Hi Zhenhua,

> Implement hashtable to store server supported command list.
> 
> AT command could be action command or parameter command. Defined
> in V.250 5.2.5.
> ---
>  gatchat/gatserver.c |   29 +++++++++++++++++++++++++++++
>  gatchat/gatserver.h |   21 +++++++++++++++++++++
>  2 files changed, 50 insertions(+), 0 deletions(-)
> 
> diff --git a/gatchat/gatserver.c b/gatchat/gatserver.c
> index 4a19b6b..829dc1d 100644
> --- a/gatchat/gatserver.c
> +++ b/gatchat/gatserver.c
> @@ -75,6 +75,16 @@ static const char
>  *server_result_to_string(GAtServerResult result) }
>  }
> 
> +/* AT command set that server supported */
> +struct at_command {
> +	int id;
> +	char *prefix;

I don't see the point for id or prefix here.  The prefix is already stored as 
the key in the hash table and frankly we should always be using that as it is 
unique for our purposes.

> +	GAtServerCommandType type;
> +	GAtServerNotifyFunc notify;
> +	gpointer user_data;
> +	GDestroyNotify destroy_notify;
> +};
> +
>  /* Basic command setting for V.250 */
>  struct v250_settings {
>  	char s3;			/* set by S3=<val> */
> @@ -99,6 +109,8 @@ struct _GAtServer {
>  	gpointer user_disconnect_data;		/* User disconnect data */
>  	GAtDebugFunc debugf;			/* Debugging output function */
>  	gpointer debug_data;			/* Data to pass to debug func */
> +	GHashTable *command_list;		/* List of supported at command */
> +	guint next_command_id;			/* Next command id */

Get rid of this part

>  	struct ring_buffer *read_buf;		/* Current read buffer */
>  	GQueue *write_queue;			/* Write buffer queue */
>  	guint max_read_attempts;		/* Max reads per select */
> @@ -714,6 +726,14 @@ static gboolean can_write_data(GIOChannel *channel,
>  GIOCondition cond, return FALSE;
>  }
> 
> +static void at_command_free(gpointer key, gpointer value, gpointer data)
> +{
> +	struct at_command *node = value;
> +
> +	g_free(node->prefix);
> +	g_free(node);
> +}
> +
>  static void write_queue_free(GQueue *write_queue)
>  {
>  	struct ring_buffer *write_buf;
> @@ -733,6 +753,11 @@ static void g_at_server_cleanup(GAtServer *server)
>  	/* Cleanup pending data to write */
>  	write_queue_free(server->write_queue);
> 
> +	/* Cleanup registered notifications */
> +	g_hash_table_foreach(server->command_list, at_command_free, NULL);

This is unnecessary if you properly initialize the hash table, see below.

> +	g_hash_table_destroy(server->command_list);
> +	server->command_list = NULL;
> +
>  	server->channel = NULL;
>  }
> 
> @@ -792,6 +817,7 @@ GAtServer *g_at_server_new(GIOChannel *io)
>  	server->ref_count = 1;
>  	v250_settings_create(&server->v250);
>  	server->channel = io;
> +	server->command_list = g_hash_table_new(g_str_hash, g_str_equal);

Use the _new_full version here and specify the destructor.

>  	server->read_buf = ring_buffer_new(BUF_SIZE);
>  	if (!server->read_buf)
>  		goto error;
> @@ -816,6 +842,9 @@ GAtServer *g_at_server_new(GIOChannel *io)
>  	return server;
> 
>  error:
> +	if (server->command_list)
> +		g_hash_table_destroy(server->command_list);
> +
>  	if (server->read_buf)
>  		ring_buffer_free(server->read_buf);
> 
> diff --git a/gatchat/gatserver.h b/gatchat/gatserver.h
> index 698f7e0..5db9321 100644
> --- a/gatchat/gatserver.h
> +++ b/gatchat/gatserver.h
> @@ -26,6 +26,7 @@
>  extern "C" {
>  #endif
> 
> +#include "gatresult.h"
>  #include "gatutil.h"
> 
>  struct _GAtServer;
> @@ -46,6 +47,26 @@ enum _GAtServerResult {
> 
>  typedef enum _GAtServerResult GAtServerResult;
> 
> +enum _GAtServerRequestType {
> +	G_AT_SERVER_REQUEST_TYPE_NONE,

> +	G_AT_SERVER_REQUEST_TYPE_ACTION,

What exactly does this one mean, how is it different from SET or NONE?

> +	G_AT_SERVER_REQUEST_TYPE_QUERY,
> +	G_AT_SERVER_REQUEST_TYPE_SET,
> +	G_AT_SERVER_REQUEST_TYPE_SUPPORT,
> +};
> +
> +typedef enum _GAtServerRequestType GAtServerRequestType;
> +
> +enum _GAtServerCommandType {
> +	G_AT_SERVER_COMMAND_TYPE_ACTION,
> +	G_AT_SERVER_COMMAND_TYPE_PARAMETER,

Again, what do these mean?  Might want to include a simple comment here.

> +};
> +
> +typedef enum _GAtServerCommandType GAtServerCommandType;
> +
> +typedef int (*GAtServerNotifyFunc)(GAtServerRequestType type, GAtResult
>  *result, +					gpointer user_data);
> +
>  GAtServer *g_at_server_new(GIOChannel *io);
> 
>  GAtServer *g_at_server_ref(GAtServer *server);
>