♻️ factorise XML build at the same place

Issue: CLDSRV-878

Author: DarkIsDude

lib/routes/veeam/list.js

@@ -1,14 +1,9 @@
 const url = require('url');
-const xml2js = require('xml2js');
 const { errors, errorInstances } = require('arsenal');
 const querystring = require('querystring');
-const metadata = require('../../metadata/wrapper');
 const { responseXMLBody } = require('arsenal/build/lib/s3routes/routesUtils');
-const { respondWithData, getResponseHeader, buildHeadXML, validPath, fetchCapacityMetrics } = require('./utils');
+const { respondWithData, getResponseHeader, buildXML, validPath, fetchCapacityMetrics, getBucket } = require('./utils');
 const { processVersions, processMasterVersions } = require('../../api/bucketGet');
-const { promisify } = require('util');
-
-const getBucket = promisify((...args) => metadata.getBucket(...args));
 
 /**
  * Utility function to build a standard response for the LIST route.
@@ -135,10 +130,7 @@ async function listVeeamFiles(request, response, bucketMd, log) {
             : file.LastModified;
         // eslint-disable-next-line no-param-reassign
         delete file.LastModified;
-        const builder = new xml2js.Builder({
-            headless: true,
-        });
-        const dataBuffer = Buffer.from(buildHeadXML(builder.buildObject(file)));
+        const dataBuffer = Buffer.from(buildXML(file));
         filesToBuild.push({
             ...getResponseHeader(request, data,
                 dataBuffer, lastModified, log),

lib/routes/veeam/utils.js

@@ -104,6 +104,17 @@ function getResponseHeader(request, bucket, dataBuffer, lastModified, log) {
     responseMetaHeaders['x-amz-request-id'] = log.getSerializedUids();
     return responseMetaHeaders;
 }
+/**
+ * Builds a headless XML string wrapped in the standard SOSAPI XML declaration.
+ *
+ * @param {object} obj - JS object to serialize to XML
+ * @returns {string} formatted XML file content
+ */
+function buildXML(obj) {
+    const builder = new xml2js.Builder({ headless: true });
+    return buildHeadXML(builder.buildObject(obj));
+}
+
 /**
  * Generic function to respond to user with data using streams
  *
@@ -136,18 +147,26 @@ async function respondWithData(request, response, log, bucket, data, lastModifie
     }
 
     response.writeHead(200);
-    // Use a single-element array so the Buffer is sent as one chunk rather
-    // than being iterated byte-by-byte by Readable.from.
-    await pipeline(Readable.from([dataBuffer]), response);
 
     let contentLength = 0;
     if (responseMetaHeaders && responseMetaHeaders['Content-Length']) {
         contentLength = responseMetaHeaders['Content-Length'];
     }
     log.end().addDefaultFields({ contentLength });
-    log.end().info('responded with streamed content', {
-        httpCode: response.statusCode,
-    });
+
+    try {
+        // Use a single-element array so the Buffer is sent as one chunk rather
+        // than being iterated byte-by-byte by Readable.from.
+        await pipeline(Readable.from([dataBuffer]), response);
+        log.end().info('responded with streamed content', {
+            httpCode: response.statusCode,
+        });
+    } catch (err) {
+        log.end().error('error streaming response', {
+            httpCode: response.statusCode,
+            error: err.message,
+        });
+    }
 }
 
 const validPath = '.system-d26a9498-cb7c-4a87-a44a-8ae204f5ba6c/';
@@ -278,8 +297,7 @@ async function buildVeeamFileData(request, bucketMd, log) {
         // ensuring no issue in a SOSAPI context. We should use this information.
     }
 
-    const builder = new xml2js.Builder({ headless: true });
-    const xmlContent = buildHeadXML(builder.buildObject(fileToBuild.value));
+    const xmlContent = buildXML(fileToBuild.value);
     const dataBuffer = Buffer.from(xmlContent);
     return { xmlContent, dataBuffer, modified, bucketData: data };
 }
@@ -290,9 +308,11 @@ module.exports = {
     respondWithData,
     getResponseHeader,
     buildHeadXML,
+    buildXML,
     validPath,
     isSystemXML,
     getFileToBuild,
     fetchCapacityMetrics,
     buildVeeamFileData,
+    getBucket,
 };