/*
Copyright (C) 2010-2011, Parrot Foundation.

=head1 NAME

src/pmc/imageiothaw.pmc - ImageIOThaw PMC

=head1 DESCRIPTION

Thaws PMCs from packfile images.

=head1 VTABLES

=over 4

=cut

*/

#include "parrot/imageio.h"

#define BYTECODE_SHIFT_OK(interp, pmc) PARROT_ASSERT( \
    PARROT_IMAGEIOTHAW(pmc)->curs <= (opcode_t *) \
    (PARROT_IMAGEIOTHAW(pmc)->img->strstart + \
    Parrot_str_byte_length((interp), PARROT_IMAGEIOTHAW(pmc)->img)))


/* HEADERIZER HFILE: none */

pmclass ImageIOThaw auto_attrs {
    ATTR STRING              *img;
    ATTR opcode_t            *curs;
    ATTR PMC                 *seen;
    ATTR PMC                 *todo;
    ATTR PackFile            *pf;
    ATTR PackFile_ConstTable *pf_ct;

/*

=item C<void init()>

Initializes the PMC.

=cut

*/

    VTABLE void init() {
        PARROT_IMAGEIOTHAW(SELF)->seen =
            Parrot_pmc_new(INTERP, enum_class_ResizablePMCArray);
        PARROT_IMAGEIOTHAW(SELF)->todo =
            Parrot_pmc_new(INTERP, enum_class_ResizableIntegerArray);

        PObj_flag_CLEAR(private1, SELF);

        PObj_custom_mark_SET(SELF);
    }


/*

=item C<void destroy()>

Destroys the PMC.

=cut

*/

    VTABLE void destroy() {
        PackFile_destroy(INTERP, PARROT_IMAGEIOTHAW(SELF)->pf);
        PARROT_IMAGEIOTHAW(SELF)->pf = NULL;
    }


/*

=item C<void mark()>

Marks the PMC as alive.

=cut

*/

    VTABLE void mark() {
        Parrot_gc_mark_STRING_alive(INTERP, PARROT_IMAGEIOTHAW(SELF)->img);
        Parrot_gc_mark_PMC_alive(INTERP, PARROT_IMAGEIOTHAW(SELF)->seen);
        Parrot_gc_mark_PMC_alive(INTERP, PARROT_IMAGEIOTHAW(SELF)->todo);
    }


/*

=item C<void set_string_native(STRING *image)>

Thaws the PMC contained in C<image>.

=cut

*/

    VTABLE void set_string_native(STRING *image) {
        if (!PObj_external_TEST(image))
            Parrot_str_pin(INTERP, image);

        PARROT_IMAGEIOTHAW(SELF)->img  = image;
        PARROT_IMAGEIOTHAW(SELF)->curs = (opcode_t *)image->strstart;

        if (PObj_flag_TEST(private1, SELF)) {
            PARROT_IMAGEIOTHAW(SELF)->pf = PARROT_IMAGEIOTHAW(SELF)->pf_ct->base.pf;
        }
        else {
            const UINTVAL header_length =
                 GROW_TO_16_BYTE_BOUNDARY(PACKFILE_HEADER_BYTES);
            int unpacked_length;

            PARROT_IMAGEIOTHAW(SELF)->pf   = PackFile_new(INTERP, 0);
            PObj_custom_destroy_SET(SELF);

            PARROT_IMAGEIOTHAW(SELF)->pf->options |= PFOPT_PMC_FREEZE_ONLY;
            unpacked_length = PackFile_unpack(INTERP, PARROT_IMAGEIOTHAW(SELF)->pf,
                                PARROT_IMAGEIOTHAW(SELF)->curs,
                                Parrot_str_byte_length(interp, image));

            if (unpacked_length)
                PARROT_IMAGEIOTHAW(SELF)->curs += header_length / sizeof (opcode_t*);
            else
                Parrot_ex_throw_from_c_args(INTERP, NULL,
                        EXCEPTION_INVALID_STRING_REPRESENTATION,
                        "PackFile header failed during unpack");
        }

        STATICSELF.shift_pmc();

        {
            PMC * const seen = PARROT_IMAGEIOTHAW(SELF)->seen;
            PMC * const todo = PARROT_IMAGEIOTHAW(SELF)->todo;
            INTVAL i, n;

            for (i = 0; i < VTABLE_elements(INTERP, todo); i++) {
                const INTVAL idx = VTABLE_get_integer_keyed_int(INTERP, todo, i);
                PMC * const current = VTABLE_get_pmc_keyed_int(INTERP, seen, idx);
                if (PMC_IS_NULL(current))
                    Parrot_ex_throw_from_c_args(interp, NULL,
                            EXCEPTION_MALFORMED_PACKFILE,
                            "NULL current PMC at %d in thaw",
                            (int)i);

                VTABLE_thaw(INTERP,  current, SELF);
                VTABLE_visit(INTERP, current, SELF);
                PMC_metadata(current) = SELF.shift_pmc();
            }

            n = i;

            /* we're done reading the image */
            PARROT_ASSERT(image->strstart + Parrot_str_byte_length(interp, image) ==
                        (char *)PARROT_IMAGEIOTHAW(SELF)->curs);

            for (i = 0; i < n; i++) {
                const INTVAL idx = VTABLE_get_integer_keyed_int(INTERP, todo, i);
                PMC * const current = VTABLE_get_pmc_keyed_int(INTERP, seen, idx);
                VTABLE_thawfinish(INTERP, current, SELF);
            }
        }

        if (!PObj_external_TEST(image))
            Parrot_str_unpin(INTERP, image);
    }


/*

=item C<PMC *get_pmc()>

Get the thawed PMC.

=cut

*/

    VTABLE PMC *get_pmc() {
        if (PObj_flag_TEST(private1, SELF))
            return PARROT_IMAGEIOTHAW(SELF)->seen;
        else
            return VTABLE_get_pmc_keyed_int(INTERP, (PARROT_IMAGEIOTHAW(SELF))->seen, 0);
    }


/*

=item C<INTVAL get_integer()>

Get the visit action.

=cut

*/

    VTABLE INTVAL get_integer() {
        return VISIT_THAW_NORMAL;
    }


/*

=item C<void set_pointer(void *value)>

Set an exterior constant table to use for cross-referencing constants.

=cut

*/

    VTABLE void set_pointer(void *value) {
        PObj_flag_SET(private1, SELF);
        PARROT_IMAGEIOTHAW(SELF)->pf_ct = (PackFile_ConstTable *)value;
    }


/*

=item C<INTVAL shift_integer()>

Retrieve an integer as the next item from the image.

=cut

*/

    VTABLE INTVAL shift_integer() {
        /* inlining PF_fetch_integer speeds up PBC thawing measurably */
        PackFile * const pf = PARROT_IMAGEIOTHAW(SELF)->pf;
        const unsigned char *stream    = (const unsigned char *)PARROT_IMAGEIOTHAW(SELF)->curs;
        const INTVAL         i         = pf->fetch_iv(stream);
        DECL_CONST_CAST;
        PARROT_IMAGEIOTHAW(SELF)->curs = (opcode_t *)PARROT_const_cast(unsigned char *,
                                                                    stream + pf->header->wordsize);
        BYTECODE_SHIFT_OK(INTERP, SELF);
        return i;
    }


/*

=item C<FLOATVAL shift_float()>

Retrieve a float as the next item from the image.

=cut

*/

    VTABLE FLOATVAL shift_float() {
        PackFile * const pf = PARROT_IMAGEIOTHAW(SELF)->pf;
        const opcode_t *curs           = PARROT_IMAGEIOTHAW(SELF)->curs;
        const FLOATVAL f = PF_fetch_number(pf, &curs);
        DECL_CONST_CAST;
        PARROT_IMAGEIOTHAW(SELF)->curs = PARROT_const_cast(opcode_t *, curs);
        BYTECODE_SHIFT_OK(INTERP, SELF);
        return f;
    }


/*

=item C<STRING *shift_string()>

Retrieve a string as the next item from the image.

=cut

*/

    VTABLE STRING *shift_string() {
        if (PObj_flag_TEST(private1, SELF)) {
            const INTVAL i = STATICSELF.shift_integer();
            BYTECODE_SHIFT_OK(INTERP, SELF);

            if (i >= 0) {
                PackFile_ConstTable *table = PARROT_IMAGEIOTHAW(SELF)->pf_ct;
                return table->str.constants[i];
            }

            /* XXX
             * only got here because constant table doesn't contain the string
             * fallback on inline strings
             */
        }

        {
            PackFile * const pf = PARROT_IMAGEIOTHAW(SELF)->pf;
            const opcode_t *curs           = PARROT_IMAGEIOTHAW(SELF)->curs;
            STRING   *s                    = PF_fetch_string(INTERP, pf, &curs);
            DECL_CONST_CAST;
            PARROT_IMAGEIOTHAW(SELF)->curs = PARROT_const_cast(opcode_t *, curs);
            BYTECODE_SHIFT_OK(INTERP, SELF);
            return s;
        }
    }


/*

=item C<PMC *shift_pmc()>

Retrieve a PMC as the next item from the image.

=cut

*/

    VTABLE PMC *shift_pmc() {
        const UINTVAL  n            = SELF.shift_integer();
        const INTVAL   id           = PackID_get_PMCID(n);
        const int      packid_flags = PackID_get_FLAGS(n);
        PMC           *pmc          = PMCNULL;
        PMC           *seen         = PARROT_IMAGEIOTHAW(SELF)->seen;
        PMC           *todo         = PARROT_IMAGEIOTHAW(SELF)->todo;

        switch (packid_flags) {
          case enum_PackID_seen:
            if (id) /* got a non-NULL PMC */
                pmc = VTABLE_get_pmc_keyed_int(INTERP, seen, id - 1);
            break;
          case enum_PackID_pbc_backref:
            {
                PackFile_ConstTable *table   = PARROT_IMAGEIOTHAW(SELF)->pf_ct;
                INTVAL               constno = SELF.shift_integer();
                INTVAL               idx     = SELF.shift_integer();
                PMC                 *olist   = table->pmc.constants[constno];
                pmc                          = VTABLE_get_pmc_keyed_int(INTERP, olist, idx);
                PARROT_ASSERT(id - 1 == VTABLE_elements(INTERP, seen));
                VTABLE_set_pmc_keyed_int(INTERP, seen, id - 1, pmc);
                break;
            }
          case enum_PackID_normal:
            {
                const INTVAL type = SELF.shift_integer();

                PARROT_ASSERT(id - 1 == VTABLE_elements(INTERP, seen));

                if (type <= 0 || type > INTERP->n_vtable_max)
                    Parrot_ex_throw_from_c_args(INTERP, NULL, 1,
                            "Unknown PMC type to thaw %d", type);

                pmc = Parrot_pmc_new_noinit(INTERP, type);

                VTABLE_set_pmc_keyed_int(INTERP, seen, id - 1, pmc);
                VTABLE_push_integer(INTERP, todo, id - 1);
            }
            break;
          default:
            Parrot_ex_throw_from_c_args(INTERP, NULL, 1,
                    "Unknown PMC id args thaw %d", packid_flags);
            break;
        }

        return pmc;
    }

}

/*

=back

=cut

*/

/*
 * Local variables:
 *   c-file-style: "parrot"
 * End:
 * vim: expandtab shiftwidth=4 cinoptions='\:2=2' :
 */