From 3a6a02deb51dfe415391185ad6f0a9e6a1c43695 Mon Sep 17 00:00:00 2001
From: Matthias Neeracher <microtherion@gmail.com>
Date: Sun, 7 Oct 2018 01:32:19 +0200
Subject: [PATCH] Compress to single data buffer instead of chunked stream

---
 Package.swift                               |  2 +-
 Sources/GzipMiddleware/GzipMiddleware.swift | 40 ++++++++++-----------
 2 files changed, 19 insertions(+), 23 deletions(-)

diff --git a/Package.swift b/Package.swift
index 3592bc0..9974960 100644
--- a/Package.swift
+++ b/Package.swift
@@ -11,7 +11,7 @@ let package = Package(
         .package(url: "https://github.com/vapor/vapor.git", from: "3.0.0"),
 
         // 🤐 Unzip archives
-        .package(url: "https://github.com/microtherion/ZIPFoundation.git", .upToNextMajor(from: "0.9.7-µ"))
+        .package(url: "https://github.com/microtherion/ZIPFoundation.git", .upToNextMajor(from: "0.9.8-µ"))
     ],
     targets: [
         .target(name: "GzipMiddleware", dependencies: ["Vapor", "ZIPFoundation"]),
diff --git a/Sources/GzipMiddleware/GzipMiddleware.swift b/Sources/GzipMiddleware/GzipMiddleware.swift
index e7d5550..f0c9f96 100644
--- a/Sources/GzipMiddleware/GzipMiddleware.swift
+++ b/Sources/GzipMiddleware/GzipMiddleware.swift
@@ -3,6 +3,15 @@ import Vapor
 import Foundation
 import ZIPFoundation
 
+private extension Data {
+    mutating func appendLittleEndian(_ word: UInt32) {
+        self.append(UInt8(word & 0xFF))
+        self.append(UInt8((word >> 8) & 0xFF))
+        self.append(UInt8((word >> 16) & 0xFF))
+        self.append(UInt8((word >> 24) & 0xFF))
+    }
+}
+
 /// Server Gzip middlere:
 /// 1. checks if the "Accept-Encoding" header contains "gzip"
 /// 2. if so, compresses the body and sets the response header "Content-Encoding" to "gzip",
@@ -30,35 +39,22 @@ public struct GzipServerMiddleware: Middleware, ServiceType {
             var headers = response.http.headers
             headers.replaceOrAdd(name: .contentEncoding, value: "gzip")
             return response.http.body.consumeData(on: request).map { data in
-                let stream  = HTTPChunkedStream(on: request)
-                let bufSize = 4096
-                var buffer  = ByteBufferAllocator().buffer(capacity: bufSize)
+                var buffer  = Data()
                 let header  : [UInt8] = [0x1f, 0x8b, 0x08, 0x00]
                 let header2 : [UInt8] = [0x00, 0x03]
-                buffer.write(bytes: header)
-                buffer.write(integer: UInt32(Date().timeIntervalSince1970), endianness: .little)
-                buffer.write(bytes: header2)
-                var write   = stream.write(.chunk(buffer))
-                let crc32   = try Data.compress(size: data.count, bufferSize: bufSize,
+                buffer.append(contentsOf: header)
+                buffer.appendLittleEndian(UInt32(Date().timeIntervalSince1970))
+                buffer.append(contentsOf: header2)
+                let crc32   = try Data.compress(size: data.count, bufferSize: 4096,
                     provider: {(offset, readSize) -> Data in
                         return data.subdata(in: offset..<offset+readSize)
                     },
                     consumer: { data -> Void in
-                        write = write.flatMap {
-                            buffer.clear()
-                            buffer.write(bytes: data)
-                            return stream.write(.chunk(buffer))
-                        }
+                        buffer.append(data)
                     })
-                write.always {
-                    buffer.clear()
-                    buffer.write(integer: crc32, endianness: .little)
-                    buffer.write(integer: UInt32(data.count), endianness: .little)
-                    stream.write(.chunk(buffer)).always {
-                        _ = stream.write(.end)
-                    }
-                }
-                let httpResponse = HTTPResponse(status: response.http.status, headers: headers, body: stream)
+                buffer.appendLittleEndian(crc32)
+                buffer.appendLittleEndian(UInt32(data.count))
+                let httpResponse = HTTPResponse(status: response.http.status, headers: headers, body: buffer)
                 return request.response(http: httpResponse)
             }
         }