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In-Reply-To: <20210708142059.Bluez.v1.1.I69278fab3bf86adb578c5cba0a39e5bcf7f9581e@changeid>
From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Thu, 8 Jul 2021 22:21:04 -0700
Message-ID: <CABBYNZKjc+2ur81SR2_jTiba6SgxNQh9piXqhmfKro511=QN8Q@mail.gmail.com>
Subject: Re: [Bluez PATCH v1 01/14] lib: add hash functions for bt_uuid_t
To:     Howard Chung <howardchung@google.com>
Cc:     "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>,
        Miao-chen Chou <mcchou@chromium.org>
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Hi Howard,

On Wed, Jul 7, 2021 at 11:23 PM Howard Chung <howardchung@google.com> wrote:
>
> This adds function GHashFunc and GEqualFunc for bt_uuid_t.
> With these functions, we can add uuids into a GHashTable with bt_uuid_t
> format.

We will likely move away from GLib dependency so I wouldn't want to
introduce a dependency to it specially as part of libbluetooth.

> Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
> ---
>
>  lib/uuid.c | 27 +++++++++++++++++++++++++++
>  lib/uuid.h |  3 +++
>  2 files changed, 30 insertions(+)
>
> diff --git a/lib/uuid.c b/lib/uuid.c
> index 3d97dc8359c7..a09f5c428b87 100644
> --- a/lib/uuid.c
> +++ b/lib/uuid.c
> @@ -16,6 +16,7 @@
>  #include <string.h>
>  #include <stdlib.h>
>  #include <errno.h>
> +#include <glib.h>
>
>  #include "lib/bluetooth.h"
>  #include "uuid.h"
> @@ -120,6 +121,32 @@ int bt_uuid_cmp(const bt_uuid_t *uuid1, const bt_uuid_t *uuid2)
>         return bt_uuid128_cmp(&u1, &u2);
>  }
>
> +guint bt_uuid_hash(gconstpointer key)
> +{
> +       const bt_uuid_t *uuid = key;
> +       bt_uuid_t uuid_128;
> +       uint64_t *val;
> +
> +       if (!uuid)
> +               return 0;
> +
> +       bt_uuid_to_uuid128(uuid, &uuid_128);
> +       val = (uint64_t *)&uuid_128.value.u128;
> +
> +       return g_int64_hash(val) ^ g_int64_hash(val+1);
> +}
> +
> +gboolean bt_uuid_equal(gconstpointer v1, gconstpointer v2)
> +{
> +       const bt_uuid_t *uuid1 = v1;
> +       const bt_uuid_t *uuid2 = v2;
> +
> +       if (!uuid1 || !uuid2)
> +               return !uuid1 && !uuid2;
> +
> +       return bt_uuid_cmp(uuid1, uuid2) == 0;
> +}
> +
>  /*
>   * convert the UUID to string, copying a maximum of n characters.
>   */
> diff --git a/lib/uuid.h b/lib/uuid.h
> index 1a4029b68730..e47ccccb9fd2 100644
> --- a/lib/uuid.h
> +++ b/lib/uuid.h
> @@ -17,6 +17,7 @@ extern "C" {
>  #endif
>
>  #include <stdint.h>
> +#include <glib.h>
>
>  #define GENERIC_AUDIO_UUID     "00001203-0000-1000-8000-00805f9b34fb"
>
> @@ -167,6 +168,8 @@ int bt_uuid128_create(bt_uuid_t *btuuid, uint128_t value);
>
>  int bt_uuid_cmp(const bt_uuid_t *uuid1, const bt_uuid_t *uuid2);
>  void bt_uuid_to_uuid128(const bt_uuid_t *src, bt_uuid_t *dst);
> +guint bt_uuid_hash(gconstpointer key);
> +gboolean bt_uuid_equal(gconstpointer v1, gconstpointer v2);
>
>  #define MAX_LEN_UUID_STR 37
>
> --
> 2.32.0.93.g670b81a890-goog
>


-- 
Luiz Augusto von Dentz