bit length")
-  if bits == 0: return 0
-  var bitsRead = 0
-  if bitReader.bitOffset > 0:
-    let bitsFromBuffer = min(bits, wordBitLength - bitReader.bitOffset)
-    result = (bitReader.overflowBuffer shr bitReader.bitOffset).leastSignificantBits(bitsFromBuffer)
-    bitReader.bitOffset = (bitReader.bitOffset + bitsFromBuffer) mod wordBitLength
-    bitsRead += bitsFromBuffer
-  while bits - bitsRead >= wordBitLength:
-    result = result or (bitReader.stream.readUint8().T shl bitsRead)
-    bitsRead += wordBitLength
-  if bits - bitsRead > 0:
-    bitReader.overflowBuffer = bitReader.stream.readUint8()
-    bitReader.bitOffset = bits - bitsRead
-    result = result or (bitReader.overflowBuffer.leastSignificantBits(bitReader.bitOffset).T shl bitsRead)
-
-proc readBool*(bitReader: BitReader): bool =
-  bitReader.readBits(1, uint8) != 0
-
-proc readSeq*[T: SomeUnsignedInt](bitReader: BitReader, maxBitLength: int, to: typedesc[T]): tuple[bitLength: int, data: seq[T]] =
-  result = (0, newSeqOfCap[T](maxBitLength /^ (sizeof(T) * wordBitLength)))
-  for _, chunkBitLength in chunks(maxBitLength, T):
-    if bitReader.atEnd(): return
-    let bitsToRead = if bitReader.stream.atEnd(): sizeof(T) * wordBitLength - bitReader.bitOffset else: chunkBitLength
-    result.bitLength += bitsToRead
-    result.data.add(bitReader.readBits(bitsToRead, T))
-- 
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