| 1 | /* Include file cached obstack implementation. |
| 2 | Written by Fred Fish (fnf@cygnus.com) |
| 3 | Copyright 1995 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | #ifndef BCACHE_H |
| 22 | #define BCACHE_H 1 |
| 23 | |
| 24 | #define BCACHE_HASHLENGTH 12 /* Number of bits in hash value */ |
| 25 | #define BCACHE_HASHSIZE (1 << BCACHE_HASHLENGTH) |
| 26 | #define BCACHE_MAXLENGTH 128 |
| 27 | |
| 28 | /* Note that the user data is stored in data[]. Since it can be any type, |
| 29 | it needs to have the same alignment as the most strict alignment of |
| 30 | any type on the host machine. So do it the same way obstack does. */ |
| 31 | |
| 32 | struct hashlink { |
| 33 | struct hashlink *next; |
| 34 | union { |
| 35 | char data[1]; |
| 36 | double dummy; |
| 37 | } d; |
| 38 | }; |
| 39 | |
| 40 | /* BCACHE_DATA is used to get the address of the cached data. */ |
| 41 | |
| 42 | #define BCACHE_DATA(p) ((p)->d.data) |
| 43 | |
| 44 | /* BCACHE_DATA_ALIGNMENT is used to get the offset of the start of |
| 45 | cached data within the hashlink struct. This value, plus the |
| 46 | size of the cached data, is the amount of space to allocate for |
| 47 | a hashlink struct to hold the next pointer and the data. */ |
| 48 | |
| 49 | #define BCACHE_DATA_ALIGNMENT \ |
| 50 | (((char *) BCACHE_DATA((struct hashlink*) 0) - (char *) 0)) |
| 51 | |
| 52 | struct bcache { |
| 53 | struct obstack cache; |
| 54 | struct hashlink **indextable[BCACHE_MAXLENGTH]; |
| 55 | int cache_hits; |
| 56 | int cache_misses; |
| 57 | int cache_bytes; |
| 58 | int cache_savings; |
| 59 | int bcache_overflows; |
| 60 | }; |
| 61 | |
| 62 | extern void * |
| 63 | bcache PARAMS ((void *bytes, int count, struct bcache *bcachep)); |
| 64 | |
| 65 | #if MAINTENANCE_CMDS |
| 66 | |
| 67 | extern void |
| 68 | print_bcache_statistics PARAMS ((struct bcache *, char *)); |
| 69 | |
| 70 | #endif /* MAINTENANCE_CMDS */ |
| 71 | |
| 72 | #endif /* BCACHE_H */ |