#include <stdlib.h>

#include "_whelk.h"

char *whelk_string_prealloc(struct whelk_string *string,size_t len)

{

    char *new;

    if (string->alloc<string->len+len)

    {

	new=realloc(string->buffer,string->len+len);

	if (!new)

	    return NULL;

	string->buffer=new;

	string->alloc=string->len+len;

    }

    return string->buffer+string->len;

}

void whelk_string_seek(struct whelk_string *string,ssize_t offset)

{

    if (offset>=0 || string->len>=(size_t)-offset)

	string->len+=offset;

    else

	string->len=0;

}

char *whelk_string_finalize(struct whelk_string *string)

{

    whelk_string_prealloc(string,1);

    string->buffer[string->len]='\0';

    return string->buffer;

}

void whelk_string_free(struct whelk_string *string)

{

    free(string->buffer);

    memset(string,0,sizeof(*string));

}