1 /* Copyright (C) 1999 Aladdin Enterprises. All rights reserved. 2 3 This software is provided AS-IS with no warranty, either express or 4 implied. 5 6 This software is distributed under license and may not be copied, 7 modified or distributed except as expressly authorized under the terms 8 of the license contained in the file LICENSE in this distribution. 9 10 For more information about licensing, please refer to 11 http://www.ghostscript.com/licensing/. For information on 12 commercial licensing, go to http://www.artifex.com/licensing/ or 13 contact Artifex Software, Inc., 101 Lucas Valley Road #110, 14 San Rafael, CA 94903, U.S.A., +1(415)492-9861. 15 */ 16 17 /* $Id: inameidx.h,v 1.4 2002/02/21 22:24:53 giles Exp $ */ 18 /* Name index definitions */ 19 20 #ifndef inameidx_INCLUDED 21 # define inameidx_INCLUDED 22 23 #include "gconfigv.h" /* defines EXTEND_NAMES */ 24 25 /* 26 * The name table machinery has two slightly different configurations: 27 * a faster one that limits the total number of names to 64K and allows 28 * names up to 16K in size, and a slightly slower one that limits 29 * the total to 4M and restricts names to 256 characters. 30 */ 31 #ifndef EXTEND_NAMES /* # of bits beyond 16 */ 32 # define EXTEND_NAMES 0 33 #endif 34 35 /* Define the size of a name sub-table. */ 36 #define NT_LOG2_SUB_SIZE (8 + (EXTEND_NAMES / 2)) 37 # define NT_SUB_SIZE (1 << NT_LOG2_SUB_SIZE) 38 # define NT_SUB_INDEX_MASK (NT_SUB_SIZE - 1) 39 40 /* 41 * Define the first few entries of the name table. Entry 0 is left unused. 42 * The entry with count = 1 is the entry for the 0-length name. 43 * The next NT_1CHAR_SIZE entries (in count order) are 1-character names. 44 */ 45 #define NT_1CHAR_SIZE 128 46 #define NT_1CHAR_FIRST 2 47 #define NT_1CHAR_NAMES_DATA\ 48 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,\ 49 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,\ 50 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,\ 51 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,\ 52 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,\ 53 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,\ 54 96, 97, 98, 99,100,101,102,103,104,105,106,107,108,109,110,111,\ 55 112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127 56 57 /* ---------------- Name count/index mapping ---------------- */ 58 59 /* 60 * We scramble the assignment order within a sub-table, so that 61 * dictionary lookup doesn't have to scramble the index. 62 * The scrambling algorithm must have three properties: 63 * - It must map 0 to 0; 64 * - It must only scramble the sub-table index; 65 * - It must be a permutation on the sub-table index. 66 * Something very simple works just fine. 67 */ 68 #define NAME_COUNT_TO_INDEX_FACTOR 23 69 #define name_count_to_index(cnt)\ 70 (((cnt) & (-NT_SUB_SIZE)) +\ 71 (((cnt) * NAME_COUNT_TO_INDEX_FACTOR) & NT_SUB_INDEX_MASK)) 72 /* 73 * The reverse permutation requires finding a number R such that 74 * NAME_COUNT_TO_INDEX_FACTOR * R = 1 mod NT_SUB_SIZE. 75 * The value given below works for NT_SUB_SIZE any power of 2 up to 4096. 76 * This is not currently used anywhere. 77 */ 78 #define NAME_INDEX_TO_COUNT_FACTOR 1959 79 #define name_index_to_count(nidx)\ 80 (((nidx) & (-NT_SUB_SIZE)) +\ 81 (((nidx) * NAME_INDEX_TO_COUNT_FACTOR) & NT_SUB_INDEX_MASK)) 82 83 #endif /* inameidx_INCLUDED */ 84