2 * Copyright (C) 1994-1999, Index Data
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.7 1999-02-02 14:51:21 adam
8 * Updated WIN32 code specific sections. Changed header.
10 * Revision 1.6 1997/09/05 15:30:10 adam
11 * Changed prototype for chr_map_input - added const.
12 * Added support for C++, headers uses extern "C" for public definitions.
14 * Revision 1.5 1996/03/11 14:52:25 quinn
15 * Fixed update bug. Repeated insertion in the same area sometimes caused
18 * Revision 1.4 1995/12/06 15:48:47 quinn
19 * Fixed update-problem.
21 * Revision 1.3 1994/09/28 16:58:33 quinn
24 * Revision 1.2 1994/09/27 20:03:52 quinn
25 * Seems relatively bug-free.
27 * Revision 1.1 1994/09/26 17:12:32 quinn
30 * Revision 1.1 1994/09/26 16:07:57 quinn
31 * Most of the functionality in place.
42 extern int is_mbuf_size[3];
44 typedef unsigned int ISAM_P;
47 * Memory buffer. Used to manage records (keys) in memory for
48 * reading and insertion/deletion.
50 typedef struct is_mbuf
54 #define IS_MBUF_TYPE_SMALL 0
55 #define IS_MBUF_TYPE_MEDIUM 1
56 #define IS_MBUF_TYPE_LARGE 2
61 char *data; /* dummy */
65 * Structure describing the virtual image of a disk block.
66 * (these blocks may grow beyond the blocksize during insertion).
68 typedef struct is_mblock
70 int num_records; /* number of records */
71 int diskpos; /* positive if this block is mapped */
72 int nextpos; /* pos of nxt blk. Only valid imm aft. rd. */
73 int bread; /* number of bytes read */
74 int state; /* state of block in rel. to disk block */
75 #define IS_MBSTATE_UNREAD 0 /* block hasn't been read */
76 #define IS_MBSTATE_PARTIAL 1 /* block has been partially read */
77 #define IS_MBSTATE_CLEAN 2 /* block is clean (unmodified) */
78 #define IS_MBSTATE_DIRTY 3 /* block has been modified */
80 is_mbuf *data; /* data contained in block */
82 struct is_mblock *next; /* next diskblock */
85 typedef struct isam_struct *ISAM;
87 * Descriptor for a specific table.
89 typedef struct is_mtable
91 int num_records; /* total number of records */
92 int pos_type; /* blocktype */
93 is_mblock *cur_mblock;
95 is_mblock *data; /* blocks contained in this table */
99 is_mblock *xmalloc_mblock();
100 is_mbuf *xmalloc_mbuf(int type);
101 void xfree_mblock(is_mblock *p);
102 void xfree_mblocks(is_mblock *l);
103 void xfree_mbuf(is_mbuf *p);
104 void xfree_mbufs(is_mbuf *l);
105 void xrelease_mblock(is_mblock *p);
106 void is_m_establish_tab(ISAM is, is_mtable *tab, ISAM_P pos);
107 void is_m_release_tab(is_mtable *tab);
108 void is_m_rewind(is_mtable *tab);
109 void is_m_replace_record(is_mtable *tab, const void *rec);
110 int is_m_write_record(is_mtable *tab, const void *rec);
111 void is_m_unread_record(is_mtable *tab);
112 int is_m_read_record(is_mtable *tab, void *buf, int keep);
113 int is_m_seek_record(is_mtable *tab, const void *rec);
114 void is_m_delete_record(is_mtable *tab);
115 int is_m_peek_record(is_mtable *tab, void *rec);
116 int is_m_read_full(is_mtable *tab, is_mblock *mblock);
117 int is_m_num_records(is_mtable *tab);