/** * User Registry Contract - QAN QVM Smart Contract (JavaScript) * * A user registry contract demonstrating state management with multiple data fields. * * Functions: * - construct: Initialize the registry with optional max user limit (called once) * - register : Register a new user * - update : Update an existing user's email * - getUser : Get user details * - deactivate : Deactivate a user (soft delete) * - activate : Reactivate a deactivated user * - list: List all registered usernames * - stats: Get registry statistics */ const DEFAULT_MAX_USERS = 100; // QVM storage slot value is limited to 32 bytes. Username and email must fit. const MAX_STORAGE_BYTES = 32; function byteLength(str) { if (typeof str !== "string") return 0; try { return new TextEncoder().encode(str).length; } catch (e) { return str.length; } } // ============================================================================ // CONSTRUCTOR - Called once during contract deployment // ============================================================================ function construct(maxUsers) { if (process.env.DB_QVM_INITIALIZED === "true") { process.stderr.write("contract is already initialized\n"); process.exit(1); } const limit = maxUsers ? parseInt(maxUsers) : DEFAULT_MAX_USERS; if (isNaN(limit) || limit <= 0) { process.stderr.write("invalid max users: must be a positive number\n"); process.exit(1); } process.stdout.write("DBW=QVM_INITIALIZED=true\n"); process.stdout.write("DBW=REG_MAX_USERS=" + limit + "\n"); process.stdout.write("DBW=REG_TOTAL_USERS=0\n"); process.stdout.write("DBW=REG_ACTIVE_USERS=0\n"); process.stdout.write("OUT=User Registry initialized with max " + limit + " users\n"); process.exit(0); } // ============================================================================ // INITIALIZE - Load state from DB (called before each function) // ============================================================================ function initialize() { if (process.env.DB_QVM_INITIALIZED !== "true") { process.stderr.write("contract is not initialized\n"); process.exit(1); } } // ============================================================================ // HELPERS - Get registry state // ============================================================================ function getMaxUsers() { return parseInt(process.env.DB_REG_MAX_USERS || String(DEFAULT_MAX_USERS)); } function getTotalUsers() { return parseInt(process.env.DB_REG_TOTAL_USERS || "0"); } function getActiveUsers() { return parseInt(process.env.DB_REG_ACTIVE_USERS || "0"); } function getUserData(username) { const upperName = username.toUpperCase(); const email = process.env["DB_REG_USER_" + upperName + "_EMAIL"]; const status = process.env["DB_REG_USER_" + upperName + "_STATUS"]; const index = process.env["DB_REG_USER_" + upperName + "_INDEX"]; if (email === undefined) { return null; } return { username: username, email: email, status: status || "active", index: index }; } // ============================================================================ // REGISTER - Register a new user // ============================================================================ function register(username, email) { initialize(); if (!username || username.trim() === "") { process.stderr.write("username cannot be empty\n"); process.exit(1); } if (!email || email.trim() === "") { process.stderr.write("email cannot be empty\n"); process.exit(1); } if (byteLength(username) > MAX_STORAGE_BYTES) { process.stderr.write("username exceeds 32 bytes (max " + MAX_STORAGE_BYTES + ", got " + byteLength(username) + ")\n"); process.exit(1); } if (byteLength(email) > MAX_STORAGE_BYTES) { process.stderr.write("email exceeds 32 bytes (max " + MAX_STORAGE_BYTES + ", got " + byteLength(email) + ")\n"); process.exit(1); } // Check if user already exists const existingUser = getUserData(username); if (existingUser !== null) { process.stderr.write("user '" + username + "' already exists\n"); process.exit(1); } // Check max users limit const totalUsers = getTotalUsers(); const maxUsers = getMaxUsers(); if (totalUsers >= maxUsers) { process.stderr.write("registry is full (max " + maxUsers + " users)\n"); process.exit(1); } const upperName = username.toUpperCase(); const userIndex = totalUsers; // Store user data process.stdout.write("DBW=REG_USER_" + upperName + "_EMAIL=" + email + "\n"); process.stdout.write("DBW=REG_USER_" + upperName + "_STATUS=active\n"); process.stdout.write("DBW=REG_USER_" + upperName + "_INDEX=" + userIndex + "\n"); // Store username in index for listing process.stdout.write("DBW=REG_INDEX_" + userIndex + "=" + username + "\n"); // Update counters process.stdout.write("DBW=REG_TOTAL_USERS=" + (totalUsers + 1) + "\n"); process.stdout.write("DBW=REG_ACTIVE_USERS=" + (getActiveUsers() + 1) + "\n"); process.stdout.write("OUT=User '" + username + "' registered with email '" + email + "'\n"); process.exit(0); } // ============================================================================ // UPDATE - Update user's email // ============================================================================ function update(username, newEmail) { initialize(); if (!username || username.trim() === "") { process.stderr.write("username cannot be empty\n"); process.exit(1); } if (!newEmail || newEmail.trim() === "") { process.stderr.write("email cannot be empty\n"); process.exit(1); } if (byteLength(username) > MAX_STORAGE_BYTES) { process.stderr.write("username exceeds 32 bytes (max " + MAX_STORAGE_BYTES + ", got " + byteLength(username) + ")\n"); process.exit(1); } if (byteLength(newEmail) > MAX_STORAGE_BYTES) { process.stderr.write("email exceeds 32 bytes (max " + MAX_STORAGE_BYTES + ", got " + byteLength(newEmail) + ")\n"); process.exit(1); } const user = getUserData(username); if (user === null) { process.stderr.write("user '" + username + "' not found\n"); process.exit(1); } const upperName = username.toUpperCase(); const oldEmail = user.email; process.stdout.write("DBW=REG_USER_" + upperName + "_EMAIL=" + newEmail + "\n"); process.stdout.write("OUT=User '" + username + "' email updated from '" + oldEmail + "' to '" + newEmail + "'\n"); process.exit(0); } // ============================================================================ // GET USER - Get user details // ============================================================================ function getUser(username) { initialize(); if (!username || username.trim() === "") { process.stderr.write("username cannot be empty\n"); process.exit(1); } if (byteLength(username) > MAX_STORAGE_BYTES) { process.stderr.write("username exceeds 32 bytes (max " + MAX_STORAGE_BYTES + ", got " + byteLength(username) + ")\n"); process.exit(1); } const user = getUserData(username); if (user === null) { process.stdout.write("OUT=User '" + username + "' not found\n"); process.exit(0); } process.stdout.write("OUT=User: " + user.username + ", Email: " + user.email + ", Status: " + user.status + "\n"); process.exit(0); } // ============================================================================ // DEACTIVATE - Soft delete a user // ============================================================================ function deactivate(username) { initialize(); if (!username || username.trim() === "") { process.stderr.write("username cannot be empty\n"); process.exit(1); } if (byteLength(username) > MAX_STORAGE_BYTES) { process.stderr.write("username exceeds 32 bytes (max " + MAX_STORAGE_BYTES + ", got " + byteLength(username) + ")\n"); process.exit(1); } const user = getUserData(username); if (user === null) { process.stderr.write("user '" + username + "' not found\n"); process.exit(1); } if (user.status === "inactive") { process.stderr.write("user '" + username + "' is already inactive\n"); process.exit(1); } const upperName = username.toUpperCase(); process.stdout.write("DBW=REG_USER_" + upperName + "_STATUS=inactive\n"); process.stdout.write("DBW=REG_ACTIVE_USERS=" + (getActiveUsers() - 1) + "\n"); process.stdout.write("OUT=User '" + username + "' deactivated\n"); process.exit(0); } // ============================================================================ // ACTIVATE - Reactivate a user // ============================================================================ function activate(username) { initialize(); if (!username || username.trim() === "") { process.stderr.write("username cannot be empty\n"); process.exit(1); } if (byteLength(username) > MAX_STORAGE_BYTES) { process.stderr.write("username exceeds 32 bytes (max " + MAX_STORAGE_BYTES + ", got " + byteLength(username) + ")\n"); process.exit(1); } const user = getUserData(username); if (user === null) { process.stderr.write("user '" + username + "' not found\n"); process.exit(1); } if (user.status === "active") { process.stderr.write("user '" + username + "' is already active\n"); process.exit(1); } const upperName = username.toUpperCase(); process.stdout.write("DBW=REG_USER_" + upperName + "_STATUS=active\n"); process.stdout.write("DBW=REG_ACTIVE_USERS=" + (getActiveUsers() + 1) + "\n"); process.stdout.write("OUT=User '" + username + "' activated\n"); process.exit(0); } // ============================================================================ // LIST - List all registered usernames // ============================================================================ function list() { initialize(); const totalUsers = getTotalUsers(); if (totalUsers === 0) { process.stdout.write("OUT=No users registered\n"); process.exit(0); } let userList = []; for (let i = 0; i < totalUsers; i++) { const username = process.env["DB_REG_INDEX_" + i]; if (username) { const user = getUserData(username); if (user) { userList.push(username + " (" + user.status + ")"); } } } process.stdout.write("OUT=Registered users: " + userList.join(", ") + "\n"); process.exit(0); } // ============================================================================ // STATS - Get registry statistics // ============================================================================ function stats() { initialize(); const maxUsers = getMaxUsers(); const totalUsers = getTotalUsers(); const activeUsers = getActiveUsers(); const inactiveUsers = totalUsers - activeUsers; const availableSlots = maxUsers - totalUsers; process.stdout.write("OUT=Registry Stats - Max: " + maxUsers + ", Total: " + totalUsers + ", Active: " + activeUsers + ", Inactive: " + inactiveUsers + ", Available: " + availableSlots + "\n"); process.exit(0); } // ============================================================================ // MAIN CONTRACT ENTRY POINT // ============================================================================ function contract(args) { if (!args || args.length === 0) { process.stderr.write("No command provided.\n"); process.stderr.write("Available: construct, register, update, getUser, deactivate, activate, list, stats\n"); process.exit(1); } const command = args[0]; switch (command) { case "construct": construct(args[1]); break; case "register": if (args.length < 3) { process.stderr.write("Usage: register \n"); process.exit(1); } register(args[1], args[2]); break; case "update": if (args.length < 3) { process.stderr.write("Usage: update \n"); process.exit(1); } update(args[1], args[2]); break; case "getUser": if (args.length < 2) { process.stderr.write("Usage: getUser \n"); process.exit(1); } getUser(args[1]); break; case "deactivate": if (args.length < 2) { process.stderr.write("Usage: deactivate \n"); process.exit(1); } deactivate(args[1]); break; case "activate": if (args.length < 2) { process.stderr.write("Usage: activate \n"); process.exit(1); } activate(args[1]); break; case "list": list(); break; case "stats": stats(); break; default: process.stderr.write("Unknown command: " + command + "\n"); process.stderr.write("Available: construct, register, update, getUser, deactivate, activate, list, stats\n"); process.exit(1); } } contract(process.argv.slice(2));

Contract - 0xd771b6502E3683b68161d035278c1bB5F6Ed5Fd9