Refactored OnboardingCodesUtil to decrease memory footprint. (#18318)

* Refactored OnboardingCodesUtil to decrease memory footprint.

OnboardingCodesUtil uses SetupPayload object that contains
a lot unnecessary data and takes a lot of flash.

Replaced using SetupPayload with PayloadContents
and QRCodeSetupPayloadGenerator with QRCodeBasicSetupPayloadGenerator.
It allowed to save about 3.28 k of flash for nrfconnect platform.

* Fixed linux builds

* Changed char span size for codes buffers and fixed builds

* Added documentation for OnboardingCodesUtil methods
* Changed char span sizes returned by codes encoding methods
to not include null terminator
* Aligned examples using GetQRCode and GetManualPairingCode
to the new API.

* Fixed EFR32 build

* Addressed review comments regarding reducing span size.

* Fixed unit tests to reset span size after every encoding call.

examples/all-clusters-app/esp32/main/DeviceWithDisplay.cpp

@@ -17,6 +17,7 @@
  */
 
 #include "DeviceWithDisplay.h"
+#include <setup_payload/QRCodeSetupPayloadGenerator.h>
 
 #if CONFIG_HAVE_DISPLAY
 using namespace ::chip;
@@ -651,8 +652,11 @@ esp_err_t InitM5Stack(std::string qrCodeText)
 
 void InitDeviceDisplay()
 {
-    std::string qrCodeText;
+    // Create buffer for QR code that can fit max size and null terminator.
+    char qrCodeBuffer[chip::QRCodeBasicSetupPayloadGenerator::kMaxQRCodeBase38RepresentationLength + 1];
+    chip::MutableCharSpan qrCodeText(qrCodeBuffer);
 
+    // Get QR Code and emulate its content using NFC tag
     GetQRCode(qrCodeText, chip::RendezvousInformationFlags(CONFIG_RENDEZVOUS_MODE));
 
     // Initialize the display device.
@@ -681,12 +685,12 @@ void InitDeviceDisplay()
 
 #if CONFIG_DEVICE_TYPE_M5STACK
 
-    InitM5Stack(qrCodeText);
+    InitM5Stack(qrCodeText.data());
 
 #elif CONFIG_DEVICE_TYPE_ESP32_WROVER_KIT
 
     // Display the QR Code
-    QRCodeScreen qrCodeScreen(qrCodeText);
+    QRCodeScreen qrCodeScreen(qrCodeText.data());
     qrCodeScreen.Display();
 
 #endif

examples/chef/esp32/main/main.cpp

@@ -45,6 +45,7 @@
 #include <app/server/Dnssd.h>
 #include <app/util/af-event.h>
 #include <app/util/af.h>
+#include <setup_payload/QRCodeSetupPayloadGenerator.h>
 
 #include "Display.h"
 #include "QRCodeScreen.h"
@@ -137,7 +138,9 @@ const char * TAG = "chef-app";
 #if CONFIG_HAVE_DISPLAY
 void printQRCode()
 {
-    std::string qrCodeText;
+    // Create buffer for QR code that can fit max size and null terminator.
+    char qrCodeBuffer[chip::QRCodeBasicSetupPayloadGenerator::kMaxQRCodeBase38RepresentationLength + 1];
+    chip::MutableCharSpan qrCodeText(qrCodeBuffer);
 
     GetQRCode(qrCodeText, chip::RendezvousInformationFlags(CONFIG_RENDEZVOUS_MODE));
 
@@ -153,8 +156,8 @@ void printQRCode()
     ScreenManager::Init();
 
     ESP_LOGI(TAG, "Opening QR code screen");
-    ESP_LOGI(TAG, "QR CODE Text: '%s'", qrCodeText.c_str());
-    ScreenManager::PushScreen(chip::Platform::New<QRCodeScreen>(qrCodeText));
+    ESP_LOGI(TAG, "QR CODE Text: '%s'", qrCodeText.data());
+    ScreenManager::PushScreen(chip::Platform::New<QRCodeScreen>(qrCodeText.data()));
 }
 #endif // CONFIG_HAVE_DISPLAY
 

examples/common/pigweed/rpc_services/Device.h

@@ -28,6 +28,7 @@
 #include "platform/ConfigurationManager.h"
 #include "platform/DiagnosticDataProvider.h"
 #include "platform/PlatformManager.h"
+#include <setup_payload/QRCodeSetupPayloadGenerator.h>
 
 namespace chip {
 namespace rpc {
@@ -146,10 +147,12 @@ class Device : public pw_rpc::nanopb::Device::Service<Device>
             snprintf(response.serial_number, sizeof(response.serial_number), CHIP_DEVICE_CONFIG_TEST_SERIAL_NUMBER);
         }
 
-        std::string qrCodeText;
+        // Create buffer for QR code that can fit max size and null terminator.
+        char qrCodeBuffer[chip::QRCodeBasicSetupPayloadGenerator::kMaxQRCodeBase38RepresentationLength + 1];
+        chip::MutableCharSpan qrCodeText(qrCodeBuffer);
         if (GetQRCode(qrCodeText, chip::RendezvousInformationFlags(chip::RendezvousInformationFlag::kBLE)) == CHIP_NO_ERROR)
         {
-            snprintf(response.pairing_info.qr_code, sizeof(response.pairing_info.qr_code), "%s", qrCodeText.c_str());
+            snprintf(response.pairing_info.qr_code, sizeof(response.pairing_info.qr_code), "%s", qrCodeText.data());
             GetQRCodeUrl(response.pairing_info.qr_code_url, sizeof(response.pairing_info.qr_code_url), qrCodeText);
             response.has_pairing_info = true;
         }

examples/light-switch-app/efr32/src/AppTask.cpp

@@ -239,11 +239,13 @@ CHIP_ERROR AppTask::Init()
 
 // Print setup info on LCD if available
 #ifdef DISPLAY_ENABLED
-    std::string QRCode;
+    // Create buffer for QR code that can fit max size and null terminator.
+    char qrCodeBuffer[chip::QRCodeBasicSetupPayloadGenerator::kMaxQRCodeBase38RepresentationLength + 1];
+    chip::MutableCharSpan QRCode(qrCodeBuffer);
 
     if (GetQRCode(QRCode, chip::RendezvousInformationFlags(chip::RendezvousInformationFlag::kBLE)) == CHIP_NO_ERROR)
     {
-        LCDWriteQRCode((uint8_t *) QRCode.c_str());
+        LCDWriteQRCode((uint8_t *) QRCode.data());
     }
     else
     {

examples/lighting-app/efr32/src/AppTask.cpp

@@ -283,11 +283,13 @@ CHIP_ERROR AppTask::Init()
 
 // Print setup info on LCD if available
 #ifdef DISPLAY_ENABLED
-    std::string QRCode;
+    // Create buffer for QR code that can fit max size and null terminator.
+    char qrCodeBuffer[chip::QRCodeBasicSetupPayloadGenerator::kMaxQRCodeBase38RepresentationLength + 1];
+    chip::MutableCharSpan QRCode(qrCodeBuffer);
 
     if (GetQRCode(QRCode, chip::RendezvousInformationFlags(chip::RendezvousInformationFlag::kBLE)) == CHIP_NO_ERROR)
     {
-        LCDWriteQRCode((uint8_t *) QRCode.c_str());
+        LCDWriteQRCode((uint8_t *) QRCode.data());
     }
     else
     {

examples/lock-app/efr32/src/AppTask.cpp

@@ -274,11 +274,13 @@ CHIP_ERROR AppTask::Init()
 
 // Print setup info on LCD if available
 #ifdef DISPLAY_ENABLED
-    std::string QRCode;
+    // Create buffer for QR code that can fit max size and null terminator.
+    char qrCodeBuffer[chip::QRCodeBasicSetupPayloadGenerator::kMaxQRCodeBase38RepresentationLength + 1];
+    chip::MutableCharSpan QRCode(qrCodeBuffer);
 
     if (GetQRCode(QRCode, chip::RendezvousInformationFlags(chip::RendezvousInformationFlag::kBLE)) == CHIP_NO_ERROR)
     {
-        LCDWriteQRCode((uint8_t *) QRCode.c_str());
+        LCDWriteQRCode((uint8_t *) QRCode.data());
     }
     else
     {

examples/ota-requestor-app/efr32/src/AppTask.cpp

@@ -170,11 +170,13 @@ CHIP_ERROR AppTask::Init()
 
 // Print setup info on LCD if available
 #ifdef DISPLAY_ENABLED
-    std::string QRCode;
+    // Create buffer for QR code that can fit max size and null terminator.
+    char qrCodeBuffer[chip::QRCodeBasicSetupPayloadGenerator::kMaxQRCodeBase38RepresentationLength + 1];
+    chip::MutableCharSpan QRCode(qrCodeBuffer);
 
     if (GetQRCode(QRCode, chip::RendezvousInformationFlags(chip::RendezvousInformationFlag::kBLE)) == CHIP_NO_ERROR)
     {
-        LCDWriteQRCode((uint8_t *) QRCode.c_str());
+        LCDWriteQRCode((uint8_t *) QRCode.data());
     }
     else
     {

examples/platform/linux/AppMain.cpp

@@ -241,7 +241,7 @@ int ChipLinuxAppInit(int argc, char * const argv[], OptionSet * customOptions)
                                                    LinuxDeviceOptions::GetInstance());
     SuccessOrExit(err);
 
-    err = GetSetupPayload(LinuxDeviceOptions::GetInstance().payload, rendezvousFlags);
+    err = GetPayloadContents(LinuxDeviceOptions::GetInstance().payload, rendezvousFlags);
     SuccessOrExit(err);
 
     ConfigurationMgr().LogDeviceConfig();
@@ -254,7 +254,7 @@ int ChipLinuxAppInit(int argc, char * const argv[], OptionSet * customOptions)
     {
         // For testing of manual pairing code with custom commissioning flow
         ChipLogProgress(NotSpecified, "==== Onboarding payload for Custom Commissioning Flows ====");
-        err = GetSetupPayload(LinuxDeviceOptions::GetInstance().payload, rendezvousFlags);
+        err = GetPayloadContents(LinuxDeviceOptions::GetInstance().payload, rendezvousFlags);
         SuccessOrExit(err);
 
         LinuxDeviceOptions::GetInstance().payload.commissioningFlow = chip::CommissioningFlow::kCustom;

examples/platform/linux/Options.h

@@ -38,7 +38,7 @@
 
 struct LinuxDeviceOptions
 {
-    chip::SetupPayload payload;
+    chip::PayloadContents payload;
     chip::Optional<uint16_t> discriminator;
     chip::Optional<std::vector<uint8_t>> spake2pVerifier;
     chip::Optional<std::vector<uint8_t>> spake2pSalt;

examples/window-app/efr32/include/WindowAppImpl.h

@@ -21,6 +21,7 @@
 #include <LEDWidget.h>
 #include <WindowApp.h>
 #include <queue.h>
+#include <setup_payload/QRCodeSetupPayloadGenerator.h>
 #include <sl_simple_button_instances.h>
 #include <string>
 #include <task.h>
@@ -77,7 +78,9 @@ class WindowAppImpl : public WindowApp
     QueueHandle_t mQueue = nullptr;
     LEDWidget mStatusLED;
     LEDWidget mActionLED;
-    std::string mQRCode;
+
+    // Get QR Code and emulate its content using NFC tag
+    char mQRCodeBuffer[chip::QRCodeBasicSetupPayloadGenerator::kMaxQRCodeBase38RepresentationLength + 1];
     Timer mIconTimer;
     LcdIcon mIcon = LcdIcon::None;
 };

examples/window-app/efr32/src/WindowAppImpl.cpp

@@ -433,9 +433,10 @@ void WindowAppImpl::UpdateLCD()
 #ifdef QR_CODE_ENABLED
     else
     {
-        if (GetQRCode(mQRCode, chip::RendezvousInformationFlags(chip::RendezvousInformationFlag::kBLE)) == CHIP_NO_ERROR)
+        chip::MutableCharSpan qrCode(mQRCodeBuffer);
+        if (GetQRCode(qrCode, chip::RendezvousInformationFlags(chip::RendezvousInformationFlag::kBLE)) == CHIP_NO_ERROR)
         {
-            LCDWriteQRCode((uint8_t *) mQRCode.c_str());
+            LCDWriteQRCode((uint8_t *) qrCode.data());
         }
     }
 #endif // QR_CODE_ENABLED

src/app/server/OnboardingCodesUtil.cpp

@@ -37,29 +37,29 @@ using namespace ::chip::DeviceLayer;
 
 void PrintOnboardingCodes(chip::RendezvousInformationFlags aRendezvousFlags)
 {
-    chip::SetupPayload payload;
+    chip::PayloadContents payload;
 
-    CHIP_ERROR err = GetSetupPayload(payload, aRendezvousFlags);
+    CHIP_ERROR err = GetPayloadContents(payload, aRendezvousFlags);
     if (err != CHIP_NO_ERROR)
     {
-        ChipLogError(AppServer, "GetSetupPayload() failed: %s", chip::ErrorStr(err));
+        ChipLogError(AppServer, "GetPayloadContents() failed: %s", chip::ErrorStr(err));
     }
 
     PrintOnboardingCodes(payload);
 }
 
-void PrintOnboardingCodes(const chip::SetupPayload & payload)
+void PrintOnboardingCodes(const chip::PayloadContents & payload)
 {
-    std::string qrCode;
-    std::string manualPairingCode;
+    char payloadBuffer[chip::QRCodeBasicSetupPayloadGenerator::kMaxQRCodeBase38RepresentationLength + 1];
+    chip::MutableCharSpan qrCode(payloadBuffer);
 
     if (GetQRCode(qrCode, payload) == CHIP_NO_ERROR)
     {
         chip::Platform::ScopedMemoryBuffer<char> qrCodeBuffer;
         const size_t qrCodeBufferMaxSize = strlen(kQrCodeBaseUrl) + strlen(kUrlDataAssignmentPhrase) + 3 * qrCode.size() + 1;
         qrCodeBuffer.Alloc(qrCodeBufferMaxSize);
 
-        ChipLogProgress(AppServer, "SetupQRCode: [%s]", qrCode.c_str());
+        ChipLogProgress(AppServer, "SetupQRCode: [%s]", qrCode.data());
         if (GetQRCodeUrl(qrCodeBuffer.Get(), qrCodeBufferMaxSize, qrCode) == CHIP_NO_ERROR)
         {
             ChipLogProgress(AppServer, "Copy/paste the below URL in a browser to see the QR Code:");
@@ -71,9 +71,10 @@ void PrintOnboardingCodes(const chip::SetupPayload & payload)
         ChipLogError(AppServer, "Getting QR code failed!");
     }
 
+    chip::MutableCharSpan manualPairingCode(payloadBuffer);
     if (GetManualPairingCode(manualPairingCode, payload) == CHIP_NO_ERROR)
     {
-        ChipLogProgress(AppServer, "Manual pairing code: [%s]", manualPairingCode.c_str());
+        ChipLogProgress(AppServer, "Manual pairing code: [%s]", manualPairingCode.data());
     }
     else
     {
@@ -85,47 +86,49 @@ void PrintOnboardingCodes(const chip::SetupPayload & payload)
 void ShareQRCodeOverNFC(chip::RendezvousInformationFlags aRendezvousFlags)
 {
     // Get QR Code and emulate its content using NFC tag
-    std::string qrCode;
+    char payloadBuffer[chip::QRCodeBasicSetupPayloadGenerator::kMaxQRCodeBase38RepresentationLength + 1];
+    chip::MutableCharSpan qrCode(payloadBuffer);
+
     ReturnOnFailure(GetQRCode(qrCode, chip::RendezvousInformationFlags(chip::RendezvousInformationFlag::kBLE)));
 
-    ReturnOnFailure(NFCMgr().StartTagEmulation(qrCode.c_str(), qrCode.size()));
+    ReturnOnFailure(NFCMgr().StartTagEmulation(qrCode.data(), qrCode.size()));
 }
 #endif
 
-CHIP_ERROR GetSetupPayload(chip::SetupPayload & aSetupPayload, chip::RendezvousInformationFlags aRendezvousFlags)
+CHIP_ERROR GetPayloadContents(chip::PayloadContents & aPayload, chip::RendezvousInformationFlags aRendezvousFlags)
 {
-    CHIP_ERROR err                      = CHIP_NO_ERROR;
-    aSetupPayload.version               = 0;
-    aSetupPayload.rendezvousInformation = aRendezvousFlags;
+    CHIP_ERROR err                 = CHIP_NO_ERROR;
+    aPayload.version               = 0;
+    aPayload.rendezvousInformation = aRendezvousFlags;
 
-    err = GetCommissionableDataProvider()->GetSetupPasscode(aSetupPayload.setUpPINCode);
+    err = GetCommissionableDataProvider()->GetSetupPasscode(aPayload.setUpPINCode);
     if (err != CHIP_NO_ERROR)
     {
         ChipLogError(AppServer, "GetCommissionableDataProvider()->GetSetupPasscode() failed: %s", chip::ErrorStr(err));
 #if defined(CHIP_DEVICE_CONFIG_USE_TEST_SETUP_PIN_CODE) && CHIP_DEVICE_CONFIG_USE_TEST_SETUP_PIN_CODE
         ChipLogProgress(AppServer, "*** Using default EXAMPLE passcode %u ***",
                         static_cast<unsigned>(CHIP_DEVICE_CONFIG_USE_TEST_SETUP_PIN_CODE));
-        aSetupPayload.setUpPINCode = CHIP_DEVICE_CONFIG_USE_TEST_SETUP_PIN_CODE;
+        aPayload.setUpPINCode = CHIP_DEVICE_CONFIG_USE_TEST_SETUP_PIN_CODE;
 #else
         return err;
 #endif
     }
 
-    err = GetCommissionableDataProvider()->GetSetupDiscriminator(aSetupPayload.discriminator);
+    err = GetCommissionableDataProvider()->GetSetupDiscriminator(aPayload.discriminator);
     if (err != CHIP_NO_ERROR)
     {
         ChipLogError(AppServer, "GetCommissionableDataProvider()->GetSetupDiscriminator() failed: %s", chip::ErrorStr(err));
         return err;
     }
 
-    err = ConfigurationMgr().GetVendorId(aSetupPayload.vendorID);
+    err = ConfigurationMgr().GetVendorId(aPayload.vendorID);
     if (err != CHIP_NO_ERROR)
     {
         ChipLogError(AppServer, "ConfigurationMgr().GetVendorId() failed: %s", chip::ErrorStr(err));
         return err;
     }
 
-    err = ConfigurationMgr().GetProductId(aSetupPayload.productID);
+    err = ConfigurationMgr().GetProductId(aPayload.productID);
     if (err != CHIP_NO_ERROR)
     {
         ChipLogError(AppServer, "ConfigurationMgr().GetProductId() failed: %s", chip::ErrorStr(err));
@@ -135,25 +138,23 @@ CHIP_ERROR GetSetupPayload(chip::SetupPayload & aSetupPayload, chip::RendezvousI
     return err;
 }
 
-CHIP_ERROR GetQRCode(std::string & aQRCode, chip::RendezvousInformationFlags aRendezvousFlags)
+CHIP_ERROR GetQRCode(chip::MutableCharSpan & aQRCode, chip::RendezvousInformationFlags aRendezvousFlags)
 {
-    chip::SetupPayload payload;
+    chip::PayloadContents payload;
 
-    CHIP_ERROR err = GetSetupPayload(payload, aRendezvousFlags);
+    CHIP_ERROR err = GetPayloadContents(payload, aRendezvousFlags);
     if (err != CHIP_NO_ERROR)
     {
-        ChipLogError(AppServer, "GetSetupPayload() failed: %s", chip::ErrorStr(err));
+        ChipLogError(AppServer, "GetPayloadContents() failed: %s", chip::ErrorStr(err));
         return err;
     }
 
     return GetQRCode(aQRCode, payload);
 }
 
-CHIP_ERROR GetQRCode(std::string & aQRCode, const chip::SetupPayload & payload)
+CHIP_ERROR GetQRCode(chip::MutableCharSpan & aQRCode, const chip::PayloadContents & payload)
 {
-    // TODO: Usage of STL will significantly increase the image size, this should be changed to more efficient method for
-    // generating payload
-    CHIP_ERROR err = chip::QRCodeSetupPayloadGenerator(payload).payloadBase38Representation(aQRCode);
+    CHIP_ERROR err = chip::QRCodeBasicSetupPayloadGenerator(payload).payloadBase38Representation(aQRCode);
     if (err != CHIP_NO_ERROR)
     {
         ChipLogError(AppServer, "Generating QR Code failed: %s", chip::ErrorStr(err));
@@ -163,7 +164,7 @@ CHIP_ERROR GetQRCode(std::string & aQRCode, const chip::SetupPayload & payload)
     return CHIP_NO_ERROR;
 }
 
-CHIP_ERROR GetQRCodeUrl(char * aQRCodeUrl, size_t aUrlMaxSize, const std::string & aQRCode)
+CHIP_ERROR GetQRCodeUrl(char * aQRCodeUrl, size_t aUrlMaxSize, const chip::CharSpan & aQRCode)
 {
     VerifyOrReturnError(aQRCodeUrl, CHIP_ERROR_INVALID_ARGUMENT);
     VerifyOrReturnError(aUrlMaxSize >= (strlen(kQrCodeBaseUrl) + strlen(kUrlDataAssignmentPhrase) + aQRCode.size() + 1),
@@ -173,24 +174,24 @@ CHIP_ERROR GetQRCodeUrl(char * aQRCodeUrl, size_t aUrlMaxSize, const std::string
     VerifyOrReturnError((writtenDataSize > 0) && (static_cast<size_t>(writtenDataSize) < aUrlMaxSize),
                         CHIP_ERROR_INVALID_STRING_LENGTH);
 
-    return EncodeQRCodeToUrl(aQRCode.c_str(), aQRCode.size(), aQRCodeUrl + writtenDataSize,
+    return EncodeQRCodeToUrl(aQRCode.data(), aQRCode.size(), aQRCodeUrl + writtenDataSize,
                              aUrlMaxSize - static_cast<size_t>(writtenDataSize));
 }
 
-CHIP_ERROR GetManualPairingCode(std::string & aManualPairingCode, chip::RendezvousInformationFlags aRendezvousFlags)
+CHIP_ERROR GetManualPairingCode(chip::MutableCharSpan & aManualPairingCode, chip::RendezvousInformationFlags aRendezvousFlags)
 {
-    chip::SetupPayload payload;
+    chip::PayloadContents payload;
 
-    CHIP_ERROR err = GetSetupPayload(payload, aRendezvousFlags);
+    CHIP_ERROR err = GetPayloadContents(payload, aRendezvousFlags);
     if (err != CHIP_NO_ERROR)
     {
-        ChipLogError(AppServer, "GetSetupPayload() failed: %s", chip::ErrorStr(err));
+        ChipLogError(AppServer, "GetPayloadContents() failed: %s", chip::ErrorStr(err));
         return err;
     }
     return GetManualPairingCode(aManualPairingCode, payload);
 }
 
-CHIP_ERROR GetManualPairingCode(std::string & aManualPairingCode, const chip::SetupPayload & payload)
+CHIP_ERROR GetManualPairingCode(chip::MutableCharSpan & aManualPairingCode, const chip::PayloadContents & payload)
 {
     CHIP_ERROR err = chip::ManualSetupPayloadGenerator(payload).payloadDecimalStringRepresentation(aManualPairingCode);
     if (err != CHIP_NO_ERROR)