/* Copyright (C) 1997, 1998 Aladdin Enterprises.  All rights reserved.

   This file is part of Aladdin Ghostscript.

   Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
   or distributor accepts any responsibility for the consequences of using it,
   or for whether it serves any particular purpose or works at all, unless he
   or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
   License (the "License") for full details.

   Every copy of Aladdin Ghostscript must include a copy of the License,
   normally in a plain ASCII text file named PUBLIC.  The License grants you
   the right to copy, modify and redistribute Aladdin Ghostscript, but only
   under certain conditions described in the License.  Among other things, the
   License requires that the copyright notice and this notice be preserved on
   all copies.
 */

/*$Id: icontext.c $ */
/* Context state operations */
#include "ghost.h"
#include "gsstruct.h"		/* for gxalloc.h */
#include "gxalloc.h"
#include "errors.h"
#include "stream.h"		/* for files.h */
#include "files.h"
#include "idict.h"
#include "igstate.h"
#include "icontext.h"
#include "interp.h"
#include "isave.h"
#include "dstack.h"
#include "estack.h"
#include "ostack.h"
#include "store.h"

/* Define the initial stack sizes. */
#define DSTACK_INITIAL 20
#define ESTACK_INITIAL 250
#define OSTACK_INITIAL 200

/* Per-context state stored in statics */
extern ref ref_array_packing;
extern ref ref_binary_object_format;
extern long zrand_state;

				/*extern ref ref_stdio[3]; *//* in files.h */

/* Initialization procedures */
void zrand_state_init(P1(long *));

/* GC descriptors */
extern_st(st_ref_stack);
#define pcst ((gs_context_state_t *)vptr)
private 
CLEAR_MARKS_PROC(context_state_clear_marks)
{
    r_clear_attrs(&pcst->userparams, l_mark);
}
private 
ENUM_PTRS_BEGIN(context_state_enum_ptrs) return 0;

ENUM_PTR3(0, gs_context_state_t, dstack, estack, ostack);
ENUM_PTR3(3, gs_context_state_t, pgs, stdio[0].value.pstruct,
	  stdio[1].value.pstruct);
case 6:
ENUM_RETURN_REF(&pcst->userparams);
ENUM_PTRS_END
private RELOC_PTRS_BEGIN(context_state_reloc_ptrs);
RELOC_PTR3(gs_context_state_t, dstack, estack, ostack);
RELOC_PTR3(gs_context_state_t, pgs, stdio[0].value.pstruct,
	   stdio[1].value.pstruct);
RELOC_REF_VAR(pcst->userparams);
r_clear_attrs(&pcst->userparams, l_mark);
RELOC_PTRS_END
#undef pcst
public_st_context_state();

/* Allocate the state of a context. */
     int
         context_state_alloc(gs_context_state_t ** ppcst,
			     const gs_dual_memory_t * dmem)
{
    gs_ref_memory_t *mem = dmem->space_local;
    gs_context_state_t *pcst = *ppcst;
    int code;
    int i;

    if (pcst == 0) {
	pcst = gs_alloc_struct((gs_memory_t *) mem, gs_context_state_t,
			       &st_context_state, "context_state_alloc");
	if (pcst == 0)
	    return_error(e_VMerror);
    }
    code = gs_interp_alloc_stacks(mem, pcst);
    if (code < 0)
	goto x0;
    pcst->pgs = int_gstate_alloc(mem);
    if (pcst->pgs == 0) {
	code = gs_note_error(e_VMerror);
	goto x1;
    }
    pcst->memory = *dmem;
    make_false(&pcst->array_packing);
    make_int(&pcst->binary_object_format, 0);
    zrand_state_init(&pcst->rand_state);
    pcst->usertime_total = 0;
    pcst->keep_usertime = false;
    {				/*
				 * Create an empty userparams dictionary of the right size.
				 * If we can't determine the size, pick an arbitrary one.
				 */
	ref *puserparams;
	uint size;

	if (dict_find_string(systemdict, "userparams", &puserparams) >= 0)
	    size = dict_length(puserparams);
	else
	    size = 20;
	code = dict_alloc(pcst->memory.space_local, size, &pcst->userparams);
	if (code < 0)
	    goto x2;
	/* PostScript code initializes the user parameters. */
    }
    /* The initial stdio values are bogus.... */
    make_file(&pcst->stdio[0], 0, 1, invalid_file_entry);
    make_file(&pcst->stdio[1], 0, 1, invalid_file_entry);
    for (i = countof(pcst->memory.spaces.indexed); --i >= 0;)
	if (dmem->spaces.indexed[i] != 0)
	    ++(dmem->spaces.indexed[i]->num_contexts);
    *ppcst = pcst;
    return 0;
  x2:gs_state_free(pcst->pgs);
  x1:gs_interp_free_stacks(mem, pcst);
  x0:if (*ppcst == 0)
	gs_free_object((gs_memory_t *) mem, pcst, "context_state_alloc");
    return code;
}

/* Load the interpreter state from a context. */
int
context_state_load(const gs_context_state_t * pcst)
{
    gs_ref_memory_t *lmem = iimemory_local;
    uint space = r_space(systemdict);
    int code;

    d_stack = *pcst->dstack;
    e_stack = *pcst->estack;
    o_stack = *pcst->ostack;
    igs = pcst->pgs;
    gs_imemory = pcst->memory;
    ref_array_packing = pcst->array_packing;
    ref_binary_object_format = pcst->binary_object_format;
    zrand_state = pcst->rand_state;
    /*
     * Set systemdict.userparams to the saved copy, and then
     * set the actual user parameters.  Be careful to disable both
     * space checking and save checking while we do this.
     */
    r_set_space(systemdict, avm_max);
    alloc_set_not_in_save(idmemory);
    code = dict_put_string(systemdict, "userparams", &pcst->userparams);
    if (code >= 0)
	code = set_user_params(&pcst->userparams);
    ref_stdio[0] = pcst->stdio[0];
    ref_stdio[1] = pcst->stdio[1];
    if (iimemory_local != lmem) {
	/*
	 * Switch references in systemdict to local objects.
	 * userdict.localdicts holds these objects.
	 */
	const ref *puserdict =
	ref_stack_index(&d_stack, ref_stack_count(&d_stack) - 1 -
			dstack_userdict_index);
	ref *plocaldicts;

	if (dict_find_string(puserdict, "localdicts", &plocaldicts) > 0 &&
	    r_has_type(plocaldicts, t_dictionary)
	    ) {
	    dict_copy(plocaldicts, systemdict);
	}
    }
    r_set_space(systemdict, space);
    if (idmemory->save_level > 0)
	alloc_set_in_save(idmemory);
    esfile_clear_cache();
    dict_set_top();		/* reload dict stack cache */
    return code;
}

/* Store the interpreter state in a context. */
int
context_state_store(gs_context_state_t * pcst)
{
    ref_stack_cleanup(&d_stack);
    ref_stack_cleanup(&e_stack);
    ref_stack_cleanup(&o_stack);
    *pcst->dstack = d_stack;
    *pcst->estack = e_stack;
    *pcst->ostack = o_stack;
    pcst->pgs = igs;
    pcst->memory = gs_imemory;
    pcst->array_packing = ref_array_packing;
    pcst->binary_object_format = ref_binary_object_format;
    pcst->rand_state = zrand_state;
    /*
     * The user parameters in systemdict.userparams are kept
     * up to date by PostScript code, but we still need to save
     * systemdict.userparams to get the correct l_new flag.
     */
    {
	ref *puserparams;

	if (dict_find_string(systemdict, "userparams", &puserparams) < 0)
	    return_error(e_Fatal);
	pcst->userparams = *puserparams;
    }
    pcst->stdio[0] = ref_stdio[0];
    pcst->stdio[1] = ref_stdio[1];
    return 0;
}

/* Free the state of a context. */
bool
context_state_free(gs_context_state_t * pcst)
{
    gs_ref_memory_t *mem = pcst->memory.space_local;
    int freed = 0;
    int i;

    /*
     * If this context is the last one referencing a particular VM
     * (local / global / system), free the entire VM space;
     * otherwise, just free the context-related structures.
     */
    for (i = countof(pcst->memory.spaces.indexed); --i >= 0;) {
	if (pcst->memory.spaces.indexed[i] != 0 &&
	    !--(pcst->memory.spaces.indexed[i]->num_contexts)
	    ) {
/****** FREE THE ENTIRE SPACE ******/
	    freed |= 1 << i;
	}
    }
    /*
     * If we freed any spaces at all, we must have freed the local
     * VM where the context structure and its substructures were
     * allocated.
     */
    if (freed)
	return freed;
    {
	gs_state *pgs = pcst->pgs;

	gs_grestoreall(pgs);
	/* Patch the saved pointer so we can do the last grestore. */
	{
	    gs_state *saved = gs_state_saved(pgs);

	    gs_state_swap_saved(saved, saved);
	}
	gs_grestore(pgs);
	gs_state_swap_saved(pgs, (gs_state *) 0);
	gs_state_free(pgs);
    }
/****** FREE USERPARAMS ******/
    gs_interp_free_stacks(mem, pcst);
    return false;
}
