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/*$Id: inamedef.h,v 1.2 2000/09/19 19:00:45 lpd Exp $ */
/* Name table definition */

#ifndef inamedef_INCLUDED
#  define inamedef_INCLUDED

#include "inameidx.h"
#include "inamestr.h"
#include "inames.h"
#include "gsstruct.h"		/* for gc_state_t */

/*
 * The name table machinery has two slightly different configurations:
 * a faster one that limits the total number of names to 64K and allows
 * names up to 16K in size, and a slightly slower one that limits
 * the total to 4M and restricts names to 256 characters.
 * The maximum number of names is 2^(16+EXTEND_NAMES)-1.
 */
#define max_name_extension_bits 6
#if EXTEND_NAMES > max_name_extension_bits
#  undef EXTEND_NAMES
#  define EXTEND_NAMES max_name_extension_bits
#endif
/*       
 * We capture the small algorithmic differences between these two
 * configurations entirely in this header file;
 * the implementation doesn't need any conditionals on EXTEND_NAMES.
 */
#define max_name_index (uint)((0x10000 << EXTEND_NAMES) - 1)
/* As explained below, we distinguish name indices from name counts. */
#define max_name_count max_name_index

/* ---------------- Structure definitions ---------------- */

/*
 * Define the structure of a name.  The pvalue member implements an
 * important optimization to avoid lookup for operator and other global
 * names.
 */
struct name_s {
/* pvalue specifies the definition status of the name: */
/*      pvalue == pv_no_defn: no definitions */
#define pv_no_defn ((ref *)0)
/*      pvalue == pv_other: other status */
#define pv_other ((ref *)1)
/*      pvalue != pv_no_defn, pvalue != pv_other: pvalue is valid */
#define pv_valid(pvalue) ((unsigned long)(pvalue) > 1)
    ref *pvalue;		/* if only defined in systemdict or */
				/* userdict, this points to the value */
};

/*typedef struct name_s name; *//* in iref.h */

/*
 * Define the structure of a name table.  Normally we would make this
 * an opaque type, but we want to be able to in-line some of the
 * access procedures.
 *
 * The name table is a two-level indexed table, consisting of
 * sub-tables of size nt_sub_size each.
 *
 * First we define the name sub-table structure.
 */
#define nt_log2_sub_size NT_LOG2_SUB_SIZE /* in inameidx.h */
# define nt_sub_size (1 << nt_log2_sub_size)
# define nt_sub_index_mask (nt_sub_size - 1)
typedef struct name_sub_table_s {
    name names[NT_SUB_SIZE];	/* must be first */
#ifdef EXTEND_NAMES
    uint high_index;		/* sub-table base index & (-1 << 16) */
#endif
} name_sub_table;

/*
 * Now define the name table itself.
 * This must be made visible so that the interpreter can use the
 * inline macros defined below.
 */
struct name_table_s {
    uint free;			/* head of free list, which is sorted in */
				/* increasing count (not index) order */
    uint sub_next;		/* index of next sub-table to allocate */
				/* if not already allocated */
    uint perm_count;		/* # of permanent (read-only) strings */
    uint sub_count;		/* index of highest allocated sub-table +1 */
    uint max_sub_count;		/* max allowable value of sub_count */
    uint name_string_attrs;	/* imemory_space(memory) | a_readonly */
    gs_memory_t *memory;
    uint hash[NT_HASH_SIZE];
    struct sub_ {		/* both ptrs are 0 or both are non-0 */
	name_sub_table *names;
	name_string_sub_table_t *strings;
    } sub[max_name_index / nt_sub_size + 1];
};
/*typedef struct name_table_s name_table; *//* in inames.h */

/* ---------------- Procedural interface ---------------- */

/*
 * Convert between names, indices, and strings.  Note that the inline
 * versions, but not the procedure versions, take a name_table argument.
 */
		/* index => string */
#define names_index_string_inline(nt, nidx)\
  ((nt)->sub[(nidx) >> nt_log2_sub_size].strings->strings +\
   ((nidx) & nt_sub_index_mask))
		/* ref => string */
#define names_string_inline(nt, pnref)\
  names_index_string_inline(nt, names_index_inline(nt, pnref))
		/* ref => index */
#if EXTEND_NAMES
#  define names_index_inline(nt_ignored, pnref)\
     ( ((const name_sub_table *)\
	((pnref)->value.pname - (r_size(pnref) & nt_sub_index_mask)))->high_index + r_size(pnref) )
#else
#  define names_index_inline(nt_ignored, pnref) r_size(pnref)
#endif
#define names_index(nt_ignored, pnref) names_index_inline(nt_ignored, pnref)
		/* index => name */
#define names_index_ptr_inline(nt, nidx)\
  ((nt)->sub[(nidx) >> nt_log2_sub_size].names->names +\
   ((nidx) & nt_sub_index_mask))
		/* index => ref */
#define names_index_ref_inline(nt, nidx, pnref)\
  make_name(pnref, nidx, names_index_ptr_inline(nt, nidx));
/* Backward compatibility */
#define name_index_inline(pnref) names_index_inline(ignored, pnref)
#define name_index_ptr_inline(nt, pnref) names_index_ptr_inline(nt, pnref)
#define name_index_ref_inline(nt, nidx, pnref)\
  names_index_ref_inline(nt, nidx, pnref)
		/* name => ref */
/* We have to set the space to system so that the garbage collector */
/* won't think names are foreign and therefore untraceable. */
#define make_name(pnref, nidx, pnm)\
  make_tasv(pnref, t_name, avm_system, (ushort)(nidx), pname, pnm)

/* ------ Garbage collection ------ */

/* Unmark all non-permanent names before a garbage collection. */
void names_unmark_all(P1(name_table * nt));

/* Finish tracing the name table by putting free names on the free list. */
void names_trace_finish(P2(name_table * nt, gc_state_t * gcst));

/* ------ Save/restore ------ */

/* Clean up the name table before a restore. */
#ifndef alloc_save_t_DEFINED	/* also in isave.h */
typedef struct alloc_save_s alloc_save_t;
#  define alloc_save_t_DEFINED
#endif
void names_restore(P2(name_table * nt, alloc_save_t * save));

#endif /* inamedef_INCLUDED */
