chore: import upstream snapshot with attribution

ggml/src/ggml-virtgpu/apir_cs_ggml-rpc-front.cpp

@@ -0,0 +1,87 @@
+#include "backend/shared/apir_cs_rpc.h"
+#include "ggml-backend-impl.h"
+#include "ggml-impl.h"
+#include "ggml-remoting.h"
+
+#include <cinttypes>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+apir_rpc_tensor apir_serialize_tensor(const ggml_tensor * tensor) {
+    apir_rpc_tensor result;
+    result.id   = reinterpret_cast<uint64_t>(tensor);
+    result.type = tensor->type;
+    if (tensor->buffer) {
+        ggml_backend_buffer_t buffer = tensor->buffer;
+
+        result.buffer = BUFFER_TO_HOST_HANDLE(buffer);
+    } else {
+        result.buffer = 0;
+    }
+    for (uint32_t i = 0; i < GGML_MAX_DIMS; i++) {
+        result.ne[i] = tensor->ne[i];
+        result.nb[i] = tensor->nb[i];
+    }
+    result.op = tensor->op;
+    for (uint32_t i = 0; i < GGML_MAX_OP_PARAMS / sizeof(int32_t); i++) {
+        result.op_params[i] = tensor->op_params[i];
+    }
+    result.flags = tensor->flags;
+    for (uint32_t i = 0; i < GGML_MAX_SRC; i++) {
+        result.src[i] = reinterpret_cast<uint64_t>(tensor->src[i]);
+    }
+    result.view_src  = reinterpret_cast<uint64_t>(tensor->view_src);
+    result.view_offs = tensor->view_offs;
+    result.data      = reinterpret_cast<uint64_t>(tensor->data);
+    if (tensor->data) {
+        if (!tensor->buffer) {
+            GGML_ABORT("%s: tensor has data but not buffer", __func__);
+        }
+        // tensor->data is serialized as an offset to the buffer base address
+        result.data -= reinterpret_cast<uint64_t>(BUFFER_TO_GGML_CONTEXT(tensor->buffer)->base);
+    }
+    snprintf(result.name, GGML_MAX_NAME, "%s", tensor->name);
+    return result;
+}
+
+void apir_add_tensor(ggml_tensor *                       tensor,
+                     std::vector<apir_rpc_tensor> &      tensors,
+                     std::unordered_set<ggml_tensor *> & visited) {
+    if (tensor == nullptr) {
+        return;
+    }
+    if (visited.find(tensor) != visited.end()) {
+        return;
+    }
+    visited.insert(tensor);
+    for (int i = 0; i < GGML_MAX_SRC; i++) {
+        apir_add_tensor(tensor->src[i], tensors, visited);
+    }
+    apir_add_tensor(tensor->view_src, tensors, visited);
+    tensors.push_back(apir_serialize_tensor(tensor));
+}
+
+void apir_serialize_graph(const ggml_cgraph * cgraph, std::vector<uint8_t> & output) {
+    uint32_t                          n_nodes = cgraph->n_nodes;
+    std::vector<apir_rpc_tensor>      tensors;
+    std::unordered_set<ggml_tensor *> visited;
+    for (uint32_t i = 0; i < n_nodes; i++) {
+        apir_add_tensor(cgraph->nodes[i], tensors, visited);
+    }
+    // serialization format:
+    // | n_nodes (4 bytes) | nodes (n_nodes * sizeof(uint64_t) | n_tensors (4 bytes) | tensors (n_tensors * sizeof(apir_rpc_tensor)) |
+    uint32_t n_tensors = tensors.size();
+    int      output_size =
+        sizeof(uint32_t) + n_nodes * sizeof(uint64_t) + sizeof(uint32_t) + n_tensors * sizeof(apir_rpc_tensor);
+    output.resize(output_size, 0);
+    memcpy(output.data(), &n_nodes, sizeof(n_nodes));
+    for (uint32_t i = 0; i < n_nodes; i++) {
+        memcpy(output.data() + sizeof(n_nodes) + i * sizeof(uint64_t), &cgraph->nodes[i], sizeof(uint64_t));
+    }
+    uint32_t * out_ntensors = (uint32_t *) (output.data() + sizeof(n_nodes) + n_nodes * sizeof(uint64_t));
+    *out_ntensors           = n_tensors;
+    apir_rpc_tensor * out_tensors =
+        (apir_rpc_tensor *) (output.data() + sizeof(n_nodes) + n_nodes * sizeof(uint64_t) + sizeof(uint32_t));
+    memcpy(out_tensors, tensors.data(), n_tensors * sizeof(apir_rpc_tensor));
+}