better test coverage, edges deterministic, step server random

src/asyncflow/runtime/actors/edge.py

@@ -6,6 +6,8 @@
 waits the sampled delay (and any resource wait) before delivering the
 message to the target node's inbox.
 """
+
+
 from collections.abc import Container, Generator, Mapping
 from typing import TYPE_CHECKING
 
@@ -16,11 +18,14 @@
 from asyncflow.metrics.edge import build_edge_metrics
 from asyncflow.runtime.rqs_state import RequestState
 from asyncflow.samplers.common_helpers import general_sampler
+from asyncflow.schemas.common.random_variables import RVConfig
 from asyncflow.schemas.settings.simulation import SimulationSettings
 from asyncflow.schemas.topology.edges import Edge
 
 if TYPE_CHECKING:
-    from asyncflow.schemas.common.random_variables import RVConfig
+    from pydantic import PositiveFloat
+
+
 
 
 class EdgeRuntime:
@@ -73,7 +78,6 @@ def __init__( # Noqa: PLR0913
     def _deliver(self, state: RequestState) -> Generator[simpy.Event, None, None]:
         """Function to deliver the state to the next node"""
         # extract the random variables defining the latency of the edge
-        random_variable: RVConfig = self.edge_config.latency
 
         uniform_variable = self.rng.uniform()
         if uniform_variable < self.edge_config.dropout_rate:
@@ -85,9 +89,15 @@ def _deliver(self, state: RequestState) -> Generator[simpy.Event, None, None]:
             )
             return
 
+        # latency
+        latency: RVConfig | PositiveFloat = self.edge_config.latency
+
         self._concurrent_connections +=1
 
-        transit_time = general_sampler(random_variable, self.rng)
+        if isinstance(latency, RVConfig):
+            transit_time = general_sampler(latency, self.rng)
+        else:
+            transit_time = latency
 
 
         # Logic to add if exists the event injection for the given edge

src/asyncflow/runtime/actors/server.py

@@ -3,11 +3,13 @@
 during the simulation
 """
 
+
 from collections.abc import Generator
 from typing import cast
 
 import numpy as np
 import simpy
+from pydantic import PositiveFloat, PositiveInt
 
 from asyncflow.config.constants import (
     EndpointStepCPU,
@@ -22,6 +24,8 @@
 from asyncflow.resources.server_containers import ServerContainers
 from asyncflow.runtime.actors.edge import EdgeRuntime
 from asyncflow.runtime.rqs_state import RequestState
+from asyncflow.samplers.common_helpers import general_sampler
+from asyncflow.schemas.common.random_variables import RVConfig
 from asyncflow.schemas.settings.simulation import SimulationSettings
 from asyncflow.schemas.topology.nodes import Server
 
@@ -75,6 +79,45 @@ def __init__( # noqa: PLR0913
             settings.enabled_sample_metrics,
         )
 
+    # ------------------------------------------------------------------
+    # HELPERS
+    # ------------------------------------------------------------------
+
+    def _sample_duration(
+        self, time: RVConfig | PositiveFloat | PositiveInt,
+        ) -> float:
+        """
+        Return a non-negative duration in seconds.
+
+        - RVConfig -> sample via general_sampler(self.rng)
+        - float/int -> cast to float
+        - Negative draws are clamped to 0.0 (e.g., Normal tails).
+        """
+        if isinstance(time, RVConfig):
+            time = float(general_sampler(time, self.rng))
+        else:
+            time = float(time)
+
+        return time
+
+    def _compute_latency_cpu(
+        self,
+        cpu_time:PositiveFloat | PositiveInt | RVConfig,
+        ) -> float:
+        """Helper to compute the latency of a cpu bound given step"""
+        return self._sample_duration(cpu_time)
+
+    def _compute_latency_io(
+        self,
+        io_time:PositiveFloat | PositiveInt | RVConfig,
+        ) -> float:
+        """Helper to compute the latency of a IO bound given step"""
+        return self._sample_duration(io_time)
+
+    # -------------------------------------------------------------------
+    # Main function to elaborate a request
+    # -------------------------------------------------------------------
+
     # right now we disable the warnings but a refactor will be done soon
     def _handle_request( # noqa: PLR0915, PLR0912, C901
         self,
@@ -103,11 +146,12 @@ def _handle_request( # noqa: PLR0915, PLR0912, C901
 
 
         # Extract the total ram to execute the endpoint
-        total_ram = sum(
-            step.step_operation[StepOperation.NECESSARY_RAM]
-            for step in selected_endpoint.steps
-            if isinstance(step.kind, EndpointStepRAM)
-        )
+        total_ram = 0
+        for step in selected_endpoint.steps:
+            if isinstance(step.kind, EndpointStepRAM):
+                ram = step.step_operation[StepOperation.NECESSARY_RAM]
+                assert isinstance(ram, int)
+                total_ram += ram
 
         # ------------------------------------------------------------------
         # CPU & RAM SCHEDULING
@@ -226,15 +270,19 @@ def _handle_request( # noqa: PLR0915, PLR0912, C901
 
                     core_locked = True
 
-                cpu_time = step.step_operation[StepOperation.CPU_TIME]
+                cpu_time = self._compute_latency_cpu(
+                    step.step_operation[StepOperation.CPU_TIME],
+                )
                 # Execute the step giving back the control to the simpy env
                 yield self.env.timeout(cpu_time)
 
             # since the object is of an Enum class we check if the step.kind
             # is one member of enum
             elif isinstance(step.kind, EndpointStepIO):
                 # define the io time
-                io_time = step.step_operation[StepOperation.IO_WAITING_TIME]
+                io_time = self._compute_latency_io(
+                    step.step_operation[StepOperation.IO_WAITING_TIME],
+                    )
 
                 if core_locked:
                     # release the core coming from a cpu step

src/asyncflow/schemas/common/random_variables.py

@@ -1,28 +1,16 @@
 """Definition of the schema for a Random variable"""
 
-from pydantic import BaseModel, field_validator, model_validator
+from pydantic import BaseModel, NonNegativeFloat, model_validator
 
 from asyncflow.config.constants import Distribution
 
 
 class RVConfig(BaseModel):
     """class to configure random variables"""
 
-    mean: float
+    mean: NonNegativeFloat
     distribution: Distribution = Distribution.POISSON
-    variance: float | None = None
-
-    @field_validator("mean", mode="before")
-    def ensure_mean_is_numeric_and_positive(
-        cls, # noqa: N805
-        v: float,
-        ) -> float:
-        """Ensure `mean` is numeric, then coerce to float."""
-        err_msg = "mean must be a number (int or float)"
-        if not isinstance(v, (float, int)):
-            raise ValueError(err_msg)  # noqa: TRY004
-
-        return float(v)
+    variance: NonNegativeFloat | None = None
 
     @model_validator(mode="after")  # type: ignore[arg-type]
     def default_variance(cls, model: "RVConfig") -> "RVConfig":  # noqa: N805

src/asyncflow/schemas/topology/edges.py

@@ -3,12 +3,7 @@
 links between different nodes
 """
 
-from pydantic import (
-    BaseModel,
-    Field,
-    field_validator,
-    model_validator,
-)
+from pydantic import BaseModel, Field, PositiveFloat, field_validator, model_validator
 from pydantic_core.core_schema import ValidationInfo
 
 from asyncflow.config.constants import (
@@ -32,8 +27,9 @@ class Edge(BaseModel):
         Identifier of the source node (where the request comes from).
     target : str
         Identifier of the destination node (where the request goes to).
-    latency : RVConfig
-        Random-variable configuration for network latency on this link.
+    latency : RVConfig | PositiveFloat
+        Random-variable configuration for network latency on this link or
+        positive float value.
     probability : float
         Probability of taking this edge when there are multiple outgoing links.
         Must be in [0.0, 1.0]. Defaults to 1.0 (always taken).
@@ -45,7 +41,7 @@ class Edge(BaseModel):
     id: str
     source: str
     target: str
-    latency: RVConfig
+    latency: RVConfig | PositiveFloat
     edge_type: SystemEdges = SystemEdges.NETWORK_CONNECTION
     dropout_rate: float = Field(
         NetworkParameters.DROPOUT_RATE,
@@ -66,10 +62,13 @@ class Edge(BaseModel):
     @field_validator("latency", mode="after")
     def ensure_latency_is_non_negative(
         cls, # noqa: N805
-        v: RVConfig,
+        v: RVConfig | PositiveFloat,
         info: ValidationInfo,
-        ) -> RVConfig:
+        ) -> RVConfig | PositiveFloat:
         """Ensures that the latency's mean and variance are positive."""
+        if not isinstance(v, RVConfig):
+            return v
+
         mean = v.mean
         variance = v.variance
 
@@ -79,9 +78,10 @@ def ensure_latency_is_non_negative(
         if mean <= 0:
             msg = f"The mean latency of the edge '{edge_id}' must be positive"
             raise ValueError(msg)
+
         if variance is not None and variance < 0: # Variance can be zero
             msg = (
-                f"The variance of the latency of the edge {edge_id}"
+                f"The variance of the latency of the edge {edge_id} "
                 "must be non negative"
             )
             raise ValueError(msg)

src/asyncflow/schemas/topology/endpoint.py

@@ -14,6 +14,7 @@
     EndpointStepRAM,
     StepOperation,
 )
+from asyncflow.schemas.common.random_variables import RVConfig
 
 
 class Step(BaseModel):
@@ -23,7 +24,7 @@ class Step(BaseModel):
     """
 
     kind: EndpointStepIO | EndpointStepCPU | EndpointStepRAM
-    step_operation: dict[StepOperation, PositiveFloat | PositiveInt]
+    step_operation: dict[StepOperation, PositiveFloat | PositiveInt | RVConfig]
 
     @field_validator("step_operation", mode="before")
     def ensure_non_empty(
@@ -85,6 +86,55 @@ def ensure_coherence_type_operation(
 
         return model
 
+    @model_validator(mode="after")  # type: ignore[arg-type]
+    def ensure_cpu_io_positive_rv(cls, model: "Step") -> "Step":  # noqa: N805
+        """
+        For CPU/IO steps: if the operation is an RVConfig, require mean > 0
+        and variance ≥ 0. Deterministic PositiveFloat è già validato.
+        """
+        # safe anche se per qualche motivo ci fossero 0/2+ chiavi
+        op_val = next(iter(model.step_operation.values()), None)
+        if op_val is None:
+            return model
+
+        if isinstance(model.kind, EndpointStepCPU) and isinstance(op_val, RVConfig):
+            if op_val.mean <= 0:
+                msg = "CPU_TIME RVConfig.mean must be > 0"
+                raise ValueError(msg)
+            if op_val.variance is not None and op_val.variance < 0:
+                msg = "CPU_TIME RVConfig.variance must be >= 0"
+                raise ValueError(msg)
+
+        if isinstance(model.kind, EndpointStepIO) and isinstance(op_val, RVConfig):
+            if op_val.mean <= 0:
+                msg = "IO_WAITING_TIME RVConfig.mean must be > 0"
+                raise ValueError(msg)
+            if op_val.variance is not None and op_val.variance < 0:
+                msg = "IO_WAITING_TIME RVConfig.variance must be >= 0"
+                raise ValueError(msg)
+
+        return model
+
+    @model_validator(mode="after")  # type: ignore[arg-type]
+    def ensure_ram_positive_int(cls, model: "Step") -> "Step":  # noqa: N805
+        """For RAM steps: operation must be a positive integer (no RVs/floats)"""
+        if not isinstance(model.kind, EndpointStepRAM):
+            return model
+
+        op_val = next(iter(model.step_operation.values()), None)
+        if op_val is None:
+            return model
+
+        if isinstance(op_val, RVConfig) or not isinstance(op_val, int):
+            msg = "NECESSARY_RAM must be a positive integer"
+            raise TypeError(msg)
+
+        if op_val <= 0:
+            msg = "NECESSARY_RAM must be > 0"
+            raise ValueError(msg)
+
+        return model
+