2 * Copyright (c) 1995-2002, Index Data.
3 * See the file LICENSE for details.
5 * Isam-D, Heikki's second Isam.
6 * The first block of an isam entry contains deltas to the
7 * (possibly long) sequence of keys. Thus small changes consist
8 * only of adding deltas to a small list, and affect only one
9 * block. Occasionally the block gets full, and needs to be
10 * merged with the rest.
14 * Detailed log at the end of the file
25 typedef struct ISAMD_s *ISAMD;
27 typedef struct ISAMD_PP_s *ISAMD_PP;
29 typedef struct ISAMD_filecat_s { /* filecategories, mostly block sizes */
30 int bsize; /* block size */
31 int mblocks; /* maximum keys before switching to larger sizes */
34 typedef struct ISAMD_M_s {
35 ISAMD_filecat filecat;
37 int (*compare_item)(const void *a, const void *b);
39 #define ISAMD_DECODE 0
40 #define ISAMD_ENCODE 1
41 void *(*code_start)(int mode);
42 void (*code_stop)(int mode, void *p);
43 void (*code_item)(int mode, void *p, char **dst, char **src);
44 void (*code_reset)(void *p);
50 typedef struct ISAMD_I_s { /* encapsulation of input data */
51 int (*read_item)(void *clientData, char **dst, int *insertMode);
55 ISAMD_M isamd_getmethod (ISAMD_M me);
57 ISAMD isamd_open (BFiles bfs, const char *name, int writeflag, ISAMD_M method);
58 int isamd_close (ISAMD is);
59 /*ISAMD_P isamd_append (ISAMD is, ISAMD_P pos, ISAMD_I data);*/
60 int isamd_append (ISAMD is, char *dictentry, int dictlen, ISAMD_I data);
64 /* Shortcut: If the isam is relatively short, we store the */
65 /* whole thing in the dictionary, and allocate no blocks at all! */
66 #define ISAMD_MAX_DICT_LEN 16
68 /*ISAMD_PP isamd_pp_open (ISAMD is, const char *dictbuf);*/
69 ISAMD_PP isamd_pp_open (ISAMD is, const char *dictbuf, int dictlen);
70 ISAMD_PP isamd_pp_create (ISAMD is, int cat);
72 void isamd_pp_close (ISAMD_PP pp);
73 int isamd_read_item (ISAMD_PP pp, char **dst);
74 int isamd_read_main_item (ISAMD_PP pp, char **dst);
75 int isamd_pp_read (ISAMD_PP pp, void *buf);
76 int isamd_pp_num (ISAMD_PP pp);
78 int isamd_block_used (ISAMD is, int type);
79 int isamd_block_size (ISAMD is, int type);
82 #define isamd_type(x) ((x) & 7)
83 #define isamd_block(x) ((x) >> 3)
84 #define isamd_addr(blk,typ) (((blk)<<3)+(typ))
86 void isamd_buildfirstblock(ISAMD_PP pp);
87 void isamd_buildlaterblock(ISAMD_PP pp);
96 * Revision 1.3 1999/08/18 08:33:41 heikki
99 * Revision 1.2 1999/07/14 13:21:34 heikki
100 * Added isam-d files. Compiles (almost) clean. Doesn't work at all
102 * Revision 1.1 1999/07/14 12:34:43 heikki
103 * Copied from isamh, starting to change things...