[babeltrace.git] / types / variant.c

/*
* variant.c
 *
 * BabelTrace - Variant Type Converter
 *
 * Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 */

#include <babeltrace/compiler.h>
#include <babeltrace/format.h>
#include <errno.h>

static
struct definition *_variant_definition_new(struct declaration *declaration,
				struct definition_scope *parent_scope,
				GQuark field_name, int index);
static
void _variant_definition_free(struct definition *definition);

void variant_copy(struct stream_pos *dest, const struct format *fdest, 
		  struct stream_pos *src, const struct format *fsrc,
		  struct definition *definition)
{
	struct definition_variant *variant =
		container_of(definition, struct definition_variant, p);
	struct declaration_variant *variant_declaration = variant->declaration;
	struct field *field;
	struct declaration *field_declaration;

	fsrc->variant_begin(src, variant_declaration);
	fdest->variant_begin(dest, variant_declaration);

	field = variant_get_current_field(variant);
	field_declaration = field->definition->declaration;
	field_declaration->copy(dest, fdest, src, fsrc, field->definition);

	fsrc->variant_end(src, variant_declaration);
	fdest->variant_end(dest, variant_declaration);
}

static
void _variant_declaration_free(struct declaration *declaration)
{
	struct declaration_variant *variant_declaration =
		container_of(declaration, struct declaration_variant, p);
	unsigned long i;

	free_declaration_scope(variant_declaration->scope);
	g_hash_table_destroy(variant_declaration->fields_by_tag);

	for (i = 0; i < variant_declaration->fields->len; i++) {
		struct declaration_field *declaration_field =
			&g_array_index(variant_declaration->fields,
				       struct declaration_field, i);
		declaration_unref(declaration_field->declaration);
	}
	g_array_free(variant_declaration->fields, true);
	g_free(variant_declaration);
}

struct declaration_variant *variant_declaration_new(const char *name,
				      struct declaration_scope *parent_scope)
{
	struct declaration_variant *variant_declaration;
	struct declaration *declaration;

	variant_declaration = g_new(struct declaration_variant, 1);
	declaration = &variant_declaration->p;
	variant_declaration->fields_by_tag = g_hash_table_new(g_direct_hash,
						       g_direct_equal);
	variant_declaration->fields = g_array_sized_new(FALSE, TRUE,
						 sizeof(struct declaration_field),
						 DEFAULT_NR_STRUCT_FIELDS);
	variant_declaration->scope = new_declaration_scope(parent_scope);
	declaration->id = CTF_TYPE_VARIANT;
	declaration->name = g_quark_from_string(name);
	declaration->alignment = 1;
	declaration->copy = variant_copy;
	declaration->declaration_free = _variant_declaration_free;
	declaration->definition_new = _variant_definition_new;
	declaration->definition_free = _variant_definition_free;
	declaration->ref = 1;
	return variant_declaration;
}

static
struct definition *
	_variant_definition_new(struct declaration *declaration,
				struct definition_scope *parent_scope,
				GQuark field_name, int index)
{
	struct declaration_variant *variant_declaration =
		container_of(declaration, struct declaration_variant, p);
	struct definition_variant *variant;
	unsigned long i;

	variant = g_new(struct definition_variant, 1);
	declaration_ref(&variant_declaration->p);
	variant->p.declaration = declaration;
	variant->declaration = variant_declaration;
	variant->p.ref = 1;
	variant->p.index = index;
	variant->scope = new_definition_scope(parent_scope, field_name);
	variant->fields = g_array_sized_new(FALSE, TRUE,
					    sizeof(struct field),
					    DEFAULT_NR_STRUCT_FIELDS);
	g_array_set_size(variant->fields, variant_declaration->fields->len);
	for (i = 0; i < variant_declaration->fields->len; i++) {
		struct declaration_field *declaration_field =
			&g_array_index(variant_declaration->fields,
				       struct declaration_field, i);
		struct field *field = &g_array_index(variant->fields,
						     struct field, i);

		field->name = declaration_field->name;
		/*
		 * All child definition are at index 0, because they are
		 * various choices of the same field.
		 */
		field->definition =
			declaration_field->declaration->definition_new(declaration_field->declaration,
							  variant->scope,
							  field->name, 0);
	}
	variant->current_field = NULL;
	return &variant->p;
}

static
void _variant_definition_free(struct definition *definition)
{
	struct definition_variant *variant =
		container_of(definition, struct definition_variant, p);
	unsigned long i;

	assert(variant->fields->len == variant->declaration->fields->len);
	for (i = 0; i < variant->fields->len; i++) {
		struct field *field = &g_array_index(variant->fields,
						     struct field, i);
		definition_unref(field->definition);
	}
	free_definition_scope(variant->scope);
	declaration_unref(variant->p.declaration);
	g_free(variant);
}

void variant_declaration_add_field(struct declaration_variant *variant_declaration,
			    const char *tag_name,
			    struct declaration *tag_declaration)
{
	struct declaration_field *field;
	unsigned long index;

	g_array_set_size(variant_declaration->fields, variant_declaration->fields->len + 1);
	index = variant_declaration->fields->len - 1;	/* last field (new) */
	field = &g_array_index(variant_declaration->fields, struct declaration_field, index);
	field->name = g_quark_from_string(tag_name);
	declaration_ref(tag_declaration);
	field->declaration = tag_declaration;
	/* Keep index in hash rather than pointer, because array can relocate */
	g_hash_table_insert(variant_declaration->fields_by_tag,
			    (gpointer) (unsigned long) field->name,
			    (gpointer) index);
	/*
	 * Alignment of variant is based on the alignment of its currently
	 * selected choice, so we leave variant alignment as-is (statically
	 * speaking).
	 */
}

struct declaration_field *
struct_declaration_get_field_from_tag(struct declaration_variant *variant_declaration, GQuark tag)
{
	unsigned long index;

	index = (unsigned long) g_hash_table_lookup(variant_declaration->fields_by_tag,
						    (gconstpointer) (unsigned long) tag);
	return &g_array_index(variant_declaration->fields, struct declaration_field, index);
}

/*
 * tag_instance is assumed to be an enumeration.
 */
int variant_definition_set_tag(struct definition_variant *variant,
			       struct definition *enum_tag)
{
	struct definition_enum *_enum =
		container_of(variant->enum_tag, struct definition_enum, p);
	struct declaration_enum *enum_declaration = _enum->declaration;
	int missing_field = 0;
	unsigned long i;

	/*
	 * Strictly speaking, each enumerator must map to a field of the
	 * variant. However, we are even stricter here by requiring that each
	 * variant choice map to an enumerator too. We then validate that the
	 * number of enumerators equals the number of variant choices.
	 */
	if (variant->declaration->fields->len != enum_get_nr_enumerators(enum_declaration))
		return -EPERM;

	for (i = 0; i < variant->declaration->fields->len; i++) {
		struct declaration_field *field_declaration =
			&g_array_index(variant->declaration->fields,
				       struct declaration_field, i);
		if (!enum_quark_to_range_set(enum_declaration, field_declaration->name)) {
			missing_field = 1;
			break;
		}
	}
	if (missing_field)
		return -EPERM;

	/*
	 * Check the enumeration: it must map each value to one and only one
	 * enumerator tag.
	 * TODO: we should also check that each range map to one and only one
	 * tag. For the moment, we will simply check this dynamically in
	 * variant_declaration_get_current_field().
	 */

	/* Set the enum tag field */
	variant->enum_tag = enum_tag;
	return 0;
}

/*
 * field returned only valid as long as the field structure is not appended to.
 */
struct field *variant_get_current_field(struct definition_variant *variant)
{
	struct definition_enum *_enum =
		container_of(variant->enum_tag, struct definition_enum, p);
	struct declaration_variant *variant_declaration = variant->declaration;
	unsigned long index;
	GArray *tag_array;
	GQuark tag;

	tag_array = _enum->value;
	/*
	 * The 1 to 1 mapping from enumeration to value should have been already
	 * checked. (see TODO above)
	 */
	assert(tag_array->len == 1);
	tag = g_array_index(tag_array, GQuark, 0);
	index = (unsigned long) g_hash_table_lookup(variant_declaration->fields_by_tag,
						    (gconstpointer) (unsigned long) tag);
	variant->current_field = &g_array_index(variant->fields, struct field, index);
	return variant->current_field;
}
Commit	Line	Data
c054553d	1	/*
e1151715	2	* variant.c
c054553d MD	3	*
	4	* BabelTrace - Variant Type Converter
	5	*
	6	* Copyright 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	7	*
	8	* Permission is hereby granted, free of charge, to any person obtaining a copy
	9	* of this software and associated documentation files (the "Software"), to deal
	10	* in the Software without restriction, including without limitation the rights
	11	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	12	* copies of the Software, and to permit persons to whom the Software is
	13	* furnished to do so, subject to the following conditions:
	14	*
	15	* The above copyright notice and this permission notice shall be included in
	16	* all copies or substantial portions of the Software.
	17	*/
	18
	19	#include <babeltrace/compiler.h>
	20	#include <babeltrace/format.h>
6ee5115e	21	#include <errno.h>
c054553d MD	22
c054553d MD	23	static
f6625916	24	struct definition _variant_definition_new(struct declaration declaration,
05c749e5 MD	25	struct definition_scope *parent_scope,
05c749e5 MD	26	GQuark field_name, int index);
c054553d	27	static
e1151715	28	void _variant_definition_free(struct definition *definition);
c054553d MD	29
	30	void variant_copy(struct stream_pos dest, const struct format fdest,
	31	struct stream_pos src, const struct format fsrc,
e1151715	32	struct definition *definition)
c054553d	33	{
e1151715 MD	34	struct definition_variant *variant =
e1151715 MD	35	container_of(definition, struct definition_variant, p);
f6625916	36	struct declaration_variant *variant_declaration = variant->declaration;
c054553d	37	struct field *field;
f6625916	38	struct declaration *field_declaration;
c054553d	39
f6625916 MD	40	fsrc->variant_begin(src, variant_declaration);
f6625916 MD	41	fdest->variant_begin(dest, variant_declaration);
c054553d	42
e19c3d69	43	field = variant_get_current_field(variant);
f6625916 MD	44	field_declaration = field->definition->declaration;
f6625916 MD	45	field_declaration->copy(dest, fdest, src, fsrc, field->definition);
c054553d	46
f6625916 MD	47	fsrc->variant_end(src, variant_declaration);
f6625916 MD	48	fdest->variant_end(dest, variant_declaration);
c054553d MD	49	}
	50
	51	static
f6625916	52	void _variant_declaration_free(struct declaration *declaration)
c054553d	53	{
f6625916 MD	54	struct declaration_variant *variant_declaration =
f6625916 MD	55	container_of(declaration, struct declaration_variant, p);
c054553d MD	56	unsigned long i;
c054553d MD	57
f6625916 MD	58	free_declaration_scope(variant_declaration->scope);
f6625916 MD	59	g_hash_table_destroy(variant_declaration->fields_by_tag);
c054553d	60
f6625916 MD	61	for (i = 0; i < variant_declaration->fields->len; i++) {
	62	struct declaration_field *declaration_field =
	63	&g_array_index(variant_declaration->fields,
	64	struct declaration_field, i);
	65	declaration_unref(declaration_field->declaration);
c054553d	66	}
f6625916 MD	67	g_array_free(variant_declaration->fields, true);
f6625916 MD	68	g_free(variant_declaration);
c054553d MD	69	}
c054553d MD	70
f6625916 MD	71	struct declaration_variant variant_declaration_new(const char name,
f6625916 MD	72	struct declaration_scope *parent_scope)
c054553d	73	{
f6625916 MD	74	struct declaration_variant *variant_declaration;
f6625916 MD	75	struct declaration *declaration;
c054553d	76
f6625916 MD	77	variant_declaration = g_new(struct declaration_variant, 1);
	78	declaration = &variant_declaration->p;
	79	variant_declaration->fields_by_tag = g_hash_table_new(g_direct_hash,
e19c3d69	80	g_direct_equal);
f6625916 MD	81	variant_declaration->fields = g_array_sized_new(FALSE, TRUE,
f6625916 MD	82	sizeof(struct declaration_field),
e19c3d69	83	DEFAULT_NR_STRUCT_FIELDS);
f6625916 MD	84	variant_declaration->scope = new_declaration_scope(parent_scope);
	85	declaration->id = CTF_TYPE_VARIANT;
	86	declaration->name = g_quark_from_string(name);
	87	declaration->alignment = 1;
	88	declaration->copy = variant_copy;
	89	declaration->declaration_free = _variant_declaration_free;
	90	declaration->definition_new = _variant_definition_new;
	91	declaration->definition_free = _variant_definition_free;
	92	declaration->ref = 1;
	93	return variant_declaration;
c054553d MD	94	}
	95
	96	static
e1151715	97	struct definition *
f6625916	98	_variant_definition_new(struct declaration *declaration,
05c749e5 MD	99	struct definition_scope *parent_scope,
05c749e5 MD	100	GQuark field_name, int index)
c054553d	101	{
f6625916 MD	102	struct declaration_variant *variant_declaration =
f6625916 MD	103	container_of(declaration, struct declaration_variant, p);
e1151715	104	struct definition_variant *variant;
ac88af75	105	unsigned long i;
c054553d	106
e1151715	107	variant = g_new(struct definition_variant, 1);
f6625916 MD	108	declaration_ref(&variant_declaration->p);
	109	variant->p.declaration = declaration;
	110	variant->declaration = variant_declaration;
c054553d	111	variant->p.ref = 1;
05c749e5 MD	112	variant->p.index = index;
05c749e5 MD	113	variant->scope = new_definition_scope(parent_scope, field_name);
c054553d MD	114	variant->fields = g_array_sized_new(FALSE, TRUE,
	115	sizeof(struct field),
	116	DEFAULT_NR_STRUCT_FIELDS);
f6625916 MD	117	g_array_set_size(variant->fields, variant_declaration->fields->len);
	118	for (i = 0; i < variant_declaration->fields->len; i++) {
	119	struct declaration_field *declaration_field =
	120	&g_array_index(variant_declaration->fields,
	121	struct declaration_field, i);
ac88af75 MD	122	struct field *field = &g_array_index(variant->fields,
	123	struct field, i);
	124
f6625916	125	field->name = declaration_field->name;
05c749e5 MD	126	/*
	127	* All child definition are at index 0, because they are
	128	* various choices of the same field.
	129	*/
e1151715	130	field->definition =
f6625916	131	declaration_field->declaration->definition_new(declaration_field->declaration,
05c749e5 MD	132	variant->scope,
05c749e5 MD	133	field->name, 0);
ac88af75	134	}
c054553d MD	135	variant->current_field = NULL;
	136	return &variant->p;
	137	}
	138
	139	static
e1151715	140	void _variant_definition_free(struct definition *definition)
c054553d	141	{
e1151715 MD	142	struct definition_variant *variant =
e1151715 MD	143	container_of(definition, struct definition_variant, p);
c054553d MD	144	unsigned long i;
c054553d MD	145
f6625916	146	assert(variant->fields->len == variant->declaration->fields->len);
c054553d MD	147	for (i = 0; i < variant->fields->len; i++) {
	148	struct field *field = &g_array_index(variant->fields,
	149	struct field, i);
e1151715	150	definition_unref(field->definition);
c054553d	151	}
e1151715	152	free_definition_scope(variant->scope);
f6625916	153	declaration_unref(variant->p.declaration);
c054553d MD	154	g_free(variant);
	155	}
	156
f6625916	157	void variant_declaration_add_field(struct declaration_variant *variant_declaration,
e19c3d69	158	const char *tag_name,
f6625916	159	struct declaration *tag_declaration)
c054553d	160	{
f6625916	161	struct declaration_field *field;
c054553d MD	162	unsigned long index;
c054553d MD	163
f6625916 MD	164	g_array_set_size(variant_declaration->fields, variant_declaration->fields->len + 1);
	165	index = variant_declaration->fields->len - 1; /* last field (new) */
	166	field = &g_array_index(variant_declaration->fields, struct declaration_field, index);
c054553d	167	field->name = g_quark_from_string(tag_name);
f6625916 MD	168	declaration_ref(tag_declaration);
f6625916 MD	169	field->declaration = tag_declaration;
c054553d	170	/* Keep index in hash rather than pointer, because array can relocate */
f6625916	171	g_hash_table_insert(variant_declaration->fields_by_tag,
c054553d MD	172	(gpointer) (unsigned long) field->name,
	173	(gpointer) index);
	174	/*
	175	* Alignment of variant is based on the alignment of its currently
	176	* selected choice, so we leave variant alignment as-is (statically
	177	* speaking).
	178	*/
	179	}
	180
f6625916 MD	181	struct declaration_field *
f6625916 MD	182	struct_declaration_get_field_from_tag(struct declaration_variant *variant_declaration, GQuark tag)
c054553d MD	183	{
	184	unsigned long index;
	185
f6625916	186	index = (unsigned long) g_hash_table_lookup(variant_declaration->fields_by_tag,
c054553d	187	(gconstpointer) (unsigned long) tag);
f6625916	188	return &g_array_index(variant_declaration->fields, struct declaration_field, index);
c054553d MD	189	}
	190
	191	/*
	192	* tag_instance is assumed to be an enumeration.
	193	*/
e1151715 MD	194	int variant_definition_set_tag(struct definition_variant *variant,
e1151715 MD	195	struct definition *enum_tag)
c054553d	196	{
e1151715 MD	197	struct definition_enum *_enum =
e1151715 MD	198	container_of(variant->enum_tag, struct definition_enum, p);
f6625916	199	struct declaration_enum *enum_declaration = _enum->declaration;
c054553d MD	200	int missing_field = 0;
	201	unsigned long i;
	202
	203	/*
	204	* Strictly speaking, each enumerator must map to a field of the
	205	* variant. However, we are even stricter here by requiring that each
	206	* variant choice map to an enumerator too. We then validate that the
	207	* number of enumerators equals the number of variant choices.
	208	*/
f6625916	209	if (variant->declaration->fields->len != enum_get_nr_enumerators(enum_declaration))
c054553d MD	210	return -EPERM;
c054553d MD	211
f6625916 MD	212	for (i = 0; i < variant->declaration->fields->len; i++) {
	213	struct declaration_field *field_declaration =
	214	&g_array_index(variant->declaration->fields,
	215	struct declaration_field, i);
	216	if (!enum_quark_to_range_set(enum_declaration, field_declaration->name)) {
c054553d MD	217	missing_field = 1;
	218	break;
	219	}
	220	}
	221	if (missing_field)
	222	return -EPERM;
	223
	224	/*
	225	* Check the enumeration: it must map each value to one and only one
	226	* enumerator tag.
	227	* TODO: we should also check that each range map to one and only one
	228	* tag. For the moment, we will simply check this dynamically in
f6625916	229	* variant_declaration_get_current_field().
c054553d MD	230	*/
	231
	232	/* Set the enum tag field */
e19c3d69	233	variant->enum_tag = enum_tag;
c054553d MD	234	return 0;
	235	}
	236
	237	/*
	238	* field returned only valid as long as the field structure is not appended to.
	239	*/
e1151715	240	struct field variant_get_current_field(struct definition_variant variant)
c054553d	241	{
e1151715 MD	242	struct definition_enum *_enum =
e1151715 MD	243	container_of(variant->enum_tag, struct definition_enum, p);
f6625916	244	struct declaration_variant *variant_declaration = variant->declaration;
c054553d MD	245	unsigned long index;
	246	GArray *tag_array;
	247	GQuark tag;
	248
	249	tag_array = _enum->value;
	250	/*
	251	* The 1 to 1 mapping from enumeration to value should have been already
	252	* checked. (see TODO above)
	253	*/
	254	assert(tag_array->len == 1);
	255	tag = g_array_index(tag_array, GQuark, 0);
f6625916	256	index = (unsigned long) g_hash_table_lookup(variant_declaration->fields_by_tag,
c054553d	257	(gconstpointer) (unsigned long) tag);
e19c3d69	258	variant->current_field = &g_array_index(variant->fields, struct field, index);
96354dac	259	return variant->current_field;
c054553d	260	}