support multi npu partially

csrc/idle_offload/npu_helper.h

@@ -0,0 +1,40 @@
+#include <vector>
+#include <string>
+#include <stdint.h>
+
+#include "spdlog/spdlog.h"
+
+#include "acl/acl.h"
+
+
+std::vector<int> get_npu_ids() {
+  std::vector<int> npu_ids;
+  uint32_t device_count = 0;
+  aclError error_code = aclrtGetDeviceCount(&device_count);
+  if (error_code != 0) {
+    spdlog::error("Failed to get NPU device count, error code: {}", error_code);
+    throw std::runtime_error("Failed to get NPU device count");
+  }
+
+  const char *env_available_npu = getenv("ASCEND_RT_VISIBLE_DEVICES");
+  if (env_available_npu) {
+    std::string npu_str(env_available_npu);
+    size_t start = 0;
+    while (start < npu_str.size()) {
+      size_t next = npu_str.find(',', start);
+      if (next == std::string::npos) {
+        next = npu_str.size();
+      }
+      npu_ids.push_back(std::stoi(npu_str.substr(start, next - start)));
+      start = next + 1;
+      if (npu_ids.size() >= device_count) {
+        break;
+      }
+    }
+  } else {
+    for (uint32_t i = 0; i < device_count; ++i) {
+      npu_ids.push_back(static_cast<int>(i));
+    }
+  }
+  return npu_ids;
+}