2 * Copyright (C) 1994-1997, Index Data I/S
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.12 1997-09-05 15:30:00 adam
8 * Changed prototype for chr_map_input - added const.
9 * Added support for C++, headers uses extern "C" for public definitions.
11 * Revision 1.11 1996/10/29 13:43:44 adam
12 * Removed definition of SYSNO.
14 * Revision 1.10 1995/09/06 16:10:57 adam
15 * More work on boolean sets.
17 * Revision 1.9 1994/09/28 16:58:26 quinn
20 * Revision 1.8 1994/09/28 12:56:09 quinn
21 * Added access functions (ISPT)
23 * Revision 1.7 1994/09/28 11:56:13 quinn
24 * Removed const from input to is_merge
26 * Revision 1.6 1994/09/28 11:29:28 quinn
27 * Added cmp parameter.
29 * Revision 1.5 1994/09/27 20:03:36 quinn
30 * Seems relatively bug-free.
32 * Revision 1.4 1994/09/26 17:05:54 quinn
35 * Revision 1.3 1994/09/26 16:08:42 quinn
36 * Most of the functionality in place.
38 * Revision 1.2 1994/09/14 13:10:35 quinn
41 * Revision 1.1 1994/09/12 08:02:07 quinn
51 #include "../isam/memory.h"
52 #include "../isam/physical.h"
58 #define IS_MAX_BLOCKTYPES 4
59 #define IS_MAX_RECORD 512
60 #define IS_DEF_REPACK_PERCENT "30" /* how much relative change before repack */
63 * Description of a blocktype (part of an isam file)
65 typedef struct isam_blocktype
67 BFile bf; /* blocked file */
69 int first_block; /* position of first data block */
70 int max_keys_block; /* max num of keys per block */
71 int max_keys_block0; /* max num of keys in first block */
72 int nice_keys_block; /* nice number of keys per block */
73 int max_keys; /* max number of keys per table */
74 int freelist; /* first free block */
75 int top; /* first unused block */
76 int index; /* placeholder. Always 0. */
77 char *dbuf; /* buffer for use in I/O operations */
81 * Handle to an open isam complex.
83 typedef struct isam_struct
85 isam_blocktype types[IS_MAX_BLOCKTYPES]; /* block_types used in this file */
86 int num_types; /* number of block types used */
88 int keysize; /* size of the keys (records) used */
89 int repack; /* how many percent to grow before repack */
90 int (*cmp)(const void *k1, const void *k2); /* compare function */
93 typedef struct ispt_struct
96 struct ispt_struct *next; /* freelist */
99 #define is_type(x) ((x) & 3) /* type part of position */
100 #define is_block(x) ((x) >> 2) /* block # part of position */
102 #define is_keysize(is) ((is)->keysize)
106 *******************************************************************
112 ISAM is_open(const char *name, int (*cmp)(const void *p1, const void *p2),
113 int writeflag, int keysize);
118 int is_close(ISAM is);
121 * Locate a table of keys in an isam file. The ISPT is an individual
122 * position marker for that table.
124 ISPT is_position(ISAM is, ISAM_P pos);
129 void is_pt_free(ISPT ip);
132 * Read a key from a table.
134 int is_readkey(ISPT ip, void *buf);
136 int is_writekey(ISPT ip, const void *buf);
138 int is_numkeys(ISPT ip);
140 void is_rewind(ISPT ip);
142 ISAM_P is_merge(ISAM is, ISAM_P pos, int num, char *data);