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Increase the packet size again for the Icon HD.

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The switch from downloading the entire data with a single large packet
to multiple smaller 256 byte packets, resulted in a considerable
performance regression. In one particular case, the difference was a
factor 6.7 slower!

I performed a small tests (using an Icon HD Net Ready) with 256, 1024
and 4096 byte packets, and the total time was respectively 21.0, 11.3
and 6.5 seconds. For a single large packet, the total time is only 5.9
seconds. Thus the difference with a 4096 byte packet is negligible.
This commit is contained in:
Jef Driesen 2014-02-17 10:27:26 +01:00
parent 991d0180d8
commit 9394773cd2
1 changed files with 8 additions and 5 deletions
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13
src/mares_iconhd.c
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@ -49,8 +49,6 @@
#define ACK 0xAA
#define EOF 0xEA
#define SZ_PACKET 256
typedef struct mares_iconhd_layout_t {
unsigned int memsize;
unsigned int rb_profile_begin;
@ -69,6 +67,7 @@ typedef struct mares_iconhd_device_t {
unsigned char fingerprint[10];
unsigned char version[140];
unsigned int model;
unsigned int packetsize;
} mares_iconhd_device_t;
static dc_status_t mares_iconhd_device_set_fingerprint (dc_device_t *abstract, const unsigned char data[], unsigned int size);
@ -219,6 +218,7 @@ mares_iconhd_device_open (dc_device_t **out, dc_context_t *context, const char *
memset (device->fingerprint, 0, sizeof (device->fingerprint));
memset (device->version, 0, sizeof (device->version));
device->model = 0;
device->packetsize = 0;
// Open the device.
int rc = serial_open (&device->port, context, name);
@ -278,13 +278,16 @@ mares_iconhd_device_open (dc_device_t **out, dc_context_t *context, const char *
case NEMOWIDE2:
case PUCK2:
device->layout = &mares_matrix_layout;
device->packetsize = 256;
break;
case ICONHDNET:
device->layout = &mares_iconhdnet_layout;
device->packetsize = 4096;
break;
case ICONHD:
default:
device->layout = &mares_iconhd_layout;
device->packetsize = 4096;
break;
}
@ -339,8 +342,8 @@ mares_iconhd_device_read (dc_device_t *abstract, unsigned int address, unsigned
while (nbytes < size) {
// Calculate the packet size.
unsigned int len = size - nbytes;
if (len > SZ_PACKET)
len = SZ_PACKET;
if (len > device->packetsize)
len = device->packetsize;
// Read the packet.
unsigned char command[] = {0xE7, 0x42,
@ -384,7 +387,7 @@ mares_iconhd_device_dump (dc_device_t *abstract, dc_buffer_t *buffer)
device_event_emit (abstract, DC_EVENT_VENDOR, &vendor);
return device_dump_read (abstract, dc_buffer_get_data (buffer),
dc_buffer_get_size (buffer), SZ_PACKET);
dc_buffer_get_size (buffer), device->packetsize);
}