buildMerkleTree

Constructs a Merkle tree from a list of data items (e.g., all sensor readings within a day) and calculates the root hash (outRoot) of the tree.

The Merkle root is a single, unique cryptographic hash that represents the integrity of the entire data list. If even a single character in the data list changes, the Merkle root will be completely different. This is used for efficiently verifying large datasets.

Parameters

Parameter	Type	Description
dataList	const std::vector<String>&	A list of data items (strings) to build the tree from.
outRoot	String&	Output: The calculated Merkle root hash (hex format).

Return Value

• bool: Returns true if the tree was built successfully, false otherwise.

Example Code (main.cpp)

#include <Arduino.h>
#include <vector>
#include "Infratic-lib.h"

// This function does not require network connectivity.
Infratic solana(""); // RPC URL not needed

void setup() {
    Serial.begin(115200);
    delay(1000);

    Serial.println("\n=== buildMerkleTree Example ===");

    std::vector<String> dataList;
    dataList.push_back("SensorData:10.5");
    dataList.push_back("SensorData:11.2");
    dataList.push_back("SensorData:10.9");
    dataList.push_back("SensorData:12.1");

    Serial.println("Building Merkle tree for data list:");
    for (size_t i = 0; i < dataList.size(); ++i) {
        Serial.println("  - " + dataList[i]);
    }

    String merkleRoot;
    if (solana.buildMerkleTree(dataList, merkleRoot)) {
        Serial.println("\n✅ Merkle tree built successfully!");
        Serial.println("   -> Merkle Root: " + merkleRoot);
        Serial.println("   -> This root hash represents all 4 data items.");
    } else {
        Serial.println("❌ Failed to build Merkle tree.");
    }
}

void loop() {
    // Can be left empty
}