r.patch: implement parallelization with OpenMP (#1782)

raster/r.patch/Makefile

@@ -2,8 +2,9 @@ MODULE_TOPDIR = ../..
 
 PGM = r.patch
 
-LIBES = $(RASTERLIB) $(GISLIB)
+LIBES = $(RASTERLIB) $(GISLIB) $(OMPLIB)
 DEPENDENCIES = $(RASTERDEP) $(GISDEP)
+EXTRA_CFLAGS = $(OMPCFLAGS)
 
 include $(MODULE_TOPDIR)/include/Make/Module.make
 

raster/r.patch/benchmark/benchmark_r_patch.py

@@ -0,0 +1,82 @@
+"""Benchmarking of r.patch
+
+@author Aaron Saw Min Sern
+"""
+
+from grass.exceptions import CalledModuleError
+from grass.pygrass.modules import Module
+from subprocess import DEVNULL
+
+import grass.benchmark as bm
+
+
+def main():
+    results = []
+
+    # Users can add more or modify existing reference maps
+    benchmark(7071, "r.patch_50M", results)
+    benchmark(14142, "r.patch_200M", results)
+    benchmark(10000, "r.patch_100M", results)
+    benchmark(20000, "r.patch_400M", results)
+
+    bm.nprocs_plot(results, filename="rpatch_benchmark.svg")
+
+
+def benchmark(size, label, results):
+    references = ["r_patch_reference_map_{}".format(i) for i in range(4)]
+    output = "benchmark_r_patch"
+
+    generate_map(rows=size, cols=size, fname=references)
+    module = Module(
+        "r.patch",
+        input=references,
+        output=output,
+        run_=False,
+        stdout_=DEVNULL,
+        overwrite=True,
+    )
+    results.append(bm.benchmark_nprocs(module, label=label, max_nprocs=24, repeat=3))
+    for r in references:
+        Module("g.remove", quiet=True, flags="f", type="raster", name=r)
+    Module("g.remove", quiet=True, flags="f", type="raster", name=output)
+
+
+def generate_map(rows, cols, fname):
+    temp = "r_patch_reference_tmp"
+
+    Module("g.region", flags="p", s=0, n=rows, w=0, e=cols, res=1)
+    # Generate using r.random.surface if r.surf.fractal fails
+    try:
+        print("Generating reference map using r.surf.fractal...")
+        for r in fname:
+            Module(
+                "r.surf.fractal",
+                output=temp,
+                overwrite=True,
+            )
+            # Make approximate half of the reference map to be null
+            Module(
+                "r.mapcalc",
+                expression=f"{r} = if({temp}, {temp}, 0, null())",
+                overwrite=True,
+            )
+    except CalledModuleError:
+        print("r.surf.fractal fails, using r.random.surface instead...")
+        for r in fname:
+            Module(
+                "r.random.surface",
+                maximum=255,
+                output=temp,
+                overwrite=True,
+            )
+            Module(
+                "r.mapcalc",
+                expression=f"{r} = if({temp} - 128, {temp}, 0, null())",
+                overwrite=True,
+            )
+
+    Module("g.remove", quiet=True, flags="f", type="raster", name=temp)
+
+
+if __name__ == "__main__":
+    main()

raster/r.patch/benchmark/benchmark_r_patch_memory.py

@@ -0,0 +1,84 @@
+"""Benchmarking of r.patch memory parameter
+
+@author Aaron Saw Min Sern
+@author Anna Petrasova
+"""
+
+from grass.exceptions import CalledModuleError
+from grass.pygrass.modules import Module
+from subprocess import DEVNULL
+
+import grass.benchmark as bm
+
+
+def main():
+    results = []
+
+    references = ["r_patch_reference_map_{}".format(i) for i in range(4)]
+    generate_map(rows=5000, cols=5000, fname=references)
+    # Users can add more or modify existing reference maps
+    benchmark(0, "r.patch_0MB", references, results)
+    benchmark(5, "r.patch_5MB", references, results)
+    benchmark(10, "r.patch_10MB", references, results)
+    benchmark(100, "r.patch_100MB", references, results)
+    benchmark(300, "r.patch_300MB", references, results)
+    for r in references:
+        Module("g.remove", quiet=True, flags="f", type="raster", name=r)
+    bm.nprocs_plot(results, filename="rpatch_benchmark_memory.svg")
+
+
+def benchmark(memory, label, references, results):
+    output = "benchmark_r_patch"
+
+    module = Module(
+        "r.patch",
+        input=references,
+        output=output,
+        memory=memory,
+        run_=False,
+        stdout_=DEVNULL,
+        overwrite=True,
+    )
+    results.append(bm.benchmark_nprocs(module, label=label, max_nprocs=24, repeat=10))
+    Module("g.remove", quiet=True, flags="f", type="raster", name=output)
+
+
+def generate_map(rows, cols, fname):
+    temp = "r_patch_reference_tmp"
+
+    Module("g.region", flags="p", s=0, n=rows, w=0, e=cols, res=1)
+    # Generate using r.random.surface if r.surf.fractal fails
+    try:
+        print("Generating reference map using r.surf.fractal...")
+        for r in fname:
+            Module(
+                "r.surf.fractal",
+                output=temp,
+                overwrite=True,
+            )
+            # Make approximate half of the reference map to be null
+            Module(
+                "r.mapcalc",
+                expression=f"{r} = if({temp}, {temp}, 0, null())",
+                overwrite=True,
+            )
+    except CalledModuleError:
+        print("r.surf.fractal fails, using r.random.surface instead...")
+        for r in fname:
+            Module(
+                "r.random.surface",
+                maximum=255,
+                output=temp,
+                overwrite=True,
+            )
+            Module(
+                "r.mapcalc",
+                expression=f"{r} = if({temp} - 128, {temp}, 0, null())",
+                overwrite=True,
+            )
+
+    Module("g.remove", quiet=True, flags="f", type="raster", name=temp)
+
+
+if __name__ == "__main__":
+    main()