From d7bd75911d7d236bd2b341cd9dbf709c87c20ee3 Mon Sep 17 00:00:00 2001
From: ed <s@ocv.me>
Date: Wed, 26 Jun 2019 18:26:18 +0000
Subject: [PATCH] add content-encoding for precompressed deps

---
 copyparty/httpcli.py | 63 +++++++++++++++++++++++++++++++++++---------
 copyparty/util.py    |  7 +++++
 docs/notes.sh        |  6 +++++
 3 files changed, 63 insertions(+), 13 deletions(-)

diff --git a/copyparty/httpcli.py b/copyparty/httpcli.py
index d3adabd0..a08dbcab 100644
--- a/copyparty/httpcli.py
+++ b/copyparty/httpcli.py
@@ -4,6 +4,7 @@ from __future__ import print_function, unicode_literals
 
 import os
 import stat
+import gzip
 import time
 import json
 from datetime import datetime
@@ -156,9 +157,7 @@ class HttpCli(object):
         # "embedded" resources
         if self.vpath.startswith(".cpr"):
             static_path = os.path.join(E.mod, "web/", self.vpath[5:])
-
-            if os.path.isfile(static_path):
-                return self.tx_file(static_path)
+            return self.tx_file(static_path)
 
         # conditional redirect to single volumes
         if self.vpath == "" and not self.uparam:
@@ -367,19 +366,34 @@ class HttpCli(object):
         self.parser.drop()
         return True
 
-    def tx_file(self, path):
-        file_ts = os.path.getmtime(fsenc(path))
-        file_dt = datetime.utcfromtimestamp(file_ts)
-        file_lastmod = file_dt.strftime("%a, %b %d %Y %H:%M:%S GMT")
-
+    def tx_file(self, req_path):
         do_send = True
         status = "200 OK"
         extra_headers = []
         logmsg = "{:4} {} {}".format("", self.req, status)
 
+        #
+        # if request is for foo.js, check if we have foo.js.gz
+
+        is_gzip = False
+        fs_path = req_path
+        try:
+            file_sz = os.path.getsize(fsenc(fs_path))
+        except:
+            is_gzip = True
+            fs_path += '.gz'
+            try:
+                file_sz = os.path.getsize(fsenc(fs_path))
+            except:
+                raise Pebkac('404 Not Found')
+        
         #
         # if-modified
 
+        file_ts = os.path.getmtime(fsenc(fs_path))
+        file_dt = datetime.utcfromtimestamp(file_ts)
+        file_lastmod = file_dt.strftime("%a, %d %b %Y %H:%M:%S GMT")
+
         if "if-modified-since" in self.headers:
             cli_lastmod = self.headers["if-modified-since"]
             try:
@@ -396,11 +410,10 @@ class HttpCli(object):
         #
         # partial
 
-        file_sz = os.path.getsize(fsenc(path))
         lower = 0
         upper = file_sz
 
-        if do_send and "range" in self.headers:
+        if do_send and not is_gzip and "range" in self.headers:
             try:
                 hrange = self.headers["range"]
                 a, b = hrange.split("=", 1)[1].split("-")
@@ -428,10 +441,35 @@ class HttpCli(object):
 
             logmsg += " [\033[36m" + str(lower) + "-" + str(upper) + "\033[0m]"
 
+        #
+        # Accept-Encoding and UA decides if we can send gzip as-is
+
+        decompress = False
+        if is_gzip:
+            if 'gzip' not in self.headers.get('accept-encoding', '').lower():
+                decompress = True
+            elif 'user-agent' in self.headers:
+                ua = self.headers['user-agent']
+                if re.match(r'MSIE [4-6]\.', ua) and ' SV1' not in ua:
+                    decompress = True
+            
+            if not decompress:
+                extra_headers.append('Content-Encoding: gzip')
+
+        if decompress:
+            open_func = gzip.open
+            open_args = [fsenc(fs_path), 'rb']
+            # Content-Length := original file size
+            upper = gzip_orig_sz(fs_path)
+        else:
+            open_func = open
+            # 512 kB is optimal for huge files, use 64k
+            open_args = [fsenc(fs_path), 'rb', 64 * 1024]
+
         #
         # send reply
 
-        mime = mimetypes.guess_type(path)[0] or "application/octet-stream"
+        mime = mimetypes.guess_type(req_path)[0] or "application/octet-stream"
 
         headers = [
             "HTTP/1.1 " + status,
@@ -449,8 +487,7 @@ class HttpCli(object):
             self.log(logmsg)
             return True
 
-        # 512 kB is optimal for huge files, use 64k
-        with open(fsenc(path), "rb", 64 * 1024) as f:
+        with open_func(*open_args) as f:
             remains = upper - lower
             f.seek(lower)
             while remains > 0:
diff --git a/copyparty/util.py b/copyparty/util.py
index c6d49385..0a09d028 100644
--- a/copyparty/util.py
+++ b/copyparty/util.py
@@ -4,6 +4,7 @@ from __future__ import print_function, unicode_literals
 
 import re
 import sys
+import struct
 import hashlib
 import threading
 import subprocess as sp  # nosec
@@ -416,5 +417,11 @@ def chkcmd(*argv):
     return sout, serr
 
 
+def gzip_orig_sz(fn):
+    with open(fsenc(fn), 'rb') as f:
+        f.seek(-4, 2)
+        return struct.unpack('I', f.read(4))[0]
+
+
 class Pebkac(Exception):
     pass
diff --git a/docs/notes.sh b/docs/notes.sh
index bdc6fee8..f77fdd35 100644
--- a/docs/notes.sh
+++ b/docs/notes.sh
@@ -43,6 +43,12 @@ mkdir -p "${dirs[@]}"
 for dir in "${dirs[@]}"; do for fn in ふが "$(printf \\xed\\x93)" 'qwe,rty;asd fgh+jkl%zxc&vbn <qwe>"rty'"'"'uio&asd&nbsp;fgh'; do echo "$dir" > "$dir/$fn.html"; done; done
 
 
+##
+## test compression
+
+wget -S --header='Accept-Encoding: gzip' -U 'MSIE 6.0; SV1' http://127.0.0.1:1234/.cpr/deps/ogv.js -O- | md5sum; p=~ed/dev/copyparty/copyparty/web/deps/ogv.js.gz; md5sum $p; gzip -d < $p | md5sum
+
+
 ##
 ## vscode