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Reduce the amount of data copying.

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This commit is contained in:
Jef Driesen 2009-11-16 08:14:29 +00:00
parent 21832851af
commit 13768188a8
1 changed files with 88 additions and 144 deletions
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232
src/uwatec_memomouse.c
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@ -36,6 +36,8 @@
rc == -1 ? DEVICE_STATUS_IO : DEVICE_STATUS_TIMEOUT \
)
#define PACKETSIZE 126
#define ACK 0x60
#define NAK 0xA8
@ -212,7 +214,7 @@ uwatec_memomouse_confirm (uwatec_memomouse_device_t *device, unsigned char value
static device_status_t
uwatec_memomouse_read_packet (uwatec_memomouse_device_t *device, unsigned char data[], unsigned int size, unsigned int *result)
{
assert (size >= 126 + 2);
assert (result != NULL);
// Receive the header of the package.
int rc = serial_read (device->port, data, 1);
@ -226,7 +228,7 @@ uwatec_memomouse_read_packet (uwatec_memomouse_device_t *device, unsigned char d
// Verify the header of the package.
unsigned int len = data[0];
if (len > 126) {
if (len + 2 > size) {
WARNING ("Unexpected answer start byte(s).");
return DEVICE_STATUS_PROTOCOL;
}
@ -249,8 +251,7 @@ uwatec_memomouse_read_packet (uwatec_memomouse_device_t *device, unsigned char d
return DEVICE_STATUS_PROTOCOL;
}
if (result)
*result = len;
*result = len;
return DEVICE_STATUS_SUCCESS;
}
@ -259,10 +260,8 @@ uwatec_memomouse_read_packet (uwatec_memomouse_device_t *device, unsigned char d
static device_status_t
uwatec_memomouse_read_packet_outer (uwatec_memomouse_device_t *device, unsigned char data[], unsigned int size, unsigned int *result)
{
unsigned int length = 0;
unsigned char package[126 + 2] = {0};
device_status_t rc = DEVICE_STATUS_SUCCESS;
while ((rc = uwatec_memomouse_read_packet (device, package, sizeof (package), &length)) != DEVICE_STATUS_SUCCESS) {
while ((rc = uwatec_memomouse_read_packet (device, data, size, result)) != DEVICE_STATUS_SUCCESS) {
// Automatically discard a corrupted packet,
// and request a new one.
if (rc != DEVICE_STATUS_PROTOCOL)
@ -277,113 +276,89 @@ uwatec_memomouse_read_packet_outer (uwatec_memomouse_device_t *device, unsigned
return rc;
}
#ifndef NDEBUG
message ("package(%i)=\"", length);
for (unsigned int i = 0; i < length; ++i) {
message ("%02x", package[i + 1]);
}
message ("\"\n");
#endif
return DEVICE_STATUS_SUCCESS;
}
if (size < length) {
static device_status_t
uwatec_memomouse_read_packet_inner (uwatec_memomouse_device_t *device, dc_buffer_t *buffer, device_progress_t *progress)
{
// Erase the current contents of the buffer.
if (!dc_buffer_clear (buffer)) {
WARNING ("Insufficient buffer space available.");
return DEVICE_STATUS_MEMORY;
}
memcpy (data, package + 1, length);
if (result)
*result = length;
return DEVICE_STATUS_SUCCESS;
}
static device_status_t
uwatec_memomouse_read_packet_inner (uwatec_memomouse_device_t *device, unsigned char *data[], unsigned int *size, device_progress_t *progress)
{
// Read the first package.
unsigned int length = 0;
unsigned char package[126] = {0};
device_status_t rc = uwatec_memomouse_read_packet_outer (device, package, sizeof (package), &length);
if (rc != DEVICE_STATUS_SUCCESS)
return rc;
// Accept the package.
rc = uwatec_memomouse_confirm (device, ACK);
if (rc != DEVICE_STATUS_SUCCESS)
return rc;
// Verify the first package contains at least
// the size of the inner package.
if (length < 2) {
WARNING ("First package is too small.");
return DEVICE_STATUS_PROTOCOL;
}
// Calculate the total size of the inner package.
unsigned int total = array_uint16_le (package) + 3;
// Update and emit a progress event.
if (progress) {
progress->maximum = total;
progress->current += length;
device_event_emit (&device->base, DEVICE_EVENT_PROGRESS, progress);
}
// Allocate memory for the entire package.
unsigned char *buffer = (unsigned char *) malloc (total * sizeof (unsigned char));
if (buffer == NULL) {
WARNING ("Memory allocation error.");
return DEVICE_STATUS_MEMORY;
}
// Copy the first package to the new memory buffer.
memcpy (buffer, package, length);
// Read the remaining packages.
unsigned int nbytes = length;
unsigned int nbytes = 0;
unsigned int total = PACKETSIZE;
while (nbytes < total) {
// Read the package.
rc = uwatec_memomouse_read_packet_outer (device, buffer + nbytes, total - nbytes, &length);
if (rc != DEVICE_STATUS_SUCCESS) {
free (buffer);
return rc;
}
// Calculate the packet size.
unsigned int length = total - nbytes;
if (length > PACKETSIZE)
length = PACKETSIZE;
// Accept the package.
rc = uwatec_memomouse_confirm (device, ACK);
if (rc != DEVICE_STATUS_SUCCESS) {
free (buffer);
// Read the packet.
unsigned char packet[PACKETSIZE + 2] = {0};
device_status_t rc = uwatec_memomouse_read_packet_outer (device, packet, length + 2, &length);
if (rc != DEVICE_STATUS_SUCCESS)
return rc;
// Accept the packet.
rc = uwatec_memomouse_confirm (device, ACK);
if (rc != DEVICE_STATUS_SUCCESS)
return rc;
if (nbytes == 0) {
// The first packet should contain at least
// the total size of the inner packet.
if (length < 2) {
WARNING ("First package is too small.");
return DEVICE_STATUS_PROTOCOL;
}
// Calculate the total size of the inner packet.
total = array_uint16_le (packet + 1) + 3;
// Pre-allocate the required amount of memory.
if (!dc_buffer_reserve (buffer, total)) {
WARNING ("Insufficient buffer space available.");
return DEVICE_STATUS_MEMORY;
}
}
// Update and emit a progress event.
if (progress) {
progress->maximum = total;
progress->current += length;
device_event_emit (&device->base, DEVICE_EVENT_PROGRESS, progress);
}
// Append the packet to the buffer.
dc_buffer_append (buffer, packet + 1, length);
nbytes += length;
}
// Obtain the pointer to the buffer contents.
unsigned char *data = dc_buffer_get_data (buffer);
// Verify the checksum.
unsigned char crc = buffer[total - 1];
unsigned char ccrc = checksum_xor_uint8 (buffer, total - 1, 0x00);
unsigned char crc = data[total - 1];
unsigned char ccrc = checksum_xor_uint8 (data, total - 1, 0x00);
if (crc != ccrc) {
free (buffer);
WARNING ("Unexpected answer CRC.");
return DEVICE_STATUS_PROTOCOL;
}
*data = buffer;
*size = total;
// Discard the header and checksum bytes.
dc_buffer_slice (buffer, 2, total - 3);
return DEVICE_STATUS_SUCCESS;
}
static device_status_t
uwatec_memomouse_dump_internal (uwatec_memomouse_device_t *device, unsigned char *data[], unsigned int *size)
uwatec_memomouse_dump_internal (uwatec_memomouse_device_t *device, dc_buffer_t *buffer)
{
// Enable progress notifications.
device_progress_t progress = DEVICE_PROGRESS_INITIALIZER;
@ -403,14 +378,10 @@ uwatec_memomouse_dump_internal (uwatec_memomouse_device_t *device, unsigned char
}
// Read the ID string.
unsigned int id_length = 0;
unsigned char *id_buffer = NULL;
device_status_t rc = uwatec_memomouse_read_packet_inner (device, &id_buffer, &id_length, NULL);
device_status_t rc = uwatec_memomouse_read_packet_inner (device, buffer, NULL);
if (rc != DEVICE_STATUS_SUCCESS)
return rc;
free (id_buffer);
// Prepare the command.
unsigned char command [9] = {
0x07, // Outer packet size.
@ -450,11 +421,6 @@ uwatec_memomouse_dump_internal (uwatec_memomouse_device_t *device, unsigned char
WARNING ("Failed to recieve the answer.");
return EXITCODE (n);
}
#ifndef NDEBUG
if (answer != ACK)
message ("Received unexpected response (%02x).\n", answer);
#endif
}
// Verify the answer.
@ -473,44 +439,18 @@ uwatec_memomouse_dump_internal (uwatec_memomouse_device_t *device, unsigned char
time_t now = time (NULL);
// Read the data packet.
rc = uwatec_memomouse_read_packet_inner (device, data, size, &progress);
rc = uwatec_memomouse_read_packet_inner (device, buffer, &progress);
if (rc != DEVICE_STATUS_SUCCESS)
return rc;
// Store the clock calibration values.
device->systime = now;
device->devtime = array_uint32_le (*data + 2 + 1);
device->devtime = array_uint32_le (dc_buffer_get_data (buffer) + 1);
return DEVICE_STATUS_SUCCESS;
}
static device_status_t
uwatec_memomouse_dump (uwatec_memomouse_device_t *device, unsigned char *data[], unsigned int *size)
{
// Give the interface some time to notice the DTR
// line change from a previous transfer (if any).
serial_sleep (500);
// Set the DTR line.
if (serial_set_dtr (device->port, 1) == -1) {
WARNING ("Failed to set the RTS line.");
return DEVICE_STATUS_IO;
}
// Start the transfer.
device_status_t rc = uwatec_memomouse_dump_internal (device, data, size);
// Clear the DTR line again.
if (serial_set_dtr (device->port, 0) == -1) {
WARNING ("Failed to set the RTS line.");
return DEVICE_STATUS_IO;
}
return rc;
}
static device_status_t
uwatec_memomouse_device_dump (device_t *abstract, dc_buffer_t *buffer)
{
@ -525,47 +465,51 @@ uwatec_memomouse_device_dump (device_t *abstract, dc_buffer_t *buffer)
return DEVICE_STATUS_MEMORY;
}
unsigned int len = 0;
unsigned char *buf = NULL;
device_status_t rc = uwatec_memomouse_dump (device, &buf, &len);
if (rc != DEVICE_STATUS_SUCCESS)
return rc;
// Give the interface some time to notice the DTR
// line change from a previous transfer (if any).
serial_sleep (500);
if (!dc_buffer_append (buffer, buf + 2, len - 3)) {
WARNING ("Insufficient buffer space available.");
free (buffer);
return DEVICE_STATUS_MEMORY;
// Set the DTR line.
if (serial_set_dtr (device->port, 1) == -1) {
WARNING ("Failed to set the RTS line.");
return DEVICE_STATUS_IO;
}
free (buffer);
// Start the transfer.
device_status_t rc = uwatec_memomouse_dump_internal (device, buffer);
return DEVICE_STATUS_SUCCESS;
// Clear the DTR line again.
if (serial_set_dtr (device->port, 0) == -1) {
WARNING ("Failed to set the RTS line.");
return DEVICE_STATUS_IO;
}
return rc;
}
static device_status_t
uwatec_memomouse_device_foreach (device_t *abstract, dive_callback_t callback, void *userdata)
{
uwatec_memomouse_device_t *device = (uwatec_memomouse_device_t*) abstract;
if (! device_is_uwatec_memomouse (abstract))
return DEVICE_STATUS_TYPE_MISMATCH;
unsigned int length = 0;
unsigned char *buffer = NULL;
device_status_t rc = uwatec_memomouse_dump (device, &buffer, &length);
if (rc != DEVICE_STATUS_SUCCESS)
return rc;
dc_buffer_t *buffer = dc_buffer_new (0);
if (buffer == NULL)
return DEVICE_STATUS_MEMORY;
rc = uwatec_memomouse_extract_dives (abstract, buffer + 2, length - 3, callback, userdata);
device_status_t rc = uwatec_memomouse_device_dump (abstract, buffer);
if (rc != DEVICE_STATUS_SUCCESS) {
free (buffer);
dc_buffer_free (buffer);
return rc;
}
free (buffer);
rc = uwatec_memomouse_extract_dives (abstract,
dc_buffer_get_data (buffer), dc_buffer_get_size (buffer), callback, userdata);
return DEVICE_STATUS_SUCCESS;
dc_buffer_free (buffer);
return rc;
}