#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "class.h"
#include "interface/class.h"

#include "http/header.h"

/**
 * SDBM hashing algorithm:
 *
 * this algorithm was created for sdbm (a public-domain reimplementation of
 * ndbm) database library. it was found to do well in scrambling bits,
 * causing better distribution of the keys and fewer splits. it also happens
 * to be a good general hashing function with good distribution. the actual
 * function is hash(i) = hash(i - 1) * 65599 + str[i]; what is included below
 * is the faster version used in gawk. [there is even a faster, duff-device
 * version] the magic constant 65599 was picked out of thin air while
 * experimenting with different constants, and turns out to be a prime. this
 * is one of the algorithms used in berkeley db (see sleepycat) and elsewhere. 
 */
static
inline
unsigned long
sdbm(unsigned char * str)
{
	unsigned long hash = 0;
	int c;

	while ((c = tolower(*str++)))
		hash = c + (hash << 6) + (hash << 16) - hash;

	return hash;
}

static
void
ctor(void * _this, va_list * params) {
	HttpHeader this = _this;
	char * name;
	char * value;

	name  = va_arg(* params, char *);
	value = va_arg(* params, char *);
	
	this->name = malloc(strlen(name) + 1);
	strcpy(this->name, name);

	this->hash = sdbm((unsigned char *)name);

	this->value = malloc(strlen(value) + 1);
	strcpy(this->value, value);
}

static
void
dtor(void * _this)
{
	HttpHeader this = _this;

	free(this->name);
	free(this->value);
}

INIT_IFACE(Class, ctor, dtor, NULL);
CREATE_CLASS(HttpHeader, NULL, IFACE(Class));

// vim: set ts=4 sw=4: