X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=util%2Fgw-db.c;h=97bb3065d91343d4f041f34d2bfce90a9b149d41;hb=e1ec9d39463f431383547891f38e30f2ff17842c;hp=5bbe23fc5a3bb6d03154cf8cbdf854727b561d4b;hpb=ad67147ba5d2e4287bacfcbdaac2e5d9058cb400;p=egate.git diff --git a/util/gw-db.c b/util/gw-db.c index 5bbe23f..97bb306 100644 --- a/util/gw-db.c +++ b/util/gw-db.c @@ -1,8 +1,57 @@ +/* + * Copyright (c) 1995, the EUROPAGATE consortium (see below). + * + * The EUROPAGATE consortium members are: + * + * University College Dublin + * Danmarks Teknologiske Videnscenter + * An Chomhairle Leabharlanna + * Consejo Superior de Investigaciones Cientificas + * + * Permission to use, copy, modify, distribute, and sell this software and + * its documentation, in whole or in part, for any purpose, is hereby granted, + * provided that: + * + * 1. This copyright and permission notice appear in all copies of the + * software and its documentation. Notices of copyright or attribution + * which appear at the beginning of any file must remain unchanged. + * + * 2. The names of EUROPAGATE or the project partners may not be used to + * endorse or promote products derived from this software without specific + * prior written permission. + * + * 3. Users of this software (implementors and gateway operators) agree to + * inform the EUROPAGATE consortium of their use of the software. This + * information will be used to evaluate the EUROPAGATE project and the + * software, and to plan further developments. The consortium may use + * the information in later publications. + * + * 4. Users of this software agree to make their best efforts, when + * documenting their use of the software, to acknowledge the EUROPAGATE + * consortium, and the role played by the software in their work. + * + * THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT WARRANTY OF ANY KIND, + * EXPRESS, IMPLIED, OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY + * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + * IN NO EVENT SHALL THE EUROPAGATE CONSORTIUM OR ITS MEMBERS BE LIABLE + * FOR ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF + * ANY KIND, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA + * OR PROFITS, WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND + * ON ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE + * USE OR PERFORMANCE OF THIS SOFTWARE. + * + */ /* Gateway utility * Europagate, 1995 * * $Log: gw-db.c,v $ - * Revision 1.1 1995/03/27 08:25:01 adam + * Revision 1.3 1995/05/16 09:40:53 adam + * LICENSE. + * + * Revision 1.2 1995/05/01 12:43:57 adam + * lgets function moved from kernel to util. + * + * Revision 1.1 1995/03/27 08:25:01 adam * New module gip: Gateway IPc module. * New module gw-db: Gateway hash-db module (user information table). * @@ -21,23 +70,26 @@ #define DB_HASH 1997 struct gw_db { - struct file_head { - char magic[8]; - int no_of_entries; - int sequence_no; + struct file_head { /* file header info */ + char magic[8]; /* start info */ + int no_of_entries; /* no of entries in table */ + int sequence_no; /* number of next to come */ } head; - int *hash_array; - int fd; - int dirty; + int *hash_array; /* hash array pointers (DB_HASH in size) */ + int fd; /* descriptor of file */ + int dirty; /* any writes so far? */ }; -struct db_bucket { - int name_length; - int info_length; - int next; - int prev; +struct db_bucket { /* information about individual entries */ + int name_length; /* length of name */ + int info_length; /* length of information */ + int next; /* next in hash chain - possibly 0 */ + int prev; /* prev in hach chain - possibly 0 */ }; +/* + * write_head: write header of table + */ static int write_head (GW_DB db) { char file_head_buf[FILE_HEAD_LEN]; @@ -55,15 +107,21 @@ static int write_head (GW_DB db) return 0; } -static unsigned hash (const char *name) +/* + * hash: calculate hash value + */ +static unsigned hash (const char *name, int length) { unsigned l = 0; - while (*name) + while (--length >= 0) l = l*65599 + *name++; return l % DB_HASH; } +/* + * lock_file: lock entire file + */ static void lock_file (int fd, int type) { struct flock area; @@ -74,11 +132,14 @@ static void lock_file (int fd, int type) fcntl (fd, F_SETLKW, &area); } +/* + * gw_db_lookup: table lookup + */ int gw_db_lookup (GW_DB db, const char *name, int name_length, void **buf, size_t *count) { struct db_bucket bucket; - unsigned l = hash (name); + unsigned l = hash (name, name_length); char *dbuf = NULL; int dsize = 0; int pos; @@ -149,13 +210,16 @@ int gw_db_lookup (GW_DB db, const char *name, int name_length, return 0; } +/* + * gw_db_insert: table insertion + */ int gw_db_insert (GW_DB db, const char *name, int name_length, const void *buf, size_t count) { struct db_bucket n_bucket; struct db_bucket bucket; off_t n_pos, r_pos; - unsigned l = hash (name); + unsigned l = hash (name, name_length); int pos = db->hash_array[l]; int r; @@ -210,6 +274,9 @@ int gw_db_insert (GW_DB db, const char *name, int name_length, return 0; } +/* + * gw_db_free: release memory associated with table + */ static GW_DB gw_db_free (GW_DB db) { free (db->hash_array); @@ -217,6 +284,9 @@ static GW_DB gw_db_free (GW_DB db) return NULL; } +/* + * gw_db_open: open and lock table for reading (and writing) + */ GW_DB gw_db_open (const char *fname, int write_flag) { char file_head_buf[FILE_HEAD_LEN]; @@ -261,7 +331,9 @@ GW_DB gw_db_open (const char *fname, int write_flag) return db; } - +/* + * gw_db_close: close table and flush + */ int gw_db_close (GW_DB db) { int r = 0; @@ -278,11 +350,17 @@ int gw_db_close (GW_DB db) return r; } +/* + * gw_db_no_ent: return number of entries in table + */ int gw_db_no_ent (GW_DB db) { return db->head.no_of_entries; } +/* + * gw_db_seq_no: return sequence number + */ int gw_db_seq_no (GW_DB db) { return db->head.sequence_no;