libdc/src/iostream.c
Jef Driesen 3ca27995e1 Add a new abstract I/O interface
The purpose of the new I/O interface is to provide a common interface
for all existing I/O implementations (serial, IrDA, bluetooth and USB
HID). With a common interface the dive computer backends can more easily
use different I/O implementations at runtime, without needing
significant code changes. For example bluetooth enabled devices can
easily switch between native bluetooth communication and serial port
emulation mode.

The new interface is modelled after the existing serial communication
api. Implementations where some of those functions are meaningless (e.g.
IrDA, bluetooth and USB), can just leave those functions unimplemented
(causing the call to fail with DC_STATUS_UNSUPPORTED), or implement it
as a no-op (always return DC_STATUS_SUCCESS).
2017-11-25 10:26:49 +01:00

255 lines
6.4 KiB
C

/*
* libdivecomputer
*
* Copyright (C) 2016 Jef Driesen
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include <stddef.h>
#include <stdlib.h>
#include <assert.h>
#include "iostream-private.h"
#include "context-private.h"
dc_iostream_t *
dc_iostream_allocate (dc_context_t *context, const dc_iostream_vtable_t *vtable)
{
dc_iostream_t *iostream = NULL;
assert(vtable != NULL);
assert(vtable->size >= sizeof(dc_iostream_t));
// Allocate memory.
iostream = (dc_iostream_t *) malloc (vtable->size);
if (iostream == NULL) {
ERROR (context, "Failed to allocate memory.");
return iostream;
}
// Initialize the base class.
iostream->vtable = vtable;
iostream->context = context;
return iostream;
}
void
dc_iostream_deallocate (dc_iostream_t *iostream)
{
free (iostream);
}
int
dc_iostream_isinstance (dc_iostream_t *iostream, const dc_iostream_vtable_t *vtable)
{
if (iostream == NULL)
return 0;
return iostream->vtable == vtable;
}
dc_status_t
dc_iostream_set_timeout (dc_iostream_t *iostream, int timeout)
{
if (iostream == NULL || iostream->vtable->set_timeout == NULL)
return DC_STATUS_UNSUPPORTED;
INFO (iostream->context, "Timeout: value=%i", timeout);
return iostream->vtable->set_timeout (iostream, timeout);
}
dc_status_t
dc_iostream_set_latency (dc_iostream_t *iostream, unsigned int value)
{
if (iostream == NULL || iostream->vtable->set_latency == NULL)
return DC_STATUS_UNSUPPORTED;
INFO (iostream->context, "Latency: value=%i", value);
return iostream->vtable->set_latency (iostream, value);
}
dc_status_t
dc_iostream_set_halfduplex (dc_iostream_t *iostream, unsigned int value)
{
if (iostream == NULL || iostream->vtable->set_halfduplex == NULL)
return DC_STATUS_UNSUPPORTED;
INFO (iostream->context, "Halfduplex: value=%i", value);
return iostream->vtable->set_halfduplex (iostream, value);
}
dc_status_t
dc_iostream_set_break (dc_iostream_t *iostream, unsigned int value)
{
if (iostream == NULL || iostream->vtable->set_break == NULL)
return DC_STATUS_UNSUPPORTED;
INFO (iostream->context, "Break: value=%i", value);
return iostream->vtable->set_break (iostream, value);
}
dc_status_t
dc_iostream_set_dtr (dc_iostream_t *iostream, unsigned int value)
{
if (iostream == NULL || iostream->vtable->set_dtr == NULL)
return DC_STATUS_UNSUPPORTED;
INFO (iostream->context, "DTR: value=%i", value);
return iostream->vtable->set_dtr (iostream, value);
}
dc_status_t
dc_iostream_set_rts (dc_iostream_t *iostream, unsigned int value)
{
if (iostream == NULL || iostream->vtable->set_rts == NULL)
return DC_STATUS_UNSUPPORTED;
INFO (iostream->context, "RTS: value=%i", value);
return iostream->vtable->set_rts (iostream, value);
}
dc_status_t
dc_iostream_get_lines (dc_iostream_t *iostream, unsigned int *value)
{
if (iostream == NULL || iostream->vtable->get_lines == NULL)
return DC_STATUS_UNSUPPORTED;
return iostream->vtable->get_lines (iostream, value);
}
dc_status_t
dc_iostream_get_available (dc_iostream_t *iostream, size_t *value)
{
if (iostream == NULL || iostream->vtable->get_available == NULL)
return DC_STATUS_UNSUPPORTED;
return iostream->vtable->get_available (iostream, value);
}
dc_status_t
dc_iostream_configure (dc_iostream_t *iostream, unsigned int baudrate, unsigned int databits, dc_parity_t parity, dc_stopbits_t stopbits, dc_flowcontrol_t flowcontrol)
{
if (iostream == NULL || iostream->vtable->configure == NULL)
return DC_STATUS_UNSUPPORTED;
INFO (iostream->context, "Configure: baudrate=%i, databits=%i, parity=%i, stopbits=%i, flowcontrol=%i",
baudrate, databits, parity, stopbits, flowcontrol);
return iostream->vtable->configure (iostream, baudrate, databits, parity, stopbits, flowcontrol);
}
dc_status_t
dc_iostream_read (dc_iostream_t *iostream, void *data, size_t size, size_t *actual)
{
dc_status_t status = DC_STATUS_SUCCESS;
size_t nbytes = 0;
if (iostream == NULL || iostream->vtable->read == NULL) {
status = DC_STATUS_UNSUPPORTED;
goto out;
}
status = iostream->vtable->read (iostream, data, size, &nbytes);
HEXDUMP (iostream->context, DC_LOGLEVEL_INFO, "Read", (unsigned char *) data, nbytes);
out:
if (actual)
*actual = nbytes;
return status;
}
dc_status_t
dc_iostream_write (dc_iostream_t *iostream, const void *data, size_t size, size_t *actual)
{
dc_status_t status = DC_STATUS_SUCCESS;
size_t nbytes = 0;
if (iostream == NULL || iostream->vtable->read == NULL) {
status = DC_STATUS_UNSUPPORTED;
goto out;
}
status = iostream->vtable->write (iostream, data, size, &nbytes);
HEXDUMP (iostream->context, DC_LOGLEVEL_INFO, "Write", (const unsigned char *) data, nbytes);
out:
if (actual)
*actual = nbytes;
return status;
}
dc_status_t
dc_iostream_flush (dc_iostream_t *iostream)
{
if (iostream == NULL || iostream->vtable->flush == NULL)
return DC_STATUS_UNSUPPORTED;
INFO (iostream->context, "Flush: none");
return iostream->vtable->flush (iostream);
}
dc_status_t
dc_iostream_purge (dc_iostream_t *iostream, dc_direction_t direction)
{
if (iostream == NULL || iostream->vtable->purge == NULL)
return DC_STATUS_UNSUPPORTED;
INFO (iostream->context, "Purge: direction=%u", direction);
return iostream->vtable->purge (iostream, direction);
}
dc_status_t
dc_iostream_sleep (dc_iostream_t *iostream, unsigned int milliseconds)
{
if (iostream == NULL || iostream->vtable->sleep == NULL)
return DC_STATUS_UNSUPPORTED;
INFO (iostream->context, "Sleep: value=%u", milliseconds);
return iostream->vtable->sleep (iostream, milliseconds);
}
dc_status_t
dc_iostream_close (dc_iostream_t *iostream)
{
dc_status_t status = DC_STATUS_SUCCESS;
if (iostream == NULL)
return DC_STATUS_SUCCESS;
if (iostream->vtable->close) {
status = iostream->vtable->close (iostream);
}
dc_iostream_deallocate (iostream);
return status;
}