[ltt-dev] [BABELTRACE PATCH] Extract int and char arrays from fields

[Julien Desfossez]

Three helper functions to ease the extraction of basic types from event
fields. For now we support signed and unsigned integers and strings.
Other functions could be added following the same principle for other
types.

Signed-off-by: Julien Desfossez <julien.desfossez at polymtl.ca>
---
 include/babeltrace/types.h |    3 +++
 types/array.c              |   27 +++++++++++++++++++++++++++
 types/integer.c            |   30 ++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 0 deletions(-)

diff --git a/include/babeltrace/types.h b/include/babeltrace/types.h
index a9fb5fe..62a0d4f 100644
--- a/include/babeltrace/types.h
+++ b/include/babeltrace/types.h
@@ -383,6 +383,8 @@ void definition_unref(struct definition *definition);
 struct declaration_integer *integer_declaration_new(size_t len, int byte_order,
 				  int signedness, size_t alignment,
 				  int base, enum ctf_string_encoding encoding);
+uint64_t get_unsigned_int(struct definition *field);
+int64_t get_signed_int(struct definition *field);
 
 /*
  * mantissa_len is the length of the number of bytes represented by the mantissa
@@ -493,6 +495,7 @@ struct declaration_array *
 uint64_t array_len(struct definition_array *array);
 struct definition *array_index(struct definition_array *array, uint64_t i);
 int array_rw(struct stream_pos *pos, struct definition *definition);
+GString *get_char_array(struct definition *field);
 
 /*
  * int_declaration and elem_declaration passed as parameter now belong
diff --git a/types/array.c b/types/array.c
index db6853f..87b2083 100644
--- a/types/array.c
+++ b/types/array.c
@@ -205,3 +205,30 @@ struct definition *array_index(struct definition_array *array, uint64_t i)
 		return NULL;
 	return g_ptr_array_index(array->elems, i);
 }
+
+GString *get_char_array(struct definition *field)
+{
+	struct definition_array *array_definition;
+	struct declaration_array *array_declaration;
+	struct declaration *elem;
+
+	array_definition = container_of(field, struct definition_array, p);
+	array_declaration = array_definition->declaration;
+	elem = array_declaration->elem;
+	if (elem->id == CTF_TYPE_INTEGER) {
+		struct declaration_integer *integer_declaration =
+			container_of(elem, struct declaration_integer, p);
+
+		if (integer_declaration->encoding == CTF_STRING_UTF8
+				|| integer_declaration->encoding == CTF_STRING_ASCII) {
+
+			if (integer_declaration->len == CHAR_BIT
+					&& integer_declaration->p.alignment == CHAR_BIT) {
+
+				return array_definition->string;
+			}
+		}
+	}
+	fprintf(stderr, "[warning] Extracting string\n");
+	return NULL;
+}
diff --git a/types/integer.c b/types/integer.c
index e55c03e..9e6df58 100644
--- a/types/integer.c
+++ b/types/integer.c
@@ -103,3 +103,33 @@ void _integer_definition_free(struct definition *definition)
 	declaration_unref(integer->p.declaration);
 	g_free(integer);
 }
+
+uint64_t get_unsigned_int(struct definition *field)
+{
+	struct definition_integer *integer_definition;
+	const struct declaration_integer *integer_declaration;
+
+	integer_definition = container_of(field, struct definition_integer, p);
+	integer_declaration = integer_definition->declaration;
+
+	if (!integer_declaration->signedness) {
+		return integer_definition->value._unsigned;
+	}
+	fprintf(stderr, "[warning] Extracting unsigned value in a signed int\n");
+	return (uint64_t)integer_definition->value._signed;
+}
+
+int64_t get_signed_int(struct definition *field)
+{
+	struct definition_integer *integer_definition;
+	const struct declaration_integer *integer_declaration;
+
+	integer_definition = container_of(field, struct definition_integer, p);
+	integer_declaration = integer_definition->declaration;
+
+	if (integer_declaration->signedness) {
+		return integer_definition->value._signed;
+	}
+	fprintf(stderr, "[warning] Extracting signed value in an unsigned int\n");
+	return (int64_t)integer_definition->value._unsigned;
+}
-- 
1.7.5.4