PROTOTYPE(discovery):gatt: add ReadCharacteristicBlob and SetMTU
* Add ReadCharacteristicBlob and SetMTU to gatt library
* This works only for linux.
Change-Id: Iab12c5a74d383ad265b128fe7f57ca9b779bf071
diff --git a/go/src/github.com/paypal/gatt/examples/explorer.go b/go/src/github.com/paypal/gatt/examples/explorer.go
index 3861cd9..4ec4d4d 100644
--- a/go/src/github.com/paypal/gatt/examples/explorer.go
+++ b/go/src/github.com/paypal/gatt/examples/explorer.go
@@ -50,6 +50,11 @@
fmt.Println("Connected")
defer p.Device().CancelConnection(p)
+ if err := p.SetMTU(500); err != nil {
+ fmt.Printf("Failed to set MTU, err: %s\n", err)
+ return
+ }
+
// Discovery services
ss, err := p.DiscoverServices(nil)
if err != nil {
@@ -81,7 +86,7 @@
// Read the characteristic, if possible.
if (c.Properties() & gatt.CharRead) != 0 {
- b, err := p.ReadCharacteristic(c)
+ b, err := p.ReadCharacteristicBlob(c)
if err != nil {
fmt.Printf("Failed to read characteristic, err: %s\n", err)
continue
diff --git a/go/src/github.com/paypal/gatt/peripheral.go b/go/src/github.com/paypal/gatt/peripheral.go
index 3aa61f8..bc69ddc 100644
--- a/go/src/github.com/paypal/gatt/peripheral.go
+++ b/go/src/github.com/paypal/gatt/peripheral.go
@@ -39,6 +39,9 @@
// ReadCharacteristic retrieves the value of a specified characteristic.
ReadCharacteristic(c *Characteristic) ([]byte, error)
+ // ReadCharacteristicBlob retrieves the value of a specified characteristic by ReadBlob.
+ ReadCharacteristicBlob(c *Characteristic) ([]byte, error)
+
// ReadDescriptor retrieves the value of a specified characteristic descriptor.
ReadDescriptor(d *Descriptor) ([]byte, error)
@@ -56,6 +59,9 @@
// ReadRSSI retrieves the current RSSI value for the remote peripheral.
ReadRSSI() int
+
+ // SetMTU sets the mtu for the remote peripheral.
+ SetMTU(mtu uint16) error
}
type subscriber struct {
diff --git a/go/src/github.com/paypal/gatt/peripheral_darwin.go b/go/src/github.com/paypal/gatt/peripheral_darwin.go
index 434e65e..643b97d 100644
--- a/go/src/github.com/paypal/gatt/peripheral_darwin.go
+++ b/go/src/github.com/paypal/gatt/peripheral_darwin.go
@@ -1,6 +1,7 @@
package gatt
import (
+ "errors"
"log"
"github.com/paypal/gatt/xpc"
@@ -120,6 +121,10 @@
return b, nil
}
+func (p *peripheral) ReadCharacteristicBlob(c *Characteristic) ([]byte, error) {
+ return nil, errors.New("Not implemented")
+}
+
func (p *peripheral) WriteCharacteristic(c *Characteristic, b []byte, noRsp bool) error {
args := xpc.Dict{
"kCBMsgArgDeviceUUID": p.id,
@@ -200,6 +205,10 @@
return rsp.MustGetInt("kCBMsgArgData")
}
+func (p *peripheral) SetMTU(mtu uint16) error {
+ return errors.New("Not implemented")
+}
+
func uuidSlice(uu []UUID) [][]byte {
us := [][]byte{}
for _, u := range uu {
diff --git a/go/src/github.com/paypal/gatt/peripheral_linux.go b/go/src/github.com/paypal/gatt/peripheral_linux.go
index 3cd9abc..277228a 100644
--- a/go/src/github.com/paypal/gatt/peripheral_linux.go
+++ b/go/src/github.com/paypal/gatt/peripheral_linux.go
@@ -1,6 +1,7 @@
package gatt
import (
+ "bytes"
"encoding/binary"
"errors"
"fmt"
@@ -215,6 +216,30 @@
return b, nil
}
+func (p *peripheral) ReadCharacteristicBlob(c *Characteristic) ([]byte, error) {
+ var buf bytes.Buffer
+ var off uint16
+ for {
+ b := make([]byte, 5)
+ op := byte(attOpReadBlobReq)
+ b[0] = op
+ binary.LittleEndian.PutUint16(b[1:3], c.vh)
+ binary.LittleEndian.PutUint16(b[3:5], off)
+
+ b = p.sendReq(op, b)
+ b = b[1:]
+ if len(b) == 0 {
+ break
+ }
+ buf.Write(b)
+ off += uint16(len(b))
+ if len(b) < int(p.mtu)-1 {
+ break
+ }
+ }
+ return buf.Bytes(), nil
+}
+
func (p *peripheral) WriteCharacteristic(c *Characteristic, value []byte, noRsp bool) error {
b := make([]byte, 3+len(value))
op := byte(attOpWriteReq)
@@ -295,7 +320,6 @@
return p.setNotifyValue(c, gattCCCIndicateFlag, f)
}
-
func (p *peripheral) ReadRSSI() int {
// TODO: implement
return -1
@@ -391,3 +415,18 @@
}
}
+
+func (p *peripheral) SetMTU(mtu uint16) error {
+ b := make([]byte, 3)
+ op := byte(attOpMtuReq)
+ b[0] = op
+ binary.LittleEndian.PutUint16(b[1:3], uint16(mtu))
+
+ b = p.sendReq(op, b)
+ serverMTU := binary.LittleEndian.Uint16(b[1:3])
+ if serverMTU < mtu {
+ mtu = serverMTU
+ }
+ p.mtu = mtu
+ return nil
+}
