Merge pull request #101 from JamieMair/100-when-a-model-cannot-be-loa…

…ded-returns-a-null-pointer-which-is-not-error-handled Added better error handling and more test coverage for loading models
JamieMair · Mar 4, 2024 · c7676d2 · c7676d2
2 parents e0acd5b + 847ffe8
commit c7676d2
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Showing 4 changed files with 102 additions and 5 deletions.
diff --git a/src/io.jl b/src/io.jl
@@ -38,14 +38,26 @@ function load_model(path::AbstractString, type::Symbol)
         throw(ArgumentError("Supplied model path could not be found. Path: $path"))
     end
 
+    absolute_path = abspath(path)
+
+
     !(type in (:MJCF, :MJB)) && error("The file type must be either MJCF or MJB.")
     mpointer = if type == :MJCF
-        error_msg = "Could not load XML model from $path"
-        LibMuJoCo.mj_loadXML(path, Ptr{Cvoid}(), error_msg, length(error_msg))
+        nbytes = 1000;
+        error_buffer = zeros(UInt8, nbytes);
+        mpointer = C_NULL
+        GC.@preserve error_buffer begin 
+            mpointer = LibMuJoCo.mj_loadXML(absolute_path, C_NULL, pointer(error_buffer), length(error_buffer))
+            if mpointer == C_NULL
+                error_str = unsafe_string(pointer(error_buffer))
+                error(error_str)
+            end
+        end
+        error_buffer = nothing # make sure the error_buffer is marked as unused
+        mpointer
     elseif type == :MJB
-        error_msg = "Could not load MJB model from $path"
-        mpointer = LibMuJoCo.mj_loadModel(path, Ptr{Cvoid}())
-        mpointer == C_NULL && error(error_msg)
+        mpointer = LibMuJoCo.mj_loadModel(absolute_path, C_NULL)
+        mpointer == C_NULL && error("Could not load MJB model from $absolute_path")
         mpointer
     end
 

diff --git a/test/configs/binary_cartpole.mjb b/test/configs/binary_cartpole.mjb
diff --git a/test/configs/broken_config.xml b/test/configs/broken_config.xml
@@ -0,0 +1,75 @@
+<!-- Cartpole Model
+
+State-Space (name/joint/parameter):
+
+- cart      slider      position (m)
+- pole      hinge       angle (rad)
+- cart      slider      velocity (m/s)
+- pole      hinge       angular velocity (rad/s)
+
+Actuators (name/actuator/parameter):
+
+- cart      motor       force x (N)
+-->
+<mujoco model='test_cartpole'>
+    <compiler inertiafromgeom='true' coordinate='local' />
+
+    <size nkey="1" />
+
+    <custom>
+        <numeric name="control_timestep" data="0.04" />
+        <numeric name="three_numbers" data="1.0 2.0 3.0" />
+    </custom>
+
+    <option timestep='0.01' />
+
+    <default>
+        <joint damping='0.05' solreflimit='.08 1' />
+        <geom contype='0' friction='1 0.1 0.1' />
+    </default>
+
+    <worldbody>
+        <camera name='fixed' pos='0 -2.5 0' quat='0.707 0.707 0 0' />
+        <geom name='floor' pos='0 0 -1' size='4 4 4' type='plane' />
+        <geom name='rail1' type='capsule' pos='0 .07 0' quat='0.707 0 0.707 0'
+            size='0.02 1.2' />
+        <geom name='rail2' type='capsule' pos='0 -.07 0' quat='0.707 0 0.707 0'
+            size='0.02 1.2' />
+        <body name='cart' pos='0 0 0'>
+            <camera name='cart' pos='0 -2.5 0' quat='0.707 0.707 0 0' />
+            <joint name='slider' type='slide' limited='true' pos='0 0 0'
+                axis='1 0 0' range='-1 1' />
+            <geom name='cart' type='box' pos='0 0 0'
+                size='0.2 0.1 0.05' rgba='0.7 0.7 0 1' />
+            <site name='cart sensor' type='box' pos='0 0 0'
+                size='0.2 0.1 0.05' rgba='0.7 0.7 0 0' />
+            <body name='pole' pos='0 0 0'>
+                <camera name='pole' pos='0 -2.5 0' quat='0.707 0.707 0 0' />
+                <joint name='hinge' type='hinge' pos='0 0 0' axis='0 1 0' />
+                <geom name='cpole' type='capsule' fromto='0 0 0 0 0 0.6'
+                    size='0.045 0.3' rgba='0 0.7 0.7 1' />
+                <site type='sphere' size='.01' name='tip' pos='.001 0 .6'
+            </body>
+        </body>
+        <body name='mocap1' pos='1 0 0.5' mocap='true'>
+            <geom name='mocap_cube' type='box' size='0.05 0.05 0.05' rgba='1 0 0 0.5' />
+        </body>
+        <body name='mocap2' pos='-1 0 0.5' mocap='true'>
+            <geom name='mocap_sphere' type='sphere' size='0.05' rgba='0 1 0 0.5' />
+        </body>
+    </worldbody>
+
+    <actuator>
+        <motor name='slide' joint='slider' gear='50' ctrllimited='true' ctrlrange='-1 1' />
+    </actuator>
+
+    <sensor>
+        <accelerometer name="accelerometer" site="cart sensor" />
+        <touch name="collision" site="cart sensor" />
+    </sensor>
+
+    <keyframe>
+        <key name="hanging_down" qpos="0 1.57" />
+    </keyframe>
+
+</mujoco>  
diff --git a/test/loading.jl b/test/loading.jl
@@ -4,6 +4,16 @@ using TestItemRunner
     @test load_model(MuJoCo.humanoid_model_file()) isa MuJoCo.Model
 end
 
+@testitem "Load Broken XML" begin
+    path = joinpath(@__DIR__, "configs", "broken_config.xml")
+    @test_throws Exception load_model(path)
+end
+
+@testitem "Load binary MuJoCo" begin
+    path = joinpath(@__DIR__, "configs", "binary_cartpole.mjb")
+    @test load_model(path) isa MuJoCo.Model
+end
+
 @testitem "Initialise Data" begin
     model = load_model(MuJoCo.humanoid_model_file())