3 files changed, 74 insertions, 0 deletions

diff --git a/Python/pywarpx/_libwarpx.py b/Python/pywarpx/_libwarpx.py
index 817f64da5..9ebbd262f 100755
--- a/Python/pywarpx/_libwarpx.py
+++ b/Python/pywarpx/_libwarpx.py
@@ -210,6 +210,7 @@ libwarpx.warpx_getGfieldCPLoVects_PML.restype = _LP_c_int
 libwarpx.warpx_getGfieldFP_PML.restype = _LP_LP_c_real
 libwarpx.warpx_getGfieldFPLoVects_PML.restype = _LP_c_int
 libwarpx.warpx_getParticleBoundaryBufferSize.restype = ctypes.c_int
+libwarpx.warpx_getParticleBoundaryBufferStructs.restype = _LP_LP_c_particlereal
 libwarpx.warpx_getParticleBoundaryBuffer.restype = _LP_LP_c_particlereal
 libwarpx.warpx_getParticleBoundaryBufferScrapedSteps.restype = _LP_LP_c_int
 
@@ -859,6 +860,50 @@ def get_particle_boundary_buffer_size(species_name, boundary):
     )
 
 
+def get_particle_boundary_buffer_structs(species_name, boundary, level):
+    '''
+
+    This returns a list of numpy arrays containing the particle struct data
+    for a species that has been scraped by a specific simulation boundary. The
+    particle data is represented as a structured numpy array and contains the
+    particle 'x', 'y', 'z', 'id', and 'cpu'.
+
+    The data for the numpy arrays are not copied, but share the underlying
+    memory buffer with WarpX. The numpy arrays are fully writeable.
+
+    Parameters
+    ----------
+
+        species_name : the species name that the data will be returned for
+        boundary     : the boundary from which to get the scraped particle data.
+                       In the form x/y/z_hi/lo or eb.
+        level        : Which AMR level to retrieve scraped particle data from.
+
+    Returns
+    -------
+
+        A List of numpy arrays.
+
+    '''
+
+    particles_per_tile = _LP_c_int()
+    num_tiles = ctypes.c_int(0)
+    data = libwarpx.warpx_getParticleBoundaryBufferStructs(
+            ctypes.c_char_p(species_name.encode('utf-8')),
+            _get_boundary_number(boundary), level,
+            ctypes.byref(num_tiles), ctypes.byref(particles_per_tile)
+    )
+
+    particle_data = []
+    for i in range(num_tiles.value):
+        arr = _array1d_from_pointer(data[i], _p_dtype, particles_per_tile[i])
+        particle_data.append(arr)
+
+    _libc.free(particles_per_tile)
+    _libc.free(data)
+    return particle_data
+
+
 def get_particle_boundary_buffer(species_name, boundary, comp_name, level):
     '''
 
@@ -879,6 +924,7 @@ def get_particle_boundary_buffer(species_name, boundary, comp_name, level):
                          timestep at which a particle was scraped will be
                          returned.
         level          : Which AMR level to retrieve scraped particle data from.
+
     Returns
     -------
 
diff --git a/Source/Python/WarpXWrappers.H b/Source/Python/WarpXWrappers.H
index 71eb5b4fd..dd7a648fc 100644
--- a/Source/Python/WarpXWrappers.H
+++ b/Source/Python/WarpXWrappers.H
@@ -114,6 +114,10 @@ extern "C" {
         const char* species_name, int boundary, int lev,
         int* num_tiles, int** particles_per_tile, const char* comp_name);
 
+    amrex::ParticleReal** warpx_getParticleBoundaryBufferStructs(
+            const char* species_name, int boundary, int lev,
+            int* num_tiles, int** particles_per_tile);
+
     void warpx_clearParticleBoundaryBuffer ();
 
   void warpx_ComputeDt ();
diff --git a/Source/Python/WarpXWrappers.cpp b/Source/Python/WarpXWrappers.cpp
index 9ee99e8ab..66db34497 100644
--- a/Source/Python/WarpXWrappers.cpp
+++ b/Source/Python/WarpXWrappers.cpp
@@ -607,6 +607,30 @@ extern "C"
         return data;
     }
 
+    amrex::ParticleReal** warpx_getParticleBoundaryBufferStructs(const char* species_name, int boundary, int lev,
+                     int* num_tiles, int** particles_per_tile)
+    {
+        const std::string name(species_name);
+        auto& particle_buffers = WarpX::GetInstance().GetParticleBoundaryBuffer();
+        auto& particle_buffer = particle_buffers.getParticleBuffer(species_name, boundary);
+
+        int i = 0;
+        for (amrex::ParIter<0,0,PIdx::nattribs, 0, amrex::PinnedArenaAllocator> pti(particle_buffer, lev); pti.isValid(); ++pti, ++i) {}
+
+        // *num_tiles = myspc.numLocalTilesAtLevel(lev);
+        *num_tiles = i;
+        *particles_per_tile = (int*) malloc(*num_tiles*sizeof(int));
+
+        amrex::ParticleReal** data = (amrex::ParticleReal**) malloc(*num_tiles*sizeof(typename WarpXParticleContainer::ParticleType*));
+        i = 0;
+        for (amrex::ParIter<0,0,PIdx::nattribs, 0, amrex::PinnedArenaAllocator> pti(particle_buffer, lev); pti.isValid(); ++pti, ++i) {
+            auto& aos = pti.GetArrayOfStructs();
+            data[i] = (amrex::ParticleReal*) aos.data();
+            (*particles_per_tile)[i] = pti.numParticles();
+        }
+        return data;
+    }
+
     void warpx_clearParticleBoundaryBuffer () {
         auto& particle_buffers = WarpX::GetInstance().GetParticleBoundaryBuffer();
         particle_buffers.clearParticles();