#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
/* #include "INLINE.h" */
#define STATES_INITIAL_SIZE 10
struct _iterator_state {
    I32  riter;
    HE*  eiter;
};
typedef struct _iterator_state iterator_state;
static int module_initialized = 0;
iterator_state **STATES;
int STATES_size;
void _initialize()
{
    int i;
    if (module_initialized) return;
    STATES = malloc(STATES_INITIAL_SIZE*sizeof(iterator_state *));
    STATES_size = STATES_INITIAL_SIZE;
    for (i=0; i<STATES_size; i++) {
        STATES[i] = (iterator_state*) 0;
    }
    module_initialized = 1;
}
void _resize_STATES()
{
    int i;
    int new_size = STATES_size * 2;
    iterator_state **new_STATES = malloc(new_size*sizeof(iterator_state*));
    for (i=0; i<STATES_size; i++) {
        new_STATES[i] = STATES[i];
    }
    for (; i<new_size; i++) {
        new_STATES[i] = (iterator_state*) 0;
    }
    free(STATES);
    STATES = new_STATES;
    STATES_size = new_size;
}
int save_iterator_state(SV* hvref)
{
    int i;
    if (hvref == (SV*) 0) {
        warn("Hash::SafeKeys::save_iterator_state: null input!");
        return -1;
    }
    HV* hv = (HV*) SvRV(hvref);
    if (hv == (HV*) 0) {
        warn("Hash::SafeKeys::save_iterator_state: null input!");
        return -1;
    }
    iterator_state *state = malloc(sizeof(iterator_state));
    _initialize();
    for (i=0; i<STATES_size; i++) {
        if (STATES[i] == (iterator_state*) 0) {
            break;
        }
    }
    if (i >= STATES_size) {
        i = STATES_size;
        _resize_STATES();
    }
    state->riter = HvRITER(hv);
    state->eiter = HvEITER(hv);
    STATES[i] = state;
    hv_iterinit(hv);
    return i;
}
int restore_iterator_state(SV* hvref, int i)
{
    if (hvref == (SV*) 0) {
        warn("Hash::SafeKeys::restore_iterator_state: null input");
        return 0;
    }
    HV* hv = (HV*) SvRV(hvref);
    if (hv == (HV*) 0) {
        warn("Hash::SafeKeys::restore_iterator_state: null input");
        return 0;
    }
    _initialize();
    if (i < 0 || i >= STATES_size) {
        warn("Hash::SafeKeys::restore_iterator_state: "
             "invalid restore key %d", i);
        return 0;
    }
    iterator_state *state = STATES[i];
    if (state != (iterator_state*) 0) {
        HvRITER(hv) = state->riter;
        HvEITER(hv) = state->eiter;
        free(state);
        STATES[i] = (iterator_state*) 0;
        return 1;
    }
    warn("Hash::SafeKeys::restore_iterator_state: "
         "operation failed for key %d", i);
    STATES[i] = (iterator_state*) 0;
    return 0;
}
MODULE = Hash::SafeKeys  PACKAGE = Hash::SafeKeys  
PROTOTYPES: DISABLE
int
save_iterator_state (hvref)
        SV *    hvref
int
restore_iterator_state (hvref, i)
        SV *    hvref
        int     i