1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/persistentdata/persistentstorage/sql/SQLite/hash.h Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,110 @@
1.4 +/*
1.5 +** 2001 September 22
1.6 +**
1.7 +** The author disclaims copyright to this source code. In place of
1.8 +** a legal notice, here is a blessing:
1.9 +**
1.10 +** May you do good and not evil.
1.11 +** May you find forgiveness for yourself and forgive others.
1.12 +** May you share freely, never taking more than you give.
1.13 +**
1.14 +*************************************************************************
1.15 +** This is the header file for the generic hash-table implemenation
1.16 +** used in SQLite.
1.17 +**
1.18 +** $Id: hash.h,v 1.11 2007/09/04 14:31:47 danielk1977 Exp $
1.19 +*/
1.20 +#ifndef _SQLITE_HASH_H_
1.21 +#define _SQLITE_HASH_H_
1.22 +
1.23 +/* Forward declarations of structures. */
1.24 +typedef struct Hash Hash;
1.25 +typedef struct HashElem HashElem;
1.26 +
1.27 +/* A complete hash table is an instance of the following structure.
1.28 +** The internals of this structure are intended to be opaque -- client
1.29 +** code should not attempt to access or modify the fields of this structure
1.30 +** directly. Change this structure only by using the routines below.
1.31 +** However, many of the "procedures" and "functions" for modifying and
1.32 +** accessing this structure are really macros, so we can't really make
1.33 +** this structure opaque.
1.34 +*/
1.35 +struct Hash {
1.36 + char keyClass; /* SQLITE_HASH_INT, _POINTER, _STRING, _BINARY */
1.37 + char copyKey; /* True if copy of key made on insert */
1.38 + int count; /* Number of entries in this table */
1.39 + int htsize; /* Number of buckets in the hash table */
1.40 + HashElem *first; /* The first element of the array */
1.41 + struct _ht { /* the hash table */
1.42 + int count; /* Number of entries with this hash */
1.43 + HashElem *chain; /* Pointer to first entry with this hash */
1.44 + } *ht;
1.45 +};
1.46 +
1.47 +/* Each element in the hash table is an instance of the following
1.48 +** structure. All elements are stored on a single doubly-linked list.
1.49 +**
1.50 +** Again, this structure is intended to be opaque, but it can't really
1.51 +** be opaque because it is used by macros.
1.52 +*/
1.53 +struct HashElem {
1.54 + HashElem *next, *prev; /* Next and previous elements in the table */
1.55 + void *data; /* Data associated with this element */
1.56 + void *pKey; int nKey; /* Key associated with this element */
1.57 +};
1.58 +
1.59 +/*
1.60 +** There are 4 different modes of operation for a hash table:
1.61 +**
1.62 +** SQLITE_HASH_INT nKey is used as the key and pKey is ignored.
1.63 +**
1.64 +** SQLITE_HASH_POINTER pKey is used as the key and nKey is ignored.
1.65 +**
1.66 +** SQLITE_HASH_STRING pKey points to a string that is nKey bytes long
1.67 +** (including the null-terminator, if any). Case
1.68 +** is ignored in comparisons.
1.69 +**
1.70 +** SQLITE_HASH_BINARY pKey points to binary data nKey bytes long.
1.71 +** memcmp() is used to compare keys.
1.72 +**
1.73 +** A copy of the key is made for SQLITE_HASH_STRING and SQLITE_HASH_BINARY
1.74 +** if the copyKey parameter to HashInit is 1.
1.75 +*/
1.76 +/* #define SQLITE_HASH_INT 1 // NOT USED */
1.77 +/* #define SQLITE_HASH_POINTER 2 // NOT USED */
1.78 +#define SQLITE_HASH_STRING 3
1.79 +#define SQLITE_HASH_BINARY 4
1.80 +
1.81 +/*
1.82 +** Access routines. To delete, insert a NULL pointer.
1.83 +*/
1.84 +void sqlite3HashInit(Hash*, int keytype, int copyKey);
1.85 +void *sqlite3HashInsert(Hash*, const void *pKey, int nKey, void *pData);
1.86 +void *sqlite3HashFind(const Hash*, const void *pKey, int nKey);
1.87 +HashElem *sqlite3HashFindElem(const Hash*, const void *pKey, int nKey);
1.88 +void sqlite3HashClear(Hash*);
1.89 +
1.90 +/*
1.91 +** Macros for looping over all elements of a hash table. The idiom is
1.92 +** like this:
1.93 +**
1.94 +** Hash h;
1.95 +** HashElem *p;
1.96 +** ...
1.97 +** for(p=sqliteHashFirst(&h); p; p=sqliteHashNext(p)){
1.98 +** SomeStructure *pData = sqliteHashData(p);
1.99 +** // do something with pData
1.100 +** }
1.101 +*/
1.102 +#define sqliteHashFirst(H) ((H)->first)
1.103 +#define sqliteHashNext(E) ((E)->next)
1.104 +#define sqliteHashData(E) ((E)->data)
1.105 +#define sqliteHashKey(E) ((E)->pKey)
1.106 +#define sqliteHashKeysize(E) ((E)->nKey)
1.107 +
1.108 +/*
1.109 +** Number of entries in a hash table
1.110 +*/
1.111 +#define sqliteHashCount(H) ((H)->count)
1.112 +
1.113 +#endif /* _SQLITE_HASH_H_ */