Revision 17:9db4a86b876a, committed 2015-12-28

Comitter:

citrusbyte

Date:

Mon Dec 28 13:06:27 2015 +0000

Parent:

16:7903152de19f

Child:

18:510895884768

Commit message:

Update comments to TimeService

Changed in this revision

--- a/M2XStreamClient.cpp	Mon Dec 28 12:48:19 2015 +0000
+++ b/M2XStreamClient.cpp	Mon Dec 28 13:06:27 2015 +0000
@@ -1,527 +1,147 @@
 #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
+static int fill_iso8601_timestamp(int32_t seconds, int32_t milli,
+                                  char* buffer, int* length);
 
-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;
+TimeService::TimeService(M2XStreamClient* client) : _client(client) {
 }
 
-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);
+int TimeService::init() {
+  _timer.start();
+  return reset();
 }
 
-int M2XStreamClient::getTimestamp32(int32_t *ts) {
-  // The maximum value of signed 64-bit integer is 0x7fffffffffffffff,
-  // which is 9223372036854775807. It consists of 19 characters, so a
-  // buffer of 20 is definitely enough here
-  int length = 20;
-  char buffer[20];
-  int status = getTimestamp(buffer, &length);
-  if (status == 200) {
-    int32_t result = 0;
-    for (int i = 0; i < length; i++) {
-      result = result * 10 + (buffer[i] - '0');
-    }
-    if (ts != NULL) { *ts = result; }
-  }
-  return status;
-}
+int TimeService::reset() {
+  int32_t ts;
+  int status = _client->getTimestamp32(&ts);
 
-int M2XStreamClient::getTimestamp(char* buffer, int *bufferLength) {
-  if (bufferLength == NULL) { return E_INVALID; }
-  if (_client->connect(_host, _port)) {
-    DBGLN("%s", "Connected to M2X server!");
-    _client->println("GET /v2/time/seconds HTTP/1.0");
-
-    writeHttpHeader(-1);
-  } else {
-    DBGLN("%s", "ERROR: Cannot connect to M2X server!");
-    return E_NOCONNECTION;
+  if (m2x_status_is_success(status)) {
+    _server_timestamp = ts;
+    _local_last_milli = _timer.read_ms();
   }
-  int status = readStatusCode(false);
-  if (status == 200) {
-    int length = readContentLength();
-    if (length < 0) {
-      close();
-      return length;
-    }
-    if (*bufferLength < length) {
-      *bufferLength = length;
-      return E_BUFFER_TOO_SMALL;
-    }
-    *bufferLength = length;
-    int index = skipHttpHeader();
-    if (index != E_OK) {
-      close();
-      return index;
-    }
-    index = 0;
-    while (index < length) {
-      DBG("%s", "Received Data: ");
-      while ((index < length) && _client->available()) {
-        buffer[index++] = _client->read();
-        DBG("%c", buffer[index - 1]);
-      }
-      DBGLNEND;
 
-      if ((!_client->connected()) &&
-          (index < length)) {
-        close();
-        return E_NOCONNECTION;
-      }
-
-      delay(200);
-    }
-  }
-  close();
   return status;
 }
 
-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);
+int TimeService::getTimestamp(char* buffer, int* length) {
+  uint32_t now = _timer.read_ms();
+  if (now < _local_last_milli) {
+    // In case of a timestamp overflow, we reset the server timestamp recorded.
+    // Notice that unlike Arduino, mbed would overflow every 30 minutes,
+    // so if 2 calls to this API are more than 30 minutes apart, we are
+    // likely to run into troubles. This is a limitation of the current
+    // mbed platform. However, we argue that it might be a rare case that
+    // 2 calls to this are 30 minutes apart. In most cases, we would call
+    // this API every few seconds or minutes, this won't be a huge problem.
+    // However, if you have a use case that would require 2 intervening
+    // calls to this be 30 minutes apart, you might want to leverage a RTC
+    // clock instead of the simple ticker here.
+    int status = reset();
+    if (!m2x_status_is_success(status)) { return status; }
+    now = _timer.read_ms();
   }
-  _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);
+  if (now < _local_last_milli) {
+    // We have already reseted the timestamp, so this cannot happen,
+    // an HTTP request cannot last 30 minutes, something else must be wrong
+    // here.
+    return E_TIMESTAMP_ERROR;
   }
-  _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;
+  uint32_t diff = now - _local_last_milli;
+  _local_last_milli = now;
+  _server_timestamp += (int32_t) (diff / 1000); // Milliseconds to seconds
+  return fill_iso8601_timestamp(_server_timestamp, (int32_t) (diff % 1000),
+                                buffer, length);
 }
 
-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;
-    }
+#define SIZE_ISO_8601 25
+static inline bool is_leap_year(int16_t y) {
+  return ((1970 + y) > 0) &&
+      !((1970 + y) % 4) &&
+      (((1970 + y) % 100) || !((1970 + y) % 400));
+}
+static inline int32_t days_in_year(int16_t y) {
+  return is_leap_year(y) ? 366 : 365;
+}
+static const uint8_t MONTH_DAYS[]={31,28,31,30,31,30,31,31,30,31,30,31};
 
-    delay(1000);
-  }
-
-  // never reached here
-  return E_NOTREACHABLE;
-}
-
-int M2XStreamClient::skipHttpHeader() {
-  return waitForString("\n\r\n");
-}
+static int fill_iso8601_timestamp(int32_t timestamp, int32_t milli,
+                                  char* buffer, int* length) {
+  int16_t year;
+  int8_t month, month_length;
+  int32_t day;
+  int8_t hour, minute, second;
 
-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;
+  if (*length < SIZE_ISO_8601) {
+    *length = SIZE_ISO_8601;
+    return E_BUFFER_TOO_SMALL;
   }
 
-  int index = skipHttpHeader();
-  if (index != E_OK) {
-    close();
-    return index;
-  }
-  index = 0;
+  second = timestamp % 60;
+  timestamp /= 60; // now it is minutes
 
-  stream_parsing_context_state state;
-  state.state = state.index = 0;
-  state.callback = callback;
-  state.context = context;
+  minute = timestamp % 60;
+  timestamp /= 60; // now it is hours
 
-  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);
+  hour = timestamp % 24;
+  timestamp /= 24; // now it is days
 
-  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;
+  year = 0;
+  day = 0;
+  while ((day += days_in_year(year)) <= timestamp) {
+    year++;
+  }
+  day -= days_in_year(year);
+  timestamp -= day; // now it is days in this year, starting at 0
 
-    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;
+  day = 0;
+  month_length = 0;
+  for (month = 0; month < 12; month++) {
+    if (month == 1) {
+      // February
+      month_length = is_leap_year(year) ? 29 : 28;
+    } else {
+      month_length = MONTH_DAYS[month];
     }
 
-    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;
+    if (timestamp >= month_length) {
+      timestamp -= month_length;
+    } else {
+      break;
+    }
   }
+  year = 1970 + year;
+  month++; // offset by 1
+  day = timestamp + 1;
 
-  int index = skipHttpHeader();
-  if (index != E_OK) {
-    close();
-    return index;
-  }
-  index = 0;
+  int i = 0, j = 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;
+  // NOTE: It seems the snprintf implementation in Arduino has bugs,
+  // we have to manually piece the string together here.
+#define INT_TO_STR(v_, width_) \
+  for (j = 0; j < (width_); j++) { \
+    buffer[i + (width_) - 1 - j] = '0' + ((v_) % 10); \
+    (v_) /= 10; \
+  } \
+  i += (width_)
 
-  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;
+  INT_TO_STR(year, 4);
+  buffer[i++] = '-';
+  INT_TO_STR(month, 2);
+  buffer[i++] = '-';
+  INT_TO_STR(day, 2);
+  buffer[i++] = 'T';
+  INT_TO_STR(hour, 2);
+  buffer[i++] = ':';
+  INT_TO_STR(minute, 2);
+  buffer[i++] = ':';
+  INT_TO_STR(second, 2);
+  buffer[i++] = '.';
+  INT_TO_STR(milli, 3);
+  buffer[i++] = 'Z';
+  buffer[i++] = '\0';
 
-    if ((!_client->connected()) &&
-        (!_client->available()) &&
-        ((index + i) < length)) {
-      jsonlite_parser_release(p);
-      close();
-      return E_NOCONNECTION;
-    }
+#undef INT_TO_STR
 
-    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);
+  *length = i;
+  return E_OK;
 }