386BSD 0.1 development

[unix-history] / usr / othersrc / public / cvs-1.3 / src / myndbm.c

/*
* Copyright (c) 1992, Brian Berliner
* 
* You may distribute under the terms of the GNU General Public License as
* specified in the README file that comes with the CVS 1.3 kit.
* 
* A simple ndbm-emulator for CVS.  It parses a text file of the format:
* 
* key  value
* 
* at dbm_open time, and loads the entire file into memory.  As such, it is
* probably only good for fairly small modules files.  Ours is about 30K in
* size, and this code works fine.
*/

#include "cvs.h"

#ifdef MY_NDBM

#ifndef lint
static char rcsid[] = "@(#)myndbm.c 1.5 92/03/31";
#endif

static void mydbm_load_file ();

/* ARGSUSED */
DBM *
mydbm_open (file, flags, mode)
   char *file;
   int flags;
   int mode;
{
   FILE *fp;
   DBM *db;

   if ((fp = fopen (file, "r")) == NULL)
       return ((DBM *) 0);

   db = (DBM *) xmalloc (sizeof (*db));
   db->dbm_list = getlist ();

   mydbm_load_file (fp, db->dbm_list);
   (void) fclose (fp);
   return (db);
}

void
mydbm_close (db)
   DBM *db;
{
   dellist (&db->dbm_list);
   free ((char *) db);
}

datum
mydbm_fetch (db, key)
   DBM *db;
   datum key;
{
   Node *p;
   char *s;
   datum val;

   /* make sure it's null-terminated */
   s = xmalloc (key.dsize + 1);
   (void) strncpy (s, key.dptr, key.dsize);
   s[key.dsize] = '\0';

   p = findnode (db->dbm_list, s);
   if (p)
   {
       val.dptr = p->data;
       val.dsize = strlen (p->data);
   }
   else
   {
       val.dptr = (char *) NULL;
       val.dsize = 0;
   }
   free (s);
   return (val);
}

datum
mydbm_firstkey (db)
   DBM *db;
{
   Node *head, *p;
   datum key;

   head = db->dbm_list->list;
   p = head->next;
   if (p != head)
   {
       key.dptr = p->key;
       key.dsize = strlen (p->key);
   }
   else
   {
       key.dptr = (char *) NULL;
       key.dsize = 0;
   }
   db->dbm_next = p->next;
   return (key);
}

datum
mydbm_nextkey (db)
   DBM *db;
{
   Node *head, *p;
   datum key;

   head = db->dbm_list->list;
   p = db->dbm_next;
   if (p != head)
   {
       key.dptr = p->key;
       key.dsize = strlen (p->key);
   }
   else
   {
       key.dptr = (char *) NULL;
       key.dsize = 0;
   }
   db->dbm_next = p->next;
   return (key);
}

static void
mydbm_load_file (fp, list)
   FILE *fp;
   List *list;
{
   char line[MAXLINELEN], value[MAXLINELEN];
   char *cp, *vp;
   int len, cont;

   for (cont = 0; fgets (line, sizeof (line), fp) != NULL;)
   {
       if ((cp = rindex (line, '\n')) != NULL)
           *cp = '\0';                 /* strip the newline */

       /*
        * Add the line to the value, at the end if this is a continuation
        * line; otherwise at the beginning, but only after any trailing
        * backslash is removed.
        */
       vp = value;
       if (cont)
           vp += strlen (value);

       /*
        * See if the line we read is a continuation line, and strip the
        * backslash if so.
        */
       len = strlen (line);
       if (len > 0)
           cp = &line[len - 1];
       else
           cp = line;
       if (*cp == '\\')
       {
           cont = 1;
           *cp = '\0';
       }
       else
       {
           cont = 0;
       }
       (void) strcpy (vp, line);
       if (value[0] == '#')
           continue;                   /* comment line */
       vp = value;
       while (*vp && isspace (*vp))
           vp++;
       if (*vp == '\0')
           continue;                   /* empty line */

       /*
        * If this was not a continuation line, add the entry to the database
        */
       if (!cont)
       {
           Node *p = getnode ();
           char *kp;

           kp = vp;
           while (*vp && !isspace (*vp))
               vp++;
           *vp++ = '\0';               /* NULL terminate the key */
           p->type = NDBMNODE;
           p->key = xstrdup (kp);
           while (*vp && isspace (*vp))
               vp++;                   /* skip whitespace to value */
           if (*vp == '\0')
           {
               error (0, 0, "warning: NULL value for key `%s'", p->key);
               freenode (p);
               continue;
           }
           p->data = xstrdup (vp);
           if (addnode (list, p) == -1)
           {
               error (0, 0, "duplicate key found for `%s'", p->key);
               freenode (p);
           }
       }
   }
}

#endif                          /* MY_NDBM */