lgets function moved from kernel to util.

[egate.git] / util / gw-db.c

diff --git a/util/gw-db.c b/util/gw-db.c
index 5bbe23f..0b84d8c 100644 (file)
--- a/util/gw-db.c
+++ b/util/gw-db.c
@@ -2,7 +2,10 @@
  * Europagate, 1995
  *
  * $Log: gw-db.c,v $
- * Revision 1.1  1995/03/27 08:25:01  adam
+ * 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 +24,26 @@
 #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 +61,21 @@ 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 +86,14 @@ 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 +164,16 @@ 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 +228,9 @@ 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 +238,9 @@ 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 +285,9 @@ 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 +304,17 @@ 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;