Limit number of sources to 1000

Author: momchil-flex

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 ### Changed
+- Limited number of distinct sources to 1000. In cases where a complicated spatial dependence of the source is desired, a ``CustomFieldSource`` or a ``CustomCurrentSource`` can be used instead of multiple distinct sources.
 
 ### Fixed
 - Properly handle `.freqs` in `output_monitors` of adjoint plugin.

tests/test_components/test_simulation.py

@@ -7,7 +7,7 @@
 import tidy3d as td
 from tidy3d.exceptions import SetupError, ValidationError, Tidy3dKeyError
 from tidy3d.components import simulation
-from tidy3d.components.simulation import MAX_NUM_MEDIUMS
+from tidy3d.components.simulation import MAX_NUM_MEDIUMS, MAX_NUM_SOURCES
 from ..utils import assert_log_level, SIM_FULL, log_capture, run_emulated
 from tidy3d.constants import LARGE_NUMBER
 
@@ -492,6 +492,7 @@ def test_validate_components_none():
 
     assert SIM._structures_not_at_edges(val=None, values=SIM.dict()) is None
     assert SIM._validate_num_mediums(val=None) is None
+    assert SIM._validate_num_sources(val=None) is None
     assert SIM._warn_monitor_mediums_frequency_range(val=None, values=SIM.dict()) is None
     assert SIM._warn_monitor_simulation_frequency_range(val=None, values=SIM.dict()) is None
     assert SIM._warn_grid_size_too_small(val=None, values=SIM.dict()) is None
@@ -1179,6 +1180,22 @@ def test_num_mediums():
         )
 
 
+def test_num_sources():
+    """Make sure we error if too many sources supplied."""
+
+    src = td.PlaneWave(
+        source_time=td.GaussianPulse(freq0=2.5e14, fwidth=1e13),
+        center=(0, 0, 0),
+        size=(td.inf, td.inf, 0),
+        direction="+",
+    )
+
+    _ = td.Simulation(size=(5, 5, 5), run_time=1e-12, sources=[src] * MAX_NUM_SOURCES)
+
+    with pytest.raises(pydantic.ValidationError):
+        _ = td.Simulation(size=(5, 5, 5), run_time=1e-12, sources=[src] * (MAX_NUM_SOURCES + 1))
+
+
 def _test_names_default():
     """makes sure default names are set"""
 

tidy3d/components/simulation.py

@@ -55,6 +55,9 @@
 # maximum number of mediums supported
 MAX_NUM_MEDIUMS = 65530
 
+# maximum number of sources
+MAX_NUM_SOURCES = 1000
+
 # maximum geometry count in a single structure
 MAX_GEOMETRY_COUNT = 100
 
@@ -445,6 +448,22 @@ def _validate_num_mediums(cls, val):
 
         return val
 
+    @pydantic.validator("sources", always=True)
+    def _validate_num_sources(cls, val):
+        """Error if too many sources present."""
+
+        if val is None:
+            return val
+
+        if len(val) > MAX_NUM_SOURCES:
+            raise SetupError(
+                f"Number of distinct sources exceeds the maximum allowed {MAX_NUM_SOURCES}. "
+                "For a complex source setup, consider using 'CustomFieldSource' or "
+                "'CustomCurrentSource' to combine multiple sources into one object."
+            )
+
+        return val
+
     @pydantic.validator("structures", always=True)
     def _validate_num_geometries(cls, val):
         """Error if too many geometries in a single structure."""