9 files changed, 153 insertions, 127 deletions

diff --git a/glucometerutils/drivers/contourusb.py b/glucometerutils/drivers/contourusb.py
index 5c9ed11..095f920 100644
--- a/glucometerutils/drivers/contourusb.py
+++ b/glucometerutils/drivers/contourusb.py
@@ -21,7 +21,7 @@ http://protocols.ascensia.com/Programming-Guide.aspx
 import datetime
 
 from glucometerutils import common
-from glucometerutils.support import contourusb, driver_base
+from glucometerutils.support import contourusb
 
 
 def _extract_timestamp(parsed_record, prefix=""):
@@ -41,11 +41,11 @@ def _extract_timestamp(parsed_record, prefix=""):
     )
 
 
-class Device(contourusb.ContourHidDevice, driver_base.GlucometerDriver):
+class Device(contourusb.ContourHidDevice):
     """Glucometer driver for FreeStyle Libre devices."""
 
-    USB_VENDOR_ID = 0x1A79  # type: int  # Bayer Health Care LLC Contour
-    USB_PRODUCT_ID = 0x6002  # type: int
+    def __init__(self, device):
+        self._hid_session = contourusb.ContourHidSession((0x1A79, 0x6002), device)
 
     def get_meter_info(self):
         self._get_info_record()
diff --git a/glucometerutils/drivers/fsinsulinx.py b/glucometerutils/drivers/fsinsulinx.py
index 5465b3a..a3e54fb 100644
--- a/glucometerutils/drivers/fsinsulinx.py
+++ b/glucometerutils/drivers/fsinsulinx.py
@@ -51,7 +51,8 @@ _InsulinxReading = collections.namedtuple(
 class Device(freestyle.FreeStyleHidDevice):
     """Glucometer driver for FreeStyle InsuLinux devices."""
 
-    USB_PRODUCT_ID = 0x3460
+    def __init__(self, device_path):
+        super().__init__(0x3460, device_path)
 
     def get_meter_info(self):
         """Return the device information in structured form."""
@@ -68,7 +69,7 @@ class Device(freestyle.FreeStyleHidDevice):
 
     def get_readings(self):
         """Iterate through the reading records in the device."""
-        for record in self._get_multirecord(b"$result?"):
+        for record in self._session.query_multirecord(b"$result?"):
             if not record or record[0] != _TYPE_GLUCOSE_READING:
                 continue
 
diff --git a/glucometerutils/drivers/fslibre.py b/glucometerutils/drivers/fslibre.py
index 4802673..2e37ec1 100644
--- a/glucometerutils/drivers/fslibre.py
+++ b/glucometerutils/drivers/fslibre.py
@@ -195,7 +195,8 @@ def _parse_arresult(record):
 class Device(freestyle.FreeStyleHidDevice):
     """Glucometer driver for FreeStyle Libre devices."""
 
-    USB_PRODUCT_ID = 0x3650
+    def __init__(self, device_path):
+        super().__init__(0x3650, device_path)
 
     def get_meter_info(self):
         """Return the device information in structured form."""
@@ -209,7 +210,7 @@ class Device(freestyle.FreeStyleHidDevice):
 
     def get_serial_number(self):
         """Overridden function as the command is not compatible."""
-        return self._send_text_command(b"$sn?").rstrip("\r\n")
+        return self._session.send_text_command(b"$sn?").rstrip("\r\n")
 
     def get_glucose_unit(self):  # pylint: disable=no-self-use
         """Returns the glucose unit of the device."""
@@ -221,7 +222,7 @@ class Device(freestyle.FreeStyleHidDevice):
 
         # First of all get the usually longer list of sensor readings, and
         # convert them to Readings objects.
-        for record in self._get_multirecord(b"$history?"):
+        for record in self._session.query_multirecord(b"$history?"):
             parsed_record = _parse_record(record, _HISTORY_ENTRY_MAP)
 
             if not parsed_record or parsed_record["errors"] != 0:
@@ -238,10 +239,10 @@ class Device(freestyle.FreeStyleHidDevice):
 
         # Then get the results of explicit scans and blood tests (and other
         # events).
-        for record in self._get_multirecord(b"$arresult?"):
+        for record in self._session.query_multirecord(b"$arresult?"):
             reading = _parse_arresult(record)
             if reading:
                 yield reading
 
     def zero_log(self):
-        self._send_text_command(b"$resetpatient")
+        self._session.send_text_command(b"$resetpatient")
diff --git a/glucometerutils/drivers/fsprecisionneo.py b/glucometerutils/drivers/fsprecisionneo.py
index 909fed8..379bdf4 100644
--- a/glucometerutils/drivers/fsprecisionneo.py
+++ b/glucometerutils/drivers/fsprecisionneo.py
@@ -56,7 +56,8 @@ _NeoReading = collections.namedtuple(
 class Device(freestyle.FreeStyleHidDevice):
     """Glucometer driver for FreeStyle Precision Neo devices."""
 
-    USB_PRODUCT_ID = 0x3850
+    def __init__(self, device_path):
+        super().__init__(0x3850, device_path)
 
     def get_meter_info(self):
         """Return the device information in structured form."""
@@ -74,7 +75,7 @@ class Device(freestyle.FreeStyleHidDevice):
 
     def get_readings(self):
         """Iterate through the reading records in the device."""
-        for record in self._get_multirecord(b"$result?"):
+        for record in self._session.query_multirecord(b"$result?"):
             cls = None
             if record and record[0] == _TYPE_GLUCOSE_READING:
                 cls = common.GlucoseReading
diff --git a/glucometerutils/support/contourusb.py b/glucometerutils/support/contourusb.py
index 9afb79d..6cd9442 100644
--- a/glucometerutils/support/contourusb.py
+++ b/glucometerutils/support/contourusb.py
@@ -15,13 +15,13 @@ import csv
 import datetime
 import logging
 import re
-from typing import Dict, Iterator, List, Text
+from typing import Dict, Iterator, List, Optional, Text, Tuple
 
 import construct
 
 from glucometerutils import exceptions
 from glucometerutils.exceptions import InvalidResponse
-from glucometerutils.support import hiddevice
+from glucometerutils.support import driver_base, hiddevice
 
 # regexr.com/4k6jb
 _HEADER_RECORD_RE = re.compile(
@@ -64,7 +64,7 @@ class FrameError(Exception):
     pass
 
 
-class ContourHidDevice(hiddevice.HidDevice):
+class ContourHidDevice(driver_base.GlucometerDriver):
     """Base class implementing the ContourUSB HID common protocol.
     """
 
@@ -77,11 +77,16 @@ class ContourHidDevice(hiddevice.HidDevice):
     mode_command = object()
     state = None
 
+    def __init__(self, usb_ids, device_path):
+        # type: (Tuple[int, int], Optional[Text]) -> None
+        super().__init__(device_path)
+        self._hid_session = hiddevice.HidSession(usb_ids, device_path)
+
     def read(self, r_size=blocksize):
         result = []
 
         while True:
-            data = self._read()
+            data = self._hid_session.read()
             dstr = data
             result.append(dstr[4 : data[3] + 4])
             if data[3] != self.blocksize - 4:
@@ -94,7 +99,7 @@ class ContourHidDevice(hiddevice.HidDevice):
         pad_length = self.blocksize - len(data)
         data += pad_length * b"\x00"
 
-        self._write(data)
+        self._hid_session.write(data)
 
     USB_VENDOR_ID = 0x1A79  # type: int  # Bayer Health Care LLC Contour
     USB_PRODUCT_ID = 0x6002  # type: int
diff --git a/glucometerutils/support/driver_base.py b/glucometerutils/support/driver_base.py
index 1caa960..d3e45b7 100644
--- a/glucometerutils/support/driver_base.py
+++ b/glucometerutils/support/driver_base.py
@@ -1,8 +1,13 @@
 from abc import ABC, abstractmethod
 from datetime import datetime
+from typing import Optional, Text
 
 
 class GlucometerDriver(ABC):
+    def __init__(self, device_path):
+        # type: (Optional[Text]) -> None
+        pass
+
     def connect(self):
         pass
 
diff --git a/glucometerutils/support/freestyle.py b/glucometerutils/support/freestyle.py
index 86c53d0..b1eb2d2 100644
--- a/glucometerutils/support/freestyle.py
+++ b/glucometerutils/support/freestyle.py
@@ -128,38 +128,31 @@ def convert_ketone_unit(raw_value):
     return raw_value / 18.0
 
 
-class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC):
-    """Base class implementing the FreeStyle HID common protocol.
-
-    This class implements opening, initializing the connection and sending
-    commands to the device, reading the response and confirming the checksums.
+ABBOTT_VENDOR_ID = 0x1A61
 
-    Commands sent to the devices over this protocol have a "message type"
-    prefixed to the command itself. Text command are usually sent with message
-    type 0x60, and the replied received with the same. Some devices may diverge
-    though.
-    """
 
-    TEXT_CMD = 0x60
-    TEXT_REPLY_CMD = 0x60
+class FreeStyleHidSession:
+    def __init__(
+        self, product_id, device_path, text_message_type, text_reply_message_type
+    ):
+        # type: (int, Optional[Text], int, int) -> None
 
-    USB_VENDOR_ID = 0x1A61  # type: int  # Abbott Diabetes Care
-    USB_PRODUCT_ID = None  # type: int
+        self._hid_session = hiddevice.HidSession(
+            (ABBOTT_VENDOR_ID, product_id), device_path
+        )
+        self._text_message_type = text_message_type
+        self._text_reply_message_type = text_reply_message_type
 
     def connect(self):
         """Open connection to the device, starting the knocking sequence."""
-        self._send_command(_INIT_COMMAND, b"")
-        response = self._read_response()
+        self.send_command(_INIT_COMMAND, b"")
+        response = self.read_response()
         if not _is_init_reply(response):
             raise exceptions.ConnectionFailed(
                 f"Connection error: unexpected message %{response[0]:02x}:{response[1].hex()}"
             )
 
-    def disconnect(self):
-        """Disconnect the device, nothing to be done."""
-        pass
-
-    def _send_command(self, message_type, command, encrypted=False):
+    def send_command(self, message_type, command, encrypted=False):
         # type: (int, bytes, bool) -> None
         """Send a raw command to the device.
 
@@ -178,12 +171,12 @@ class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC)
         )
 
         logging.debug("Sending packet: %r", usb_packet)
-        self._write(usb_packet)
+        self._hid_session.write(usb_packet)
 
-    def _read_response(self, encrypted=False):
+    def read_response(self, encrypted=False):
         # type: (bool) -> Tuple[int, bytes]
         """Read the response from the device and extracts it."""
-        usb_packet = self._read()
+        usb_packet = self._hid_session.read()
 
         logging.debug("Read packet: %r", usb_packet)
 
@@ -205,7 +198,7 @@ class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC)
         # unencrypted, so we need to inspect them before we decide what the
         # message content is.
         if _is_keepalive_response(message):
-            return self._read_response(encrypted=encrypted)
+            return self.read_response(encrypted=encrypted)
 
         if _is_unknown_message_error(message):
             raise exceptions.CommandError("Invalid command")
@@ -218,21 +211,21 @@ class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC)
 
         return message
 
-    def _send_text_command(self, command):
+    def send_text_command(self, command):
         # type: (bytes) -> Text
         """Send a command to the device that expects a text reply."""
-        self._send_command(self.TEXT_CMD, command)
+        self.send_command(self._text_message_type, command)
 
         # Reply can stretch multiple buffers
         full_content = b""
         while True:
-            message_type, content = self._read_response()
+            message_type, content = self.read_response()
 
             logging.debug(
                 "Received message: type %02x content %s", message_type, content.hex()
             )
 
-            if message_type != self.TEXT_REPLY_CMD:
+            if message_type != self._text_reply_message_type:
                 raise exceptions.InvalidResponse(
                     f"Message type {message_type:02x}: content does not match expectations: {content!r}"
                 )
@@ -258,22 +251,84 @@ class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC)
         # unknown codepoint.
         return message.decode("ascii", "replace")
 
+    def query_multirecord(self, command):
+        # type: (bytes) -> Iterator[List[Text]]
+        """Queries for, and returns, "multirecords" results.
+
+        Multirecords are used for querying events, readings, history and similar
+        other data out of a FreeStyle device. These are comma-separated values,
+        variable-length.
+
+        The validation includes the general HID framing parsing, as well as
+        validation of the record count, and of the embedded records checksum.
+
+        Args:
+          command: The text command to send to the device for the query.
+
+        Returns:
+          A CSV reader object that returns a record for each line in the
+          reply buffer.
+        """
+        message = self.send_text_command(command)
+        logging.debug("Received multirecord message:\n%s", message)
+        if message == "Log Empty\r\n":
+            return iter(())
+
+        match = _MULTIRECORDS_FORMAT.search(message)
+        if not match:
+            raise exceptions.InvalidResponse(message)
+
+        records_str = match.group("message")
+        _verify_checksum(records_str, match.group("checksum"))
+
+        logging.debug("Received multi-record string: %s", records_str)
+
+        return csv.reader(records_str.split("\r\n"))
+
+
+class FreeStyleHidDevice(driver_base.GlucometerDriver):
+    """Base class implementing the FreeStyle HID common protocol.
+
+    This class implements opening, initializing the connection and sending
+    commands to the device, reading the response and confirming the checksums.
+
+    Commands sent to the devices over this protocol have a "message type"
+    prefixed to the command itself. Text command are usually sent with message
+    type 0x60, and the replied received with the same. Some devices may diverge
+    though.
+    """
+
+    def __init__(self, product_id, device_path, text_cmd=0x60, text_reply_cmd=0x60):
+        # type: (int, Optional[Text], int, int) -> None
+        super().__init__(device_path)
+        self._session = FreeStyleHidSession(
+            product_id, device_path, text_cmd, text_reply_cmd
+        )
+
+    def connect(self):
+        """Open connection to the device, starting the knocking sequence."""
+        self._session.connect()
+
+    def disconnect(self):
+        """Disconnect the device, nothing to be done."""
+        pass
+
     # Some of the commands are also shared across devices that use this HID
     # protocol, but not many. Only provide here those that do seep to change
     # between them.
     def _get_version(self):
         # type: () -> Text
         """Return the software version of the device."""
-        return self._send_text_command(b"$swver?").rstrip("\r\n")
+        return self._session.send_text_command(b"$swver?").rstrip("\r\n")
 
     def get_serial_number(self):
         # type: () -> Text
         """Returns the serial number of the device."""
-        return self._send_text_command(b"$serlnum?").rstrip("\r\n")
+        return self._session.send_text_command(b"$serlnum?").rstrip("\r\n")
 
     def get_patient_name(self):
         # type: () -> Optional[Text]
-        patient_name = self._send_text_command(b"$ptname?").rstrip("\r\n")
+        patient_name = self._session.send_text_command(b"$ptname?").rstrip("\r\n")
         if not patient_name:
             return None
         return patient_name
@@ -285,7 +340,7 @@ class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC)
         except UnicodeDecodeError:
             raise ValueError("Only ASCII-safe names are tested working")
 
-        result = self._send_text_command(b"$ptname," + encoded_name)
+        result = self._session.send_text_command(b"$ptname," + encoded_name)
 
     def get_datetime(self):
         # type: () -> datetime.datetime
@@ -294,8 +349,8 @@ class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC)
         This is one of the few commands that appear common to many of the
         FreeStyle devices that use the HID framing protocol.
         """
-        date = self._send_text_command(b"$date?").rstrip("\r\n")
-        time = self._send_text_command(b"$time?").rstrip("\r\n")
+        date = self._session.send_text_command(b"$date?").rstrip("\r\n")
+        time = self._session.send_text_command(b"$time?").rstrip("\r\n")
 
         # Year is returned as an offset to 2000.
         month, day, year = (int(x) for x in date.split(","))
@@ -318,41 +373,7 @@ class FreeStyleHidDevice(hiddevice.HidDevice, driver_base.GlucometerDriver, ABC)
         date_cmd = f"$date,{date.month},{date.day},{date.year - 2000}"
         time_cmd = f"$time,{date.hour},{date.minute}"
 
-        self._send_text_command(bytes(date_cmd, "ascii"))
-        self._send_text_command(bytes(time_cmd, "ascii"))
+        self._session.send_text_command(bytes(date_cmd, "ascii"))
+        self._session.send_text_command(bytes(time_cmd, "ascii"))
 
         return self.get_datetime()
-
-    def _get_multirecord(self, command):
-        # type: (bytes) -> Iterator[List[Text]]
-        """Queries for, and returns, "multirecords" results.
-
-        Multirecords are used for querying events, readings, history and similar
-        other data out of a FreeStyle device. These are comma-separated values,
-        variable-length.
-
-        The validation includes the general HID framing parsing, as well as
-        validation of the record count, and of the embedded records checksum.
-
-        Args:
-          command: (bytes) the text command to send to the device for the query.
-
-        Returns:
-          (csv.reader): a CSV reader object that returns a record for each line
-             in the record file.
-        """
-        message = self._send_text_command(command)
-        logging.debug("Received multirecord message:\n%s", message)
-        if message == "Log Empty\r\n":
-            return iter(())
-
-        match = _MULTIRECORDS_FORMAT.search(message)
-        if not match:
-            raise exceptions.InvalidResponse(message)
-
-        records_str = match.group("message")
-        _verify_checksum(records_str, match.group("checksum"))
-
-        logging.debug("Received multi-record string: %s", records_str)
-
-        return csv.reader(records_str.split("\r\n"))
diff --git a/glucometerutils/support/hiddevice.py b/glucometerutils/support/hiddevice.py
index 43461e7..41ad17c 100644
--- a/glucometerutils/support/hiddevice.py
+++ b/glucometerutils/support/hiddevice.py
@@ -6,44 +6,34 @@
 
 import logging
 import os
-from typing import BinaryIO, Optional, Text
+from typing import BinaryIO, Optional, Text, Tuple
 
 from glucometerutils import exceptions
 
 
-class HidDevice:
-    """A device speaking USB HID protocol driver base.
+class HidSession:
+    """An access class to speak to USB HID based devices.
 
-    This class does not implement an actual driver by itself, but provides an
-    easier access to the boilerplate code required for speaking USB HID.
-
-    This helper wraps around an optional dependency on hidapi library: if
-    present the driver will auto-detect the device, if not the device path needs
-    to be provided and should point to a device implementing Linux's hidraw
-    interface.
-
-    The following constants can be set by the actual drivers:
-
-      USB_VENDOR_ID: (int) USB vendor ID for the device.
-      USB_PRODUCT_ID: (int) USB product ID for the device.
-
-    If the VID/PID pair is not provided, the driver will require a device path
-    to be used.
-
-    Optional parameters available:
-
-      TIMEOUT_MS: (int, default: 0) the read timeout in milliseconds, used
-        for hidapi reads only. If < 1, hidapi will be provided no timeout.
+    This class does not implement a full driver, but rather provide simpler read/write
+    methods abstracting the HID library.
     """
 
-    USB_VENDOR_ID = None  # type: int
-    USB_PRODUCT_ID = None  # type: int
+    def __init__(self, usb_id, device, timeout_ms=0):
+        # type: (Optional[Tuple[int, int]], Optional[Text], int) -> None
+        """Construct a new session object.
+
+        Args:
+          usb_id: Optional pair of vendor_id and product_id for the session.
+            This is required to use the hidapi library.
+          device: Optional path to Linux hidraw-style device path. If not provided,
+            usb_id needs to be provided instead.
+          timeout_ms: Timeout in milliseconds for read operations. Only relevant when
+            using hidapi library.
+        """
 
-    TIMEOUT_MS = 0  # type: int
+        self._timeout_ms = timeout_ms
 
-    def __init__(self, device):
-        # type: (Optional[Text]) -> None
-        if None in (self.USB_VENDOR_ID, self.USB_PRODUCT_ID) and not device:
+        if not usb_id and not device:
             raise exceptions.CommandLineError(
                 "--device parameter is required, should point to a /dev/hidraw "
                 "device node representing the meter."
@@ -63,8 +53,10 @@ class HidDevice:
             try:
                 import hid
 
+                assert usb_id
+                vendor_id, product_id = usb_id
                 self.hidapi_handle_ = hid.device()
-                self.hidapi_handle_.open(self.USB_VENDOR_ID, self.USB_PRODUCT_ID)
+                self.hidapi_handle_.open(vendor_id, product_id)
             except ImportError:
                 raise exceptions.ConnectionFailed(
                     message='Missing requied "hidapi" module.'
@@ -74,7 +66,7 @@ class HidDevice:
                     message=f"Unable to connect to meter: {e}."
                 )
 
-    def _write(self, report):
+    def write(self, report):
         # type: (bytes) -> None
         """Writes a report to the HID handle."""
 
@@ -86,7 +78,7 @@ class HidDevice:
         if written < 0:
             raise exceptions.CommandError()
 
-    def _read(self, size=64):
+    def read(self, size=64):
         # type: (int) -> bytes
         """Read a report from the HID handle.
 
@@ -96,4 +88,4 @@ class HidDevice:
         if self.handle_:
             return bytes(self.handle_.read(size))
 
-        return bytes(self.hidapi_handle_.read(size, timeout_ms=self.TIMEOUT_MS))
+        return bytes(self.hidapi_handle_.read(size, timeout_ms=self._timeout_ms))
diff --git a/reversing_tools/abbott/freestyle_hid_console.py b/reversing_tools/abbott/freestyle_hid_console.py
index 654a97c..0ed4705 100755
--- a/reversing_tools/abbott/freestyle_hid_console.py
+++ b/reversing_tools/abbott/freestyle_hid_console.py
@@ -45,11 +45,11 @@ def main():
 
     logging.basicConfig(level=args.vlog)
 
-    device = freestyle.FreeStyleHidDevice(args.device)
-    device.TEXT_CMD = args.text_cmd_type
-    device.TEXT_REPLY_CMD = args.text_reply_type
+    session = freestyle.FreeStyleHidSession(
+        None, args.device, args.text_cmd_type, args.text_reply_type
+    )
 
-    device.connect()
+    session.connect()
 
     while True:
         if sys.stdin.isatty():
@@ -59,7 +59,7 @@ def main():
             print(f">>> {command}")
 
         try:
-            print(device._send_text_command(bytes(command, "ascii")))
+            print(session.send_text_command(bytes(command, "ascii")))
         except exceptions.InvalidResponse as error:
             print(f"! {error}")