/*
Copyright (C) 2001-2010, Parrot Foundation.
$Id: resizablestringarray.pmc 46300 2010-05-05 03:58:50Z jimmy $

=head1 NAME

src/pmc/resizablestringarray.pmc - resizable array for strings only

=head1 DESCRIPTION

ResizableStringArray implements a resizeable array which stores Parrot strings
only. Any ints or floats assigned to elements of the array will first be
converted to String PMCs and then to native Parrot strings.  PMCs assigned to
to elements of the array will be stringified by having their C<get_string>
method called.

=cut

*/

/* HEADERIZER HFILE: none */
/* HEADERIZER BEGIN: static */
/* HEADERIZER END: static */

pmclass ResizableStringArray extends FixedStringArray auto_attrs provides array {
    ATTR UINTVAL resize_threshold; /*max capacity before resizing */

/*

=head2 Functions

=over 4

=item C<STRING *get_string_keyed_int(INTVAL key)>

Returns the Parrot string value of the element at index C<key>.

=cut

*/

    VTABLE STRING *get_string_keyed_int(INTVAL key) {

        STRING **str_array;
        INTVAL size;
        GET_ATTR_size(INTERP, SELF, size);

        if (key < 0) {
            if (key < -size)
                Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_OUT_OF_BOUNDS,
                    "ResizableStringArray: index out of bounds!");
            else
                key += size;
        }

        if (key >= size)
            return CONST_STRING(INTERP, "");

        GET_ATTR_str_array(INTERP, SELF, str_array);

        if (!str_array[key])
            str_array[key] = Parrot_str_new(INTERP, NULL, 0);

        return str_array[key];
    }

/*

=item C<void set_string_keyed_int(INTVAL key, STRING *value)>

Sets the Parrot string value of the element at index C<key> to C<value>.

=cut

*/

    VTABLE void set_string_keyed_int(INTVAL key, STRING *value) {

        STRING **str_array;
        INTVAL   size;
        GET_ATTR_size(INTERP, SELF, size);

        if (key < 0) {
            if (key < -size)
                Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_OUT_OF_BOUNDS,
                    "ResizableStringArray: index out of bounds!");
            else
                key += size;
        }

        if (key >= size)
            SELF.set_integer_native(key+1);

        GET_ATTR_str_array(INTERP, SELF, str_array);
        str_array[key] = value;
    }

/*

=item C<void push_string(STRING *value)>

Extends the array by adding an element of value C<*value> to the end of
the array.

=cut

*/

    VTABLE void push_string(STRING *value) {
        INTVAL next_idx;
        GET_ATTR_size(INTERP, SELF, next_idx);
        SELF.set_string_keyed_int(next_idx, value);
    }

/*

=item C<STRING *pop_string()>

Removes and returns the last element in the array.

=cut

*/

    VTABLE STRING *pop_string() {
        STRING *value;
        INTVAL  size;
        GET_ATTR_size(INTERP, SELF, size);

        if (size == 0)
            Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_OUT_OF_BOUNDS,
                    "ResizableStringArray: Can't pop from an empty array!");

        value = SELF.get_string_keyed_int(size - 1);
        SELF.set_integer_native(size - 1);
        return value;
    }

/*

=item C<PMC *pop_pmc()>

Removes and returns the last element in the array.

=cut

*/

    VTABLE PMC *pop_pmc() {
        STRING *strval = SELF.pop_string();
        PMC    *value  = Parrot_pmc_new(INTERP, enum_class_String);

        VTABLE_set_string_native(INTERP, value, strval);

        return value;
    }

/*

=item C<INTVAL pop_integer()>

Removes and returns the last element in the array.

=cut

*/

    VTABLE INTVAL pop_integer() {
        PMC * const pmcval = SELF.pop_pmc();
        return VTABLE_get_integer(INTERP, pmcval);
    }

/*

=item C<FLOATVAL pop_float()>

Removes and returns the last element in the array.

=cut

*/

    VTABLE FLOATVAL pop_float() {
        PMC * const pmcval = SELF.pop_pmc();
        return VTABLE_get_number(INTERP, pmcval);
    }

/*

=item C<void set_integer_native(INTVAL size)>

Resizes the array to C<size> elements.

=cut

*/

    VTABLE void set_integer_native(INTVAL new_size) {

        STRING **str_array;
        INTVAL   resize_threshold;

        if (new_size < 0)
            Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_OUT_OF_BOUNDS,
                    "ResizableStringArray: Can't resize!");

        GET_ATTR_str_array(INTERP, SELF, str_array);
        GET_ATTR_resize_threshold(INTERP, SELF, resize_threshold);
        if (!str_array) {
            /* empty - used fixed routine */
            if (new_size < 8) {
                SUPER(8);
                SET_ATTR_size(INTERP, SELF, new_size);
                SET_ATTR_resize_threshold(INTERP, SELF, 8);
            }
            else {
                SUPER(new_size);
                SET_ATTR_resize_threshold(INTERP, SELF, new_size);
            }
        }
        else if (new_size <= resize_threshold) {
            /* zero out anything that was previously allocated
             * if we're growing the array */
            INTVAL old_size;
            GET_ATTR_size(INTERP, SELF, old_size);
            if (new_size > old_size) {
                INTVAL i;
                for (i = old_size; i < new_size; ++i)
                    str_array[i] = NULL;
            }

            SET_ATTR_size(INTERP, SELF, new_size);
            /* we could shrink here if necessary */
            return;
        }
        else {
            INTVAL i   = resize_threshold;
            INTVAL cur = i;

            if (cur < 8192)
                cur = (new_size < 2 * cur) ? (2 * cur) : new_size;
            else {
                cur = new_size + 4096;
                cur &= ~0xfff;
            }

            SET_ATTR_str_array(INTERP, SELF,
                    mem_gc_realloc_n_typed_zeroed(INTERP, str_array,
                            cur, resize_threshold, STRING*));
            GET_ATTR_str_array(INTERP, SELF, str_array);

            for (; i < cur; ++i)
                str_array[i] = NULL;

            SET_ATTR_size(INTERP, SELF, new_size);
            SET_ATTR_resize_threshold(INTERP, SELF, cur);
        }
    }

/*

=item C<PMC *clone()>

Creates and returns a copy of the array.

=cut

*/

    VTABLE PMC *clone() {
        PMC * const copy = SUPER();
        INTVAL size;
        GET_ATTR_size(INTERP, SELF, size);
        /* copy trimmed extra space */
        SET_ATTR_resize_threshold(INTERP, copy, size);
        return copy;
    }

/*

=item C<STRING *shift_string()>

Removes and returns an item from the start of the array.

=cut

*/

    VTABLE STRING *shift_string() {
        STRING *value;
        INTVAL  size;
        GET_ATTR_size(INTERP, SELF, size);

        if (size == 0)
            Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_OUT_OF_BOUNDS,
                    "ResizableStringArray: Can't shift from an empty array!");

        value = SELF.get_string_keyed_int(0);
        SELF.delete_keyed_int(0);
        return value;
    }

/*

=item C<PMC *shift_pmc()>

Removes and returns the first element in the array.

=cut

*/

    VTABLE PMC *shift_pmc() {
        STRING * const strval = SELF.shift_string();
        PMC    * const value  = Parrot_pmc_new(INTERP, enum_class_String);

        VTABLE_set_string_native(INTERP, value, strval);

        return value;
    }

/*

=item C<INTVAL shift_integer()>

Removes and returns the first element in the array.

=cut

*/

    VTABLE INTVAL shift_integer() {
        PMC * const pmcval = SELF.shift_pmc();
        return VTABLE_get_integer(INTERP, pmcval);
    }

/*

=item C<FLOATVAL shift_float()>

Removes and returns the first element in the array.

=cut

*/

    VTABLE FLOATVAL shift_float() {
        PMC * const pmcval = SELF.shift_pmc();
        return VTABLE_get_number(INTERP, pmcval);
    }


/*

=item C<void push_pmc(PMC *value)>

Extends the array by adding an element of value C<*value> to the end of
the array.

=cut

*/

    VTABLE void push_pmc(PMC *value) {
        STRING * const strvalue = VTABLE_get_string(INTERP, value);
        SELF.push_string(strvalue);
    }

/*

=item C<void push_integer(INTVAL value)>

Extends the array by adding an element of value C<*value> to the end of
the array.

=cut

*/

    VTABLE void push_integer(INTVAL value) {
        PMC    * const ret = Parrot_pmc_new(INTERP, enum_class_String);
        STRING *val;

        VTABLE_set_integer_native(INTERP, ret, value);
        val = VTABLE_get_string(INTERP, ret);
        SELF.push_string(val);
    }

/*

=item C<void push_float(FLOAT value)>

Extends the array by adding an element of value C<*value> to the end of
the array.

=cut

*/

    VTABLE void push_float(FLOATVAL value) {
        PMC    * const ret = Parrot_pmc_new(INTERP, enum_class_String);
        STRING *val;

        VTABLE_set_number_native(INTERP, ret, value);
        val = VTABLE_get_string(INTERP, ret);
        SELF.push_string(val);
    }

/*

=item C<PMC *shift_pmc()>

Removes and returns a String PMC from the start of the array.

=cut

*/

    VTABLE PMC *shift_pmc() {
        UINTVAL  size;
        PMC     *ret;
        STRING  *value;

        GET_ATTR_size(INTERP, SELF, size);

        if (size == 0)
            Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_OUT_OF_BOUNDS,
                    "ResizableStringArray: Can't shift from an empty array!");

        value = SELF.get_string_keyed_int(0);
        ret   = Parrot_pmc_new(INTERP, enum_class_String);

        VTABLE_set_string_native(INTERP, ret, value);
        SELF.delete_keyed_int(0);

        return ret;
    }

/*

=item C<void unshift_string(STRING *value)>

Extends the array by adding an element of value C<*value> to the start
of the array.

=cut

*/

    VTABLE void unshift_string(STRING *value) {
        STRING  **str_array;
        UINTVAL   size, i;

        GET_ATTR_size(INTERP, SELF, size);
        SELF.set_integer_native(size + 1);

        GET_ATTR_str_array(INTERP, SELF, str_array);
        for (i = size; i; --i)
            str_array[i] = str_array[i - 1];

        SELF.set_string_keyed_int(0, value);
    }


/*

=item C<void unshift_pmc(PMC *value)>

Extends the array by adding an element of value C<*value> to the front of
the array.

=cut

*/

    VTABLE void unshift_pmc(PMC *value) {
        STRING * const strvalue = VTABLE_get_string(INTERP, value);
        SELF.unshift_string(strvalue);
    }

/*

=item C<void unshift_integer(INTVAL value)>

Extends the array by adding an element of value C<*value> to the front of
the array.

=cut

*/

    VTABLE void unshift_integer(INTVAL value) {
        PMC    * const ret = Parrot_pmc_new(INTERP, enum_class_String);
        STRING *val;

        VTABLE_set_integer_native(INTERP, ret, value);
        val = VTABLE_get_string(INTERP, ret);
        SELF.unshift_string(val);
    }

/*

=item C<void unshift_float(FLOAT value)>

Extends the array by adding an element of value C<*value> to the front of
the array.

=cut

*/

    VTABLE void unshift_float(FLOATVAL value) {
        PMC    * const ret = Parrot_pmc_new(INTERP, enum_class_String);
        STRING *val;

        VTABLE_set_number_native(INTERP, ret, value);
        val = VTABLE_get_string(INTERP, ret);
        SELF.unshift_string(val);
    }

/*

=item C<void delete_keyed_int(INTVAL key)>

Converts C<key> to a PMC key and calls C<delete_keyed()> with it.

=cut

*/

    VTABLE void delete_keyed_int(INTVAL key) {
        STRING  **str_array;
        UINTVAL   size, i;

        GET_ATTR_str_array(INTERP, SELF, str_array);
        GET_ATTR_size(INTERP, SELF, size);

        for (i = key; i < size - 1; ++i)
            str_array[i] = str_array[i + 1];

        SELF.set_integer_native(size - 1);
    }

/*

=item C<void delete_keyed(PMC *key)>

Removes the element at C<*key>.

=cut

*/

    VTABLE void delete_keyed(PMC *key) {
        const INTVAL idx = VTABLE_get_integer(INTERP, key);
        STRING  **str_array;
        UINTVAL   size, i;

        GET_ATTR_str_array(INTERP, SELF, str_array);
        GET_ATTR_size(INTERP, SELF, size);

        for (i = idx; i < size - 1; ++i)
            str_array[i] = str_array[i + 1];

        SELF.set_integer_native(size - 1);
    }

/*

=item C<void splice(PMC *value, INTVAL offset, INTVAL count)>

Replaces C<count> elements starting at C<offset> with the elements in
C<value>.

Note that the C<value> PMC can be of any of the various array types.

Note that this implementation can be *VERY *inefficient as it manipulates
everything via the VTABLE api.

=cut

*/

    VTABLE void splice(PMC *value, INTVAL offset, INTVAL count) {

        INTVAL length, elems, shift, i;

        if (value->vtable->base_type != SELF->vtable->base_type &&
                value->vtable->base_type != enum_class_FixedStringArray)
            Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_INVALID_OPERATION,
                    "ResizableStringArray: illegal type for splice!");

        length = VTABLE_elements(INTERP, SELF);
        elems  = VTABLE_elements(INTERP, value);
        shift  = elems - count;

        /* start from end? */
        if (offset < 0)
            offset += length;

        if (offset < 0)
            Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_OUT_OF_BOUNDS,
                "illegal splice offset\n");

        /* shrink the array */
        if (shift < 0) {
            /* start at offset so we don't overwrite values we'll need */
            for (i = offset+count; i < length; ++i)
                VTABLE_set_pmc_keyed_int(INTERP, SELF, i + shift,
                    VTABLE_get_pmc_keyed_int(INTERP, SELF, i));

            SELF.set_integer_native(length + shift);
        }
        /* grow the array */
        else if (shift > 0) {
            SELF.set_integer_native(length + shift);

            /* move the existing values */
            /* start at length-1 so we don't overwrite values we'll need */
            for (i = length - 1; i >= offset; --i)
                VTABLE_set_pmc_keyed_int(INTERP, SELF, i + shift,
                    VTABLE_get_pmc_keyed_int(INTERP, SELF, i));
        }

        /* copy the new values */
        for (i = 0; i < elems; ++i)
            VTABLE_set_pmc_keyed_int(INTERP, SELF, i + offset,
                VTABLE_get_pmc_keyed_int(INTERP, value, i));
    }

/*

=item METHOD PMC* shift()

=item METHOD PMC* pop()

Method forms to remove and return a PMC from the beginning or
end of the array.

=cut

*/

    METHOD shift() {
        PMC * const value = SELF.shift_pmc();
        RETURN(PMC *value);
    }

    METHOD pop() {
        PMC * const value = SELF.pop_pmc();
        RETURN(PMC *value);
    }

/*

=item METHOD unshift(PMC* value)

=item METHOD push(PMC* value)

Method forms to add a PMC to the beginning or end of the array.

=cut

*/

    METHOD unshift(PMC* value) {
        SELF.unshift_pmc(value);
    }

    METHOD push(PMC* value) {
        SELF.push_pmc(value);
    }

}

/*

=back

=head1 SEE ALSO

F<docs/pdds/pdd17_basic_types.pod>.

=cut

*/

/*
 * Local variables:
 *   c-file-style: "parrot"
 * End:
 * vim: expandtab shiftwidth=4:
 */
