Add readv and writev for more efficient API packets (#2342)

esphome/components/api/api_connection.cpp

@@ -702,15 +702,7 @@ bool APIConnection::send_log_message(int level, const char *tag, const char *lin
   // string message = 3;
   buffer.encode_string(3, line, strlen(line));
   // SubscribeLogsResponse - 29
-  bool success = this->send_buffer(buffer, 29);
-  if (!success) {
-    buffer = this->create_buffer();
-    // bool send_failed = 4;
-    buffer.encode_bool(4, true);
-    return this->send_buffer(buffer, 29);
-  } else {
-    return true;
-  }
+  return this->send_buffer(buffer, 29);
 }
 
 HelloResponse APIConnection::hello(const HelloRequest &msg) {
@@ -783,8 +775,23 @@ void APIConnection::subscribe_home_assistant_states(const SubscribeHomeAssistant
 bool APIConnection::send_buffer(ProtoWriteBuffer buffer, uint32_t message_type) {
   if (this->remove_)
     return false;
-  if (!this->helper_->can_write_without_blocking())
-    return false;
+  if (!this->helper_->can_write_without_blocking()) {
+    delay(0);
+    APIError err = helper_->loop();
+    if (err != APIError::OK) {
+      on_fatal_error();
+      ESP_LOGW(TAG, "%s: Socket operation failed: %s errno=%d", client_info_.c_str(), api_error_to_str(err), errno);
+      return false;
+    }
+    if (!this->helper_->can_write_without_blocking()) {
+      // SubscribeLogsResponse
+      if (message_type != 29) {
+        ESP_LOGV(TAG, "Cannot send message because of TCP buffer space");
+      }
+      delay(0);
+      return false;
+    }
+  }
 
   APIError err = this->helper_->write_packet(message_type, buffer.get_buffer()->data(), buffer.get_buffer()->size());
   if (err == APIError::WOULD_BLOCK)

esphome/components/api/api_frame_helper.cpp

@@ -125,13 +125,6 @@ APIError APINoiseFrameHelper::init() {
     HELPER_LOG("Setting nonblocking failed with errno %d", errno);
     return APIError::TCP_NONBLOCKING_FAILED;
   }
-  int enable = 1;
-  err = socket_->setsockopt(IPPROTO_TCP, TCP_NODELAY, &enable, sizeof(int));
-  if (err != 0) {
-    state_ = State::FAILED;
-    HELPER_LOG("Setting nodelay failed with errno %d", errno);
-    return APIError::TCP_NODELAY_FAILED;
-  }
 
   // init prologue
   prologue_.insert(prologue_.end(), PROLOGUE_INIT, PROLOGUE_INIT + strlen(PROLOGUE_INIT));
@@ -494,12 +487,13 @@ APIError APINoiseFrameHelper::write_packet(uint16_t type, const uint8_t *payload
   size_t total_len = 3 + mbuf.size;
   tmpbuf[1] = (uint8_t)(mbuf.size >> 8);
   tmpbuf[2] = (uint8_t) mbuf.size;
+
+  struct iovec iov;
+  iov.iov_base = &tmpbuf[0];
+  iov.iov_len = total_len;
+
   // write raw to not have two packets sent if NAGLE disabled
-  aerr = write_raw_(&tmpbuf[0], total_len);
-  if (aerr != APIError::OK) {
-    return aerr;
-  }
-  return APIError::OK;
+  return write_raw_(&iov, 1);
 }
 APIError APINoiseFrameHelper::try_send_tx_buf_() {
   // try send from tx_buf
@@ -526,16 +520,19 @@ APIError APINoiseFrameHelper::try_send_tx_buf_() {
  * @param data The data to write
  * @param len The length of data
  */
-APIError APINoiseFrameHelper::write_raw_(const uint8_t *data, size_t len) {
-  if (len == 0)
+APIError APINoiseFrameHelper::write_raw_(const struct iovec *iov, int iovcnt) {
+  if (iovcnt == 0)
     return APIError::OK;
   int err;
   APIError aerr;
 
-  // uncomment for even more debugging
+  size_t total_write_len = 0;
+  for (int i = 0; i < iovcnt; i++) {
 #ifdef HELPER_LOG_PACKETS
-  ESP_LOGVV(TAG, "Sending raw: %s", hexencode(data, len).c_str());
+    ESP_LOGVV(TAG, "Sending raw: %s", hexencode(reinterpret_cast<uint8_t *>(iov[i].iov_base), iov[i].iov_len).c_str());
 #endif
+    total_write_len += iov[i].iov_len;
+  }
 
   if (!tx_buf_.empty()) {
     // try to empty tx_buf_ first
@@ -546,41 +543,56 @@ APIError APINoiseFrameHelper::write_raw_(const uint8_t *data, size_t len) {
 
   if (!tx_buf_.empty()) {
     // tx buf not empty, can't write now because then stream would be inconsistent
-    tx_buf_.insert(tx_buf_.end(), data, data + len);
+    for (int i = 0; i < iovcnt; i++) {
+      tx_buf_.insert(tx_buf_.end(), reinterpret_cast<uint8_t *>(iov[i].iov_base),
+                     reinterpret_cast<uint8_t *>(iov[i].iov_base) + iov[i].iov_len);
+    }
     return APIError::OK;
   }
 
-  ssize_t sent = socket_->write(data, len);
+  ssize_t sent = socket_->writev(iov, iovcnt);
   if (is_would_block(sent)) {
     // operation would block, add buffer to tx_buf
-    tx_buf_.insert(tx_buf_.end(), data, data + len);
+    for (int i = 0; i < iovcnt; i++) {
+      tx_buf_.insert(tx_buf_.end(), reinterpret_cast<uint8_t *>(iov[i].iov_base),
+                     reinterpret_cast<uint8_t *>(iov[i].iov_base) + iov[i].iov_len);
+    }
     return APIError::OK;
   } else if (sent == -1) {
     // an error occured
     state_ = State::FAILED;
     HELPER_LOG("Socket write failed with errno %d", errno);
     return APIError::SOCKET_WRITE_FAILED;
-  } else if (sent != len) {
+  } else if (sent != total_write_len) {
     // partially sent, add end to tx_buf
-    tx_buf_.insert(tx_buf_.end(), data + sent, data + len);
+    size_t to_consume = sent;
+    for (int i = 0; i < iovcnt; i++) {
+      if (to_consume >= iov[i].iov_len) {
+        to_consume -= iov[i].iov_len;
+      } else {
+        tx_buf_.insert(tx_buf_.end(), reinterpret_cast<uint8_t *>(iov[i].iov_base) + to_consume,
+                       reinterpret_cast<uint8_t *>(iov[i].iov_base) + iov[i].iov_len);
+        to_consume = 0;
+      }
+    }
     return APIError::OK;
   }
   // fully sent
   return APIError::OK;
 }
 APIError APINoiseFrameHelper::write_frame_(const uint8_t *data, size_t len) {
-  APIError aerr;
-
   uint8_t header[3];
   header[0] = 0x01;  // indicator
   header[1] = (uint8_t)(len >> 8);
   header[2] = (uint8_t) len;
 
-  aerr = write_raw_(header, 3);
-  if (aerr != APIError::OK)
-    return aerr;
-  aerr = write_raw_(data, len);
-  return aerr;
+  struct iovec iov[2];
+  iov[0].iov_base = header;
+  iov[0].iov_len = 3;
+  iov[1].iov_base = const_cast<uint8_t *>(data);
+  iov[1].iov_len = len;
+
+  return write_raw_(iov, 2);
 }
 
 /** Initiate the data structures for the handshake.
@@ -709,13 +721,6 @@ APIError APIPlaintextFrameHelper::init() {
     HELPER_LOG("Setting nonblocking failed with errno %d", errno);
     return APIError::TCP_NONBLOCKING_FAILED;
   }
-  int enable = 1;
-  err = socket_->setsockopt(IPPROTO_TCP, TCP_NODELAY, &enable, sizeof(int));
-  if (err != 0) {
-    state_ = State::FAILED;
-    HELPER_LOG("Setting nodelay failed with errno %d", errno);
-    return APIError::TCP_NODELAY_FAILED;
-  }
 
   state_ = State::DATA;
   return APIError::OK;
@@ -863,15 +868,13 @@ APIError APIPlaintextFrameHelper::write_packet(uint16_t type, const uint8_t *pay
   ProtoVarInt(payload_len).encode(header);
   ProtoVarInt(type).encode(header);
 
-  aerr = write_raw_(&header[0], header.size());
-  if (aerr != APIError::OK) {
-    return aerr;
-  }
-  aerr = write_raw_(payload, payload_len);
-  if (aerr != APIError::OK) {
-    return aerr;
-  }
-  return APIError::OK;
+  struct iovec iov[2];
+  iov[0].iov_base = &header[0];
+  iov[0].iov_len = header.size();
+  iov[1].iov_base = const_cast<uint8_t *>(payload);
+  iov[1].iov_len = payload_len;
+
+  return write_raw_(iov, 2);
 }
 APIError APIPlaintextFrameHelper::try_send_tx_buf_() {
   // try send from tx_buf
@@ -896,16 +899,19 @@ APIError APIPlaintextFrameHelper::try_send_tx_buf_() {
  * @param data The data to write
  * @param len The length of data
  */
-APIError APIPlaintextFrameHelper::write_raw_(const uint8_t *data, size_t len) {
-  if (len == 0)
+APIError APIPlaintextFrameHelper::write_raw_(const struct iovec *iov, int iovcnt) {
+  if (iovcnt == 0)
     return APIError::OK;
   int err;
   APIError aerr;
 
-  // uncomment for even more debugging
+  size_t total_write_len = 0;
+  for (int i = 0; i < iovcnt; i++) {
 #ifdef HELPER_LOG_PACKETS
-  ESP_LOGVV(TAG, "Sending raw: %s", hexencode(data, len).c_str());
+    ESP_LOGVV(TAG, "Sending raw: %s", hexencode(reinterpret_cast<uint8_t *>(iov[i].iov_base), iov[i].iov_len).c_str());
 #endif
+    total_write_len += iov[i].iov_len;
+  }
 
   if (!tx_buf_.empty()) {
     // try to empty tx_buf_ first
@@ -916,23 +922,38 @@ APIError APIPlaintextFrameHelper::write_raw_(const uint8_t *data, size_t len) {
 
   if (!tx_buf_.empty()) {
     // tx buf not empty, can't write now because then stream would be inconsistent
-    tx_buf_.insert(tx_buf_.end(), data, data + len);
+    for (int i = 0; i < iovcnt; i++) {
+      tx_buf_.insert(tx_buf_.end(), reinterpret_cast<uint8_t *>(iov[i].iov_base),
+                     reinterpret_cast<uint8_t *>(iov[i].iov_base) + iov[i].iov_len);
+    }
     return APIError::OK;
   }
 
-  ssize_t sent = socket_->write(data, len);
+  ssize_t sent = socket_->writev(iov, iovcnt);
   if (is_would_block(sent)) {
     // operation would block, add buffer to tx_buf
-    tx_buf_.insert(tx_buf_.end(), data, data + len);
+    for (int i = 0; i < iovcnt; i++) {
+      tx_buf_.insert(tx_buf_.end(), reinterpret_cast<uint8_t *>(iov[i].iov_base),
+                     reinterpret_cast<uint8_t *>(iov[i].iov_base) + iov[i].iov_len);
+    }
     return APIError::OK;
   } else if (sent == -1) {
     // an error occured
     state_ = State::FAILED;
     HELPER_LOG("Socket write failed with errno %d", errno);
     return APIError::SOCKET_WRITE_FAILED;
-  } else if (sent != len) {
+  } else if (sent != total_write_len) {
     // partially sent, add end to tx_buf
-    tx_buf_.insert(tx_buf_.end(), data + sent, data + len);
+    size_t to_consume = sent;
+    for (int i = 0; i < iovcnt; i++) {
+      if (to_consume >= iov[i].iov_len) {
+        to_consume -= iov[i].iov_len;
+      } else {
+        tx_buf_.insert(tx_buf_.end(), reinterpret_cast<uint8_t *>(iov[i].iov_base) + to_consume,
+                       reinterpret_cast<uint8_t *>(iov[i].iov_base) + iov[i].iov_len);
+        to_consume = 0;
+      }
+    }
     return APIError::OK;
   }
   // fully sent

esphome/components/api/api_frame_helper.h

@@ -58,6 +58,7 @@ const char *api_error_to_str(APIError err);
 
 class APIFrameHelper {
  public:
+  virtual ~APIFrameHelper() = default;
   virtual APIError init() = 0;
   virtual APIError loop() = 0;
   virtual APIError read_packet(ReadPacketBuffer *buffer) = 0;
@@ -96,7 +97,7 @@ class APINoiseFrameHelper : public APIFrameHelper {
   APIError try_read_frame_(ParsedFrame *frame);
   APIError try_send_tx_buf_();
   APIError write_frame_(const uint8_t *data, size_t len);
-  APIError write_raw_(const uint8_t *data, size_t len);
+  APIError write_raw_(const struct iovec *iov, int iovcnt);
   APIError init_handshake_();
   APIError check_handshake_finished_();
   void send_explicit_handshake_reject_(const std::string &reason);
@@ -154,7 +155,7 @@ class APIPlaintextFrameHelper : public APIFrameHelper {
 
   APIError try_read_frame_(ParsedFrame *frame);
   APIError try_send_tx_buf_();
-  APIError write_raw_(const uint8_t *data, size_t len);
+  APIError write_raw_(const struct iovec *iov, int iovcnt);
 
   std::unique_ptr<socket::Socket> socket_;
 

esphome/components/socket/bsd_sockets_impl.cpp

@@ -5,6 +5,10 @@
 
 #include <string.h>
 
+#ifdef ARDUINO_ARCH_ESP32
+#include <esp_idf_version.h>
+#endif
+
 namespace esphome {
 namespace socket {
 
@@ -75,7 +79,51 @@ class BSDSocketImpl : public Socket {
   }
   int listen(int backlog) override { return ::listen(fd_, backlog); }
   ssize_t read(void *buf, size_t len) override { return ::read(fd_, buf, len); }
+  ssize_t readv(const struct iovec *iov, int iovcnt) override {
+#if defined(ARDUINO_ARCH_ESP32) && ESP_IDF_VERSION_MAJOR < 4
+    // esp-idf v3 doesn't have readv, emulate it
+    ssize_t ret = 0;
+    for (int i = 0; i < iovcnt; i++) {
+      ssize_t err = this->read(reinterpret_cast<uint8_t *>(iov[i].iov_base), iov[i].iov_len);
+      if (err == -1) {
+        if (ret != 0)
+          // if we already read some don't return an error
+          break;
+        return err;
+      }
+      ret += err;
+      if (err != iov[i].iov_len)
+        break;
+    }
+    return ret;
+#else
+    return ::readv(fd_, iov, iovcnt);
+#endif
+  }
   ssize_t write(const void *buf, size_t len) override { return ::write(fd_, buf, len); }
+  ssize_t send(void *buf, size_t len, int flags) { return ::send(fd_, buf, len, flags); }
+  ssize_t writev(const struct iovec *iov, int iovcnt) override {
+#if defined(ARDUINO_ARCH_ESP32) && ESP_IDF_VERSION_MAJOR < 4
+    // esp-idf v3 doesn't have writev, emulate it
+    ssize_t ret = 0;
+    for (int i = 0; i < iovcnt; i++) {
+      ssize_t err =
+          this->send(reinterpret_cast<uint8_t *>(iov[i].iov_base), iov[i].iov_len, i == iovcnt - 1 ? 0 : MSG_MORE);
+      if (err == -1) {
+        if (ret != 0)
+          // if we already wrote some don't return an error
+          break;
+        return err;
+      }
+      ret += err;
+      if (err != iov[i].iov_len)
+        break;
+    }
+    return ret;
+#else
+    return ::writev(fd_, iov, iovcnt);
+#endif
+  }
   int setblocking(bool blocking) override {
     int fl = ::fcntl(fd_, F_GETFL, 0);
     if (blocking) {

esphome/components/socket/headers.h

@@ -81,6 +81,11 @@ struct sockaddr_storage {
 };
 typedef uint32_t socklen_t;
 
+struct iovec {
+  void *iov_base;
+  size_t iov_len;
+};
+
 #ifdef ARDUINO_ARCH_ESP8266
 // arduino-esp8266 declares a global vars called INADDR_NONE/ANY which are invalid with the define
 #ifdef INADDR_ANY
@@ -104,6 +109,7 @@ typedef uint32_t socklen_t;
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/ioctl.h>
+#include <sys/uio.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <stdint.h>

esphome/components/socket/lwip_raw_tcp_impl.cpp

@@ -371,7 +371,23 @@ class LWIPRawImpl : public Socket {
 
     return read;
   }
-  ssize_t write(const void *buf, size_t len) override {
+  ssize_t readv(const struct iovec *iov, int iovcnt) override {
+    ssize_t ret = 0;
+    for (int i = 0; i < iovcnt; i++) {
+      ssize_t err = read(reinterpret_cast<uint8_t *>(iov[i].iov_base), iov[i].iov_len);
+      if (err == -1) {
+        if (ret != 0)
+          // if we already read some don't return an error
+          break;
+        return err;
+      }
+      ret += err;
+      if (err != iov[i].iov_len)
+        break;
+    }
+    return ret;
+  }
+  ssize_t internal_write(const void *buf, size_t len) {
     if (pcb_ == nullptr) {
       errno = ECONNRESET;
       return -1;
@@ -400,25 +416,60 @@ class LWIPRawImpl : public Socket {
       errno = ECONNRESET;
       return -1;
     }
-    if (tcp_nagle_disabled(pcb_)) {
-      LWIP_LOG("tcp_output(%p)", pcb_);
-      err = tcp_output(pcb_);
-      if (err == ERR_ABRT) {
-        LWIP_LOG("  -> err ERR_ABRT");
-        // sometimes lwip returns ERR_ABRT for no apparent reason
-        // the connection works fine afterwards, and back with ESPAsyncTCP we
-        // indirectly also ignored this error
-        // FIXME: figure out where this is returned and what it means in this context
-        return to_send;
-      }
-      if (err != ERR_OK) {
-        LWIP_LOG("  -> err %d", err);
-        errno = ECONNRESET;
-        return -1;
-      }
-    }
     return to_send;
   }
+  int internal_output() {
+    LWIP_LOG("tcp_output(%p)", pcb_);
+    err_t err = tcp_output(pcb_);
+    if (err == ERR_ABRT) {
+      LWIP_LOG("  -> err ERR_ABRT");
+      // sometimes lwip returns ERR_ABRT for no apparent reason
+      // the connection works fine afterwards, and back with ESPAsyncTCP we
+      // indirectly also ignored this error
+      // FIXME: figure out where this is returned and what it means in this context
+      return 0;
+    }
+    if (err != ERR_OK) {
+      LWIP_LOG("  -> err %d", err);
+      errno = ECONNRESET;
+      return -1;
+    }
+    return 0;
+  }
+  ssize_t write(const void *buf, size_t len) override {
+    ssize_t written = internal_write(buf, len);
+    if (written == -1)
+      return -1;
+    if (written == 0)
+      // no need to output if nothing written
+      return 0;
+    int err = internal_output();
+    if (err == -1)
+      return -1;
+    return written;
+  }
+  ssize_t writev(const struct iovec *iov, int iovcnt) override {
+    ssize_t written = 0;
+    for (int i = 0; i < iovcnt; i++) {
+      ssize_t err = internal_write(reinterpret_cast<uint8_t *>(iov[i].iov_base), iov[i].iov_len);
+      if (err == -1) {
+        if (written != 0)
+          // if we already read some don't return an error
+          break;
+        return err;
+      }
+      written += err;
+      if (err != iov[i].iov_len)
+        break;
+    }
+    if (written == 0)
+      // no need to output if nothing written
+      return 0;
+    int err = internal_output();
+    if (err == -1)
+      return -1;
+    return written;
+  }
   int setblocking(bool blocking) override {
     if (pcb_ == nullptr) {
       errno = ECONNRESET;

esphome/components/socket/socket.h

@@ -31,7 +31,9 @@ class Socket {
   virtual int setsockopt(int level, int optname, const void *optval, socklen_t optlen) = 0;
   virtual int listen(int backlog) = 0;
   virtual ssize_t read(void *buf, size_t len) = 0;
+  virtual ssize_t readv(const struct iovec *iov, int iovcnt) = 0;
   virtual ssize_t write(const void *buf, size_t len) = 0;
+  virtual ssize_t writev(const struct iovec *iov, int iovcnt) = 0;
   virtual int setblocking(bool blocking) = 0;
   virtual int loop() { return 0; };
 };