1 /* Copyright 2015 Google Inc. All Rights Reserved. 2 3 Distributed under MIT license. 4 See file LICENSE for detail or copy at https://opensource.org/licenses/MIT 5 */ 6 namespace Org.Brotli.Dec 7 { 8 /// <summary>Lookup tables to map prefix codes to value ranges.</summary> 9 /// <remarks> 10 /// Lookup tables to map prefix codes to value ranges. 11 /// <p> This is used during decoding of the block lengths, literal insertion lengths and copy 12 /// lengths. 13 /// <p> Range represents values: [offset, offset + 2 ^ n_bits) 14 /// </remarks> 15 internal sealed class Prefix 16 { 17 internal static readonly int[] BlockLengthOffset = new int[] { 1, 5, 9, 13, 17, 25, 33, 41, 49, 65, 81, 97, 113, 145, 177, 209, 241, 305, 369, 497, 753, 1265, 2289, 4337, 8433, 16625 }; 18 19 internal static readonly int[] BlockLengthNBits = new int[] { 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 7, 8, 9, 10, 11, 12, 13, 24 }; 20 21 internal static readonly int[] InsertLengthOffset = new int[] { 0, 1, 2, 3, 4, 5, 6, 8, 10, 14, 18, 26, 34, 50, 66, 98, 130, 194, 322, 578, 1090, 2114, 6210, 22594 }; 22 23 internal static readonly int[] InsertLengthNBits = new int[] { 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 7, 8, 9, 10, 12, 14, 24 }; 24 25 internal static readonly int[] CopyLengthOffset = new int[] { 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 18, 22, 30, 38, 54, 70, 102, 134, 198, 326, 582, 1094, 2118 }; 26 27 internal static readonly int[] CopyLengthNBits = new int[] { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 7, 8, 9, 10, 24 }; 28 29 internal static readonly int[] InsertRangeLut = new int[] { 0, 0, 8, 8, 0, 16, 8, 16, 16 }; 30 31 internal static readonly int[] CopyRangeLut = new int[] { 0, 8, 0, 8, 16, 0, 16, 8, 16 }; 32 } 33 } 34