Pass string objects by reference (#5378)

Author: dav1901

cores/esp8266/MD5Builder.h

@@ -34,10 +34,10 @@ class MD5Builder {
     void add(const uint8_t * data, const uint16_t len);
     void add(const char * data){ add((const uint8_t*)data, strlen(data)); }
     void add(char * data){ add((const char*)data); }
-    void add(const String data){ add(data.c_str()); }
+    void add(const String& data){ add(data.c_str()); }
     void addHexString(const char * data);
     void addHexString(char * data){ addHexString((const char*)data); }
-    void addHexString(const String data){ addHexString(data.c_str()); }
+    void addHexString(const String& data){ addHexString(data.c_str()); }
     bool addStream(Stream & stream, const size_t maxLen);
     void calculate(void);
     void getBytes(uint8_t * output);

libraries/ESP8266WiFi/src/ESP8266WiFiSTA.cpp

@@ -487,7 +487,7 @@ bool ESP8266WiFiSTAClass::hostname(const char* aHostname) {
  * @param aHostname max length:32
  * @return ok
  */
-bool ESP8266WiFiSTAClass::hostname(String aHostname) {
+bool ESP8266WiFiSTAClass::hostname(const String& aHostname) {
     return hostname((char*) aHostname.c_str());
 }
 

libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h

@@ -71,7 +71,7 @@ class ESP8266WiFiSTAClass {
         String hostname();
         bool hostname(char* aHostname);
         bool hostname(const char* aHostname);
-        bool hostname(String aHostname);
+        bool hostname(const String& aHostname);
 
         // STA WiFi info
         wl_status_t status();

libraries/ESP8266WiFi/src/WiFiClient.cpp

@@ -132,7 +132,7 @@ int WiFiClient::connect(const char* host, uint16_t port)
     return 0;
 }
 
-int WiFiClient::connect(const String host, uint16_t port)
+int WiFiClient::connect(const String& host, uint16_t port)
 {
     return connect(host.c_str(), port);
 }

libraries/ESP8266WiFi/src/WiFiClient.h

@@ -55,7 +55,7 @@ class WiFiClient : public Client, public SList<WiFiClient> {
   uint8_t status();
   virtual int connect(IPAddress ip, uint16_t port);
   virtual int connect(const char *host, uint16_t port);
-  virtual int connect(const String host, uint16_t port);
+  virtual int connect(const String& host, uint16_t port);
   virtual size_t write(uint8_t);
   virtual size_t write(const uint8_t *buf, size_t size);
   virtual size_t write_P(PGM_P buf, size_t size);

libraries/ESP8266WiFi/src/WiFiClientSecureAxTLS.cpp

@@ -116,7 +116,7 @@ int WiFiClientSecure::connect(const char* name, uint16_t port)
     return _connectSSL(name);
 }
 
-int WiFiClientSecure::connect(const String host, uint16_t port)
+int WiFiClientSecure::connect(const String& host, uint16_t port)
 {
     return connect(host.c_str(), port);
 }

libraries/ESP8266WiFi/src/WiFiClientSecureAxTLS.h

@@ -36,7 +36,7 @@ class WiFiClientSecure : public WiFiClient {
   ~WiFiClientSecure() override;
 
   int connect(IPAddress ip, uint16_t port) override;
-  int connect(const String host, uint16_t port) override;
+  int connect(const String& host, uint16_t port) override;
   int connect(const char* name, uint16_t port) override;
 
   bool verify(const char* fingerprint, const char* domain_name);

libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp

@@ -218,7 +218,7 @@ int WiFiClientSecure::connect(const char* name, uint16_t port) {
   return _connectSSL(name);
 }
 
-int WiFiClientSecure::connect(const String host, uint16_t port) {
+int WiFiClientSecure::connect(const String& host, uint16_t port) {
   return connect(host.c_str(), port);
 }
 
@@ -1108,7 +1108,7 @@ bool WiFiClientSecure::probeMaxFragmentLength(const char* name, uint16_t port, u
   return WiFiClientSecure::probeMaxFragmentLength(remote_addr, port, len);
 }
 
-bool WiFiClientSecure::probeMaxFragmentLength(const String host, uint16_t port, uint16_t len) {
+bool WiFiClientSecure::probeMaxFragmentLength(const String& host, uint16_t port, uint16_t len) {
   return WiFiClientSecure::probeMaxFragmentLength(host.c_str(), port, len);
 }
 

libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.h

@@ -37,7 +37,7 @@ class WiFiClientSecure : public WiFiClient {
     ~WiFiClientSecure() override;
 
     int connect(IPAddress ip, uint16_t port) override;
-    int connect(const String host, uint16_t port) override;
+    int connect(const String& host, uint16_t port) override;
     int connect(const char* name, uint16_t port) override;
 
     uint8_t connected() override;
@@ -119,7 +119,7 @@ class WiFiClientSecure : public WiFiClient {
     // Check for Maximum Fragment Length support for given len
     static bool probeMaxFragmentLength(IPAddress ip, uint16_t port, uint16_t len);
     static bool probeMaxFragmentLength(const char *hostname, uint16_t port, uint16_t len);
-    static bool probeMaxFragmentLength(const String host, uint16_t port, uint16_t len);
+    static bool probeMaxFragmentLength(const String& host, uint16_t port, uint16_t len);
 
     // AXTLS compatible wrappers
     // Cannot implement this mode, we need FP before we can connect: bool verify(const char* fingerprint, const char* domain_name)

libraries/ESP8266mDNS/ESP8266mDNS.h

@@ -76,23 +76,23 @@ class MDNSResponder {
   void addService(const char *service, const char *proto, uint16_t port){
     addService((char *)service, (char *)proto, port);
   }
-  void addService(String service, String proto, uint16_t port){
+  void addService(const String& service, const String& proto, uint16_t port){
     addService(service.c_str(), proto.c_str(), port);
   }
 
   bool addServiceTxt(char *name, char *proto, char * key, char * value);
   bool addServiceTxt(const char *name, const char *proto, const char *key,const char * value){
     return addServiceTxt((char *)name, (char *)proto, (char *)key, (char *)value);
   }
-  bool addServiceTxt(String name, String proto, String key, String value){
+  bool addServiceTxt(const String& name, const String& proto, const String& key, const String& value){
     return addServiceTxt(name.c_str(), proto.c_str(), key.c_str(), value.c_str());
   }
 
   int queryService(char *service, char *proto);
   int queryService(const char *service, const char *proto){
     return queryService((char *)service, (char *)proto);
   }
-  int queryService(String service, String proto){
+  int queryService(const String& service, const String& proto){
     return queryService(service.c_str(), proto.c_str());
   }
   String hostname(int idx);