diff --git a/src/libkshark.h b/src/libkshark.h
index e34a32f..f2e29ac 100644
--- a/src/libkshark.h
+++ b/src/libkshark.h
@@ -121,6 +121,205 @@ void kshark_hash_id_free(struct kshark_hash_id *hash);
 
 int *kshark_hash_ids(struct kshark_hash_id *hash);
 
+struct kshark_data_stream;
+
+/** A function type to be used by the method interface of the data stream. */
+typedef char *(*stream_get_str_func) (struct kshark_data_stream *,
+				      const struct kshark_entry *);
+
+/** A function type to be used by the method interface of the data stream. */
+typedef const int (*stream_get_int_func) (struct kshark_data_stream *,
+					  const struct kshark_entry *);
+
+/** A function type to be used by the method interface of the data stream. */
+typedef int (*stream_find_id_func) (struct kshark_data_stream *,
+				    const char *);
+
+/** A function type to be used by the method interface of the data stream. */
+typedef int *(*stream_get_ids_func) (struct kshark_data_stream *);
+
+/** A function type to be used by the method interface of the data stream. */
+typedef int (*stream_get_names_func) (struct kshark_data_stream *,
+				      const struct kshark_entry *,
+				      char ***);
+
+/** Event field format identifier. */
+typedef enum kshark_event_field_format {
+	/** A field of unknown type. */
+	KS_INVALID_FIELD,
+
+	/** Integer number */
+	KS_INTEGER_FIELD,
+
+	/** Floating-point number */
+	KS_FLOAT_FIELD
+} kshark_event_field_format;
+
+/** A function type to be used by the method interface of the data stream. */
+typedef kshark_event_field_format
+(*stream_event_field_type) (struct kshark_data_stream *,
+			    const struct kshark_entry *,
+			    const char *);
+
+/** A function type to be used by the method interface of the data stream. */
+typedef const int (*stream_read_event_field) (struct kshark_data_stream *,
+					      const struct kshark_entry *,
+					      const char *,
+					      int64_t *);
+
+/** A function type to be used by the method interface of the data stream. */
+typedef const int (*stream_read_record_field) (struct kshark_data_stream *,
+					       void *,
+					       const char *,
+					       int64_t *);
+
+struct kshark_context;
+
+/** A function type to be used by the method interface of the data stream. */
+typedef ssize_t (*load_entries_func) (struct kshark_data_stream *,
+				      struct kshark_context *,
+				      struct kshark_entry ***);
+
+/** A function type to be used by the method interface of the data stream. */
+typedef ssize_t (*load_matrix_func) (struct kshark_data_stream *,
+				     struct kshark_context *,
+				     int16_t **event_array,
+				     int16_t **cpu_array,
+				     int32_t **pid_array,
+				     int64_t **offset_array,
+				     int64_t **ts_array);
+
+/** Data interface identifier. */
+typedef enum kshark_data_interface_id {
+	/** An interface with unknown type. */
+	KS_INVALID_INTERFACE,
+
+	/** Generic interface suitable for Ftrace data. */
+	KS_GENERIC_DATA_INTERFACE,
+} kshark_data_interface_id;
+
+/**
+ * Structure representing the interface of methods used to operate over
+ * the data from a given stream.
+ */
+struct kshark_generic_stream_interface {
+	/** Interface version identifier. */
+	kshark_data_interface_id	type; /* MUST BE FIRST ENTRY. */
+
+	/** Method used to retrieve the Process Id of the entry. */
+	stream_get_int_func	get_pid;
+
+	/** Method used to retrieve the Event Id of the entry. */
+	stream_get_int_func	get_event_id;
+
+	/** Method used to retrieve the Event name of the entry. */
+	stream_get_str_func	get_event_name;
+
+	/** Method used to retrieve the Task name of the entry. */
+	stream_get_str_func	get_task;
+
+	/** Method used to retrieve the Info string of the entry. */
+	stream_get_str_func	get_info;
+
+	/**
+	 * Method used to retrieve an unspecified auxiliary info of the trace
+	 * record.
+	 */
+	stream_get_str_func	aux_info;
+
+	/** Method used to retrieve Id of the Event from its name. */
+	stream_find_id_func	find_event_id;
+
+	/** Method used to retrieve the array of Ids of all Events. */
+	stream_get_ids_func	get_all_event_ids;
+
+	/** Method used to dump the entry's content to string. */
+	stream_get_str_func	dump_entry;
+
+	/**
+	 * Method used to retrieve the array of all field names of a given
+	 * event.
+	 */
+	stream_get_names_func	get_all_event_field_names;
+
+	/** Method used to access the type of an event's data field. */
+	stream_event_field_type		get_event_field_type;
+
+	/** Method used to access the value of an event's data field. */
+	stream_read_event_field		read_event_field_int64;
+
+	/** Method used to access the value of an event's data field. */
+	stream_read_record_field	read_record_field_int64;
+
+	/** Method used to load the data in the form of entries. */
+	load_entries_func	load_entries;
+
+	/** Method used to load the data in matrix form. */
+	load_matrix_func	load_matrix;
+
+	/** Generic data handle. */
+	void			*handle;
+};
+
+/** The limit in size of the data format identifier string. */
+#define KS_DATA_FORMAT_SIZE	15
+
+/** Structure representing a stream of trace data. */
+struct kshark_data_stream {
+	/** Data stream identifier. */
+	uint16_t		stream_id;
+
+	/** The number of CPUs presented in this data stream. */
+	int			n_cpus;
+
+	/**
+	 * The number of distinct event types presented in this data stream.
+	 */
+	int			n_events;
+
+	/** The Process Id of the Idle task. */
+	int			idle_pid;
+
+	/** Trace data file pathname. */
+	char			*file;
+
+	/** Stream name. */
+	char			*name;
+
+	/** Hash table of task PIDs. */
+	struct kshark_hash_id	*tasks;
+
+	/** A mutex, used to protect the access to the input file. */
+	pthread_mutex_t		input_mutex;
+
+	/** Hash of tasks to filter on. */
+	struct kshark_hash_id	*show_task_filter;
+
+	/** Hash of tasks to not display. */
+	struct kshark_hash_id	*hide_task_filter;
+
+	/** Hash of events to filter on. */
+	struct kshark_hash_id	*show_event_filter;
+
+	/** Hash of events to not display. */
+	struct kshark_hash_id	*hide_event_filter;
+
+	/** Hash of CPUs to filter on. */
+	struct kshark_hash_id	*show_cpu_filter;
+
+	/** Hash of CPUs to not display. */
+	struct kshark_hash_id	*hide_cpu_filter;
+
+	/** The type of the data. */
+	char			data_format[KS_DATA_FORMAT_SIZE];
+
+	/**
+	 * The interface of methods used to operate over the data from a given
+	 * stream.
+	 */
+	void				*interface;
+};
+
 /** Size of the task's hash table. */
 #define KS_TASK_HASH_SHIFT 16
 #define KS_TASK_HASH_SIZE (1 << KS_TASK_HASH_SHIFT)
