feat(MLRsearch): MLRsearch v7

Replaces MLRv2, suitable for "big bang" upgrade across CSIT.
PyPI metadata updated only partially (full edits will come separately).
Pylint wants less complexity, but the differences are only minor.

+ Use the same (new CSIT) defaults everywhere, also in Python library.
+ Update also PLRsearch to use the new result class.
+ Make upper bound optional in UTI.
+ Fix ASTF approximate duration detection.
+ Do not keep approximated_receive_rate (for MRR) in result structure.

Change-Id: I03406f32d5c93f56b527cb3f93791b61955dfd74
Signed-off-by: Vratko Polak <vrpolak@cisco.com>

1 files changed, 95 insertions, 0 deletions

diff --git a/resources/libraries/python/MLRsearch/target_spec.py b/resources/libraries/python/MLRsearch/target_spec.py
new file mode 100644
index 0000000000..5279ba00a1
--- /dev/null
+++ b/resources/libraries/python/MLRsearch/target_spec.py
@@ -0,0 +1,95 @@
+# Copyright (c) 2023 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Module defining TargetSpec class."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from typing import Optional
+
+from .discrete_width import DiscreteWidth
+
+
+@dataclass(frozen=True, eq=True)
+class TargetSpec:
+    """Composite object holding attributes specifying one search target.
+
+    Abstractly, this has several similar meanings.
+    With discrete_width attribute this specifies when a selector is Done.
+    With expansion_coefficient attribute it tells selector how quickly
+    should it expand interval in external search.
+    With "preceding" attribute it helps selector, so it does not need to point
+    to preceding target separately from its current target.
+    Without those three attributes this object is still sufficient
+    for LoadStats to classify loads as lower bound, upper bound, or unknown.
+    """
+
+    loss_ratio: float
+    """Target loss ratio. Equal and directly analogous to goal loss ratio,
+    but applicable also for non-final targets."""
+    exceed_ratio: float
+    """Target exceed ratio. Equal and directly analogous to goal exceed ratio,
+    but applicable also for non-final targets."""
+    discrete_width: DiscreteWidth
+    """Target relative width. Analogous to goal relative width,
+    but coarser for non-final targets."""
+    trial_duration: float
+    """Duration to use for trials for this target. Shorter trials have lesser
+    (and more complicated) impact when determining upper and lower bounds."""
+    duration_sum: float
+    """Sum of trial durations sufficient to classify a load
+    as an upper or lower bound.
+    For non-final targets, this is shorter than goal duration_sum."""
+    expansion_coefficient: int = field(repr=False)
+    """Equal and directly analogous to goal expansion coefficient,
+    but applicable also for non-final targets."""
+    fail_fast: bool = field(repr=False)
+    """Copied from goal. If true and min load is not an upper bound, raise."""
+    preceding: Optional[TargetSpec] = field(repr=False)
+    """Reference to next coarser target (if any) belonging to the same goal."""
+
+    # No conversions or validations, as this is an internal structure.
+
+    def __str__(self) -> str:
+        """Convert into a short human-readable string.
+
+        :returns: The short string.
+        :rtype: str
+        """
+        return (
+            f"lr={self.loss_ratio},er={self.exceed_ratio}"
+            f",ds={self.duration_sum}"
+        )
+
+    def with_preceding(self, preceding: Optional[TargetSpec]) -> TargetSpec:
+        """Create an equivalent instance but with different preceding field.
+
+        This is useful in initialization. Create semi-initialized targets
+        starting from final one, than add references in reversed order.
+
+        :param preceding: New value for preceding field, cannot be None.
+        :type preceding: Optional[TargetSpec]
+        :returns: Instance with the new value applied.
+        :rtype: TargetSpec
+        """
+        return TargetSpec(
+            loss_ratio=self.loss_ratio,
+            exceed_ratio=self.exceed_ratio,
+            discrete_width=self.discrete_width,
+            trial_duration=self.trial_duration,
+            duration_sum=self.duration_sum,
+            expansion_coefficient=self.expansion_coefficient,
+            fail_fast=self.fail_fast,
+            preceding=preceding,
+        )