move around files

lxc/execute.js

@@ -0,0 +1,56 @@
+const { writeFileSync, unlinkSync, mkdirSync } = require('fs');
+const { spawn } = require('child_process');
+
+const OUTPUT_LIMIT = 65535;
+const LXC_ROOT = '/var/lib/lxc/piston/rootfs';
+
+function execute(language, source, stdin = '', args = []) {
+    return new Promise(resolve => {
+        const id = new Date().getTime() + '_' + Math.floor(Math.random() * 10000000);
+
+        mkdirSync(`${LXC_ROOT}/tmp/${id}`);
+        writeFileSync(`${LXC_ROOT}/tmp/${id}/code.code`, source);
+        writeFileSync(`${LXC_ROOT}/tmp/${id}/stdin.stdin`, stdin);
+        writeFileSync(`${LXC_ROOT}/tmp/${id}/args.args`, args.join('\n'));
+
+        const process = spawn(__dirname + '/execute', [
+            language.name,
+            id,
+        ]);
+
+        let stdout = '';
+        let stderr = '';
+        let output = '';
+
+        process.stderr.on('data', chunk => {
+            if (stderr.length >= OUTPUT_LIMIT) return;
+
+            stderr += chunk;
+            output += chunk;
+        });
+
+        process.stdout.on('data', chunk => {
+            if (stdout.length >= OUTPUT_LIMIT) return;
+
+            stdout += chunk;
+            output += chunk;
+        });
+
+        process.on('exit', code => {
+            stderr = stderr.trim().substring(0, OUTPUT_LIMIT);
+            stdout = stdout.trim().substring(0, OUTPUT_LIMIT);
+            output = output.trim().substring(0, OUTPUT_LIMIT);
+
+            resolve({
+                stdout,
+                stderr,
+                output,
+                ran: code === 0,
+            });
+        });
+    });
+}
+
+module.exports = {
+    execute,
+};