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