2 * Copyright (C) 1994, Index Data I/S
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.10 1995-09-06 16:10:57 adam
8 * More work on boolean sets.
10 * Revision 1.9 1994/09/28 16:58:26 quinn
13 * Revision 1.8 1994/09/28 12:56:09 quinn
14 * Added access functions (ISPT)
16 * Revision 1.7 1994/09/28 11:56:13 quinn
17 * Removed const from input to is_merge
19 * Revision 1.6 1994/09/28 11:29:28 quinn
20 * Added cmp parameter.
22 * Revision 1.5 1994/09/27 20:03:36 quinn
23 * Seems relatively bug-free.
25 * Revision 1.4 1994/09/26 17:05:54 quinn
28 * Revision 1.3 1994/09/26 16:08:42 quinn
29 * Most of the functionality in place.
31 * Revision 1.2 1994/09/14 13:10:35 quinn
34 * Revision 1.1 1994/09/12 08:02:07 quinn
44 #include "../isam/memory.h"
45 #include "../isam/physical.h"
47 #define IS_MAX_BLOCKTYPES 4
48 #define IS_MAX_RECORD 512
49 #define IS_DEF_REPACK_PERCENT "30" /* how much relative change before repack */
51 typedef unsigned int SYSNO; /* should be somewhere else */
54 * Description of a blocktype (part of an isam file)
56 typedef struct isam_blocktype
58 BFile bf; /* blocked file */
60 int first_block; /* position of first data block */
61 int max_keys_block; /* max num of keys per block */
62 int max_keys_block0; /* max num of keys in first block */
63 int nice_keys_block; /* nice number of keys per block */
64 int max_keys; /* max number of keys per table */
65 int freelist; /* first free block */
66 int top; /* first unused block */
67 int index; /* placeholder. Always 0. */
68 char *dbuf; /* buffer for use in I/O operations */
72 * Handle to an open isam complex.
74 typedef struct isam_struct
76 isam_blocktype types[IS_MAX_BLOCKTYPES]; /* block_types used in this file */
77 int num_types; /* number of block types used */
79 int keysize; /* size of the keys (records) used */
80 int repack; /* how many percent to grow before repack */
81 int (*cmp)(const void *k1, const void *k2); /* compare function */
84 typedef struct ispt_struct
87 struct ispt_struct *next; /* freelist */
90 #define is_type(x) ((x) & 3) /* type part of position */
91 #define is_block(x) ((x) >> 2) /* block # part of position */
93 #define is_keysize(is) ((is)->keysize)
97 *******************************************************************
103 ISAM is_open(const char *name, int (*cmp)(const void *p1, const void *p2),
104 int writeflag, int keysize);
109 int is_close(ISAM is);
112 * Locate a table of keys in an isam file. The ISPT is an individual
113 * position marker for that table.
115 ISPT is_position(ISAM is, ISAM_P pos);
120 void is_pt_free(ISPT ip);
123 * Read a key from a table.
125 int is_readkey(ISPT ip, void *buf);
127 int is_writekey(ISPT ip, const void *buf);
129 int is_numkeys(ISPT ip);
131 void is_rewind(ISPT ip);
133 ISAM_P is_merge(ISAM is, ISAM_P pos, int num, char *data);