framed_transport.cpp

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#include "jsonrpc/transport/framed_transport.hpp"
 
#include <stdexcept>
 
#include "jsonrpc/utils/string_utils.hpp"
 
namespace jsonrpc::transport {
 
void FramedTransport::FrameMessage(
    std::ostream &output, const std::string &message) {
  output << "Content-Length: " << message.size() << "\r\n"
         << "Content-Type: application/vscode-jsonrpc; charset=utf-8\r\n"
         << "\r\n"
         << message;
}
 
auto FramedTransport::ReadHeadersFromStream(std::istream &input)
    -> FramedTransport::HeaderMap {
  HeaderMap headers;
  std::string line;
 
  while (std::getline(input, line) && !line.empty() && line != "\r") {
    auto colon_pos = line.find(':');
    if (colon_pos != std::string::npos) {
      std::string header_key = utils::Trim(line.substr(0, colon_pos));
      std::string header_value = utils::Trim(line.substr(colon_pos + 1));
      headers[header_key] = header_value;
    }
  }
 
  if (headers.empty()) {
    throw std::runtime_error("Failed to read headers");
  }
 
  return headers;
}
 
auto FramedTransport::ReadContentLengthFromStream(std::istream &input) -> int {
  auto headers = ReadHeadersFromStream(input);
  auto it = headers.find("Content-Length");
  if (it == headers.end()) {
    throw std::runtime_error("Content-Length header missing");
  }
  return ParseContentLength(it->second);
}
 
auto FramedTransport::ReadContent(
    std::istream &input, std::size_t content_length) -> std::string {
  std::string content(content_length, '\0');
  input.read(content.data(), static_cast<std::streamsize>(content_length));
  if (input.gcount() != static_cast<std::streamsize>(content_length)) {
    throw std::runtime_error("Failed to read the expected content length");
  }
  return content;
}
 
auto FramedTransport::ReceiveFramedMessage(std::istream &input) -> std::string {
  int content_length = ReadContentLengthFromStream(input);
  return ReadContent(input, content_length);
}
 
auto FramedTransport::ParseContentLength(const std::string &header_value)
    -> int {
  try {
    return std::stoi(header_value);
  } catch (const std::invalid_argument &) {
    throw std::runtime_error("Invalid Content-Length value");
  } catch (const std::out_of_range &) {
    throw std::runtime_error("Content-Length value out of range");
  }
}
 
}  // namespace jsonrpc::transport