server/include/shstr.h

#ifndef SHSTR_H__
#define SHSTR_H__

//// OLD STUFF

/* The size of the shared strings hashtable. This must be smaller than
 * 32767, but 947 ought to be plenty enough.
 */
#define TABLESIZE 4133

/* This specifies how many characters the hashing routine should look at.
 * You may actually save CPU by increasing this number if the typical string
 * is large.
 */
#ifndef MAXSTRING
#define MAXSTRING 20
#endif

/* In the unlikely occurence that 16383 references to a string are too
 * few, you can modify the below type to something bigger.
 * (The top bit of "refcount" is used to signify that "u.array" points
 * at the array entry.)
 */
#define REFCOUNT_TYPE int

/* The offsetof macro is part of ANSI C, but many compilers lack it, for
 * example "gcc -ansi"
 */
#if !defined (offsetof)
#define offsetof(type, member) (int)&(((type *)0)->member)
#endif

/* SS(string) will return the address of the shared_string struct which 
 * contains "string".
 */
#define SS(x) ((shared_string *) ((x) - offsetof(shared_string, string)))

#define SS_STATISTICS

#define SS_DUMP_TABLE   1
#define SS_DUMP_TOTALS  2

#ifdef SS_STATISTICS
static struct statistics {
    int calls;
    int hashed;
    int strcmps;
    int search;
    int linked;
} add_stats, add_ref_stats, free_stats, find_stats, hash_stats;
#define GATHER(n) (++n)
#else /* !SS_STATISTICS */
#define GATHER(n)
#endif /* SS_STATISTICS */

#define TOPBIT  ((unsigned REFCOUNT_TYPE) 1 << (sizeof(REFCOUNT_TYPE) * CHAR_BIT - 1))

#define PADDING ((2 * sizeof(long) - sizeof(REFCOUNT_TYPE)) % sizeof(long)) + 1

typedef struct _shared_string {
    union {
        struct _shared_string **array;
        struct _shared_string *previous;
    } u;
    struct _shared_string *next;
    /* The top bit of "refcount" is used to signify that "u.array" points
     * at the array entry.
     */
    unsigned REFCOUNT_TYPE refcount;
    /* Padding will be unused memory, since we can't know how large 
     * the padding when allocating memory. We assume here that
     * sizeof(long) is a good boundary.
     */
    char string[PADDING];
} shared_string;

extern void init_hash_table(void);
extern const char *add_string(const char *str);
extern const char *add_refcount(const char *str);
extern int query_refcount(const char *str);
extern const char *find_string(const char *str);
extern void free_string(const char *str);
extern void ss_dump_statistics(void);
extern const char *ss_dump_table(int what);
extern int buf_overflow(const char *buf1, const char *buf2, int bufsize);

//// NEW STUFF

#if 0
struct shstr
{
  const char *s;
  operator const char *() const { return s; };
  shstr &operator =(const char *str) { s = str; };
};
#else
typedef const char *shstr;
#endif

#endif

Revision:	1.4
Committed:	Thu Aug 31 17:54:14 2006 UTC (20 years, 1 month ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.3:	+15 -0 lines
Log Message:	rewrote object serialiser, parser is next
#	User	Rev	Content
1	root	1.2	#ifndef SHSTR_H__
2			#define SHSTR_H__
3
4	root	1.4	//// OLD STUFF
5
6	root	1.1	/* The size of the shared strings hashtable. This must be smaller than
7			* 32767, but 947 ought to be plenty enough.
8			*/
9			#define TABLESIZE 4133
10
11			/* This specifies how many characters the hashing routine should look at.
12			* You may actually save CPU by increasing this number if the typical string
13			* is large.
14			*/
15			#ifndef MAXSTRING
16			#define MAXSTRING 20
17			#endif
18
19			/* In the unlikely occurence that 16383 references to a string are too
20			* few, you can modify the below type to something bigger.
21			* (The top bit of "refcount" is used to signify that "u.array" points
22			* at the array entry.)
23			*/
24			#define REFCOUNT_TYPE int
25
26			/* The offsetof macro is part of ANSI C, but many compilers lack it, for
27			* example "gcc -ansi"
28			*/
29			#if !defined (offsetof)
30			#define offsetof(type, member) (int)&(((type *)0)->member)
31			#endif
32
33			/* SS(string) will return the address of the shared_string struct which
34			* contains "string".
35			*/
36			#define SS(x) ((shared_string *) ((x) - offsetof(shared_string, string)))
37
38			#define SS_STATISTICS
39
40			#define SS_DUMP_TABLE 1
41			#define SS_DUMP_TOTALS 2
42
43			#ifdef SS_STATISTICS
44			static struct statistics {
45			int calls;
46			int hashed;
47			int strcmps;
48			int search;
49			int linked;
50			} add_stats, add_ref_stats, free_stats, find_stats, hash_stats;
51			#define GATHER(n) (++n)
52			#else /* !SS_STATISTICS */
53			#define GATHER(n)
54			#endif /* SS_STATISTICS */
55
56			#define TOPBIT ((unsigned REFCOUNT_TYPE) 1 << (sizeof(REFCOUNT_TYPE) * CHAR_BIT - 1))
57
58			#define PADDING ((2 * sizeof(long) - sizeof(REFCOUNT_TYPE)) % sizeof(long)) + 1
59
60			typedef struct _shared_string {
61			union {
62	root	1.3	struct _shared_string **array;
63			struct _shared_string *previous;
64	root	1.1	} u;
65			struct _shared_string *next;
66			/* The top bit of "refcount" is used to signify that "u.array" points
67			* at the array entry.
68			*/
69			unsigned REFCOUNT_TYPE refcount;
70			/* Padding will be unused memory, since we can't know how large
71			* the padding when allocating memory. We assume here that
72			* sizeof(long) is a good boundary.
73			*/
74			char string[PADDING];
75			} shared_string;
76	root	1.2
77			extern void init_hash_table(void);
78			extern const char add_string(const char str);
79			extern const char add_refcount(const char str);
80			extern int query_refcount(const char *str);
81			extern const char find_string(const char str);
82			extern void free_string(const char *str);
83			extern void ss_dump_statistics(void);
84			extern const char *ss_dump_table(int what);
85			extern int buf_overflow(const char buf1, const char buf2, int bufsize);
86
87	root	1.4	//// NEW STUFF
88
89			#if 0
90			struct shstr
91			{
92			const char *s;
93			operator const char *() const { return s; };
94			shstr &operator =(const char *str) { s = str; };
95			};
96			#else
97			typedef const char *shstr;
98			#endif
99
100	root	1.2	#endif
101