Data update

Task/SHA-256-Merkle-tree/JavaScript/sha-256-merkle-tree.js

@@ -0,0 +1,95 @@
+#!/usr/bin/env node
+
+const fs = require('fs');
+const crypto = require('crypto');
+
+function computeMerkleRoot(filename = null, blockSize = 1024 * 1024) {
+    let data;
+
+    if (filename) {
+        // Read file synchronously
+        data = fs.readFileSync(filename);
+    } else {
+        // Read from stdin
+        data = fs.readFileSync(0); // 0 is stdin file descriptor
+    }
+
+    const stack = [];
+    let offset = 0;
+
+    // Process blocks
+    while (offset < data.length) {
+        const block = data.slice(offset, offset + blockSize);
+
+        // Create a node: [tree-level, hash]
+        const hash = crypto.createHash('sha256').update(block).digest();
+        const node = [0, hash];
+        stack.push(node);
+
+        // Concatenate adjacent pairs at the same level
+        while (stack.length >= 2 && stack[stack.length - 2][0] === stack[stack.length - 1][0]) {
+            const a = stack[stack.length - 2];
+            const b = stack[stack.length - 1];
+            const level = a[0];
+
+            // Combine hashes
+            const combinedHash = crypto.createHash('sha256')
+                .update(Buffer.concat([a[1], b[1]]))
+                .digest();
+
+            // Replace last two elements with combined node
+            stack.splice(-2, 2, [level + 1, combinedHash]);
+        }
+
+        offset += blockSize;
+    }
+
+    // Combine remaining nodes even across different levels
+    while (stack.length > 1) {
+        const a = stack[stack.length - 2];
+        const b = stack[stack.length - 1];
+        const al = a[0];
+        const bl = b[0];
+
+        const combinedHash = crypto.createHash('sha256')
+            .update(Buffer.concat([a[1], b[1]]))
+            .digest();
+
+        // Replace last two elements with combined node
+        stack.splice(-2, 2, [Math.max(al, bl) + 1, combinedHash]);
+    }
+
+    return stack[0][1].toString('hex');
+}
+
+// Command line interface
+function main() {
+    const args = process.argv.slice(2);
+    let filename = null;
+    let blockSize = 1024 * 1024; // Default 1MB
+
+    // Simple argument parsing
+    for (let i = 0; i < args.length; i++) {
+        if (args[i] === '--block-size' && i + 1 < args.length) {
+            blockSize = parseInt(args[i + 1]);
+            i++; // Skip next argument
+        } else if (!args[i].startsWith('--')) {
+            filename = args[i];
+        }
+    }
+
+    try {
+        const result = computeMerkleRoot(filename, blockSize);
+        console.log(result);
+    } catch (error) {
+        console.error('Error:', error.message);
+        process.exit(1);
+    }
+}
+
+// Run if this script is executed directly
+if (require.main === module) {
+    main();
+}
+
+module.exports = { computeMerkleRoot };