2 * Copyright (C) 1994, Index Data I/S
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.5 1996-03-11 14:52:25 quinn
8 * Fixed update bug. Repeated insertion in the same area sometimes caused
11 * Revision 1.4 1995/12/06 15:48:47 quinn
12 * Fixed update-problem.
14 * Revision 1.3 1994/09/28 16:58:33 quinn
17 * Revision 1.2 1994/09/27 20:03:52 quinn
18 * Seems relatively bug-free.
20 * Revision 1.1 1994/09/26 17:12:32 quinn
23 * Revision 1.1 1994/09/26 16:07:57 quinn
24 * Most of the functionality in place.
31 extern int is_mbuf_size[3];
33 typedef unsigned int ISAM_P;
36 * Memory buffer. Used to manage records (keys) in memory for
37 * reading and insertion/deletion.
39 typedef struct is_mbuf
43 #define IS_MBUF_TYPE_SMALL 0
44 #define IS_MBUF_TYPE_MEDIUM 1
45 #define IS_MBUF_TYPE_LARGE 2
50 char *data; /* dummy */
54 * Structure describing the virtual image of a disk block.
55 * (these blocks may grow beyond the blocksize during insertion).
57 typedef struct is_mblock
59 int num_records; /* number of records */
60 int diskpos; /* positive if this block is mapped */
61 int nextpos; /* pos of nxt blk. Only valid imm aft. rd. */
62 int bread; /* number of bytes read */
63 int state; /* state of block in rel. to disk block */
64 #define IS_MBSTATE_UNREAD 0 /* block hasn't been read */
65 #define IS_MBSTATE_PARTIAL 1 /* block has been partially read */
66 #define IS_MBSTATE_CLEAN 2 /* block is clean (unmodified) */
67 #define IS_MBSTATE_DIRTY 3 /* block has been modified */
69 is_mbuf *data; /* data contained in block */
71 struct is_mblock *next; /* next diskblock */
74 typedef struct isam_struct *ISAM;
76 * Descriptor for a specific table.
78 typedef struct is_mtable
80 int num_records; /* total number of records */
81 int pos_type; /* blocktype */
82 is_mblock *cur_mblock;
84 is_mblock *data; /* blocks contained in this table */
88 is_mblock *xmalloc_mblock();
89 is_mbuf *xmalloc_mbuf(int type);
90 void xfree_mblock(is_mblock *p);
91 void xfree_mblocks(is_mblock *l);
92 void xfree_mbuf(is_mbuf *p);
93 void xfree_mbufs(is_mbuf *l);
94 void xrelease_mblock(is_mblock *p);
95 void is_m_establish_tab(ISAM is, is_mtable *tab, ISAM_P pos);
96 void is_m_release_tab(is_mtable *tab);
97 void is_m_rewind(is_mtable *tab);
98 void is_m_replace_record(is_mtable *tab, const void *rec);
99 int is_m_write_record(is_mtable *tab, const void *rec);
100 void is_m_unread_record(is_mtable *tab);
101 int is_m_read_record(is_mtable *tab, void *buf, int keep);
102 int is_m_seek_record(is_mtable *tab, const void *rec);
103 void is_m_delete_record(is_mtable *tab);
104 int is_m_peek_record(is_mtable *tab, void *rec);
105 int is_m_read_full(is_mtable *tab, is_mblock *mblock);
106 int is_m_num_records(is_mtable *tab);