Annotation of embedaddon/sqlite3/ext/fts1/fts1_hash.h, revision 1.1.1.1
1.1 misho 1: /*
2: ** 2001 September 22
3: **
4: ** The author disclaims copyright to this source code. In place of
5: ** a legal notice, here is a blessing:
6: **
7: ** May you do good and not evil.
8: ** May you find forgiveness for yourself and forgive others.
9: ** May you share freely, never taking more than you give.
10: **
11: *************************************************************************
12: ** This is the header file for the generic hash-table implemenation
13: ** used in SQLite. We've modified it slightly to serve as a standalone
14: ** hash table implementation for the full-text indexing module.
15: **
16: */
17: #ifndef _FTS1_HASH_H_
18: #define _FTS1_HASH_H_
19:
20: /* Forward declarations of structures. */
21: typedef struct fts1Hash fts1Hash;
22: typedef struct fts1HashElem fts1HashElem;
23:
24: /* A complete hash table is an instance of the following structure.
25: ** The internals of this structure are intended to be opaque -- client
26: ** code should not attempt to access or modify the fields of this structure
27: ** directly. Change this structure only by using the routines below.
28: ** However, many of the "procedures" and "functions" for modifying and
29: ** accessing this structure are really macros, so we can't really make
30: ** this structure opaque.
31: */
32: struct fts1Hash {
33: char keyClass; /* HASH_INT, _POINTER, _STRING, _BINARY */
34: char copyKey; /* True if copy of key made on insert */
35: int count; /* Number of entries in this table */
36: fts1HashElem *first; /* The first element of the array */
37: void *(*xMalloc)(int); /* malloc() function to use */
38: void (*xFree)(void *); /* free() function to use */
39: int htsize; /* Number of buckets in the hash table */
40: struct _fts1ht { /* the hash table */
41: int count; /* Number of entries with this hash */
42: fts1HashElem *chain; /* Pointer to first entry with this hash */
43: } *ht;
44: };
45:
46: /* Each element in the hash table is an instance of the following
47: ** structure. All elements are stored on a single doubly-linked list.
48: **
49: ** Again, this structure is intended to be opaque, but it can't really
50: ** be opaque because it is used by macros.
51: */
52: struct fts1HashElem {
53: fts1HashElem *next, *prev; /* Next and previous elements in the table */
54: void *data; /* Data associated with this element */
55: void *pKey; int nKey; /* Key associated with this element */
56: };
57:
58: /*
59: ** There are 2 different modes of operation for a hash table:
60: **
61: ** FTS1_HASH_STRING pKey points to a string that is nKey bytes long
62: ** (including the null-terminator, if any). Case
63: ** is respected in comparisons.
64: **
65: ** FTS1_HASH_BINARY pKey points to binary data nKey bytes long.
66: ** memcmp() is used to compare keys.
67: **
68: ** A copy of the key is made if the copyKey parameter to fts1HashInit is 1.
69: */
70: #define FTS1_HASH_STRING 1
71: #define FTS1_HASH_BINARY 2
72:
73: /*
74: ** Access routines. To delete, insert a NULL pointer.
75: */
76: void sqlite3Fts1HashInit(fts1Hash*, int keytype, int copyKey);
77: void *sqlite3Fts1HashInsert(fts1Hash*, const void *pKey, int nKey, void *pData);
78: void *sqlite3Fts1HashFind(const fts1Hash*, const void *pKey, int nKey);
79: void sqlite3Fts1HashClear(fts1Hash*);
80:
81: /*
82: ** Shorthand for the functions above
83: */
84: #define fts1HashInit sqlite3Fts1HashInit
85: #define fts1HashInsert sqlite3Fts1HashInsert
86: #define fts1HashFind sqlite3Fts1HashFind
87: #define fts1HashClear sqlite3Fts1HashClear
88:
89: /*
90: ** Macros for looping over all elements of a hash table. The idiom is
91: ** like this:
92: **
93: ** fts1Hash h;
94: ** fts1HashElem *p;
95: ** ...
96: ** for(p=fts1HashFirst(&h); p; p=fts1HashNext(p)){
97: ** SomeStructure *pData = fts1HashData(p);
98: ** // do something with pData
99: ** }
100: */
101: #define fts1HashFirst(H) ((H)->first)
102: #define fts1HashNext(E) ((E)->next)
103: #define fts1HashData(E) ((E)->data)
104: #define fts1HashKey(E) ((E)->pKey)
105: #define fts1HashKeysize(E) ((E)->nKey)
106:
107: /*
108: ** Number of entries in a hash table
109: */
110: #define fts1HashCount(H) ((H)->count)
111:
112: #endif /* _FTS1_HASH_H_ */
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