Implement number of files to keep option

Author: sjanuary

headless_zip.js

@@ -19,6 +19,8 @@ var path = require('path')
 var JSZip = require("jszip");
 
 var dirToWriteTo;
+var filesToKeep = 10;
+var filesWritten = [];
 
 function onError(err) {
 	console.error('Headless Zip: an error occurred:', err)
@@ -35,10 +37,18 @@ function deleteDir(directory) {
 	}
 }
 
+function deleteFile(filename) {
+	fs.unlink(filename)
+}
+
 module.exports.setHeadlessOutputDir = function setHeadlessOutputDir(dir) {
 	dirToWriteTo = dir;
 }
 
+module.exports.setFilesToKeep = function setFilesToKeep(numFiles) {
+	filesToKeep = numFiles;
+}
+
 function timestamp() {
 	var date = new Date(Date.now())
 	var timestamp = pad(date.getDate().toString()) + pad((date.getMonth() + 1).toString()) + date.getFullYear().toString().substr(2,3) + '_'
@@ -63,14 +73,20 @@ module.exports.headlessZip = function headlessZip(dirToZip) {
 		outputFileName = 'nodeappmetrics' + timestamp() + '.hcd'
 	}
 
+	filesWritten.push(outputFileName)
+	if(filesWritten.length > filesToKeep) {
+		var earliest = filesWritten.shift()
+		deleteFile(earliest)
+	}
+
 	var zip = new JSZip();
 	fs.readdir(dirToZip, function(error, files) {
 		if (error) {
-      			onError(error)
-      			return
-    		}
+				onError(error)
+				return
+		}
 		for (var i = 0, len = files.length; i < len; i++) {
-      			zip.file(files[i], fs.readFileSync(path.join(dirToZip, files[i])), {compression : "DEFLATE"})
+			zip.file(files[i], fs.readFileSync(path.join(dirToZip, files[i])), {compression : "DEFLATE"})
 		}
 
 		zip.generateNodeStream({type:'nodebuffer',streamFiles:true})

index.js

@@ -258,6 +258,10 @@ module.exports.monitor = function() {
       if(headlessOutputDir) {
         headlessZip.setHeadlessOutputDir(headlessOutputDir);
       }
+      var headlessFilesToKeep = agent.getOption('com.ibm.diagnostics.healthcenter.headless.files.to.keep');
+      if(headlessFilesToKeep && !isNaN(headlessFilesToKeep) && headlessFilesToKeep > 0) {
+	headlessZip.setFilesToKeep(headlessFilesToKeep);
+      }
     }
     return this.api;
 };