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