chore: point strings optimization

Author: soudrug

src/InfluxData.cpp

@@ -29,7 +29,8 @@
 
 void InfluxData::setTimestamp(long int seconds) 
 { 
-    _timestamp = timeStampToString(seconds) + "000000000"; 
+    _timestamp = timeStampToString(seconds,9);
+    strcat(_timestamp, "000000000"); 
 }
 
  String InfluxData::toString() const { 

src/Options.cpp

@@ -32,8 +32,12 @@ WriteOptions& WriteOptions::addDefaultTag(const String &name, const String &valu
     if(_defaultTags.length() > 0) {
         _defaultTags += ',';
     }
-    _defaultTags += escapeKey(name);
+    char *s = escapeKey(name);
+    _defaultTags += s;
+    delete [] s;
+    s = escapeKey(value);
     _defaultTags += '=';
-    _defaultTags += escapeKey(value);
+    _defaultTags += s;
+    delete [] s;
     return *this; 
 }

src/Point.cpp

@@ -28,32 +28,38 @@
 #include "Point.h"
 #include "util/helpers.h"
 
-Point::Point(const String & measurement):
-    _measurement(escapeKey(measurement, false)),
-    _tags(""),
-    _fields(""),
-    _timestamp("")
+Point::Point(const String & measurement)
 {
+    _measurement = escapeKey(measurement, false);
+    _timestamp = nullptr;
+}
 
+Point::~Point() {
+    delete [] _measurement;
+    delete [] _timestamp;
 }
 
 void Point::addTag(const String &name, String value) {
     if(_tags.length() > 0) {
         _tags += ',';
     }
-    _tags += escapeKey(name);
+    char *s = escapeKey(name);
+    _tags += s;
+    delete [] s;
     _tags += '=';
-    _tags += escapeKey(value);
+    s = escapeKey(value);
+    _tags += s;
+    delete [] s;
 }
 
 void Point::addField(const String &name, long long value) {
-  char buff[50];
+  char buff[23];
   snprintf(buff, 50, "%lld", value);
   putField(name, String(buff)+"i");
 }
 
 void Point::addField(const String &name, unsigned long long value) {
-  char buff[50];
+  char buff[23];
   snprintf(buff, 50, "%llu", value);
   putField(name, String(buff)+"i");
 }
@@ -110,7 +116,9 @@ void Point::putField(const String &name, const String &value) {
     if(_fields.length() > 0) {
         _fields += ',';
     }
-    _fields += escapeKey(name);
+    char *s = escapeKey(name);
+    _fields += s;
+    delete [] s;
     _fields += '=';
     _fields += value;
 }
@@ -121,7 +129,7 @@ String Point::toLineProtocol(const String &includeTags) const {
 
 String Point::createLineProtocol(const String &incTags) const {
     String line;
-    line.reserve(_measurement.length() + 1 + incTags.length() + 1 + _tags.length() + 1 + _fields.length() + 1 + _timestamp.length());
+    line.reserve(strLen(_measurement) + 1 + incTags.length() + 1 + _tags.length() + 1 + _fields.length() + 1 + strLen(_timestamp));
     line += _measurement;
     if(incTags.length()>0) {
         line += ",";
@@ -160,22 +168,32 @@ void  Point::setTime(WritePrecision precision) {
             setTime(getTimeStamp(&tv,0));
             break;
         case WritePrecision::NoTime:
-            _timestamp = "";
+            setTime((char *)nullptr);
             break;
     }
 }
 
 void  Point::setTime(unsigned long long timestamp) {
-    _timestamp = timeStampToString(timestamp);
+    setTime(timeStampToString(timestamp));
+}
+
+void Point::setTime(const String &timestamp) {
+    setTime(cloneStr(timestamp.c_str()));
+}
+
+void Point::setTime(const char *timestamp) {
+    setTime(cloneStr(timestamp));    
 }
 
-void  Point::setTime(const String &timestamp) {
-    _timestamp = timestamp;
+void Point::setTime(char *timestamp) {
+    delete [] _timestamp;
+    timestamp = timestamp;
 }
 
 void  Point::clearFields() {
     _fields = (char *)nullptr;
-    _timestamp = (char *)nullptr;
+    delete [] _timestamp;
+    _timestamp = nullptr;
 }
 
 void Point:: clearTags() {

src/Point.h

@@ -39,6 +39,7 @@ class Point {
 friend class InfluxDBClient;
   public:
     Point(const String &measurement);
+    virtual ~Point();
     // Adds string tag 
     void addTag(const String &name, String value);
     // Add field with various types
@@ -62,6 +63,8 @@ friend class InfluxDBClient;
     void setTime(unsigned long long timestamp);
     // Set timestamp in offset since epoch (1.1.1970 00:00:00). Correct precision must be set InfluxDBClient::setWriteOptions.
     void setTime(const String &timestamp);
+    // Set timestamp in offset since epoch (1.1.1970 00:00:00). Correct precision must be set InfluxDBClient::setWriteOptions.
+    void setTime(const char *timestamp);
     // Clear all fields. Usefull for reusing point  
     void clearFields();
     // Clear tags
@@ -71,19 +74,21 @@ friend class InfluxDBClient;
     // True if a point contains at least one tag
     bool hasTags() const   { return _tags.length() > 0; }
     // True if a point contains timestamp
-    bool hasTime() const   { return _timestamp.length() > 0; }
+    bool hasTime() const   { return strLen(_timestamp) > 0; }
     // Creates line protocol with optionally added tags
     String toLineProtocol(const String &includeTags = "") const;
     // returns current timestamp
     String getTime() const { return _timestamp; } 
   protected:
-    String _measurement;
+    char *_measurement;
     String _tags;
     String _fields;
-    String _timestamp;
+    char *_timestamp;
   protected:    
     // method for formating field into line protocol
     void putField(const String &name, const String &value);
+    // set timestamp
+    void setTime(char *timestamp);
     // Creates line protocol string
     String createLineProtocol(const String &incTags) const;
 };

src/util/helpers.cpp

@@ -68,36 +68,34 @@ unsigned long long getTimeStamp(struct timeval *tv, int secFracDigits) {
     return tsVal;
 }
 
-String timeStampToString(unsigned long long timestamp) {
-    static char buff[50];
-    snprintf(buff, 50, "%llu", timestamp);
-    return String(buff);
+char *timeStampToString(unsigned long long timestamp, int extraCharsSpace) {
+    //22 is max long long string length (18)
+    char *buff = new char[22+extraCharsSpace+1];
+    snprintf(buff, 22, "%llu", timestamp);
+    return buff;
 }
 
-String escapeKey(const String &key, bool escapeEqual) {
-    String ret;
-    ret.reserve(key.length()+5); //5 is estimate of  chars needs to escape,
+static char escapeChars[] = "=\r\n\t ,";
 
-    for (char c: key)
-    {
-        switch (c)
-        {
-            case '\r':
-            case '\n':
-            case '\t':
-            case ' ':
-            case ',':
-                ret += '\\';
-                break;
-            case '=':
-                if(escapeEqual) {
-                    ret += '\\';
-                }
-                break;
+char *escapeKey(const String &key, bool escapeEqual) {
+    char c,*ret,*d,*s = (char *)key.c_str();
+    int n = 0;
+    while ((c = *s++)) {
+        if(strchr(escapeEqual?escapeChars:escapeChars+1, c)) {
+            n++;
         }
-        ret += c;
     }
-    return ret;
+    ret = new char[key.length()+n+1];
+    s = (char *)key.c_str();
+    d = ret;
+    while ((c = *s++)) {
+       if (strchr(escapeEqual?escapeChars:escapeChars+1,c)) {
+           *d++ = '\\';
+      }
+      *d++ = c;
+   }
+   *d = 0;
+   return ret;
 }
 
 String escapeValue(const char *value) {
@@ -175,3 +173,16 @@ uint8_t getNumLength(long long l) {
     } while(l);
     return c;
 }
+
+char *cloneStr(const char *str) {
+  char *ret = new char[strlen(str)+1];
+  strcpy(ret, str);
+  return ret;
+}
+
+size_t strLen(const char *str) {
+    if(!str) {
+        return 0;
+    }
+    return strlen(str);
+}

src/util/helpers.h

@@ -39,10 +39,10 @@ void timeSync(const char *tzInfo, const char* ntpServer1, const char* ntpServer2
 unsigned long long getTimeStamp(struct timeval *tv, int secFracDigits = 3);
 
 // Converts unsigned long long timestamp to String
-String timeStampToString(unsigned long long timestamp);
+char *timeStampToString(unsigned long long timestamp, int extraCharsSpace = 0);
 
 // Escape invalid chars in measurement, tag key, tag value and field key
-String escapeKey(const String &key, bool escapeEqual = true);
+char *escapeKey(const String &key, bool escapeEqual = true);
 
 // Escape invalid chars in field value
 String escapeValue(const char *value);
@@ -54,5 +54,10 @@ bool isValidID(const char *idString);
 const char *bool2string(bool val);
 // Returns number of digits
 uint8_t getNumLength(long long l);
+// Like strdup, but uses new
+char *cloneStr(const char *str);
+// Like strlen, but accepts nullptr
+size_t strLen(const char *str);
+
 
 #endif //_INFLUXDB_CLIENT_HELPERS_H

test/TestBase.cpp

@@ -43,7 +43,7 @@ Point *TestBase::createPoint(const String &measurement) {
     return point;
 }
 
-bool testAssertm(int line, bool state,String message) {
+bool testAssertm(int line, bool state, const String &message) {
   if(!state) {
     ++TestBase::failures;
     Serial.printf("Assert failure line %d%s%s\n", line, message.length()>0?": ":"",message.c_str());

test/TestBase.h

@@ -56,7 +56,7 @@ class TestBase {
     static Point *createPoint(const String &measurement);
 };
 
-bool testAssertm(int line, bool state,String message);
+bool testAssertm(int line, bool state,const String &message);
 bool testAssert(int line, bool state);
 
 #endif //_E2E_TEST_H_