(mynewt-nimble) branch master updated: nimble/host: Optimize characteristics discovery

[andk]

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andk pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/mynewt-nimble.git


The following commit(s) were added to refs/heads/master by this push:
     new 1d866e41a nimble/host: Optimize characteristics discovery
1d866e41a is described below

commit 1d866e41afa67eecf059a0e39c529370a78ef231
Author: Andrzej Kaczmarek <andrzej.kaczma...@codecoup.pl>
AuthorDate: Wed Oct 9 15:40:29 2024 +0200

    nimble/host: Optimize characteristics discovery
    
    We can stop characteristics discovery as soon as there are less than 2
    attributes left. This means if last characteristic has descriptor (e.g.
    CCC) we will save single ATT_READ_BY_TYPE_REQ/RSP transaction.
    
    As a side-effect we also resume discovery starting from the next handle
    after last characteristic value handle instead of characteristic
    declaration handle, but this is ok since there cannot be any atrtibutes
    (so also characteristic declarations) between characteristic declaration
    and characteristic value.
---
 nimble/host/src/ble_gattc.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/nimble/host/src/ble_gattc.c b/nimble/host/src/ble_gattc.c
index 45ee869c8..b3c8e04e1 100644
--- a/nimble/host/src/ble_gattc.c
+++ b/nimble/host/src/ble_gattc.c
@@ -2299,7 +2299,9 @@ ble_gattc_disc_all_chrs_rx_adata(struct ble_gattc_proc 
*proc,
         rc = BLE_HS_EBADDATA;
         goto done;
     }
-    proc->disc_all_chrs.prev_handle = adata->att_handle;
+
+    /* We'll resume after characteristic value */
+    proc->disc_all_chrs.prev_handle = chr.val_handle;
 
     rc = 0;
 
@@ -2328,7 +2330,10 @@ ble_gattc_disc_all_chrs_rx_complete(struct 
ble_gattc_proc *proc, int status)
         return BLE_HS_EDONE;
     }
 
-    if (proc->disc_all_chrs.prev_handle == proc->disc_all_chrs.end_handle) {
+    /* We can stop discovery if there are less than 2 attributes left since
+     * complete characteristic requires at least 2 handles.
+     */
+    if (proc->disc_all_chrs.prev_handle + 1 >= proc->disc_all_chrs.end_handle 
- 1) {
         /* Characteristic discovery complete. */
         ble_gattc_disc_all_chrs_cb(proc, BLE_HS_EDONE, 0, NULL);
         return BLE_HS_EDONE;