http: Wire up HTTP compression to the build system

This allows to actually build unit with support for zlib, zstd and
brotli compression.

Any or all can be specified. E.g.

  $ ./configure --zlib ...

  $ ./configure --zlib --zstd --brotli ...

During configure you will see if support for the requested compressions
has been found and what version of the library is being used.

E.g.

  ...
  checking for zlib ... found
   + zlib version: 1.3.1.zlib-ng
  checking for zstd ... found
   + zstd version: 1.5.6
  checking for brotli ... found
   + brotli version: 1.1.0
  ...
  Unit configuration summary:
  ...
    zlib support: .............. YES
    zstd support: .............. YES
    brotli support: ............ YES
  ...

Co-authored-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

6 files changed, 132 insertions, 2 deletions

diff --git a/auto/compression b/auto/compression
new file mode 100644
index 00000000..684242f2
--- /dev/null
+++ b/auto/compression
@@ -0,0 +1,96 @@
+
+# Copyright (C) Alejandro Colomar
+# Copyright (C) Andrew Clayton
+# Copyright (C) NGINX, Inc.
+
+
+NXT_HAVE_ZLIB=no
+NXT_ZLIB_CFLAGS=
+NXT_ZLIB_LIBS=
+
+NXT_HAVE_ZSTD=no
+NXT_ZSTD_CFLAGS=
+NXT_ZSTD_LIBS=
+
+NXT_HAVE_BROTLI=no
+NXT_BROTLI_CFLAGS=
+NXT_BROTLI_LIBS=
+
+
+if [ $NXT_ZLIB = YES ]; then
+    NXT_ZLIB_CFLAGS="$(pkgconf --cflags-only-I zlib 2>/dev/null || echo "")"
+    NXT_ZLIB_LIBS="$(pkgconf --libs zlib 2>/dev/null || echo "-lz")"
+
+    nxt_feature="zlib"
+    nxt_feature_name=NXT_HAVE_ZLIB
+    nxt_feature_run=no
+    nxt_feature_incs=$NXT_ZLIB_CFLAGS
+    nxt_feature_libs=$NXT_ZLIB_LIBS
+    nxt_feature_test="#include <stdio.h>
+
+                      #include <zlib.h>
+
+                      int main(void) {
+                          puts(zlibVersion());
+                          return 0;
+                      }"
+    . auto/feature
+
+    if [ $nxt_found = yes ]; then
+        NXT_HAVE_ZLIB=YES
+        echo " + zlib version: $(pkgconf --modversion zlib)"
+    fi
+fi
+
+
+if [ $NXT_ZSTD = YES ]; then
+    NXT_ZSTD_CFLAGS="$(pkgconf --cflags-only-I libzstd 2>/dev/null || echo "")"
+    NXT_ZSTD_LIBS="$(pkgconf --libs libzstd 2>/dev/null || echo "-lzstd")"
+
+    nxt_feature="zstd"
+    nxt_feature_name=NXT_HAVE_ZSTD
+    nxt_feature_run=no
+    nxt_feature_incs=$NXT_ZSTD_CFLAGS
+    nxt_feature_libs=$NXT_ZSTD_LIBS
+    nxt_feature_test="#include <stdio.h>
+
+                      #include <zstd.h>
+
+                      int main(void) {
+                          printf(\"zstd version: %u\n\", ZSTD_versionNumber());
+                          return 0;
+                      }"
+    . auto/feature
+
+    if [ $nxt_found = yes ]; then
+        NXT_HAVE_ZSTD=YES
+        echo " + zstd version: $(pkgconf --modversion libzstd)"
+    fi
+fi
+
+
+if [ $NXT_BROTLI = YES ]; then
+    NXT_BROTLI_CFLAGS="$(pkgconf --cflags-only-I libbrotlienc 2>/dev/null || echo "")"
+    NXT_BROTLI_LIBS="$(pkgconf --libs libbrotlienc 2>/dev/null || echo "-lbrotlienc")"
+
+    nxt_feature="brotli"
+    nxt_feature_name=NXT_HAVE_BROTLI
+    nxt_feature_run=no
+    nxt_feature_incs=$NXT_BROTLI_CFLAGS
+    nxt_feature_libs=$NXT_BROTLI_LIBS
+    nxt_feature_test="#include <stdio.h>
+
+                      #include <brotli/encode.h>
+
+                      int main(void) {
+                          printf(\"brotli version: %d\n\",
+                                 BrotliEncoderVersion());
+                          return 0;
+                      }"
+    . auto/feature
+
+    if [ $nxt_found = yes ]; then
+        NXT_HAVE_BROTLI=YES
+        echo " + brotli version: $(pkgconf --modversion libbrotlienc)"
+    fi
+fi
diff --git a/auto/help b/auto/help
index 94854762..1093256d 100644
--- a/auto/help
+++ b/auto/help
@@ -50,6 +50,10 @@ cat << END
 
   --openssl            enable OpenSSL library usage
 
+  --zlib               enable zlib compression
+  --zstd               enable zstd compression
+  --brotli             enable brotli compression
+
   --njs                enable njs library usage
 
   --otel               enable otel library usage
diff --git a/auto/options b/auto/options
index 7aa7a73a..f1994858 100644
--- a/auto/options
+++ b/auto/options
@@ -26,6 +26,10 @@ NXT_GNUTLS=NO
 NXT_CYASSL=NO
 NXT_POLARSSL=NO
 
+NXT_ZLIB=NO
+NXT_ZSTD=NO
+NXT_BROTLI=NO
+
 NXT_NJS=NO
 NXT_OTEL=NO
 
@@ -112,6 +116,10 @@ do
         --cyassl)                        NXT_CYASSL=YES                      ;;
         --polarssl)                      NXT_POLARSSL=YES                    ;;
 
+        --zlib)                          NXT_ZLIB=YES                        ;;
+        --zstd)                          NXT_ZSTD=YES                        ;;
+        --brotli)                        NXT_BROTLI=YES                      ;;
+
         --njs)                           NXT_NJS=YES                         ;;
         --otel)                          NXT_OTEL=YES                        ;;
 
diff --git a/auto/sources b/auto/sources
index 02740397..28cdc834 100644
--- a/auto/sources
+++ b/auto/sources
@@ -107,6 +107,7 @@ NXT_LIB_SRCS=" \
     src/nxt_http_websocket.c \
     src/nxt_h1proto_websocket.c \
     src/nxt_fs.c \
+    src/nxt_http_compression.c \
 "
 
 
@@ -215,6 +216,21 @@ if [ $NXT_POLARSSL = YES ]; then
 fi
 
 
+if [ "$NXT_HAVE_ZLIB" = "YES" ]; then
+    NXT_LIB_SRCS="$NXT_LIB_SRCS src/nxt_zlib.c"
+fi
+
+
+if [ "$NXT_HAVE_ZSTD" = "YES" ]; then
+    NXT_LIB_SRCS="$NXT_LIB_SRCS src/nxt_zstd.c"
+fi
+
+
+if [ "$NXT_HAVE_BROTLI" = "YES" ]; then
+    NXT_LIB_SRCS="$NXT_LIB_SRCS src/nxt_brotli.c"
+fi
+
+
 if [ "$NXT_REGEX" = "YES" ]; then
     if [ "$NXT_HAVE_PCRE2" = "YES" ]; then
         NXT_LIB_SRCS="$NXT_LIB_SRCS $NXT_LIB_PCRE2_SRCS"
diff --git a/auto/summary b/auto/summary
index eba88be4..4a0888a6 100644
--- a/auto/summary
+++ b/auto/summary
@@ -28,6 +28,9 @@ Unit configuration summary:
   IPv6 support: .............. $NXT_INET6
   Unix domain sockets support: $NXT_UNIX_DOMAIN
   TLS support: ............... $NXT_OPENSSL
+  zlib support: .............. $NXT_ZLIB
+  zstd support: .............. $NXT_ZSTD
+  brotli support: ............ $NXT_BROTLI
   Regex support: ............. $NXT_REGEX
   njs support: ............... $NXT_NJS
   otel support: .............. $NXT_OTEL
diff --git a/configure b/configure
index 05a992ee..aba56e8a 100755
--- a/configure
+++ b/configure
@@ -127,6 +127,7 @@ NXT_LIBRT=
 . auto/unix
 . auto/os/conf
 . auto/ssltls
+. auto/compression
 
 if [ $NXT_REGEX = YES ]; then
     . auto/pcre
@@ -169,11 +170,13 @@ END
 
 NXT_LIB_AUX_CFLAGS="$NXT_OPENSSL_CFLAGS $NXT_GNUTLS_CFLAGS \\
                     $NXT_CYASSL_CFLAGS $NXT_POLARSSL_CFLAGS \\
-                    $NXT_PCRE_CFLAGS"
+                    $NXT_PCRE_CFLAGS $NXT_ZLIB_CFLAGS $NXT_ZSTD_CFLAGS \\
+                    $NXT_BROTLI_CFLAGS"
 
 NXT_LIB_AUX_LIBS="$NXT_OPENSSL_LIBS $NXT_GNUTLS_LIBS \\
                     $NXT_CYASSL_LIBS $NXT_POLARSSL_LIBS \\
-                    $NXT_PCRE_LIB"
+                    $NXT_PCRE_LIB $NXT_ZLIB_LIBS $NXT_ZSTD_LIBS \\
+                    $NXT_BROTLI_LIBS"
 
 if [ $NXT_NJS != NO ]; then
     . auto/njs