diff options
Diffstat (limited to '')
-rw-r--r-- | libraries/sqlite/unix/sqlite-3.5.1/src/hash.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/libraries/sqlite/unix/sqlite-3.5.1/src/hash.h b/libraries/sqlite/unix/sqlite-3.5.1/src/hash.h new file mode 100644 index 0000000..e3274e9 --- /dev/null +++ b/libraries/sqlite/unix/sqlite-3.5.1/src/hash.h | |||
@@ -0,0 +1,110 @@ | |||
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. | ||
14 | ** | ||
15 | ** $Id: hash.h,v 1.11 2007/09/04 14:31:47 danielk1977 Exp $ | ||
16 | */ | ||
17 | #ifndef _SQLITE_HASH_H_ | ||
18 | #define _SQLITE_HASH_H_ | ||
19 | |||
20 | /* Forward declarations of structures. */ | ||
21 | typedef struct Hash Hash; | ||
22 | typedef struct HashElem HashElem; | ||
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 Hash { | ||
33 | char keyClass; /* SQLITE_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 | int htsize; /* Number of buckets in the hash table */ | ||
37 | HashElem *first; /* The first element of the array */ | ||
38 | struct _ht { /* the hash table */ | ||
39 | int count; /* Number of entries with this hash */ | ||
40 | HashElem *chain; /* Pointer to first entry with this hash */ | ||
41 | } *ht; | ||
42 | }; | ||
43 | |||
44 | /* Each element in the hash table is an instance of the following | ||
45 | ** structure. All elements are stored on a single doubly-linked list. | ||
46 | ** | ||
47 | ** Again, this structure is intended to be opaque, but it can't really | ||
48 | ** be opaque because it is used by macros. | ||
49 | */ | ||
50 | struct HashElem { | ||
51 | HashElem *next, *prev; /* Next and previous elements in the table */ | ||
52 | void *data; /* Data associated with this element */ | ||
53 | void *pKey; int nKey; /* Key associated with this element */ | ||
54 | }; | ||
55 | |||
56 | /* | ||
57 | ** There are 4 different modes of operation for a hash table: | ||
58 | ** | ||
59 | ** SQLITE_HASH_INT nKey is used as the key and pKey is ignored. | ||
60 | ** | ||
61 | ** SQLITE_HASH_POINTER pKey is used as the key and nKey is ignored. | ||
62 | ** | ||
63 | ** SQLITE_HASH_STRING pKey points to a string that is nKey bytes long | ||
64 | ** (including the null-terminator, if any). Case | ||
65 | ** is ignored in comparisons. | ||
66 | ** | ||
67 | ** SQLITE_HASH_BINARY pKey points to binary data nKey bytes long. | ||
68 | ** memcmp() is used to compare keys. | ||
69 | ** | ||
70 | ** A copy of the key is made for SQLITE_HASH_STRING and SQLITE_HASH_BINARY | ||
71 | ** if the copyKey parameter to HashInit is 1. | ||
72 | */ | ||
73 | /* #define SQLITE_HASH_INT 1 // NOT USED */ | ||
74 | /* #define SQLITE_HASH_POINTER 2 // NOT USED */ | ||
75 | #define SQLITE_HASH_STRING 3 | ||
76 | #define SQLITE_HASH_BINARY 4 | ||
77 | |||
78 | /* | ||
79 | ** Access routines. To delete, insert a NULL pointer. | ||
80 | */ | ||
81 | void sqlite3HashInit(Hash*, int keytype, int copyKey); | ||
82 | void *sqlite3HashInsert(Hash*, const void *pKey, int nKey, void *pData); | ||
83 | void *sqlite3HashFind(const Hash*, const void *pKey, int nKey); | ||
84 | HashElem *sqlite3HashFindElem(const Hash*, const void *pKey, int nKey); | ||
85 | void sqlite3HashClear(Hash*); | ||
86 | |||
87 | /* | ||
88 | ** Macros for looping over all elements of a hash table. The idiom is | ||
89 | ** like this: | ||
90 | ** | ||
91 | ** Hash h; | ||
92 | ** HashElem *p; | ||
93 | ** ... | ||
94 | ** for(p=sqliteHashFirst(&h); p; p=sqliteHashNext(p)){ | ||
95 | ** SomeStructure *pData = sqliteHashData(p); | ||
96 | ** // do something with pData | ||
97 | ** } | ||
98 | */ | ||
99 | #define sqliteHashFirst(H) ((H)->first) | ||
100 | #define sqliteHashNext(E) ((E)->next) | ||
101 | #define sqliteHashData(E) ((E)->data) | ||
102 | #define sqliteHashKey(E) ((E)->pKey) | ||
103 | #define sqliteHashKeysize(E) ((E)->nKey) | ||
104 | |||
105 | /* | ||
106 | ** Number of entries in a hash table | ||
107 | */ | ||
108 | #define sqliteHashCount(H) ((H)->count) | ||
109 | |||
110 | #endif /* _SQLITE_HASH_H_ */ | ||