2 * Copyright (C) 1994, Index Data I/S
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.7 1994-09-28 11:56:13 quinn
8 * Removed const from input to is_merge
10 * Revision 1.6 1994/09/28 11:29:28 quinn
11 * Added cmp parameter.
13 * Revision 1.5 1994/09/27 20:03:36 quinn
14 * Seems relatively bug-free.
16 * Revision 1.4 1994/09/26 17:05:54 quinn
19 * Revision 1.3 1994/09/26 16:08:42 quinn
20 * Most of the functionality in place.
22 * Revision 1.2 1994/09/14 13:10:35 quinn
25 * Revision 1.1 1994/09/12 08:02:07 quinn
35 #include "../isam/memory.h"
36 #include "../isam/physical.h"
38 #define IS_MAX_BLOCKTYPES 4
39 #define IS_MAX_RECORD 512
40 #define IS_DEF_REPACK_PERCENT "30" /* how much relative change before repack */
42 typedef unsigned int SYSNO; /* should be somewhere else */
45 * Description of a blocktype (part of an isam file)
47 typedef struct isam_blocktype
49 BFile bf; /* blocked file */
51 int first_block; /* position of first data block */
52 int max_keys_block; /* max num of keys per block */
53 int max_keys_block0; /* max num of keys in first block */
54 int nice_keys_block; /* nice number of keys per block */
55 int max_keys; /* max number of keys per table */
56 int freelist; /* first free block */
57 int top; /* first unused block */
58 int index; /* placeholder. Always 0. */
59 char *dbuf; /* buffer for use in I/O operations */
63 * Handle to an open isam complex.
65 typedef struct isam_struct
67 isam_blocktype types[IS_MAX_BLOCKTYPES]; /* block_types used in this file */
68 int num_types; /* number of block types used */
70 int keysize; /* size of the keys (records) used */
71 int repack; /* how many percent to grow before repack */
72 int (*cmp)(const void *k1, const void *k2); /* compare function */
75 typedef struct ispt_struct
77 struct is_mtable *tab;
78 struct ispt_struct *next; /* freelist */
81 #define is_type(x) ((x) & 3) /* type part of position */
82 #define is_block(x) ((x) >> 2) /* block # part of position */
84 #define is_keysize(is) ((is)->keysize)
88 *******************************************************************
94 ISAM is_open(const char *name, int (*cmp)(const void *p1, const void *p2),
100 int is_close(ISAM is);
103 * Locate a table of keys in an isam file. The ISPT is an individual
104 * position marker for that table.
106 ISPT is_position(ISAM is, ISAM_P pos);
111 void is_pt_free(ISPT ip);
114 * Read a key from a table.
116 int is_readkey(ISPT ip, void *buf);
118 int is_writekey(ISPT ip, const void *buf);
120 ISAM_P is_merge(ISAM is, ISAM_P pos, int num, char *data);