python: Add digest-hook fifo format parsing

Signed-off-by: Philipp Jungkamp <Philipp.Jungkamp@opal-rt.com>

python/villas/node/digest.py

@@ -0,0 +1,117 @@
+"""
+Author: Philipp Jungkamp <Philipp.Jungkamp@opal-rt.com>
+SPDX-FileCopyrightText: 2023 OPAL-RT Germany GmbH
+SPDX-License-Identifier: Apache-2.0
+"""  # noqa: E501
+
+import hashlib
+from dataclasses import dataclass
+from typing import Iterable
+
+from villas.node.sample import Sample, Timestamp
+
+
+@dataclass
+class Frame(list[Sample]):
+    """
+    A frame VILLASnode of sample indicated by the new_frame flag.
+    """
+
+    def __init__(self, it: Iterable[Sample]):
+        super().__init__(it)
+
+    def __repr__(self) -> str:
+        return f"{self.__class__.__name__}({super().__repr__()})"
+
+    def _raw_digest(self, algorithm) -> bytes:
+        hash = hashlib.new(algorithm)
+
+        for sample in self:
+            hash.update(sample._as_digest_bytes())
+
+        return hash.digest()
+
+    def digest(self, algorithm: str) -> "Digest":
+        """
+        A digest for a frame of samples that is comparable to the digest hook.
+        """
+
+        return Digest.fromframe(self, algorithm)
+
+    def group(samples: list[Sample]) -> list["Frame"]:
+        """
+        Group samples into Frames according to their new_frame flag.
+        """
+
+        samples.sort()
+
+        if not samples:
+            return []
+
+        frames = []
+        current_frame = Frame([samples[0]])
+        for sample in samples[1:]:
+            if sample.new_frame:
+                frames.append(current_frame)
+                current_frame = Frame([sample])
+            else:
+                current_frame.append(sample)
+        frames.append(current_frame)
+
+        return frames
+
+
+@dataclass
+class Digest:
+    first: tuple[Timestamp, int]
+    last: tuple[Timestamp, int]
+    algorithm: str
+    bytes: bytes
+
+    @staticmethod
+    def fromframe(frame: Frame, algorithm: str) -> "Digest":
+        first = frame[0]
+        last = frame[-1]
+
+        def isnone(x):
+            return x is None
+
+        if any(map(isnone, [first.ts_origin, last.ts_origin])):
+            raise ValueError("Missing origin timestamp for digest.")
+
+        if any(map(isnone, [first.sequence, last.sequence])):
+            raise ValueError("Missing sequence number for digest.")
+
+        return Digest(
+            first=(first.ts_origin, first.sequence),  # type: ignore[arg-type]
+            last=(last.ts_origin, last.sequence),  # type: ignore[arg-type]
+            algorithm=algorithm,
+            bytes=frame._raw_digest(algorithm),
+        )
+
+    @staticmethod
+    def _parse_timestamp(s: str) -> tuple[Timestamp, int]:
+        ts, seq = s.split("-")
+        sec, nsec = ts.split(".")
+        return Timestamp(seconds=int(sec), nanoseconds=int(nsec)), int(seq)
+
+    @staticmethod
+    def parse(s: str) -> "Digest":
+        first, last, algorithm, digest = s.split(" ")
+        return Digest(
+            first=Digest._parse_timestamp(first),
+            last=Digest._parse_timestamp(last),
+            algorithm=algorithm,
+            bytes=bytes.fromhex(digest),
+        )
+
+    @staticmethod
+    def _dump_timestamp(timestamp: Timestamp, sequence: int) -> str:
+        return f"{timestamp.seconds}.{timestamp.nanoseconds}-{sequence}"
+
+    def dump(self) -> str:
+        first = Digest._dump_timestamp(*self.first)
+        last = Digest._dump_timestamp(*self.last)
+        algorithm = self.algorithm
+        digest = self.bytes.hex().upper()
+        return f"{first} {last} {algorithm} {digest}"

python/villas/node/formats.py

@@ -9,7 +9,7 @@ from dataclasses import dataclass, field
 from itertools import groupby
 from typing import Iterable
 
-from villas.node.sample import Sample, Timestamp, Signal
+from villas.node.sample import Sample, Signal, Timestamp
 
 
 class SignalList(list[type]):

python/villas/node/sample.py

@@ -5,13 +5,11 @@ SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Syst
 SPDX-License-Identifier: Apache-2.0
 """  # noqa: E501
 
-import hashlib
 from ctypes import c_double, c_float, sizeof
 from dataclasses import dataclass, field
 from datetime import datetime, timezone
 from functools import total_ordering
 from sys import byteorder as native
-from typing import Iterable
 
 assert sizeof(c_float) == 4
 assert sizeof(c_double) == 8
@@ -133,50 +131,3 @@ class Sample:
             ]
             + list(map(signal_to_bytes, self.data))
         )
-
-
-@dataclass
-class Frame(list[Sample]):
-    """
-    A frame VILLASnode of sample indicated by the new_frame flag.
-    """
-
-    def __init__(self, it: Iterable[Sample]):
-        super().__init__(it)
-
-    def __repr__(self) -> str:
-        return f"{self.__class__.__name__}({super().__repr__()})"
-
-    def digest(self, algorithm: str) -> bytes:
-        """
-        A digest for a frame of samples that is comparable to the digest hook.
-        """
-
-        hash = hashlib.new(algorithm)
-
-        for sample in self:
-            hash.update(sample._as_digest_bytes())
-
-        return hash.digest()
-
-    def group(samples: list[Sample]) -> list["Frame"]:
-        """
-        Group samples into Frames according to their new_frame flag.
-        """
-
-        samples.sort()
-
-        if not samples:
-            return []
-
-        frames = []
-        current_frame = Frame([samples[0]])
-        for sample in samples[1:]:
-            if sample.new_frame:
-                frames.append(current_frame)
-                current_frame = Frame([sample])
-            else:
-                current_frame.append(sample)
-        frames.append(current_frame)
-
-        return frames

python/villas/node/test_digest.py

@@ -0,0 +1,111 @@
+"""
+Author: Philipp Jungkamp <Philipp.Jungkamp@opal-rt.com>
+SPDX-FileCopyrightText: 2023 OPAL-RT Germany GmbH
+SPDX-License-Identifier: Apache-2.0
+"""  # noqa: E501
+
+from cmath import sqrt
+
+from villas.node.digest import Digest, Frame
+from villas.node.sample import Sample, Timestamp
+
+
+def test_frame_repr():
+    smp1 = Sample(
+        ts_origin=Timestamp(123456780),
+        ts_received=Timestamp(123456781),
+        sequence=4,
+        new_frame=True,
+        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
+    )
+
+    smp2 = Sample(
+        ts_origin=Timestamp(123456789),
+        ts_received=Timestamp(123456790),
+        sequence=5,
+        new_frame=False,
+        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
+    )
+
+    frame = Frame([smp1, smp2])
+    assert frame == eval(repr(frame))
+
+
+def test_frame_group():
+    smp1 = Sample(
+        ts_origin=Timestamp(123456780),
+        ts_received=Timestamp(123456781),
+        sequence=4,
+        new_frame=True,
+        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
+    )
+
+    smp2 = Sample(
+        ts_origin=Timestamp(123456789),
+        ts_received=Timestamp(123456790),
+        sequence=5,
+        new_frame=False,
+        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
+    )
+
+    smp3 = Sample(
+        ts_origin=Timestamp(123456791),
+        ts_received=Timestamp(123456793),
+        sequence=6,
+        new_frame=True,
+        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
+    )
+
+    frames = list(Frame.group([smp1, smp2, smp3]))
+    assert len(frames) == 2
+    assert list(map(len, frames)) == [2, 1]
+    assert frames == [[smp1, smp2], [smp3]]
+
+
+def test_digest_fromframe():
+    smp1 = Sample(
+        ts_origin=Timestamp(123456780),
+        ts_received=Timestamp(123456781),
+        sequence=4,
+        new_frame=True,
+        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
+    )
+
+    smp2 = Sample(
+        ts_origin=Timestamp(123456789),
+        ts_received=Timestamp(123456790),
+        sequence=5,
+        new_frame=False,
+        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
+    )
+
+    algorithm = "sha256"
+
+    digest_hex = (
+        "a573e3b0953a1e4f69addf631d6229bb714d263b4f362f0847e96c3838c83217"  # noqa: E501
+    )
+
+    digest = Digest(
+        first=(Timestamp(123456780), 4),
+        last=(Timestamp(123456789), 5),
+        algorithm=algorithm,
+        bytes=bytes.fromhex(digest_hex),
+    )
+
+    assert Frame([smp1, smp2]).digest(algorithm) == digest
+
+
+def test_digest():
+    digest_str = "1695904705.856457323-0 1695904709.956060462-41 sha256 8E49482DDDAFF6E3B7411D7D20CA338002126FE109EC1BA5932C02FC5E7EFD23"  # noqa: E501
+
+    digest = Digest(
+        first=(Timestamp(1695904705, 856457323), 0),
+        last=(Timestamp(1695904709, 956060462), 41),
+        algorithm="sha256",
+        bytes=bytes.fromhex(
+            "8E49482DDDAFF6E3B7411D7D20CA338002126FE109EC1BA5932C02FC5E7EFD23"
+        ),  # noqa: E501
+    )
+
+    assert Digest.parse(digest_str) == digest
+    assert digest_str == digest.dump()

python/villas/node/test_formats.py

@@ -3,10 +3,12 @@ Author: Philipp Jungkamp <Philipp.Jungkamp@opal-rt.com>
 SPDX-FileCopyrightText: 2023 OPAL-RT Germany GmbH
 SPDX-License-Identifier: Apache-2.0
 """  # noqa: E501
-from villas.node.sample import Sample, Timestamp
-from villas.node.formats import SignalList, VillasHuman
+
 from cmath import sqrt
 
+from villas.node.formats import SignalList, VillasHuman
+from villas.node.sample import Sample, Timestamp
+
 
 def test_signal_list_repr():
     signal_list = SignalList("21fb2ic")

python/villas/node/test_sample.py

@@ -3,9 +3,11 @@ Author: Philipp Jungkamp <Philipp.Jungkamp@opal-rt.com>
 SPDX-FileCopyrightText: 2023 OPAL-RT Germany GmbH
 SPDX-License-Identifier: Apache-2.0
 """  # noqa: E501
-from villas.node.sample import Sample, Timestamp, Frame
-from datetime import datetime, timezone
+
 from cmath import sqrt
+from datetime import datetime, timezone
+
+from villas.node.sample import Sample, Timestamp
 
 
 def test_timestamp_repr():
@@ -93,78 +95,3 @@ def test_sample_as_digest_bytes():
     digest_bytes_hex = "15cd5b070000000000000000000000000400000000000000000000000000f03f00000000000000400000000000000840012a00000000000000000000000000803f"  # noqa: E501
     digest_bytes = bytes.fromhex(digest_bytes_hex)
     assert smp._as_digest_bytes() == digest_bytes, smp._as_digest_bytes().hex()
-
-
-def test_frame_repr():
-    smp1 = Sample(
-        ts_origin=Timestamp(123456780),
-        ts_received=Timestamp(123456781),
-        sequence=4,
-        new_frame=True,
-        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
-    )
-
-    smp2 = Sample(
-        ts_origin=Timestamp(123456789),
-        ts_received=Timestamp(123456790),
-        sequence=5,
-        new_frame=False,
-        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
-    )
-
-    frame = Frame([smp1, smp2])
-    assert frame == eval(repr(frame))
-
-
-def test_frame_group():
-    smp1 = Sample(
-        ts_origin=Timestamp(123456780),
-        ts_received=Timestamp(123456781),
-        sequence=4,
-        new_frame=True,
-        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
-    )
-
-    smp2 = Sample(
-        ts_origin=Timestamp(123456789),
-        ts_received=Timestamp(123456790),
-        sequence=5,
-        new_frame=False,
-        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
-    )
-
-    smp3 = Sample(
-        ts_origin=Timestamp(123456791),
-        ts_received=Timestamp(123456793),
-        sequence=6,
-        new_frame=True,
-        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
-    )
-
-    frames = list(Frame.group([smp1, smp2, smp3]))
-    assert len(frames) == 2
-    assert list(map(len, frames)) == [2, 1]
-    assert frames == [[smp1, smp2], [smp3]]
-
-
-def test_frame_digest():
-    smp1 = Sample(
-        ts_origin=Timestamp(123456780),
-        ts_received=Timestamp(123456781),
-        sequence=4,
-        new_frame=True,
-        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
-    )
-
-    smp2 = Sample(
-        ts_origin=Timestamp(123456789),
-        ts_received=Timestamp(123456790),
-        sequence=5,
-        new_frame=False,
-        data=[1.0, 2.0, 3.0, True, 42, sqrt(complex(-1))],
-    )
-
-    digest = bytes.fromhex(
-        "a573e3b0953a1e4f69addf631d6229bb714d263b4f362f0847e96c3838c83217"
-    )  # noqa: E501
-    assert Frame([smp1, smp2]).digest("sha256") == digest