Diff: M2XStreamClient/M2XStreamClient.cpp

Revision:

3:78f223d34f36

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/M2XStreamClient/M2XStreamClient.cpp	Tue Mar 05 02:34:44 2019 +0000
@@ -0,0 +1,460 @@
+#include "M2XStreamClient.h"
+
+#include <jsonlite.h>
+
+#include "StreamParseFunctions.h"
+#include "LocationParseFunctions.h"
+
+const char* M2XStreamClient::kDefaultM2XHost = "api-m2x.att.com";
+
+static int write_delete_values(Print* print, const char* from, const char* end);
+int print_encoded_string(Print* print, const char* str);
+int tolower(int ch);
+
+#if defined(ARDUINO_PLATFORM) || defined(MBED_PLATFORM)
+int tolower(int ch)
+{
+  // Arduino and mbed use ASCII table, so we can simplify the implementation
+  if ((ch >= 'A') && (ch <= 'Z')) {
+    return (ch + 32);
+  }
+  return ch;
+}
+#else
+// For other platform, we use libc's tolower by default
+#include <ctype.h>
+#endif
+
+M2XStreamClient::M2XStreamClient(Client* client,
+                                 const char* key,
+                                 int case_insensitive,
+                                 const char* host,
+                                 int port,
+                                 const char* path_prefix) : _client(client),
+                                             _key(key),
+                                             _case_insensitive(case_insensitive),
+                                             _host(host),
+                                             _port(port),
+                                             _path_prefix(path_prefix),
+                                             _null_print() {
+}
+
+int M2XStreamClient::listStreamValues(const char* deviceId, const char* streamName,
+                                      stream_value_read_callback callback, void* context,
+                                      const char* query) {
+  if (_client->connect(_host, _port)) {
+    DBGLN("%s", "Connected to M2X server!");
+    _client->print("GET ");
+    if (_path_prefix)
+        _client->print(_path_prefix);
+    _client->print("/v2/devices/");
+    print_encoded_string(_client, deviceId);
+    _client->print("/streams/");
+    print_encoded_string(_client, streamName);
+    _client->print("/values.json");
+
+    if (query) {
+      if (query[0] != '?') {
+        _client->print('?');
+      }
+      _client->print(query);
+    }
+
+    _client->println(" HTTP/1.0");
+    writeHttpHeader(-1);
+  } else {
+    DBGLN("%s", "ERROR: Cannot connect to M2X server!");
+    return E_NOCONNECTION;
+  }
+  int status = readStatusCode(false);
+  if (status == 200) {
+    readStreamValue(callback, context);
+  }
+
+  close();
+  return status;
+}
+
+int M2XStreamClient::readLocation(const char* deviceId,
+                                  location_read_callback callback,
+                                  void* context) {
+  if (_client->connect(_host, _port)) {
+    DBGLN("%s", "Connected to M2X server!");
+    _client->print("GET ");
+    if (_path_prefix)
+        _client->print(_path_prefix);
+    _client->print("/v2/devices/");
+    print_encoded_string(_client, deviceId);
+    _client->println("/location HTTP/1.0");
+
+    writeHttpHeader(-1);
+  } else {
+    DBGLN("%s", "ERROR: Cannot connect to M2X server!");
+    return E_NOCONNECTION;
+  }
+  int status = readStatusCode(false);
+  if (status == 200) {
+    readLocation(callback, context);
+  }
+
+  close();
+  return status;
+}
+
+int M2XStreamClient::deleteValues(const char* deviceId, const char* streamName,
+                                  const char* from, const char* end) {
+  if (_client->connect(_host, _port)) {
+    DBGLN("%s", "Connected to M2X server!");
+    int length = write_delete_values(&_null_print, from, end);
+    writeDeleteHeader(deviceId, streamName, length);
+    write_delete_values(_client, from, end);
+  } else {
+    DBGLN("%s", "ERROR: Cannot connect to M2X server!");
+    return E_NOCONNECTION;
+  }
+
+  return readStatusCode(true);
+}
+
+static int write_delete_values(Print* print, const char* from,
+                               const char* end) {
+  int bytes = 0;
+  bytes += print->print("{\"from\":\"");
+  bytes += print->print(from);
+  bytes += print->print("\",\"end\":\"");
+  bytes += print->print(end);
+  bytes += print->print("\"}");
+  return bytes;
+}
+
+// Encodes and prints string using Percent-encoding specified
+// in RFC 1738, Section 2.2
+int print_encoded_string(Print* print, const char* str) {
+  int bytes = 0;
+  for (int i = 0; str[i] != 0; i++) {
+    if (((str[i] >= 'A') && (str[i] <= 'Z')) ||
+        ((str[i] >= 'a') && (str[i] <= 'z')) ||
+        ((str[i] >= '0') && (str[i] <= '9')) ||
+        (str[i] == '-') || (str[i] == '_') ||
+        (str[i] == '.') || (str[i] == '~')) {
+      bytes += print->print(str[i]);
+    } else {
+      // Encode all other characters
+      bytes += print->print('%');
+      bytes += print->print(HEX(str[i] / 16));
+      bytes += print->print(HEX(str[i] % 16));
+    }
+  }
+  return bytes;
+}
+
+void M2XStreamClient::writePutHeader(const char* deviceId,
+                                     const char* streamName,
+                                     int contentLength) {
+  _client->print("PUT ");
+  if (_path_prefix)
+    _client->print(_path_prefix);
+  _client->print("/v2/devices/");
+  print_encoded_string(_client, deviceId);
+  _client->print("/streams/");
+  print_encoded_string(_client, streamName);
+  _client->println("/value HTTP/1.0");
+
+  writeHttpHeader(contentLength);
+}
+
+void M2XStreamClient::writeDeleteHeader(const char* deviceId,
+                                        const char* streamName,
+                                        int contentLength) {
+  _client->print("DELETE ");
+  if (_path_prefix)
+    _client->print(_path_prefix);
+  _client->print("/v2/devices/");
+  print_encoded_string(_client, deviceId);
+  _client->print("/streams/");
+  print_encoded_string(_client, streamName);
+  _client->print("/values");
+  _client->println(" HTTP/1.0");
+
+  writeHttpHeader(contentLength);
+}
+
+void M2XStreamClient::writeHttpHeader(int contentLength) {
+  _client->println(USER_AGENT);
+  _client->print("X-M2X-KEY: ");
+  _client->println(_key);
+
+  _client->print("Host: ");
+  print_encoded_string(_client, _host);
+  if (_port != kDefaultM2XPort) {
+    _client->print(":");
+    // port is an integer, does not need encoding
+    _client->print(_port);
+  }
+  _client->println();
+
+  if (contentLength > 0) {
+    _client->println("Content-Type: application/json");
+    DBG("%s", "Content Length: ");
+    DBGLN("%d", contentLength);
+
+    _client->print("Content-Length: ");
+    _client->println(contentLength);
+  }
+  _client->println();
+}
+
+int M2XStreamClient::waitForString(const char* str) {
+  int currentIndex = 0;
+  if (str[currentIndex] == '\0') return E_OK;
+
+  while (true) {
+    while (_client->available()) {
+      char c = _client->read();
+      DBG("%c", c);
+
+      int cmp;
+      if (_case_insensitive) {
+        cmp = tolower(c) - tolower(str[currentIndex]);
+      } else {
+        cmp = c - str[currentIndex];
+      }
+
+      if ((str[currentIndex] == '*') || (cmp == 0)) {
+        currentIndex++;
+        if (str[currentIndex] == '\0') {
+          return E_OK;
+        }
+      } else {
+        // start from the beginning
+        currentIndex = 0;
+      }
+    }
+
+    if (!_client->connected()) {
+      DBGLN("%s", "ERROR: The client is disconnected from the server!");
+
+      close();
+      return E_DISCONNECTED;
+    }
+
+    delay(1000);
+  }
+  // never reached here
+  return E_NOTREACHABLE;
+}
+
+int M2XStreamClient::readStatusCode(bool closeClient) {
+  int responseCode = 0;
+  int ret = waitForString("HTTP/*.* ");
+  if (ret != E_OK) {
+    if (closeClient) close();
+    return ret;
+  }
+
+  // ret is not needed from here(since it must be E_OK), so we can use it
+  // as a regular variable now.
+  ret = 0;
+  while (true) {
+    while (_client->available()) {
+      char c = _client->read();
+      DBG("%c", c);
+
+      responseCode = responseCode * 10 + (c - '0');
+      ret++;
+      if (ret == 3) {
+        if (closeClient) close();
+        return responseCode;
+      }
+    }
+
+    if (!_client->connected()) {
+      DBGLN("%s", "ERROR: The client is disconnected from the server!");
+
+      if (closeClient) close();
+      return E_DISCONNECTED;
+    }
+
+    delay(1000);
+  }
+
+  // never reached here
+  return E_NOTREACHABLE;
+}
+
+int M2XStreamClient::readContentLength() {
+  int ret = waitForString("Content-Length: ");
+  if (ret != E_OK) {
+    return ret;
+  }
+
+  // From now on, ret is not needed, we can use it
+  // to keep the final result
+  ret = 0;
+  while (true) {
+    while (_client->available()) {
+      char c = _client->read();
+      DBG("%c", c);
+
+      if ((c == '\r') || (c == '\n')) {
+        return (ret == 0) ? (E_INVALID) : (ret);
+      } else {
+        ret = ret * 10 + (c - '0');
+      }
+    }
+
+    if (!_client->connected()) {
+      DBGLN("%s", "ERROR: The client is disconnected from the server!");
+
+      return E_DISCONNECTED;
+    }
+
+    delay(1000);
+  }
+
+  // never reached here
+  return E_NOTREACHABLE;
+}
+
+int M2XStreamClient::skipHttpHeader() {
+  return waitForString("\r\n\r\n");
+}
+
+void M2XStreamClient::close() {
+  // Eats up buffered data before closing
+  _client->flush();
+  _client->stop();
+}
+
+int M2XStreamClient::readStreamValue(stream_value_read_callback callback,
+                                     void* context) {
+  const int BUF_LEN = 64;
+  char buf[BUF_LEN];
+
+  int length = readContentLength();
+  if (length < 0) {
+    close();
+    return length;
+  }
+
+  int index = skipHttpHeader();
+  if (index != E_OK) {
+    close();
+    return index;
+  }
+  index = 0;
+
+  stream_parsing_context_state state;
+  state.state = state.index = 0;
+  state.callback = callback;
+  state.context = context;
+
+  jsonlite_parser_callbacks cbs = jsonlite_default_callbacks;
+  cbs.key_found = on_stream_key_found;
+  cbs.number_found = on_stream_number_found;
+  cbs.string_found = on_stream_string_found;
+  cbs.context.client_state = &state;
+
+  jsonlite_parser p = jsonlite_parser_init(jsonlite_parser_estimate_size(5));
+  jsonlite_parser_set_callback(p, &cbs);
+
+  jsonlite_result result = jsonlite_result_unknown;
+  while (index < length) {
+    int i = 0;
+
+    DBG("%s", "Received Data: ");
+    while ((i < BUF_LEN) && _client->available()) {
+      buf[i++] = _client->read();
+      DBG("%c", buf[i - 1]);
+    }
+    DBGLNEND;
+
+    if ((!_client->connected()) &&
+        (!_client->available()) &&
+        ((index + i) < length)) {
+      jsonlite_parser_release(p);
+      close();
+      return E_NOCONNECTION;
+    }
+
+    result = jsonlite_parser_tokenize(p, buf, i);
+    if ((result != jsonlite_result_ok) &&
+        (result != jsonlite_result_end_of_stream)) {
+      jsonlite_parser_release(p);
+      close();
+      return E_JSON_INVALID;
+    }
+
+    index += i;
+  }
+
+  jsonlite_parser_release(p);
+  close();
+  return (result == jsonlite_result_ok) ? (E_OK) : (E_JSON_INVALID);
+}
+
+int M2XStreamClient::readLocation(location_read_callback callback,
+                                  void* context) {
+  const int BUF_LEN = 40;
+  char buf[BUF_LEN];
+
+  int length = readContentLength();
+  if (length < 0) {
+    close();
+    return length;
+  }
+
+  int index = skipHttpHeader();
+  if (index != E_OK) {
+    close();
+    return index;
+  }
+  index = 0;
+
+  location_parsing_context_state state;
+  state.state = state.index = 0;
+  state.callback = callback;
+  state.context = context;
+
+  jsonlite_parser_callbacks cbs = jsonlite_default_callbacks;
+  cbs.key_found = on_location_key_found;
+  cbs.string_found = on_location_string_found;
+  cbs.context.client_state = &state;
+
+  jsonlite_parser p = jsonlite_parser_init(jsonlite_parser_estimate_size(5));
+  jsonlite_parser_set_callback(p, &cbs);
+
+  jsonlite_result result = jsonlite_result_unknown;
+  while (index < length) {
+    int i = 0;
+
+    DBG("%s", "Received Data: ");
+    while ((i < BUF_LEN) && _client->available()) {
+      buf[i++] = _client->read();
+      DBG("%c", buf[i - 1]);
+    }
+    DBGLNEND;
+
+    if ((!_client->connected()) &&
+        (!_client->available()) &&
+        ((index + i) < length)) {
+      jsonlite_parser_release(p);
+      close();
+      return E_NOCONNECTION;
+    }
+
+    result = jsonlite_parser_tokenize(p, buf, i);
+    if ((result != jsonlite_result_ok) &&
+        (result != jsonlite_result_end_of_stream)) {
+      jsonlite_parser_release(p);
+      close();
+      return E_JSON_INVALID;
+    }
+
+    index += i;
+  }
+
+  jsonlite_parser_release(p);
+  close();
+  return (result == jsonlite_result_ok) ? (E_OK) : (E_JSON_INVALID);
+}