From 0f8f6639bb526da293a28b431a51da80ef6aabbc Mon Sep 17 00:00:00 2001
From: =?utf8?q?Paul=20H=C3=A4nsch?= <paul@plutz.net>
Date: Thu, 1 Jun 2023 14:27:43 +0200
Subject: [PATCH] performance: avoid process forking

---
 file.sh | 49 ++++++++++++++++++++++++++++++++++---------------
 1 file changed, 34 insertions(+), 15 deletions(-)

diff --git a/file.sh b/file.sh
index 0d1f4ea..a9006e6 100755
--- a/file.sh
+++ b/file.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-# Copyright 2016 - 2019 Paul Hänsch
+# Copyright 2016 - 2023 Paul Hänsch
 #
 # This file is part of cgilite.
 # 
@@ -48,24 +48,32 @@ file_type(){
 }
 
 FILE(){
-  local file file_size file_date http_date cachedate range mime
-  file="$1" mime="$2"
+  local file="$1" mime="$2"
+  local file_size file_date http_date cachedate range
 
   if ! [ -f "$file" ]; then
     printf 'Content-Length: 0\r\nStatus: 404 Not Found\r\n\r\n'
-    exit 0
+    return 0
   elif ! [ -r "$file" ]; then
     printf 'Content-Length: 0\r\nStatus: 403 Forbidden\r\n\r\n'
-    exit 0
+    return 0
   fi
 
-  file_size="$(stat -Lc %s "$file")"
-  file_date="$(stat -Lc %Y "$file")"
+  read file_size file_date <<-EOF
+	$(stat -Lc "%s	%Y" "$file")
+	EOF
   http_date="$(date -ud "@$file_date" +"%a, %d %b %Y %T GMT")"
+
+  [ ! "$HTTP_IF_MODIFIED_SINCE" -a "$cgilite_headers" ] \
+  &&    HTTP_IF_MODIFIED_SINCE="$(HEADER If-Modified-Since)"
+  [ ! "$HTTP_RANGE"             -a "$cgilite_headers" ] \
+  &&    HTTP_RANGE="$(HEADER Range)"
+
   cachedate="$(
     # Parse the allowable date formats from Section 3.3.1 of
     # https://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html
-    HEADER If-Modified-Since \
+    # HEADER If-Modified-Since \
+    printf %s "$HTTP_IF_MODIFIED_SINCE" \
     | sed -E 's;^[^ ]+, ([0-9]{2}) (...) ([0-9]{4}) (..:..:..) GMT$;\3-\2-\1 \4;;
               s;^[^ ]+, ([0-9]{2})-(...)-([789][0-9]) (..:..:..) GMT$;19\3-\2-\1 \4;;
               s;^[^ ]+, ([0-9]{2})-(...)-([0-6][0-9]) (..:..:..) GMT$;20\3-\2-\1 \4;;
@@ -76,14 +84,25 @@ FILE(){
     | xargs -r0 date +%s -ud 2>&-
   )"
 
-  range="$(HEADER Range |sed -nE 's;^bytes=([0-9]+-[0-9]*|-[0-9]+)$;\1;p;q;')"
+  range="${HTTP_RANGE#bytes=}"
   case "$range" in
-    *-) range="${range}$((file_size - 1))";;
-    -*) [ ${range#-} -le $file_size ] \
-        && range="$((file_size - ${range#-}))-$((file_size - 1))" \
-        || range="0-$((file_size - 1))";;
-    *-*) [ ${range#*-} -ge $file_size ] \
-         && range="${range%-*}-$((file_size - 1))";;
+    *[^0-9]*-*|*-*[^0-9]*)
+      range=""
+      ;;
+    *-)
+      range="${range}$((file_size - 1))"
+      ;;
+    -*)
+      [ ${range#-} -le $file_size ] \
+      && range="$((file_size - ${range#-}))-$((file_size - 1))" \
+      || range="0-$((file_size - 1))"
+      ;;
+    *-*)
+      [ ${range#*-} -ge $file_size ] \
+      && range="${range%-*}-$((file_size - 1))"
+      ;;
+    *) range=""
+      ;;
   esac
 
   if [ "$file_date" -lt "$cachedate" ] 2>&-; then
-- 
2.39.2