2 * Copyright (C) 1994, Index Data I/S
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.6 1994-09-28 11:29:28 quinn
10 * Revision 1.5 1994/09/27 20:03:36 quinn
11 * Seems relatively bug-free.
13 * Revision 1.4 1994/09/26 17:05:54 quinn
16 * Revision 1.3 1994/09/26 16:08:42 quinn
17 * Most of the functionality in place.
19 * Revision 1.2 1994/09/14 13:10:35 quinn
22 * Revision 1.1 1994/09/12 08:02:07 quinn
32 #include "../isam/memory.h"
33 #include "../isam/physical.h"
35 #define IS_MAX_BLOCKTYPES 4
36 #define IS_MAX_RECORD 512
37 #define IS_DEF_REPACK_PERCENT "30" /* how much relative change before repack */
39 typedef unsigned int SYSNO; /* should be somewhere else */
42 * Description of a blocktype (part of an isam file)
44 typedef struct isam_blocktype
46 BFile bf; /* blocked file */
48 int first_block; /* position of first data block */
49 int max_keys_block; /* max num of keys per block */
50 int max_keys_block0; /* max num of keys in first block */
51 int nice_keys_block; /* nice number of keys per block */
52 int max_keys; /* max number of keys per table */
53 int freelist; /* first free block */
54 int top; /* first unused block */
55 int index; /* placeholder. Always 0. */
56 char *dbuf; /* buffer for use in I/O operations */
60 * Handle to an open isam complex.
62 typedef struct isam_struct
64 isam_blocktype types[IS_MAX_BLOCKTYPES]; /* block_types used in this file */
65 int num_types; /* number of block types used */
67 int keysize; /* size of the keys (records) used */
68 int repack; /* how many percent to grow before repack */
69 int (*cmp)(const void *k1, const void *k2); /* compare function */
72 typedef struct ispt_struct
74 struct is_mtable *tab;
75 struct ispt_struct *next; /* freelist */
78 #define is_type(x) ((x) & 3) /* type part of position */
79 #define is_block(x) ((x) >> 2) /* block # part of position */
81 #define is_keysize(is) ((is)->keysize)
85 *******************************************************************
91 ISAM is_open(const char *name, int (*cmp)(const void *p1, const void *p2),
97 int is_close(ISAM is);
100 * Locate a table of keys in an isam file. The ISPT is an individual
101 * position marker for that table.
103 ISPT is_position(ISAM is, ISAM_P pos);
108 void is_pt_free(ISPT ip);
111 * Read a key from a table.
113 int is_readkey(ISPT ip, void *buf);
115 int is_writekey(ISPT ip, const void *buf);
117 ISAM_P is_merge(ISAM is, ISAM_P pos, int num, const char *data);