2 * Copyright (C) 1994, Index Data I/S
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.8 1994-09-28 12:56:09 quinn
8 * Added access functions (ISPT)
10 * Revision 1.7 1994/09/28 11:56:13 quinn
11 * Removed const from input to is_merge
13 * Revision 1.6 1994/09/28 11:29:28 quinn
14 * Added cmp parameter.
16 * Revision 1.5 1994/09/27 20:03:36 quinn
17 * Seems relatively bug-free.
19 * Revision 1.4 1994/09/26 17:05:54 quinn
22 * Revision 1.3 1994/09/26 16:08:42 quinn
23 * Most of the functionality in place.
25 * Revision 1.2 1994/09/14 13:10:35 quinn
28 * Revision 1.1 1994/09/12 08:02:07 quinn
38 #include "../isam/memory.h"
39 #include "../isam/physical.h"
41 #define IS_MAX_BLOCKTYPES 4
42 #define IS_MAX_RECORD 512
43 #define IS_DEF_REPACK_PERCENT "30" /* how much relative change before repack */
45 typedef unsigned int SYSNO; /* should be somewhere else */
48 * Description of a blocktype (part of an isam file)
50 typedef struct isam_blocktype
52 BFile bf; /* blocked file */
54 int first_block; /* position of first data block */
55 int max_keys_block; /* max num of keys per block */
56 int max_keys_block0; /* max num of keys in first block */
57 int nice_keys_block; /* nice number of keys per block */
58 int max_keys; /* max number of keys per table */
59 int freelist; /* first free block */
60 int top; /* first unused block */
61 int index; /* placeholder. Always 0. */
62 char *dbuf; /* buffer for use in I/O operations */
66 * Handle to an open isam complex.
68 typedef struct isam_struct
70 isam_blocktype types[IS_MAX_BLOCKTYPES]; /* block_types used in this file */
71 int num_types; /* number of block types used */
73 int keysize; /* size of the keys (records) used */
74 int repack; /* how many percent to grow before repack */
75 int (*cmp)(const void *k1, const void *k2); /* compare function */
78 typedef struct ispt_struct
81 struct ispt_struct *next; /* freelist */
84 #define is_type(x) ((x) & 3) /* type part of position */
85 #define is_block(x) ((x) >> 2) /* block # part of position */
87 #define is_keysize(is) ((is)->keysize)
91 *******************************************************************
97 ISAM is_open(const char *name, int (*cmp)(const void *p1, const void *p2),
103 int is_close(ISAM is);
106 * Locate a table of keys in an isam file. The ISPT is an individual
107 * position marker for that table.
109 ISPT is_position(ISAM is, ISAM_P pos);
114 void is_pt_free(ISPT ip);
117 * Read a key from a table.
119 int is_readkey(ISPT ip, void *buf);
121 int is_writekey(ISPT ip, const void *buf);
123 ISAM_P is_merge(ISAM is, ISAM_P pos, int num, char *data);