xref: /illumos-gate/usr/src/cmd/sgs/include/_string_table.h (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef	__STRING_TABLE_DOT_H
27 #define	__STRING_TABLE_DOT_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/types.h>
32 #include <sys/avl.h>
33 #include <string_table.h>
34 
35 #ifdef __cplusplus
36 extern "C" {
37 #endif
38 
39 /*
40  * A string is represented in a string table using two values: length, and
41  * value.  Grouping all the strings of a given length together allows for
42  * efficient matching of tail strings, as each input string value is hashed.
43  * Each string table uses a 2-level AVL tree of AVL trees to represent this
44  * organization.
45  *
46  * The outer (main) AVL tree contains LenNode structures.  The search key for
47  * nodes on this main tree is the string length.  Each such node represents
48  * all strings of a given length, and all strings of that length are found
49  * within.
50  *
51  * The strings within each LenNode are maintained using a secondary AVL tree
52  * of StrNode structures.  The search key for this inner tree is the string
53  * itself.  The strings are maintained in lexical order.
54  */
55 typedef struct {
56 	avl_node_t	sn_avlnode;	/* AVL book-keeping */
57 	const char	*sn_str;	/* string */
58 	size_t		sn_refcnt;	/* reference count */
59 } StrNode;
60 
61 typedef struct {
62 	avl_node_t	ln_avlnode;	/* AVL book-keeping */
63 	avl_tree_t	*ln_strtree;	/* AVL tree of associated strings */
64 	size_t		ln_strlen;	/* length of associated strings */
65 } LenNode;
66 
67 /*
68  * Define a master string data item.  Other strings may be suffixes of this
69  * string.  The final string table will consist of the master string values,
70  * laid end to end, with the other strings referencing their tails.
71  */
72 typedef	struct str_master	Str_master;
73 
74 struct str_master {
75 	const char	*sm_str;	/* pointer to master string */
76 	Str_master	*sm_next;	/* used for tracking master strings */
77 	size_t		sm_strlen;	/* length of master string */
78 	uint_t		sm_hashval;	/* hashval of master string */
79 	size_t		sm_stroff;	/* offset into destination strtab */
80 };
81 
82 /*
83  * Define a hash data item.  This item represents an individual string that has
84  * been input into the String hash table.  The string may either be a suffix of
85  * another string, or a master string.
86  */
87 typedef	struct str_hash	Str_hash;
88 
89 struct str_hash {
90 	size_t		hi_strlen;	/* string length */
91 	size_t		hi_refcnt;	/* number of references to str */
92 	uint_t		hi_hashval;	/* hash for string */
93 	Str_master	*hi_mstr;	/* pointer to master string */
94 	Str_hash	*hi_next;	/* next entry in hash bucket */
95 };
96 
97 /*
98  * Controlling data structure for a String Table.
99  */
100 struct str_tbl {
101 	avl_tree_t	*st_lentree;		/* AVL tree of string lengths */
102 	char		*st_strbuf;		/* string buffer */
103 	Str_hash	**st_hashbcks;		/* hash buckets */
104 	Str_master	*st_mstrlist;		/* list of all master strings */
105 	size_t		st_fullstrsize;		/* uncompressed table size */
106 	size_t		st_nextoff;		/* next available string */
107 	size_t		st_strsize;		/* compressed size */
108 	size_t		st_strcnt;		/* number of strings */
109 	uint_t		st_hbckcnt;		/* number of buckets in */
110 						/*    hashlist */
111 	uint_t		st_flags;
112 };
113 
114 #define	FLG_STTAB_COMPRESS	0x01		/* compressed string table */
115 #define	FLG_STTAB_COOKED	0x02		/* offset has been assigned */
116 
117 /*
118  * Starting value for use with string hashing functions inside of string_table.c
119  */
120 #define	HASHSEED		5381
121 
122 #ifdef __cplusplus
123 }
124 #endif
125 
126 #endif /* __STRING_TABLE_DOT_H */
127