Re: [PATCH 07/19] Read temperature type characteristic

[Gustavo Padovan <padovan@profusion.mobi>]

* Santiago Carot <sancane@gmail.com> [2011-09-20 22:40:56 +0200]:

> Hello,
> 
> 2011/9/20 Gustavo Padovan <padovan@profusion.mobi>:
> > Hi Santiago,
> >
> > * Santiago Carot-Nemesio <sancane@gmail.com> [2011-09-20 19:47:19 +0200]:
> >
> >> ---
> >>  thermometer/thermometer.c |   54 ++++++++++++++++++++++++++++++++++++++++++++-
> >>  1 files changed, 53 insertions(+), 1 deletions(-)
> >>
> >> diff --git a/thermometer/thermometer.c b/thermometer/thermometer.c
> >> index f0b977e..2dcc4ba 100644
> >> --- a/thermometer/thermometer.c
> >> +++ b/thermometer/thermometer.c
> >> @@ -39,6 +39,14 @@
> >>  #define INTERMEDIATE_TEMPERATURE_UUID        "00002a1e-0000-1000-8000-00805f9b34fb"
> >>  #define MEASUREMENT_INTERVAL_UUID    "00002a21-0000-1000-8000-00805f9b34fb"
> >>
> >> +struct properties {
> >> +     gboolean        intermediate;
> >> +     guint8          *type;
> >> +     guint16         *interval;
> >> +     guint16         *max;
> >> +     guint16         *min;
> >> +};
> >> +
> >>  struct thermometer {
> >>       DBusConnection          *conn;          /* The connection to the bus */
> >>       struct btd_device       *dev;           /* Device reference */
> >> @@ -47,6 +55,7 @@ struct thermometer {
> >>       gint                    attioid;        /* Att watcher id */
> >>       gint                    attindid;       /* Att incications id */
> >>       GSList                  *chars;         /* Characteristics */
> >> +     struct properties       properties;     /* Thermometer's properties */
> >
> > fold type, interval, max and min here seems a better idea.
> >
> >>  };
> >>
> >>  struct characteristic {
> >> @@ -63,6 +72,24 @@ struct descriptor {
> >>
> >>  static GSList *thermometers = NULL;
> >>
> >> +static gchar* temptype2str(uint8_t value)
> >> +{
> >> +     switch (value) {
> >> +     case 1: return "Armpit";
> >> +     case 2: return "Body";
> >> +     case 3: return "Ear";
> >> +     case 4: return "Finger";
> >> +     case 5: return "Intestines";
> >> +     case 6: return "Mouth";
> >> +     case 7: return "Rectum";
> >> +     case 8: return "Toe";
> >> +     case 9: return "Tympanum";
> >> +     default:
> >> +             error("Temperature type %d reserved for future use", value);
> >> +             return NULL;
> >> +     };
> >> +}
> >> +
> >>  static void destroy_char(gpointer user_data)
> >>  {
> >>       struct characteristic *c = user_data;
> >> @@ -87,6 +114,11 @@ static void destroy_thermometer(gpointer user_data)
> >>       if (t->chars)
> >>               g_slist_free_full(t->chars, destroy_char);
> >>
> >> +     g_free(t->properties.type);
> >> +     g_free(t->properties.interval);
> >> +     g_free(t->properties.max);
> >> +     g_free(t->properties.min);
> >> +
> >>       dbus_connection_unref(t->conn);
> >>       btd_device_unref(t->dev);
> >>       g_free(t->svc_range);
> >> @@ -113,7 +145,27 @@ static void discover_desc_cb(guint8 status, const guint8 *pdu, guint16 len,
> >>  static void read_temp_type_cb(guint8 status, const guint8 *pdu, guint16 len,
> >>                                                       gpointer user_data)
> >>  {
> >> -     /* TODO */
> >> +     struct characteristic *ch = user_data;
> >> +     struct thermometer *t = ch->t;
> >> +     uint8_t value;
> >> +     int vlen;
> >> +
> >> +     if (status != 0) {
> >> +             DBG("Temperature Type value read failed: %s",
> >> +                                                     att_ecode2str(status));
 >> +             return;
> >> +     }
> >> +
> >> +     if (!dec_read_resp(pdu, len, &value, &vlen)) {
> >> +             DBG("Protocol error");
> >> +             return;
> >> +     }
> >> +
> >> +     DBG("TEMPERATURE TYPE: %s", temptype2str(value));
> >> +     if (!t->properties.type)
> >> +             t->properties.type = g_new0(guint8, 1);
> >
> > Is there a good reason why this is allocated memory? I'm no seeing the point.
> 
> The reason for doing that is because "type" is an optional attribute
> in HTP. Another sollution could be use a flag in addition to the type
> field. I thought it's easier and simpler to use a pointer instead two
> fields to manage this stuff.

What if type = -1 as flag? You are wasting memory here and using dereferences
where it is not needed.

	Gustavo