feat: large file upload with websocket-client

Add two APIs:
One for websocket chunked transfer,
Another one for splitting large files into multiple websocket requests for transfer.

include/cinatra/coro_http_client.hpp

@@ -348,6 +348,92 @@ class coro_http_client : public std::enable_shared_from_this<coro_http_client> {
     co_return data;
   }
 
+  async_simple::coro::Lazy<resp_data> async_send_ws_multiple(
+      std::string msg, bool need_mask = true, opcode op = opcode::text) {
+    resp_data data{};
+    size_t msg_length = msg.length();
+    int msg_offset = 0;
+
+    websocket ws{};
+    if (op == opcode::close) {
+      msg = ws.format_close_payload(close_code::normal, msg.data(), msg.size());
+      data = co_await async_send_ws(msg, need_mask, op);
+      co_return data;
+    }
+
+    while (msg_length > 0) {
+      if (msg_length > websocket_split_part_size_) {
+        std::string part(msg.data() + msg_offset, websocket_split_part_size_);
+        data = co_await async_send_ws(part, need_mask, op);
+        if (data.net_err) {
+          co_return data;
+        }
+        msg_offset += websocket_split_part_size_;
+        msg_length -= websocket_split_part_size_;
+      }
+      else {
+        std::string part(msg.data() + msg_offset, msg_length);
+        msg_length = 0;
+        data = co_await async_send_ws(part, need_mask, op);
+        if (data.net_err) {
+          co_return data;
+        }
+      }
+    }
+    data.eof = true;
+    co_return data;
+  }
+
+  async_simple::coro::Lazy<resp_data> async_send_ws_chuncked(
+      std::string msg, uint64_t max_part_size, bool need_mask = true,
+      opcode op = opcode::text) {
+    resp_data data{};
+
+    websocket ws{};
+    if (op == opcode::close) {
+      msg = ws.format_close_payload(close_code::normal, msg.data(), msg.size());
+    }
+
+    std::string total_data = ws.encode_frame(msg, op, need_mask);
+    bool is_first_part = true;
+    total_data.append(msg);
+    size_t msg_length = total_data.length();
+    int msg_offset = 0;
+
+    while (msg_length > 0) {
+      std::cout << msg_length << std::endl;
+      if (msg_length > max_part_size) {
+        std::string part(total_data.data() + msg_offset, max_part_size);
+        std::vector<asio::const_buffer> buffers{
+            asio::buffer(part.data(), max_part_size)};
+        auto [ec, _] = co_await async_write(buffers);
+        if (ec) {
+          data.net_err = ec;
+          data.status = 404;
+          co_return data;
+        }
+        msg_length -= max_part_size;
+        msg_offset += max_part_size;
+      }
+      else {
+        std::string last_part(total_data.data() + msg_offset, msg_length);
+        std::vector<asio::const_buffer> buffers{
+            asio::buffer(last_part.data(), last_part.size())};
+        auto [ec, _] = co_await async_write(buffers);
+        if (ec) {
+          data.net_err = ec;
+          data.status = 404;
+          co_return data;
+        }
+
+        msg_offset += msg_length;
+        msg_length = 0;
+      }
+    }
+    data.eof = true;
+    co_return data;
+  }
+
   async_simple::coro::Lazy<resp_data> async_send_ws_close(
       std::string msg = "") {
     return async_send_ws(std::move(msg), false, opcode::close);

lang/coro_http_client_introduction.md

@@ -465,6 +465,28 @@ enum opcode : std::uint8_t {
 async_simple::coro::Lazy<resp_data> async_send_ws(std::string msg,
                                                   bool need_mask = true,
                                                   opcode op = opcode::text);
+
+/// 后两个api是为了解决待发送的websocket数据过大的问题，
+/// websocket数据过大情况下一次性传入所有buffer到asio::async_write会出错
+
+/// 多批次发送websocket 数据,
+/// 内部由websocket_split_part_size_变量限制为3M。超过3M分割为多个websocket请求发送
+/// \param msg 要发送的websocket 数据
+/// \param need_mask 是否需要对数据进行mask，默认会mask
+/// \param op opcode 一般为text、binary或 close 等类型
+async_simple::coro::Lazy<resp_data> async_send_ws_multiple(std::string msg,
+                                                  bool need_mask = true,
+                                                  opcode op = opcode::text);
+
+/// 分段形式发送websocket 数据
+/// \param msg 要发送的websocket 数据
+/// \param max_part_size 每段发送的数据最大大小
+/// \param need_mask 是否需要对数据进行mask，默认会mask
+/// \param op opcode 一般为text、binary或 close 等类型
+async_simple::coro::Lazy<resp_data> async_send_ws_chuncked(std::string msg,
+                                                  uint64_t max_part_size,
+                                                  bool need_mask = true,
+                                                  opcode op = opcode::text);
 ```
 
 websocket 例子: