Files
crossdesk/src/tools/file_transfer.cpp

312 lines
9.3 KiB
C++

#include "file_transfer.h"
#include <atomic>
#include <chrono>
#include "rd_log.h"
namespace crossdesk {
namespace {
std::atomic<uint32_t> g_next_file_id{1};
} // namespace
uint32_t FileSender::NextFileId() { return g_next_file_id.fetch_add(1); }
int FileSender::SendFile(const std::filesystem::path& path,
const std::string& label, const SendFunc& send,
std::size_t chunk_size, uint32_t file_id) {
if (!send) {
LOG_ERROR("FileSender::SendFile: send function is empty");
return -1;
}
std::error_code ec;
if (!std::filesystem::exists(path, ec) ||
!std::filesystem::is_regular_file(path, ec)) {
LOG_ERROR("FileSender::SendFile: file [{}] not found or not regular",
path.string().c_str());
return -1;
}
uint64_t total_size = std::filesystem::file_size(path, ec);
if (ec) {
LOG_ERROR("FileSender::SendFile: failed to get size of [{}]: {}",
path.string().c_str(), ec.message().c_str());
return -1;
}
std::ifstream ifs(path, std::ios::binary);
if (!ifs.is_open()) {
LOG_ERROR("FileSender::SendFile: failed to open [{}]",
path.string().c_str());
return -1;
}
LOG_INFO("FileSender send file {}, total size {}, file_id={}",
path.string().c_str(), total_size, file_id);
if (file_id == 0) {
file_id = NextFileId();
}
const uint32_t final_file_id = file_id;
uint64_t offset = 0;
bool is_first = true;
std::string file_name = label.empty() ? path.filename().string() : label;
std::vector<char> buffer;
buffer.resize(chunk_size);
while (ifs && offset < total_size) {
uint64_t remaining = total_size - offset;
uint32_t to_read =
static_cast<uint32_t>(std::min<uint64_t>(remaining, chunk_size));
ifs.read(buffer.data(), static_cast<std::streamsize>(to_read));
std::streamsize bytes_read = ifs.gcount();
if (bytes_read <= 0) {
break;
}
bool is_last = (offset + static_cast<uint64_t>(bytes_read) >= total_size);
const std::string* name_ptr = is_first ? &file_name : nullptr;
std::vector<char> chunk = BuildChunk(
final_file_id, offset, total_size, buffer.data(),
static_cast<uint32_t>(bytes_read), name_ptr, is_first, is_last);
int ret = send(chunk.data(), chunk.size());
if (ret != 0) {
LOG_ERROR("FileSender::SendFile: send failed for [{}], ret={}",
path.string().c_str(), ret);
return ret;
}
offset += static_cast<uint64_t>(bytes_read);
is_first = false;
}
return 0;
}
std::vector<char> FileSender::BuildChunk(uint32_t file_id, uint64_t offset,
uint64_t total_size, const char* data,
uint32_t data_size,
const std::string* file_name,
bool is_first, bool is_last) {
FileChunkHeader header{};
header.magic = kFileChunkMagic;
header.file_id = file_id;
header.offset = offset;
header.total_size = total_size;
header.chunk_size = data_size;
header.name_len =
(file_name && is_first) ? static_cast<uint16_t>(file_name->size()) : 0;
header.flags = 0;
if (is_first) header.flags |= 0x01;
if (is_last) header.flags |= 0x02;
std::size_t total_size_bytes =
sizeof(FileChunkHeader) + header.name_len + header.chunk_size;
std::vector<char> buffer;
buffer.resize(total_size_bytes);
std::size_t offset_bytes = 0;
memcpy(buffer.data() + offset_bytes, &header, sizeof(FileChunkHeader));
offset_bytes += sizeof(FileChunkHeader);
if (header.name_len > 0 && file_name) {
memcpy(buffer.data() + offset_bytes, file_name->data(), header.name_len);
offset_bytes += header.name_len;
}
if (header.chunk_size > 0 && data) {
memcpy(buffer.data() + offset_bytes, data, header.chunk_size);
}
return buffer;
}
// ---------- FileReceiver ----------
FileReceiver::FileReceiver() : output_dir_(GetDefaultDesktopPath()) {}
FileReceiver::FileReceiver(const std::filesystem::path& output_dir)
: output_dir_(output_dir) {
std::error_code ec;
if (!output_dir_.empty()) {
std::filesystem::create_directories(output_dir_, ec);
if (ec) {
LOG_ERROR("FileReceiver: failed to create output dir [{}]: {}",
output_dir_.string().c_str(), ec.message().c_str());
}
}
}
std::filesystem::path FileReceiver::GetDefaultDesktopPath() {
#ifdef _WIN32
const char* home_env = std::getenv("USERPROFILE");
#else
const char* home_env = std::getenv("HOME");
#endif
if (!home_env) {
return std::filesystem::path{};
}
std::filesystem::path desktop_path =
std::filesystem::path(home_env) / "Desktop";
std::error_code ec;
std::filesystem::create_directories(desktop_path, ec);
if (ec) {
LOG_ERROR("FileReceiver: failed to create desktop directory [{}]: {}",
desktop_path.string().c_str(), ec.message().c_str());
}
return desktop_path;
}
bool FileReceiver::OnData(const char* data, size_t size) {
if (!data || size < sizeof(FileChunkHeader)) {
LOG_ERROR("FileReceiver::OnData: invalid buffer");
return false;
}
FileChunkHeader header{};
memcpy(&header, data, sizeof(FileChunkHeader));
if (header.magic != kFileChunkMagic) {
return false;
}
std::size_t header_and_name =
sizeof(FileChunkHeader) + static_cast<std::size_t>(header.name_len);
if (size < header_and_name ||
size < header_and_name + static_cast<std::size_t>(header.chunk_size)) {
LOG_ERROR("FileReceiver::OnData: buffer too small for header + payload");
return false;
}
const char* name_ptr = data + sizeof(FileChunkHeader);
std::string file_name;
const std::string* file_name_ptr = nullptr;
if (header.name_len > 0) {
file_name.assign(name_ptr,
name_ptr + static_cast<std::size_t>(header.name_len));
file_name_ptr = &file_name;
}
const char* payload = data + header_and_name;
std::size_t payload_size =
static_cast<std::size_t>(header.chunk_size); // may be 0
return HandleChunk(header, payload, payload_size, file_name_ptr);
}
bool FileReceiver::HandleChunk(const FileChunkHeader& header,
const char* payload, size_t payload_size,
const std::string* file_name) {
auto it = contexts_.find(header.file_id);
if (it == contexts_.end()) {
// new file context must start with first chunk.
if ((header.flags & 0x01) == 0) {
LOG_ERROR("FileReceiver: received non-first chunk for unknown file_id={}",
header.file_id);
return false;
}
FileContext ctx;
ctx.total_size = header.total_size;
std::string filename;
if (file_name && !file_name->empty()) {
filename = *file_name;
} else {
filename = "received_" + std::to_string(header.file_id);
}
ctx.file_name = filename;
std::filesystem::path save_path = output_dir_.empty()
? std::filesystem::path(filename)
: output_dir_ / filename;
// if file exists, append timestamp.
std::error_code ec;
if (std::filesystem::exists(save_path, ec)) {
auto now = std::chrono::system_clock::now();
auto ts = std::chrono::duration_cast<std::chrono::milliseconds>(
now.time_since_epoch())
.count();
save_path = save_path.parent_path() /
(save_path.stem().string() + "_" + std::to_string(ts) +
save_path.extension().string());
}
ctx.ofs.open(save_path, std::ios::binary | std::ios::trunc);
if (!ctx.ofs.is_open()) {
LOG_ERROR("FileReceiver: failed to open [{}] for writing",
save_path.string().c_str());
return false;
}
contexts_.emplace(header.file_id, std::move(ctx));
it = contexts_.find(header.file_id);
}
FileContext& ctx = it->second;
if (payload_size > 0 && payload) {
ctx.ofs.seekp(static_cast<std::streamoff>(header.offset), std::ios::beg);
ctx.ofs.write(payload, static_cast<std::streamsize>(payload_size));
if (!ctx.ofs.good()) {
LOG_ERROR("FileReceiver: write failed for file_id={}", header.file_id);
return false;
}
ctx.received += static_cast<uint64_t>(payload_size);
}
// Send ACK after processing chunk
if (on_send_ack_) {
FileTransferAck ack{};
ack.magic = kFileAckMagic;
ack.file_id = header.file_id;
ack.acked_offset = header.offset + static_cast<uint64_t>(payload_size);
ack.total_size = header.total_size;
ack.flags = 0;
bool is_last = (header.flags & 0x02) != 0;
if (is_last || ctx.received >= ctx.total_size) {
ack.flags |= 0x01; // completed
}
int ret = on_send_ack_(ack);
if (ret != 0) {
LOG_ERROR("FileReceiver: failed to send ACK for file_id={}, ret={}",
header.file_id, ret);
}
}
bool is_last = (header.flags & 0x02) != 0;
if (is_last || ctx.received >= ctx.total_size) {
ctx.ofs.close();
std::filesystem::path saved_path =
output_dir_.empty() ? std::filesystem::path(ctx.file_name)
: output_dir_ / ctx.file_name;
LOG_INFO("FileReceiver: file received complete, file_id={}, size={}",
header.file_id, ctx.received);
if (on_file_complete_) {
on_file_complete_(saved_path);
}
contexts_.erase(header.file_id);
}
return true;
}
} // namespace crossdesk