1 package net.jpountz.lz4;
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
21 static final int DEFAULT_COMPRESSION_LEVEL = 8+1;
22 static final int MAX_COMPRESSION_LEVEL = 16+1;
24 static final int MEMORY_USAGE = 14;
25 static final int NOT_COMPRESSIBLE_DETECTION_LEVEL = 6;
27 static final int MIN_MATCH = 4;
29 static final int HASH_LOG = MEMORY_USAGE - 2;
30 static final int HASH_TABLE_SIZE = 1 << HASH_LOG;
32 static final int SKIP_STRENGTH = Math.max(NOT_COMPRESSIBLE_DETECTION_LEVEL, 2);
33 static final int COPY_LENGTH = 8;
34 static final int LAST_LITERALS = 5;
35 static final int MF_LIMIT = COPY_LENGTH + MIN_MATCH;
36 static final int MIN_LENGTH = MF_LIMIT + 1;
38 static final int MAX_DISTANCE = 1 << 16;
40 static final int ML_BITS = 4;
41 static final int ML_MASK = (1 << ML_BITS) - 1;
42 static final int RUN_BITS = 8 - ML_BITS;
43 static final int RUN_MASK = (1 << RUN_BITS) - 1;
45 static final int LZ4_64K_LIMIT = (1 << 16) + (MF_LIMIT - 1);
46 static final int HASH_LOG_64K = HASH_LOG + 1;
47 static final int HASH_TABLE_SIZE_64K = 1 << HASH_LOG_64K;
49 static final int HASH_LOG_HC = 15;
50 static final int HASH_TABLE_SIZE_HC = 1 << HASH_LOG_HC;
51 static final int OPTIMAL_ML = ML_MASK - 1 + MIN_MATCH;