xref: /aosp_15_r20/external/brotli/csharp/org/brotli/dec/Transform.cs (revision f4ee7fba7774faf2a30f13154332c0a06550dbc4) 
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>Transformations on dictionary words.</summary>
9 	internal sealed class Transform
10 	{
11 		private readonly byte[] prefix;
12 
13 		private readonly int type;
14 
15 		private readonly byte[] suffix;
16 
Transform(string prefix, int type, string suffix)17 		internal Transform(string prefix, int type, string suffix)
18 		{
19 			this.prefix = ReadUniBytes(prefix);
20 			this.type = type;
21 			this.suffix = ReadUniBytes(suffix);
22 		}
23 
ReadUniBytes(string uniBytes)24 		internal static byte[] ReadUniBytes(string uniBytes)
25 		{
26 			byte[] result = new byte[uniBytes.Length];
27 			for (int i = 0; i < result.Length; ++i)
28 			{
29 				result[i] = unchecked((byte)uniBytes[i]);
30 			}
31 			return result;
32 		}
33 
34 		internal static readonly Org.Brotli.Dec.Transform[] Transforms = new Org.Brotli.Dec.Transform[] { new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, string.Empty), new Org.Brotli.Dec.Transform(string.Empty,
35 			Org.Brotli.Dec.WordTransformType.Identity, " "), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.Identity, " "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitFirst1, string.Empty), new Org.Brotli.Dec.Transform
36 			(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseFirst, " "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " the "), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.Identity
37 			, string.Empty), new Org.Brotli.Dec.Transform("s ", Org.Brotli.Dec.WordTransformType.Identity, " "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " of "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType
38 			.UppercaseFirst, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " and "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitFirst2, string.Empty), new Org.Brotli.Dec.Transform
39 			(string.Empty, Org.Brotli.Dec.WordTransformType.OmitLast1, string.Empty), new Org.Brotli.Dec.Transform(", ", Org.Brotli.Dec.WordTransformType.Identity, " "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity
40 			, ", "), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.UppercaseFirst, " "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " in "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType
41 			.Identity, " to "), new Org.Brotli.Dec.Transform("e ", Org.Brotli.Dec.WordTransformType.Identity, " "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "\""), new Org.Brotli.Dec.Transform(string.Empty,
42 			Org.Brotli.Dec.WordTransformType.Identity, "."), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "\">"), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "\n"), new
43 			Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitLast3, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "]"), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType
44 			.Identity, " for "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitFirst3, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitLast2, string.Empty), new Org.Brotli.Dec.Transform
45 			(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " a "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " that "), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.UppercaseFirst
46 			, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, ". "), new Org.Brotli.Dec.Transform(".", Org.Brotli.Dec.WordTransformType.Identity, string.Empty), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType
47 			.Identity, ", "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitFirst4, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " with "), new Org.Brotli.Dec.Transform
48 			(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "'"), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " from "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity
49 			, " by "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitFirst5, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitFirst6, string.Empty), new Org.Brotli.Dec.Transform
50 			(" the ", Org.Brotli.Dec.WordTransformType.Identity, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitLast4, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType
51 			.Identity, ". The "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseAll, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " on "), new Org.Brotli.Dec.Transform
52 			(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " as "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " is "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitLast7
53 			, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitLast1, "ing "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "\n\t"), new Org.Brotli.Dec.Transform(string.Empty
54 			, Org.Brotli.Dec.WordTransformType.Identity, ":"), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.Identity, ". "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "ed "), new Org.Brotli.Dec.Transform
55 			(string.Empty, Org.Brotli.Dec.WordTransformType.OmitFirst9, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitFirst7, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType
56 			.OmitLast6, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "("), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseFirst, ", "), new Org.Brotli.Dec.Transform
57 			(string.Empty, Org.Brotli.Dec.WordTransformType.OmitLast8, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " at "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType
58 			.Identity, "ly "), new Org.Brotli.Dec.Transform(" the ", Org.Brotli.Dec.WordTransformType.Identity, " of "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.OmitLast5, string.Empty), new Org.Brotli.Dec.Transform(
59 			string.Empty, Org.Brotli.Dec.WordTransformType.OmitLast9, string.Empty), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.UppercaseFirst, ", "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseFirst
60 			, "\""), new Org.Brotli.Dec.Transform(".", Org.Brotli.Dec.WordTransformType.Identity, "("), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseAll, " "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType
61 			.UppercaseFirst, "\">"), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "=\""), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.Identity, "."), new Org.Brotli.Dec.Transform(".com/",
62 			Org.Brotli.Dec.WordTransformType.Identity, string.Empty), new Org.Brotli.Dec.Transform(" the ", Org.Brotli.Dec.WordTransformType.Identity, " of the "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseFirst
63 			, "'"), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, ". This "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, ","), new Org.Brotli.Dec.Transform(".", Org.Brotli.Dec.WordTransformType
64 			.Identity, " "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseFirst, "("), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseFirst, "."), new Org.Brotli.Dec.Transform
65 			(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, " not "), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.Identity, "=\""), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "er "
66 			), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.UppercaseAll, " "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "al "), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType
67 			.UppercaseAll, string.Empty), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "='"), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseAll, "\""), new Org.Brotli.Dec.Transform
68 			(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseFirst, ". "), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.Identity, "("), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity,
69 			"ful "), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.UppercaseFirst, ". "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "ive "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType
70 			.Identity, "less "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseAll, "'"), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "est "), new Org.Brotli.Dec.Transform
71 			(" ", Org.Brotli.Dec.WordTransformType.UppercaseFirst, "."), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseAll, "\">"), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.Identity, "='"
72 			), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseFirst, ","), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity, "ize "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType
73 			.UppercaseAll, "."), new Org.Brotli.Dec.Transform("\u00c2\u00a0", Org.Brotli.Dec.WordTransformType.Identity, string.Empty), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.Identity, ","), new Org.Brotli.Dec.Transform(string.Empty
74 			, Org.Brotli.Dec.WordTransformType.UppercaseFirst, "=\""), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseAll, "=\""), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.Identity
75 			, "ous "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseAll, ", "), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseFirst, "='"), new Org.Brotli.Dec.Transform(" ",
76 			Org.Brotli.Dec.WordTransformType.UppercaseFirst, ","), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.UppercaseAll, "=\""), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.UppercaseAll, ", "), new Org.Brotli.Dec.Transform
77 			(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseAll, ","), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseAll, "("), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.
78 			UppercaseAll, ". "), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.UppercaseAll, "."), new Org.Brotli.Dec.Transform(string.Empty, Org.Brotli.Dec.WordTransformType.UppercaseAll, "='"), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType
79 			.UppercaseAll, ". "), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.UppercaseFirst, "=\""), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType.UppercaseAll, "='"), new Org.Brotli.Dec.Transform(" ", Org.Brotli.Dec.WordTransformType
80 			.UppercaseFirst, "='") };
81 
TransformDictionaryWord(byte[] dst, int dstOffset, byte[] word, int wordOffset, int len, Org.Brotli.Dec.Transform transform)82 		internal static int TransformDictionaryWord(byte[] dst, int dstOffset, byte[] word, int wordOffset, int len, Org.Brotli.Dec.Transform transform)
83 		{
84 			int offset = dstOffset;
85 			// Copy prefix.
86 			byte[] @string = transform.prefix;
87 			int tmp = @string.Length;
88 			int i = 0;
89 			// In most cases tmp < 10 -> no benefits from System.arrayCopy
90 			while (i < tmp)
91 			{
92 				dst[offset++] = @string[i++];
93 			}
94 			// Copy trimmed word.
95 			int op = transform.type;
96 			tmp = Org.Brotli.Dec.WordTransformType.GetOmitFirst(op);
97 			if (tmp > len)
98 			{
99 				tmp = len;
100 			}
101 			wordOffset += tmp;
102 			len -= tmp;
103 			len -= Org.Brotli.Dec.WordTransformType.GetOmitLast(op);
104 			i = len;
105 			while (i > 0)
106 			{
107 				dst[offset++] = word[wordOffset++];
108 				i--;
109 			}
110 			if (op == Org.Brotli.Dec.WordTransformType.UppercaseAll || op == Org.Brotli.Dec.WordTransformType.UppercaseFirst)
111 			{
112 				int uppercaseOffset = offset - len;
113 				if (op == Org.Brotli.Dec.WordTransformType.UppercaseFirst)
114 				{
115 					len = 1;
116 				}
117 				while (len > 0)
118 				{
119 					tmp = dst[uppercaseOffset] & unchecked((int)(0xFF));
120 					if (tmp < unchecked((int)(0xc0)))
121 					{
122 						if (tmp >= 'a' && tmp <= 'z')
123 						{
124 							dst[uppercaseOffset] ^= unchecked((byte)32);
125 						}
126 						uppercaseOffset += 1;
127 						len -= 1;
128 					}
129 					else if (tmp < unchecked((int)(0xe0)))
130 					{
131 						dst[uppercaseOffset + 1] ^= unchecked((byte)32);
132 						uppercaseOffset += 2;
133 						len -= 2;
134 					}
135 					else
136 					{
137 						dst[uppercaseOffset + 2] ^= unchecked((byte)5);
138 						uppercaseOffset += 3;
139 						len -= 3;
140 					}
141 				}
142 			}
143 			// Copy suffix.
144 			@string = transform.suffix;
145 			tmp = @string.Length;
146 			i = 0;
147 			while (i < tmp)
148 			{
149 				dst[offset++] = @string[i++];
150 			}
151 			return offset - dstOffset;
152 		}
153 	}
154 }
155