/*
* lftp - file transfer program
*
* Copyright (c) 1996-2012 by Alexander V. Lukyanov (lav@yars.free.net)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef KEYVALUE_H
#define KEYVALUE_H
#include "xstring.h"
class StringMangler
{
typedef const char *(*mangle_t)(const char *);
mangle_t mangle;
public:
const char *operator()(const char *s) { return mangle?mangle(s):s; }
StringMangler(mangle_t m=0) { mangle=m; }
};
class KeyValueDB
{
public:
class Pair
{
public:
xstring_c key;
xstring_c value;
Pair *next;
Pair(const char *k,const char *v)
: key(k), value(v), next(0) {}
virtual ~Pair() {}
int KeyCompare(const char *s) const
{
return strcmp(s,key);
}
void SetValue(const char *v) { value.set(v); }
};
protected:
void Purge(Pair **p)
{
Pair *to_free=*p;
if(current==to_free)
current=to_free->next;
*p=to_free->next;
delete to_free;
}
Pair **LookupPair(const char *key) const;
void AddPair(Pair *p)
{
p->next=chain;
chain=p;
}
virtual Pair *NewPair(const char *id,const char *value)
{
return new Pair(id,value);
}
int Lock(int fd,int type);
Pair *chain;
Pair *current;
public:
void Add(const char *id,const char *value);
void Remove(const char *id);
const char *Lookup(const char *id) const;
void Empty()
{
while(chain)
Purge(&chain);
}
int Write(int fd);
int Read(int fd);
void Sort();
char *Format(StringMangler m=0); // returns formatted contents (malloc'ed)
void Rewind()
{
current=chain;
}
const char *CurrentKey() const
{
if(!current)
return 0;
return current->key;
}
const char *CurrentValue() const
{
if(!current)
return 0;
return current->value;
}
bool Next()
{
if(current==0)
return false;
current=current->next;
return current!=0;
}
KeyValueDB()
{
chain=0;
current=0;
}
virtual ~KeyValueDB()
{
Empty();
}
static int KeyCompare(const Pair *a,const Pair *b)
{
return strcmp(a->key,b->key);
}
static int VKeyCompare(const void *a,const void *b);
};
#endif //KEYVALUE_H