ASR_BASE

Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/external/subpack/net/nginx-util/src/ubus-cxx.hpp b/external/subpack/net/nginx-util/src/ubus-cxx.hpp
new file mode 100644
index 0000000..6c193cf
--- /dev/null
+++ b/external/subpack/net/nginx-util/src/ubus-cxx.hpp
@@ -0,0 +1,354 @@
+#ifndef _UBUS_CXX_HPP
+#define _UBUS_CXX_HPP
+
+#include <libubus.h>
+#include <cassert>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <utility>
+#include <vector>
+
+#ifndef NDEBUG
+#include <iostream>
+#endif
+
+namespace ubus {
+
+static constexpr int call_timeout = 500;
+
+using msg_ptr = std::shared_ptr<const blob_attr>;
+
+using strings = std::vector<std::string>;
+
+inline auto concat(strings dest)
+{
+    return dest;
+}
+
+template <class... Strings>
+inline auto concat(strings dest, strings src, Strings... more)
+{
+    dest.reserve(dest.size() + src.size());
+    dest.insert(std::end(dest), std::make_move_iterator(std::begin(src)),
+                std::make_move_iterator(std::end(src)));
+    return concat(std::move(dest), std::move(more)...);
+}
+
+template <class S, class... Strings>
+inline auto concat(strings dest, S src, Strings... more)
+{
+    dest.emplace_back(std::move(src));
+    return concat(std::move(dest), std::move(more)...);
+}
+
+class iterator {
+  private:
+    const strings& keys;
+
+    const size_t n = 0;
+
+    size_t i = 0;
+
+    const blob_attr* pos = nullptr;
+
+    std::unique_ptr<iterator> cur{};
+
+    iterator* parent = nullptr;
+
+    size_t rem = 0;
+
+    [[nodiscard]] inline auto matches() const -> bool
+    {
+        return (keys[i].empty() || blobmsg_name(cur->pos) == keys[i]);
+    }
+
+    explicit iterator(iterator* par)
+        : keys{par->keys}, n{par->n}, pos{par->pos}, cur{this}, parent{par}
+    {
+        if (pos != nullptr) {
+            rem = blobmsg_data_len(pos);
+            pos = static_cast<blob_attr*>(blobmsg_data(pos));
+        }
+    }
+
+  public:
+    explicit iterator(const blob_attr* msg, const strings& key_filter = {""})
+        : keys{key_filter}, n{keys.size() - 1}, pos{msg}, cur{this}
+    {
+        if (pos != nullptr) {
+            rem = blobmsg_data_len(pos);
+            pos = static_cast<blob_attr*>(blobmsg_data(pos));
+
+            if (rem == 0) {
+                pos = nullptr;
+            }
+            else if (i != n || !matches()) {
+                ++*this;
+            }
+        }
+    }
+
+    inline iterator(iterator&&) noexcept = default;
+
+    inline iterator(const iterator&) = delete;
+
+    inline auto operator=(const iterator&) -> iterator& = delete;
+
+    inline auto operator=(iterator &&) -> iterator& = delete;
+
+    inline auto operator*()
+    {
+        return cur->pos;
+    }
+
+    inline auto operator!=(const iterator& rhs)
+    {
+        return (cur->rem != rhs.cur->rem || cur->pos != rhs.cur->pos);
+    }
+
+    auto operator++() -> iterator&;
+
+    inline ~iterator()
+    {
+        if (cur.get() == this) {
+            static_cast<void>(cur.release());
+        }
+    }
+};
+
+class message {
+  private:
+    const msg_ptr msg{};  // initialized by callback.
+
+    const strings keys{};
+
+  public:
+    inline explicit message(msg_ptr message_ptr, strings key_filter = {""})
+        : msg{std::move(message_ptr)}, keys{std::move(key_filter)}
+    {}
+
+    inline message(message&&) = default;
+
+    inline message(const message&) = delete;
+
+    inline auto operator=(message &&) -> message& = delete;
+
+    inline auto operator=(const message&) -> message& = delete;
+
+    [[nodiscard]] inline auto begin() const -> iterator
+    {
+        return iterator{msg.get(), keys};
+    }
+
+    [[nodiscard]] inline auto end() const -> iterator
+    {
+        return iterator{nullptr, keys};
+    }
+
+    inline explicit operator bool() const
+    {
+        return begin() != end();
+    }
+
+    template <class... Strings>
+    auto filter(Strings... key_filter)
+    {
+        strings both{};
+        if (keys.size() != 1 || !keys[0].empty()) {
+            both = keys;
+        }
+        both = concat(std::move(both), std::move(key_filter)...);
+        return std::move(message{msg, std::move(both)});
+    }
+
+    inline ~message() = default;
+};
+
+class lock_shared_resources {
+  private:
+    static std::mutex inuse;
+
+  public:
+    inline lock_shared_resources()
+    {
+        inuse.lock();
+    }
+
+    inline lock_shared_resources(lock_shared_resources&&) noexcept = default;
+
+    inline lock_shared_resources(const lock_shared_resources&) = delete;
+
+    inline auto operator=(const lock_shared_resources&) -> auto& = delete;
+
+    inline auto operator=(lock_shared_resources &&) -> auto&& = delete;
+
+    // NOLINTNEXTLINE(readability-convert-member-functions-to-static)
+    inline auto get_context() -> ubus_context*  // is member to enforce inuse.
+    {
+        static auto ubus_freeing = [](ubus_context* ctx) { ubus_free(ctx); };
+        static std::unique_ptr<ubus_context, decltype(ubus_freeing)> lazy_ctx{ubus_connect(nullptr),
+                                                                              ubus_freeing};
+
+        if (!lazy_ctx) {  // it could be available on a later call:
+
+            lazy_ctx.reset(ubus_connect(nullptr));
+
+            if (!lazy_ctx) {
+                throw std::runtime_error("ubus error: cannot connect context");
+            }
+        }
+
+        return lazy_ctx.get();
+    }
+
+    // NOLINTNEXTLINE(readability-convert-member-functions-to-static)
+    inline auto get_blob_buf() -> blob_buf*  // is member to enforce inuse.
+    {
+        static blob_buf buf;
+
+        static auto blob_buf_freeing = [](blob_buf* b) { blob_buf_free(b); };
+        static std::unique_ptr<blob_buf, decltype(blob_buf_freeing)>
+            created_to_free_on_the_end_of_life{&buf, blob_buf_freeing};
+
+        blob_buf_init(&buf, 0);
+
+        return &buf;
+    }
+
+    inline ~lock_shared_resources()
+    {
+        inuse.unlock();
+    }
+};
+
+template <class F>
+auto call(const char* path, const char* method, F set_arguments, int timeout = call_timeout)
+    -> message;
+
+inline auto call(const char* path, const char* method, int timeout = call_timeout) -> message
+{
+    return call(
+        path, method, [](blob_buf* /*buf*/) { return 0; }, timeout);
+}
+
+inline auto call(const char* path, int timeout = call_timeout) -> message
+{
+    return call(path, "", timeout);
+}
+
+// ------------------------- implementation: ----------------------------------
+
+std::mutex lock_shared_resources::inuse;
+
+inline auto iterator::operator++() -> iterator&
+{
+    for (;;) {
+#ifndef NDEBUG
+        std::cout << std::string(i, '>') << " look for " << keys[i] << " at ";
+        std::cout << blobmsg_name(cur->pos) << std::endl;
+#endif
+
+        auto id = blob_id(cur->pos);
+        if ((id == BLOBMSG_TYPE_TABLE || id == BLOBMSG_TYPE_ARRAY) && i < n && matches() &&
+            blobmsg_data_len(cur->pos) > 0)
+        {  // immmerge:
+            ++i;
+
+            auto* tmp = cur.release();
+
+            struct new_iterator : public iterator  // use private constructor:
+            {
+                explicit new_iterator(iterator* par) : iterator{par} {}
+            };
+            cur = std::make_unique<new_iterator>(tmp);
+        }
+        else {
+            while (true) {
+                cur->rem -= blob_pad_len(cur->pos);
+                cur->pos = blob_next(cur->pos);
+                auto len = blob_pad_len(cur->pos);
+
+                if (cur->rem > 0 && len <= cur->rem && len >= sizeof(blob_attr)) {
+                    break;
+                }
+
+                // emerge:
+                auto* tmp = cur->parent;
+
+                if (tmp == nullptr) {
+                    cur->pos = nullptr;
+                    return *cur;
+                }
+
+                cur.reset(tmp);
+
+                --i;
+            }
+        }
+        if (i == n && matches()) {
+            return *cur;
+        }
+    }
+}
+
+template <class F>
+inline auto call(const char* path, const char* method, F set_arguments, int timeout) -> message
+{
+    auto shared = lock_shared_resources{};
+
+    auto* ctx = shared.get_context();
+
+    uint32_t id = 0;
+    int err = ubus_lookup_id(ctx, path, &id);
+
+    if (err == 0) {  // call
+        ubus_request request{};
+
+        auto* buf = shared.get_blob_buf();
+        err = set_arguments(buf);
+        if (err == 0) {
+            err = ubus_invoke_async(ctx, id, method, buf->head, &request);
+        }
+
+        if (err == 0) {
+            msg_ptr message_ptr;
+
+            /* Cannot capture message_ptr, the lambda would be another type.
+             * Pass a location where to save the message as priv pointer when
+             * invoking and get it back here:
+             */
+            request.priv = &message_ptr;
+
+            request.data_cb = [](ubus_request* req, int /*type*/, blob_attr* msg) {
+                if (req == nullptr || msg == nullptr) {
+                    return;
+                }
+
+                auto* saved = static_cast<msg_ptr*>(req->priv);
+                if (saved == nullptr || *saved) {
+                    return;
+                }
+
+                saved->reset(blob_memdup(msg), free);
+                if (!*saved) {
+                    throw std::bad_alloc();
+                }
+            };
+
+            err = ubus_complete_request(ctx, &request, timeout);
+
+            if (err == 0) {
+                return message{message_ptr};
+            }
+        }
+    }
+
+    std::string errmsg = "ubus::call error: cannot invoke";
+    errmsg += " (" + std::to_string(err) + ") " + path + " " + method;
+    throw std::runtime_error(errmsg);
+}
+
+}  // namespace ubus
+
+#endif