#74 Define go -> cgo -> cuda interface

.gitignore

@@ -12,3 +12,5 @@ node_modules/
 initial-rank
 initial_guess_impact_results
 *enwiki*
+*.so
+*.o

cosmos/poc/cuda/README.md

@@ -0,0 +1,14 @@
+# Cuda support
+
+## Install required libs
+```bash
+
+```
+
+## Development 
+To execute cuda code run.
+
+```bash
+nvcc -shared -o librank.so rank.cu --compiler-options '-fPIC' && sudo cp librank.so /usr/lib/
+go run *.go
+```

cosmos/poc/cuda/rank.cu

@@ -0,0 +1,17 @@
+#include <stdint.h>
+#include <stdio.h>
+#include "types.h"
+
+extern "C" {
+
+    void calculate_rank(
+        uint64_t *stakes, uint64_t stakesSize, /* User stakes and corresponding array size */
+        cid *cids, uint64_t cidsSize, /* Cids links */
+        cid_link *inLinks, cid_link *outLinks /* Incoming and Outgoing cids links */
+    ) {
+
+        for(int i = 0; i < stakesSize; i++) {
+            printf("%lu \n", stakes[i]);
+        }
+    }
+};

cosmos/poc/cuda/rank.h

@@ -0,0 +1,8 @@
+#include <stdint.h>
+#include "types.h"
+
+void calculate_rank(
+    uint64_t *stakes, uint64_t stakesSize, /* User stakes and corresponding array size */
+    cid **cids, uint64_t cidsSize, /* Cids links */
+    cid_link **inLinks, cid_link **outLinks /* Incoming and Outgoing cids links */
+);

cosmos/poc/cuda/test_type_compatibilities.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"unsafe"
+)
+
+/*
+#cgo CFLAGS: -I.
+#cgo LDFLAGS: -L. -lrank
+#cgo LDFLAGS: -lcudart
+#include "rank.h"
+*/
+import "C"
+
+type CidLink struct {
+	oppositeCidIndex uint64
+	userIndex        uint64
+}
+
+type Cid struct {
+	inLinksStartIndex  uint64
+	inLinksCount       uint64
+	outLinksStartIndex uint64
+	outLinksCount      uint64
+}
+
+func main() {
+
+	/* --- Stakes ------------------------------------ */
+	stakes := make([]uint64, 2)
+
+	for i := range stakes {
+		stakes[i] = uint64(rand.Intn(30))
+	}
+
+	cStakes := (*C.ulong)(&stakes[0])
+	cStakesLen := C.ulong(len(stakes))
+
+	/* --- Cids ------------------------------------   */
+	cids := make([]Cid, 10)
+
+	cCids := (**C.cid)(unsafe.Pointer(&cids[0]))
+	cCidsLen := C.ulong(len(cids))
+
+	/* --- Cids Links -------------------------------  */
+	inLinks := make([]CidLink, 100)
+	outLinks := make([]CidLink, 100)
+
+	cInLinks := (**C.cid_link)(unsafe.Pointer(&inLinks[0]))
+	cOutLinks := (**C.cid_link)(unsafe.Pointer(&outLinks[0]))
+
+	/* --- Run Computation --------------------------  */
+	fmt.Printf("Invoking cuda library...\n")
+	C.calculate_rank(
+		cStakes, cStakesLen,
+		cCids, cCidsLen,
+		cInLinks, cOutLinks,
+	)
+}

cosmos/poc/cuda/types.h

@@ -0,0 +1,22 @@
+#ifndef TYPES_HEADER_FILE
+#define TYPES_HEADER_FILE
+
+#include <stdint.h>
+
+/* Go -> CGO passing types */
+typedef struct {
+    /* Index of opposite cid in cids array */
+    uint64_t opposite_cid_index;
+    /* Index of user stake in stakes array */
+    uint64_t user_index;
+} cid_link;
+
+typedef struct {
+	uint64_t in_links_start_index;
+	uint64_t in_links_count;
+
+	uint64_t out_links_start_index;
+	uint64_t out_links_count;
+} cid;
+
+#endif