Add support for if-modified-since header

index.js

@@ -1,9 +1,20 @@
-var s3 = new (require('aws-sdk')).S3({params:{Bucket: process.env.S3_BUCKET_NAME}});
+const AWS = require('aws-sdk')
+const zlib = require('zlib')
+
+var s3Options = {
+	params: { Bucket: process.env.S3_BUCKET_NAME },
+}
+
+if (process.env.S3_ENDPOINT) {
+	s3Options.endpoint = new AWS.Endpoint(process.env.S3_ENDPOINT)
+}
+
+const s3 = new AWS.S3(s3Options);
 
 module.exports = {
 
-	requestReceived: function(req, res, next) {
-		if(req.method !== 'GET') {
+	requestReceived: function (req, res, next) {
+		if (!['HEAD', 'GET'].includes(req.method)) {
 			return next();
 		}
 
@@ -14,38 +25,78 @@ module.exports = {
 		}
 
 		s3.getObject({
-				Key: key
+			Key: key
 		}, function (err, result) {
 
 			if (!err && result) {
-				return res.send(200, result.Body);
+				const ifModifiedSince = new Date(req.headers['if-modified-since']);
+				const lastModified = new Date(result['LastModified']);
+
+				if ('LastModified' in result) {
+					res.setHeader('Last-Modified', lastModified.toUTCString());
+				}
+
+				if (ifModifiedSince &&
+					lastModified &&
+					ifModifiedSince < Date.now() &&
+					lastModified < ifModifiedSince) {
+
+					res.send(304);
+					return
+				}
+
+				if (result['ContentEncoding'] === 'gzip') {
+					zlib.gunzip(result.Body, (gzip_err, gzip_res) => {
+						if (gzip_err) console.log(gzip.err)
+						res.send(200, gzip_res)
+					})
+					return
+				}
+
+				res.send(200, result.Body)
 			}
 
 			next();
 		});
 	},
 
-	pageLoaded: function(req, res, next) {
-		if(req.prerender.statusCode !== 200) {
-			return next();
+	pageLoaded: function (req, res, next) {
+		if (req.prerender.statusCode !== 200) {
+			next()
+			return
 		}
 
 		var key = req.prerender.url;
-		
+
 		if (process.env.S3_PREFIX_KEY) {
 			key = process.env.S3_PREFIX_KEY + '/' + key;
 		}
 
-		s3.putObject({
+		var putObjectParams = {
 			Key: key,
 			ContentType: 'text/html;charset=UTF-8',
-			StorageClass: 'REDUCED_REDUNDANCY',
 			Body: req.prerender.content
-		}, function(err, result) {
+		}
 
-			if (err) console.error(err);
+		const putObject = function (params) {
+			s3.putObject(params, function (err, _) {
 
-			next();
-		});
+				if (err) console.error(err);
+
+				next();
+			});
+		}
+
+		if (['yes', 'true'].includes(process.env.S3_ENABLE_COMPRESSION)) {
+			putObjectParams.ContentEncoding = 'gzip'
+			zlib.gzip(putObjectParams.Body, (gzip_err, gzip_res) => {
+				if (gzip_err) console.error(gzip_err)
+				putObjectParams.Body = gzip_res
+				putObject(putObjectParams)
+			})
+			return
+		}
+
+		putObject(putObjectParams)
 	}
-};
+};