2 * Copyright (C) 1994, Index Data I/S
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.11 1996-10-29 13:43:44 adam
8 * Removed definition of SYSNO.
10 * Revision 1.10 1995/09/06 16:10:57 adam
11 * More work on boolean sets.
13 * Revision 1.9 1994/09/28 16:58:26 quinn
16 * Revision 1.8 1994/09/28 12:56:09 quinn
17 * Added access functions (ISPT)
19 * Revision 1.7 1994/09/28 11:56:13 quinn
20 * Removed const from input to is_merge
22 * Revision 1.6 1994/09/28 11:29:28 quinn
23 * Added cmp parameter.
25 * Revision 1.5 1994/09/27 20:03:36 quinn
26 * Seems relatively bug-free.
28 * Revision 1.4 1994/09/26 17:05:54 quinn
31 * Revision 1.3 1994/09/26 16:08:42 quinn
32 * Most of the functionality in place.
34 * Revision 1.2 1994/09/14 13:10:35 quinn
37 * Revision 1.1 1994/09/12 08:02:07 quinn
47 #include "../isam/memory.h"
48 #include "../isam/physical.h"
50 #define IS_MAX_BLOCKTYPES 4
51 #define IS_MAX_RECORD 512
52 #define IS_DEF_REPACK_PERCENT "30" /* how much relative change before repack */
55 * Description of a blocktype (part of an isam file)
57 typedef struct isam_blocktype
59 BFile bf; /* blocked file */
61 int first_block; /* position of first data block */
62 int max_keys_block; /* max num of keys per block */
63 int max_keys_block0; /* max num of keys in first block */
64 int nice_keys_block; /* nice number of keys per block */
65 int max_keys; /* max number of keys per table */
66 int freelist; /* first free block */
67 int top; /* first unused block */
68 int index; /* placeholder. Always 0. */
69 char *dbuf; /* buffer for use in I/O operations */
73 * Handle to an open isam complex.
75 typedef struct isam_struct
77 isam_blocktype types[IS_MAX_BLOCKTYPES]; /* block_types used in this file */
78 int num_types; /* number of block types used */
80 int keysize; /* size of the keys (records) used */
81 int repack; /* how many percent to grow before repack */
82 int (*cmp)(const void *k1, const void *k2); /* compare function */
85 typedef struct ispt_struct
88 struct ispt_struct *next; /* freelist */
91 #define is_type(x) ((x) & 3) /* type part of position */
92 #define is_block(x) ((x) >> 2) /* block # part of position */
94 #define is_keysize(is) ((is)->keysize)
98 *******************************************************************
104 ISAM is_open(const char *name, int (*cmp)(const void *p1, const void *p2),
105 int writeflag, int keysize);
110 int is_close(ISAM is);
113 * Locate a table of keys in an isam file. The ISPT is an individual
114 * position marker for that table.
116 ISPT is_position(ISAM is, ISAM_P pos);
121 void is_pt_free(ISPT ip);
124 * Read a key from a table.
126 int is_readkey(ISPT ip, void *buf);
128 int is_writekey(ISPT ip, const void *buf);
130 int is_numkeys(ISPT ip);
132 void is_rewind(ISPT ip);
134 ISAM_P is_merge(ISAM is, ISAM_P pos, int num, char *data);