[WIP] HTTP Compression Supportcompr

17 files changed, 1186 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 8f7553f3..0c0d0319 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
 
   --debug              enable debug logging
diff --git a/auto/options b/auto/options
index 0550c699..3becefb8 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_TEST_BUILD_EPOLL=NO
@@ -109,6 +113,10 @@ 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                         ;;
 
         --test-build-epoll)              NXT_TEST_BUILD_EPOLL=YES            ;;
diff --git a/auto/sources b/auto/sources
index f34d7fd7..3feafa2a 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 \
 "
 
 
@@ -211,6 +212,21 @@ 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 dd7a60a0..d7238152 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
 
diff --git a/configure b/configure
index 2cb4d457..ed256f84 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
@@ -168,11 +169,13 @@ 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
diff --git a/src/nxt_brotli.c b/src/nxt_brotli.c
new file mode 100644
index 00000000..0c9b3658
--- /dev/null
+++ b/src/nxt_brotli.c
@@ -0,0 +1,86 @@
+/*
+ *
+ */
+
+/* XXX Remove */
+#define _GNU_SOURCE
+#include <unistd.h>
+
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <brotli/encode.h>
+
+#include <nxt_http_compression.h>
+
+static void nxt_brotli_free(const nxt_http_comp_compressor_ctx_t *ctx)
+{
+    BrotliEncoderState *brotli = ctx->brotli_ctx;
+
+    BrotliEncoderDestroyInstance(brotli);
+}
+
+static void nxt_brotli_init(nxt_http_comp_compressor_ctx_t *ctx)
+{
+    BrotliEncoderState **brotli = &ctx->brotli_ctx;
+
+    *brotli = BrotliEncoderCreateInstance(NULL, NULL, NULL);
+    BrotliEncoderSetParameter(*brotli, BROTLI_PARAM_QUALITY, ctx->level);
+
+    printf("%7d %s: brotli compression level [%d]\n", gettid(), __func__,
+           ctx->level);
+}
+
+static size_t nxt_brotli_compressed_size(const nxt_http_comp_compressor_ctx_t *ctx,
+                                         size_t in_len)
+{
+    return BrotliEncoderMaxCompressedSize(in_len);
+}
+
+static ssize_t nxt_brotli_compress(nxt_http_comp_compressor_ctx_t *ctx,
+                                   const uint8_t *in_buf, size_t in_len,
+                                   uint8_t *out_buf, size_t out_len, bool last)
+{
+    bool ok;
+    size_t out_bytes;
+    uint8_t *outp;
+    BrotliEncoderState *brotli = ctx->brotli_ctx;
+
+    printf("%7d %s: last/%s\n", gettid(), __func__, last ? "true" : "false");
+    printf("%7d %s: in_len [%lu] out_len [%lu]\n", gettid(),  __func__,
+           in_len, out_len);
+
+    outp = out_buf;
+
+    ok = BrotliEncoderCompressStream(brotli, BROTLI_OPERATION_PROCESS,
+                                     &in_len, &in_buf, &out_bytes, &outp,
+                                     NULL);
+
+    ok = BrotliEncoderCompressStream(brotli, BROTLI_OPERATION_FLUSH,
+                                     &in_len, &in_buf, &out_bytes, &outp,
+                                     NULL);
+
+    printf("%7d %s: in_len [%lu] out_len [%lu] out_bytes [%lu]\n", gettid(),
+           __func__, in_len, out_len, out_bytes);
+    if (last) {
+        ok = BrotliEncoderCompressStream(brotli, BROTLI_OPERATION_FINISH,
+                                         &in_len, &in_buf, &out_bytes, &outp,
+                                         NULL);
+        nxt_brotli_free(ctx);
+    }
+
+    printf("%7d %s: in_len [%lu] out_len [%lu] out_bytes [%lu]\n", gettid(),
+           __func__, in_len, out_len, out_bytes);
+    printf("%7d %s: buf [%p] outp [%p]\n", gettid(), __func__, out_buf, outp);
+
+    return out_len - out_bytes;
+}
+
+const nxt_http_comp_operations_t  nxt_comp_brotli_ops = {
+    .init               = nxt_brotli_init,
+    .compressed_size    = nxt_brotli_compressed_size,
+    .deflate            = nxt_brotli_compress,
+    .free_ctx           = nxt_brotli_free,
+};
diff --git a/src/nxt_conf_validation.c b/src/nxt_conf_validation.c
index 4aaa1b9a..e3a75a29 100644
--- a/src/nxt_conf_validation.c
+++ b/src/nxt_conf_validation.c
@@ -13,6 +13,7 @@
 #include <nxt_http.h>
 #include <nxt_sockaddr.h>
 #include <nxt_http_route_addr.h>
+#include <nxt_http_compression.h>
 #include <nxt_regex.h>
 
 
@@ -138,6 +139,14 @@ static nxt_int_t nxt_conf_vldt_threads(nxt_conf_validation_t *vldt,
     nxt_conf_value_t *value, void *data);
 static nxt_int_t nxt_conf_vldt_thread_stack_size(nxt_conf_validation_t *vldt,
     nxt_conf_value_t *value, void *data);
+static nxt_int_t nxt_conf_vldt_compressors(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value, void *data);
+static nxt_int_t nxt_conf_vldt_compression(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value);
+static nxt_int_t nxt_conf_vldt_compression_encoding(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value, void *data);
+static nxt_int_t nxt_conf_vldt_compression_level(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value, void *data);
 static nxt_int_t nxt_conf_vldt_routes(nxt_conf_validation_t *vldt,
     nxt_conf_value_t *value, void *data);
 static nxt_int_t nxt_conf_vldt_routes_member(nxt_conf_validation_t *vldt,
@@ -242,6 +251,8 @@ static nxt_conf_vldt_object_t  nxt_conf_vldt_setting_members[];
 static nxt_conf_vldt_object_t  nxt_conf_vldt_http_members[];
 static nxt_conf_vldt_object_t  nxt_conf_vldt_websocket_members[];
 static nxt_conf_vldt_object_t  nxt_conf_vldt_static_members[];
+static nxt_conf_vldt_object_t  nxt_conf_vldt_compression_members[];
+static nxt_conf_vldt_object_t  nxt_conf_vldt_compressor_members[];
 static nxt_conf_vldt_object_t  nxt_conf_vldt_forwarded_members[];
 static nxt_conf_vldt_object_t  nxt_conf_vldt_client_ip_members[];
 #if (NXT_TLS)
@@ -368,6 +379,11 @@ static nxt_conf_vldt_object_t  nxt_conf_vldt_http_members[] = {
     }, {
         .name       = nxt_string("server_version"),
         .type       = NXT_CONF_VLDT_BOOLEAN,
+    }, {
+        .name       = nxt_string("compression"),
+        .type       = NXT_CONF_VLDT_OBJECT,
+        .validator  = nxt_conf_vldt_object,
+        .u.members  = nxt_conf_vldt_compression_members,
     },
 
     NXT_CONF_VLDT_END
@@ -402,6 +418,40 @@ static nxt_conf_vldt_object_t  nxt_conf_vldt_static_members[] = {
 };
 
 
+static nxt_conf_vldt_object_t  nxt_conf_vldt_compression_members[] = {
+    {
+        .name       = nxt_string("types"),
+        .type       = NXT_CONF_VLDT_STRING | NXT_CONF_VLDT_ARRAY,
+        .validator  = nxt_conf_vldt_match_patterns,
+    }, {
+        .name       = nxt_string("compressors"),
+        .type       = NXT_CONF_VLDT_OBJECT | NXT_CONF_VLDT_ARRAY,
+        .validator  = nxt_conf_vldt_compressors,
+    },
+
+    NXT_CONF_VLDT_END
+};
+
+
+static nxt_conf_vldt_object_t  nxt_conf_vldt_compressor_members[] = {
+    {
+        .name       = nxt_string("encoding"),
+        .type       = NXT_CONF_VLDT_STRING,
+        .flags      = NXT_CONF_VLDT_REQUIRED,
+        .validator  = nxt_conf_vldt_compression_encoding,
+    }, {
+        .name       = nxt_string("level"),
+        .type       = NXT_CONF_VLDT_INTEGER,
+        .validator  = nxt_conf_vldt_compression_level,
+    }, {
+        .name       = nxt_string("min_length"),
+        .type       = NXT_CONF_VLDT_INTEGER,
+    },
+
+    NXT_CONF_VLDT_END
+};
+
+
 static nxt_conf_vldt_object_t  nxt_conf_vldt_listener_members[] = {
     {
         .name       = nxt_string("pass"),
@@ -2113,6 +2163,62 @@ nxt_conf_vldt_thread_stack_size(nxt_conf_validation_t *vldt,
 
 
 static nxt_int_t
+nxt_conf_vldt_compressors(nxt_conf_validation_t *vldt, nxt_conf_value_t *value,
+    void *data)
+{
+    if (nxt_conf_type(value) == NXT_CONF_ARRAY) {
+        return nxt_conf_vldt_array_iterator(vldt, value,
+                                            &nxt_conf_vldt_compression);
+    }
+
+    /* NXT_CONF_OBJECT */
+
+    return nxt_conf_vldt_object_iterator(vldt, value,
+                                         &nxt_conf_vldt_compressor_members);
+}
+
+
+static nxt_int_t
+nxt_conf_vldt_compression(nxt_conf_validation_t *vldt, nxt_conf_value_t *value)
+{
+    if (nxt_conf_type(value) != NXT_CONF_OBJECT) {
+        return nxt_conf_vldt_error(vldt,
+                                   "The \"compressors\" array must contain "
+                                   "only object values.");
+    }
+
+    return nxt_conf_vldt_object(vldt, value, nxt_conf_vldt_compressor_members);
+}
+
+
+static nxt_int_t
+nxt_conf_vldt_compression_encoding(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value, void *data)
+{
+    nxt_str_t  token;
+
+    nxt_conf_get_string(value, &token);
+
+    if (nxt_http_comp_compressor_is_valid(&token)) {
+        return NXT_OK;
+    }
+
+    return nxt_conf_vldt_error(vldt, "\"%V\" is not a supported compressor.",
+                               &token);
+}
+
+
+static nxt_int_t
+nxt_conf_vldt_compression_level(nxt_conf_validation_t *vldt,
+    nxt_conf_value_t *value, void *data)
+{
+    /* XXX Fill me in */
+
+    return NXT_OK;
+}
+
+
+static nxt_int_t
 nxt_conf_vldt_routes(nxt_conf_validation_t *vldt, nxt_conf_value_t *value,
     void *data)
 {
diff --git a/src/nxt_http.h b/src/nxt_http.h
index 5fab5c67..a8ada3f4 100644
--- a/src/nxt_http.h
+++ b/src/nxt_http.h
@@ -110,6 +110,7 @@ typedef struct {
     nxt_http_field_t                *content_type;
     nxt_http_field_t                *content_length;
     nxt_off_t                       content_length_n;
+    const nxt_str_t                 *mime_type;
 } nxt_http_response_t;
 
 
diff --git a/src/nxt_http_compression.c b/src/nxt_http_compression.c
new file mode 100644
index 00000000..dd91d890
--- /dev/null
+++ b/src/nxt_http_compression.c
@@ -0,0 +1,586 @@
+/*
+ *
+ */
+
+#include <nxt_auto_config.h>
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include <nxt_router.h>
+#include <nxt_http.h>
+#include <nxt_tstr.h>
+#include <nxt_conf.h>
+#include <nxt_http_compression.h>
+
+#define NXT_COMP_LEVEL_UNSET               INT8_MIN
+
+typedef enum nxt_http_comp_scheme_e        nxt_http_comp_scheme_t;
+typedef struct nxt_http_comp_type_s        nxt_http_comp_type_t;
+typedef struct nxt_http_comp_opts_s        nxt_http_comp_opts_t;
+typedef struct nxt_http_comp_compressor_s  nxt_http_comp_compressor_t;
+typedef struct nxt_http_comp_ctx_s         nxt_http_comp_ctx_t;
+
+enum nxt_http_comp_scheme_e {
+    NXT_HTTP_COMP_SCHEME_IDENTITY = 0,
+#if NXT_HAVE_ZLIB
+    NXT_HTTP_COMP_SCHEME_DEFLATE,
+    NXT_HTTP_COMP_SCHEME_GZIP,
+#endif
+#if NXT_HAVE_ZSTD
+    NXT_HTTP_COMP_SCHEME_ZSTD,
+#endif
+#if NXT_HAVE_BROTLI
+    NXT_HTTP_COMP_SCHEME_BROTLI,
+#endif
+
+    /* keep last */
+    NXT_HTTP_COMP_SCHEME_UNKNOWN
+};
+#define NXT_NR_COMPRESSORS  NXT_HTTP_COMP_SCHEME_UNKNOWN
+
+struct nxt_http_comp_type_s {
+    nxt_str_t                         token;
+    nxt_http_comp_scheme_t            scheme;
+    int8_t                            def_compr;
+
+    const nxt_http_comp_operations_t  *cops;
+};
+
+struct nxt_http_comp_opts_s {
+    int8_t                      level;
+    nxt_off_t                   min_len;
+};
+
+struct nxt_http_comp_compressor_s {
+    const nxt_http_comp_type_t  *type;
+    nxt_http_comp_opts_t        opts;
+};
+
+struct nxt_http_comp_ctx_s {
+    nxt_uint_t idx;
+
+    nxt_off_t resp_clen;
+    nxt_off_t clen_procd;
+
+    nxt_http_comp_compressor_ctx_t ctx;
+};
+
+static nxt_tstr_t                  *accept_encoding_query;
+static nxt_http_route_rule_t       *mime_types_rule;
+static nxt_http_comp_compressor_t  *enabled_compressors;
+static nxt_uint_t                  nr_enabled_compressors;
+
+static nxt_thread_declare_data(nxt_http_comp_ctx_t, compressor_ctx);
+
+static const nxt_conf_map_t  compressors_opts_map[] = {
+    {
+        nxt_string("level"),
+        NXT_CONF_MAP_INT,
+        offsetof(nxt_http_comp_opts_t, level),
+    }, {
+        nxt_string("min_length"),
+        NXT_CONF_MAP_SIZE,
+        offsetof(nxt_http_comp_opts_t, min_len),
+    },
+};
+
+static const nxt_http_comp_type_t  compressors[] = {
+    /* Keep this first */
+    {
+        .token      = nxt_string("identity"),
+        .scheme     = NXT_HTTP_COMP_SCHEME_IDENTITY,
+    },
+#if NXT_HAVE_ZLIB
+    {
+        .token      = nxt_string("deflate"),
+        .scheme     = NXT_HTTP_COMP_SCHEME_DEFLATE,
+        .def_compr  = NXT_HTTP_COMP_ZLIB_DEFAULT_LEVEL,
+        .cops       = &nxt_comp_deflate_ops,
+    }, {
+        .token      = nxt_string("gzip"),
+        .scheme     = NXT_HTTP_COMP_SCHEME_GZIP,
+        .def_compr  = NXT_HTTP_COMP_ZLIB_DEFAULT_LEVEL,
+        .cops       = &nxt_comp_gzip_ops,
+    },
+#endif
+#if NXT_HAVE_ZSTD
+    {
+        .token      = nxt_string("zstd"),
+        .scheme     = NXT_HTTP_COMP_SCHEME_ZSTD,
+        .def_compr  = NXT_HTTP_COMP_ZSTD_DEFAULT_LEVEL,
+        .cops       = &nxt_comp_zstd_ops,
+    },
+#endif
+#if NXT_HAVE_BROTLI
+    {
+        .token      = nxt_string("br"),
+        .scheme     = NXT_HTTP_COMP_SCHEME_BROTLI,
+        .def_compr  = NXT_HTTP_COMP_BROTLI_DEFAULT_LEVEL,
+        .cops       = &nxt_comp_brotli_ops,
+    },
+#endif
+};
+
+static void print_compressor(const nxt_http_comp_compressor_t *c)
+{
+    printf("token    : %s\n", c->type->token.start);
+    printf("scheme   : %d\n", c->type->scheme);
+    printf("level    : %d\n", c->opts.level);
+    printf("min_len  : %ld\n", c->opts.min_len);
+}
+
+static void print_comp_config(size_t n)
+{
+    for (size_t i = 0; i < n; i++) {
+        nxt_http_comp_compressor_t *compr = enabled_compressors + i;
+
+        print_compressor(compr);
+        printf("\n");
+    }
+}
+
+nxt_int_t
+nxt_http_comp_compress_response(nxt_buf_t *out)
+{
+    nxt_buf_t          *b;
+    size_t in_len;
+    size_t buf_len;
+    ssize_t cbytes;
+    uint8_t *buf;
+    bool last = false;
+    nxt_http_comp_compressor_t  *compressor;
+
+    printf("%s: \n", __func__);
+
+    b = out;
+
+    if (b->mem.pos == NULL) {
+        return NXT_OK;
+    }
+
+    if (compressor_ctx.idx == NXT_HTTP_COMP_SCHEME_IDENTITY) {
+        printf("%s: NXT_HTTP_COMP_SCHEME_IDENTITY [skipping/identity]\n",
+               __func__);
+        return NXT_OK;
+    }
+
+    compressor = &enabled_compressors[compressor_ctx.idx];
+
+    in_len = b->mem.free - b->mem.pos;
+//   last = !b->next || (b->next && b->next->is_last == 1);
+    if ((b->next && b->next->is_last == 1)
+        || compressor_ctx.resp_clen == compressor_ctx.clen_procd
+                                       + (nxt_off_t)in_len)
+    {
+        last = true;
+    }
+
+    buf_len = compressor->type->cops->compressed_size(&compressor_ctx.ctx,
+                                                      in_len);
+    buf = nxt_malloc(buf_len);
+    cbytes = compressor->type->cops->deflate(&compressor_ctx.ctx, b->mem.pos,
+                                             in_len, buf, buf_len, last);
+    printf("%s: cbytes = %ld\n", __func__, cbytes);
+    /* XXX What if new buffer is larger than original buffer... ? */
+    if (cbytes != -1) {
+        compressor_ctx.clen_procd += in_len;
+        b->mem.free = nxt_cpymem(b->mem.pos, buf, cbytes);
+    }
+    nxt_free(buf);
+
+    return NXT_OK;
+}
+
+static nxt_uint_t
+nxt_http_comp_compressor_lookup_enabled(const nxt_str_t *token)
+{
+    if (token->start[0] == '*') {
+        return NXT_HTTP_COMP_SCHEME_IDENTITY;
+    }
+
+    for (size_t i = 0, n = nr_enabled_compressors; i < n; i++) {
+        if (nxt_strstr_eq(token, &enabled_compressors[i].type->token)) {
+            return i;
+        }
+    }
+
+    return NXT_HTTP_COMP_SCHEME_UNKNOWN;
+}
+
+/*
+ * We need to parse the 'Accept-Encoding` header as described by
+ * <https://www.rfc-editor.org/rfc/rfc9110.html#field.accept-encoding>
+ * which can take forms such as
+ *
+ *  Accept-Encoding: compress, gzip
+ *  Accept-Encoding:
+ *  Accept-Encoding: *
+ *  Accept-Encoding: compress;q=0.5, gzip;q=1.0
+ *  Accept-Encoding: gzip;q=1.0, identity;q=0.5, *;q=0
+ *
+ *  '*:q=0' means if the content being served has no 'Content-Coding'
+ *  matching an 'Accept-Encoding' entry then don't send any response.
+ *
+ * 'indentity;q=0' seems to basically mean the same thing...
+ */
+static nxt_int_t
+nxt_http_comp_select_compressor(const nxt_str_t *token)
+{
+    bool identity_allowed = true;
+    char *str;
+    char *saveptr;
+    double weight = 0.0;
+    nxt_int_t idx = 0;
+
+    str = strndup((char *)token->start, token->length);
+
+    for ( ; ; str = NULL) {
+        char *tkn, *qptr;
+        double qval = -1.0;
+        nxt_uint_t ecidx;
+        nxt_str_t enc;
+        nxt_http_comp_scheme_t scheme;
+
+        tkn = strtok_r(str, ", ", &saveptr);
+        if (tkn == NULL) {
+            break;
+        }
+
+        qptr = strstr(tkn, ";q=");
+        if (qptr != NULL) {
+            qval = atof(qptr + 3);
+        }
+
+        enc.start = (u_char *)tkn;
+        enc.length = qptr != NULL ? (size_t)(qptr - tkn) : strlen(tkn);
+
+        ecidx = nxt_http_comp_compressor_lookup_enabled(&enc);
+        if (ecidx == NXT_HTTP_COMP_SCHEME_UNKNOWN) {
+            continue;
+        }
+
+        scheme = enabled_compressors[ecidx].type->scheme;
+
+        printf("%s: %.*s [%f] [%d:%d]\n", __func__, (int)enc.length, enc.start,
+               qval, ecidx, scheme);
+
+        if (qval == 0.0 && scheme == NXT_HTTP_COMP_SCHEME_IDENTITY) {
+            identity_allowed = false;
+        }
+
+        if (qval != -1.0 && (qval == 0.0 || qval < weight)) {
+            continue;
+        }
+
+        idx = ecidx;
+        weight = qval;
+    }
+
+    free(str);
+
+    printf("%s: Selected compressor : %s\n", __func__,
+           enabled_compressors[idx].type->token.start);
+
+    printf("%s: idx [%u], identity_allowed [%s]\n", __func__, idx,
+           identity_allowed ? "true" : "false");
+
+    if (idx == NXT_HTTP_COMP_SCHEME_IDENTITY && !identity_allowed) {
+        return -1;
+    }
+
+    return idx;
+}
+
+static nxt_int_t
+nxt_http_comp_set_header(nxt_http_request_t *r, nxt_uint_t index)
+{
+    const nxt_str_t *token;
+    nxt_http_field_t *f;
+
+    static const nxt_str_t  content_encoding_str =
+                                    nxt_string("Content-Encoding");
+
+    f = nxt_list_add(r->resp.fields);
+    if (nxt_slow_path(f == NULL)) {
+        return NXT_ERROR;
+    }
+
+    r->resp.content_length = NULL;
+    r->resp.content_length_n = -1;
+
+    f->hash = 0;
+    f->skip = 0;
+    f->hopbyhop = 0;
+
+    token = &enabled_compressors[index].type->token;
+
+    f->name = content_encoding_str.start;
+    f->name_length = content_encoding_str.length;
+    f->value = token->start;
+    f->value_length = token->length;
+
+    return NXT_OK;
+}
+
+static bool
+nxt_http_comp_is_resp_content_encoded(const nxt_http_request_t *r)
+{
+    nxt_http_field_t *f;
+
+    printf("%s: \n", __func__);
+
+    nxt_list_each(f, r->resp.fields) {
+        printf("%s: %s: %s\n", __func__, f->name, f->value);
+        if (nxt_strcasecmp(f->name, (const u_char *)"Content-Encoding") == 0) {
+            return true;
+        }
+    } nxt_list_loop;
+
+    return false;
+}
+
+nxt_int_t
+nxt_http_comp_check_compression(nxt_task_t *task, nxt_http_request_t *r)
+{
+    int8_t level;
+    nxt_str_t mime_type = { };
+    nxt_int_t ret, idx;
+    nxt_off_t min_len;
+    nxt_str_t accept_encoding;
+    nxt_router_conf_t *rtcf;
+    nxt_http_comp_compressor_t *compressor;
+
+    printf("%s: \n", __func__);
+
+    compressor_ctx = (nxt_http_comp_ctx_t){ .resp_clen = -1 };
+
+    if (r->resp.content_length_n == 0) {
+        return NXT_OK;
+    }
+
+    if (r->resp.mime_type != NULL) {
+        mime_type = *r->resp.mime_type;
+    } else if (r->resp.content_type != NULL) {
+        mime_type.start = r->resp.content_type->value;
+        mime_type.length = r->resp.content_type->value_length;
+    }
+
+    if (mime_type.start == NULL) {
+        return NXT_OK;
+    }
+
+    printf("%s: Response Content-Type [%.*s]\n", __func__,
+           (int)mime_type.length, mime_type.start);
+
+    if (mime_types_rule != NULL) {
+        ret = nxt_http_route_test_rule(r, mime_types_rule,
+                                       mime_type.start,
+                                       mime_type.length);
+        printf("%s: mime_type : %d (%.*s)\n", __func__, ret,
+               (int)mime_type.length, mime_type.start);
+
+        if (ret == 0) {
+            return NXT_OK;
+        }
+    }
+
+    rtcf = r->conf->socket_conf->router_conf;
+
+    if (nxt_http_comp_is_resp_content_encoded(r)) {
+        return NXT_OK;
+    }
+
+    /* XXX Should checking the Accept-Encoding header come first? */
+    ret = nxt_tstr_query_init(&r->tstr_query, rtcf->tstr_state, &r->tstr_cache,
+                              r, r->mem_pool);
+    if (nxt_slow_path(ret == NXT_ERROR)) {
+        return NXT_ERROR;
+    }
+
+    nxt_tstr_query(task, r->tstr_query, accept_encoding_query,
+                   &accept_encoding);
+    if (nxt_slow_path(nxt_tstr_query_failed(r->tstr_query))) {
+        return NXT_ERROR;
+    }
+
+    printf("%s: Accept-Encoding: %s\n", __func__, accept_encoding.start);
+
+    idx = nxt_http_comp_select_compressor(&accept_encoding);
+    if (idx == -1) {
+        /*
+         * XXX Needs to trigger the right HTTP error status code
+         * for unsuppported media or something...
+         */
+        return NXT_ERROR;
+    }
+
+    if (idx == NXT_HTTP_COMP_SCHEME_IDENTITY) {
+        return NXT_OK;
+    }
+
+    compressor = &enabled_compressors[idx];
+
+    if (r->resp.content_length_n > -1) {
+        compressor_ctx.resp_clen = r->resp.content_length_n;
+    } else if (r->resp.content_length != NULL) {
+        compressor_ctx.resp_clen =
+                    strtol((char *)r->resp.content_length->value, NULL, 10);
+    }
+
+    min_len = compressor->opts.min_len;
+
+    if (compressor_ctx.resp_clen > -1 && compressor_ctx.resp_clen < min_len) {
+        printf("%s: %ld < %ld [skipping/clen]\n", __func__,
+               compressor_ctx.resp_clen , min_len);
+        return NXT_OK;
+    }
+
+    nxt_http_comp_set_header(r, idx);
+
+    compressor_ctx.idx = idx;
+
+    level = enabled_compressors[idx].opts.level;
+    compressor_ctx.ctx.level = level == NXT_COMP_LEVEL_UNSET ?
+                            enabled_compressors[idx].type->def_compr : level;
+
+    compressor->type->cops->init(&compressor_ctx.ctx);
+
+    return NXT_OK;
+}
+
+static nxt_uint_t
+nxt_http_comp_compressor_token2idx(const nxt_str_t *token)
+{
+    for (nxt_uint_t i = 0, n = nxt_nitems(compressors); i < n; i++) {
+        if (nxt_strstr_eq(token, &compressors[i].token)) {
+            return i;
+        }
+    }
+
+    return NXT_HTTP_COMP_SCHEME_UNKNOWN;
+}
+
+bool
+nxt_http_comp_compressor_is_valid(const nxt_str_t *token)
+{
+    nxt_uint_t  idx;
+
+    idx = nxt_http_comp_compressor_token2idx(token);
+    if (idx != NXT_HTTP_COMP_SCHEME_UNKNOWN) {
+        return true;
+    }
+
+    return false;
+}
+
+static nxt_int_t
+nxt_http_comp_set_compressor(nxt_router_conf_t *rtcf,
+                             const nxt_conf_value_t *comp, nxt_uint_t index)
+{
+    nxt_int_t               ret;
+    nxt_str_t               token;
+    nxt_uint_t              cidx;
+    nxt_conf_value_t        *obj;
+
+    printf("%s: \n", __func__);
+
+    static nxt_str_t  token_str = nxt_string("encoding");
+
+    obj = nxt_conf_get_object_member(comp, &token_str, NULL);
+    if (obj == NULL) {
+        return NXT_ERROR;
+    }
+
+    nxt_conf_get_string(obj, &token);
+    cidx = nxt_http_comp_compressor_token2idx(&token);
+
+    enabled_compressors[index].type = &compressors[cidx];
+    enabled_compressors[index].opts.level = NXT_COMP_LEVEL_UNSET;
+    enabled_compressors[index].opts.min_len = -1;
+    printf("%s: %s\n", __func__, enabled_compressors[index].type->token.start);
+
+    ret = nxt_conf_map_object(rtcf->mem_pool, comp, compressors_opts_map,
+                              nxt_nitems(compressors_opts_map),
+                              &enabled_compressors[index].opts);
+    if (nxt_slow_path(ret == NXT_ERROR)) {
+        return NXT_ERROR;
+    }
+
+    return NXT_OK;
+}
+
+nxt_int_t
+nxt_http_comp_compression_init(nxt_task_t *task, nxt_router_conf_t *rtcf,
+                               const nxt_conf_value_t *comp_conf)
+{
+    nxt_int_t         ret;
+    nxt_uint_t        n = 1;  /* 'identity' */
+    nxt_conf_value_t  *comps, *mimes;
+
+    static const nxt_str_t  accept_enc_str =
+                                    nxt_string("$header_accept_encoding");
+    static const nxt_str_t  comps_str = nxt_string("compressors");
+    static const nxt_str_t  mimes_str = nxt_string("types");
+
+    printf("%s: \n", __func__);
+
+    mimes = nxt_conf_get_object_member(comp_conf, &mimes_str, NULL);
+    if (mimes != NULL) {
+        mime_types_rule = nxt_http_route_types_rule_create(task,
+                                                           rtcf->mem_pool,
+                                                           mimes);
+        if (nxt_slow_path(mime_types_rule == NULL)) {
+            return NXT_ERROR;
+        }
+    }
+
+    accept_encoding_query = nxt_tstr_compile(rtcf->tstr_state, &accept_enc_str,
+                                             NXT_TSTR_STRZ);
+    if (nxt_slow_path(accept_encoding_query == NULL)) {
+        return NXT_ERROR;
+    }
+
+    comps = nxt_conf_get_object_member(comp_conf, &comps_str, NULL);
+    if (nxt_slow_path(comps == NULL)) {
+        return NXT_ERROR;
+    }
+
+    if (nxt_conf_type(comps) == NXT_CONF_OBJECT) {
+        n++;
+    } else {
+        n += nxt_conf_object_members_count(comps);
+    }
+    nr_enabled_compressors = n;
+
+    enabled_compressors = nxt_mp_zalloc(rtcf->mem_pool,
+                                        sizeof(nxt_http_comp_compressor_t) * n);
+
+    enabled_compressors[0] =
+        (nxt_http_comp_compressor_t){ .type = &compressors[0],
+                                      .opts.level = NXT_COMP_LEVEL_UNSET,
+                                      .opts.min_len = -1 };
+
+    if (nxt_conf_type(comps) == NXT_CONF_OBJECT) {
+        /* XXX Remove me... */
+        print_comp_config(nr_enabled_compressors);
+        return nxt_http_comp_set_compressor(rtcf, comps, 1);
+    }
+
+    for (nxt_uint_t i = 1; i < n; i++) {
+        nxt_conf_value_t  *obj;
+
+        obj = nxt_conf_get_array_element(comps, i - 1);
+        ret = nxt_http_comp_set_compressor(rtcf, obj, i);
+        if (ret == NXT_ERROR) {
+            return NXT_ERROR;
+        }
+    }
+
+    nr_enabled_compressors = n;
+    /* XXX Remove me... */
+    print_comp_config(nr_enabled_compressors);
+
+    return NXT_OK;
+}
diff --git a/src/nxt_http_compression.h b/src/nxt_http_compression.h
new file mode 100644
index 00000000..a76f3993
--- /dev/null
+++ b/src/nxt_http_compression.h
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) Andrew Clayton
+ * Copyright (C) F5, Inc.
+ */
+
+#ifndef _NXT_COMPRESSION_H_INCLUDED_
+#define _NXT_COMPRESSION_H_INCLUDED_
+
+#include <nxt_auto_config.h>
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#if NXT_HAVE_ZLIB
+#include <zlib.h>
+#endif
+
+#if NXT_HAVE_ZSTD
+#include <zstd.h>
+#endif
+
+#if NXT_HAVE_BROTLI
+#include <brotli/encode.h>
+#endif
+
+#include <nxt_main.h>
+#include <nxt_router.h>
+#include <nxt_string.h>
+#include <nxt_conf.h>
+
+#if NXT_HAVE_ZLIB
+#define NXT_HTTP_COMP_ZLIB_DEFAULT_LEVEL       Z_DEFAULT_COMPRESSION
+#endif
+#if NXT_HAVE_ZSTD
+#define NXT_HTTP_COMP_ZSTD_DEFAULT_LEVEL       ZSTD_CLEVEL_DEFAULT
+#endif
+#if NXT_HAVE_BROTLI
+#define NXT_HTTP_COMP_BROTLI_DEFAULT_LEVEL     BROTLI_DEFAULT_QUALITY
+#endif
+
+typedef struct nxt_http_comp_compressor_ctx_s  nxt_http_comp_compressor_ctx_t;
+typedef struct nxt_http_comp_operations_s      nxt_http_comp_operations_t;
+
+struct nxt_http_comp_compressor_ctx_s {
+    int8_t level;
+
+    union {
+#if NXT_HAVE_ZLIB
+        z_stream zlib_ctx;
+#endif
+#if NXT_HAVE_ZSTD
+        ZSTD_CStream *zstd_ctx;
+#endif
+#if NXT_HAVE_BROTLI
+        BrotliEncoderState *brotli_ctx;
+#endif
+    };
+};
+
+struct nxt_http_comp_operations_s {
+    void     (*init)(nxt_http_comp_compressor_ctx_t *ctx);
+    size_t   (*compressed_size)(const nxt_http_comp_compressor_ctx_t *ctx,
+                                size_t in_len);
+    ssize_t  (*deflate)(nxt_http_comp_compressor_ctx_t *ctx,
+                        const uint8_t *in_buf, size_t in_len,
+                        uint8_t *out_buf, size_t out_len, bool last);
+    void     (*free_ctx)(const nxt_http_comp_compressor_ctx_t *ctx);
+};
+
+#if NXT_HAVE_ZLIB
+extern const nxt_http_comp_operations_t  nxt_comp_deflate_ops;
+extern const nxt_http_comp_operations_t  nxt_comp_gzip_ops;
+#endif
+
+#if NXT_HAVE_ZSTD
+extern const nxt_http_comp_operations_t  nxt_comp_zstd_ops;
+#endif
+
+#if NXT_HAVE_BROTLI
+extern const nxt_http_comp_operations_t  nxt_comp_brotli_ops;
+#endif
+
+extern bool nxt_http_comp_compressor_is_valid(const nxt_str_t *token);
+extern nxt_int_t nxt_http_comp_check_compression(nxt_task_t *task,
+    nxt_http_request_t *r);
+extern nxt_int_t nxt_http_comp_compress_response(nxt_buf_t *out);
+extern nxt_int_t nxt_http_comp_compression_init(nxt_task_t *task,
+    nxt_router_conf_t *rtcf, const nxt_conf_value_t *comp_conf);
+
+#endif  /* _NXT_COMPRESSION_H_INCLUDED_ */
diff --git a/src/nxt_http_request.c b/src/nxt_http_request.c
index 425a4607..0a89b327 100644
--- a/src/nxt_http_request.c
+++ b/src/nxt_http_request.c
@@ -6,6 +6,7 @@
 
 #include <nxt_router.h>
 #include <nxt_http.h>
+#include <nxt_http_compression.h>
 
 
 static nxt_int_t nxt_http_validate_host(nxt_str_t *host, nxt_mp_t *mp);
@@ -311,6 +312,8 @@ nxt_http_request_start(nxt_task_t *task, void *obj, void *data)
     nxt_socket_conf_t   *skcf;
     nxt_http_request_t  *r;
 
+    printf("%s: \n", __func__);
+
     r = obj;
 
     r->state = &nxt_http_request_body_state;
@@ -636,6 +639,13 @@ nxt_http_request_header_send(nxt_task_t *task, nxt_http_request_t *r,
     nxt_http_field_t   *server, *date, *content_length;
     nxt_socket_conf_t  *skcf;
 
+    printf("%s: \n", __func__);
+
+    ret = nxt_http_comp_check_compression(task, r);
+    if (nxt_slow_path(ret != NXT_OK)) {
+        goto fail;
+    }
+
     ret = nxt_http_set_headers(r);
     if (nxt_slow_path(ret != NXT_OK)) {
         goto fail;
@@ -726,6 +736,10 @@ nxt_http_request_ws_frame_start(nxt_task_t *task, nxt_http_request_t *r,
 void
 nxt_http_request_send(nxt_task_t *task, nxt_http_request_t *r, nxt_buf_t *out)
 {
+    printf("%s: \n", __func__);
+
+    nxt_http_comp_compress_response(out);
+
     if (nxt_fast_path(r->proto.any != NULL)) {
         nxt_http_proto[r->protocol].send(task, r, out);
     }
diff --git a/src/nxt_http_route.c b/src/nxt_http_route.c
index 852f5739..0e0e8e7a 100644
--- a/src/nxt_http_route.c
+++ b/src/nxt_http_route.c
@@ -656,6 +656,8 @@ nxt_http_action_init(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
     nxt_router_conf_t       *rtcf;
     nxt_http_action_conf_t  acf;
 
+    printf("%s: \n", __func__);
+
     nxt_memzero(&acf, sizeof(acf));
 
     ret = nxt_conf_map_object(tmcf->mem_pool, cv, nxt_http_route_action_conf,
diff --git a/src/nxt_http_static.c b/src/nxt_http_static.c
index ee25015e..c8828782 100644
--- a/src/nxt_http_static.c
+++ b/src/nxt_http_static.c
@@ -647,6 +647,8 @@ nxt_http_static_send_ready(nxt_task_t *task, void *obj, void *data)
         body_handler = NULL;
     }
 
+    r->resp.mime_type = mtype;
+
     nxt_http_request_header_send(task, r, body_handler, NULL);
 
     r->state = &nxt_http_static_send_state;
@@ -799,6 +801,8 @@ nxt_http_static_body_handler(nxt_task_t *task, void *obj, void *data)
     nxt_work_queue_t    *wq;
     nxt_http_request_t  *r;
 
+    printf("%s: \n", __func__);
+
     r = obj;
     fb = r->out;
 
@@ -859,6 +863,8 @@ nxt_http_static_buf_completion(nxt_task_t *task, void *obj, void *data)
     nxt_off_t           rest;
     nxt_http_request_t  *r;
 
+    printf("%s: \n", __func__);
+
     b = obj;
     r = data;
 
diff --git a/src/nxt_router.c b/src/nxt_router.c
index 48870d20..50ec44b5 100644
--- a/src/nxt_router.c
+++ b/src/nxt_router.c
@@ -21,6 +21,7 @@
 #include <nxt_router_request.h>
 #include <nxt_app_queue.h>
 #include <nxt_port_queue.h>
+#include <nxt_http_compression.h>
 
 #define NXT_SHARED_PORT_ID  0xFFFFu
 
@@ -1655,6 +1656,8 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
     static const nxt_str_t  static_path = nxt_string("/settings/http/static");
     static const nxt_str_t  websocket_path =
                                 nxt_string("/settings/http/websocket");
+    static const nxt_str_t  compression_path =
+                                nxt_string("/settings/http/compression");
     static const nxt_str_t  forwarded_path = nxt_string("/forwarded");
     static const nxt_str_t  client_ip_path = nxt_string("/client_ip");
 
@@ -2002,6 +2005,8 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
             nxt_str_null(&skcf->body_temp_path);
 
             if (http != NULL) {
+                nxt_conf_value_t  *comp;
+
                 ret = nxt_conf_map_object(mp, http, nxt_router_http_conf,
                                           nxt_nitems(nxt_router_http_conf),
                                           skcf);
@@ -2009,6 +2014,11 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
                     nxt_alert(task, "http map error");
                     goto fail;
                 }
+
+                comp = nxt_conf_get_path(root, &compression_path);
+                if (comp != NULL) {
+                    nxt_http_comp_compression_init(task, rtcf, comp);
+                }
             }
 
             if (websocket != NULL) {
diff --git a/src/nxt_zlib.c b/src/nxt_zlib.c
new file mode 100644
index 00000000..2dcc53a8
--- /dev/null
+++ b/src/nxt_zlib.c
@@ -0,0 +1,79 @@
+/*
+ *
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <zlib.h>
+
+#include <nxt_http_compression.h>
+
+static void nxt_zlib_gzip_init(nxt_http_comp_compressor_ctx_t *ctx)
+{
+    int ret;
+    z_stream *z = &ctx->zlib_ctx;
+
+    *z = (z_stream){ };
+
+    ret = deflateInit2(z, ctx->level, Z_DEFLATED, 9 + 16, 8,
+                       Z_DEFAULT_STRATEGY);
+}
+
+static void nxt_zlib_deflate_init(nxt_http_comp_compressor_ctx_t *ctx)
+{
+    int ret;
+    z_stream *z = &ctx->zlib_ctx;
+
+    *z = (z_stream){ };
+
+    ret = deflateInit2(z, ctx->level, Z_DEFLATED, 9, 8, Z_DEFAULT_STRATEGY);
+}
+
+static size_t nxt_zlib_compressed_size(const nxt_http_comp_compressor_ctx_t *ctx,
+                                       size_t in_len)
+{
+    z_stream *z = &ctx->zlib_ctx;
+
+    return deflateBound(z, in_len);
+}
+
+static ssize_t nxt_zlib_deflate(nxt_http_comp_compressor_ctx_t *ctx,
+                                const uint8_t *in_buf, size_t in_len,
+                                uint8_t *out_buf, size_t out_len, bool last)
+{
+    int ret;
+    z_stream *z = &ctx->zlib_ctx;
+    size_t compressed_bytes = z->total_out;
+
+    z->avail_in = in_len;
+    z->next_in = (z_const Bytef *)in_buf;
+
+    z->avail_out = out_len;
+    z->next_out = out_buf;
+
+    ret = deflate(z, last ? Z_FINISH : Z_SYNC_FLUSH);
+    if (ret == Z_STREAM_ERROR || ret == Z_BUF_ERROR) {
+        deflateEnd(z);
+        printf("%s: ret = %d\n", __func__, ret);
+        return -1;
+    }
+
+    if (last)
+        deflateEnd(z);
+
+    return z->total_out - compressed_bytes;
+}
+
+const nxt_http_comp_operations_t  nxt_comp_deflate_ops = {
+    .init               = nxt_zlib_deflate_init,
+    .compressed_size    = nxt_zlib_compressed_size,
+    .deflate            = nxt_zlib_deflate,
+};
+
+const nxt_http_comp_operations_t  nxt_comp_gzip_ops = {
+    .init               = nxt_zlib_gzip_init,
+    .compressed_size    = nxt_zlib_compressed_size,
+    .deflate            = nxt_zlib_deflate,
+};
diff --git a/src/nxt_zstd.c b/src/nxt_zstd.c
new file mode 100644
index 00000000..07da9ef6
--- /dev/null
+++ b/src/nxt_zstd.c
@@ -0,0 +1,73 @@
+/*
+ *
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <zstd.h>
+
+#include <nxt_http_compression.h>
+
+static void nxt_zstd_free(const nxt_http_comp_compressor_ctx_t *ctx)
+{
+    ZSTD_CStream *zstd = ctx->zstd_ctx;
+
+    ZSTD_freeCStream(zstd);
+}
+
+static void nxt_zstd_init(nxt_http_comp_compressor_ctx_t *ctx)
+{
+    ZSTD_CStream **zstd = &ctx->zstd_ctx;
+
+    *zstd = ZSTD_createCStream();
+    ZSTD_initCStream(*zstd, ctx->level);
+
+    printf("%s: zstd compression level [%d]\n", __func__, ctx->level);
+}
+
+static size_t nxt_zstd_compressed_size(const nxt_http_comp_compressor_ctx_t *ctx,
+                                       size_t in_len)
+{
+    return ZSTD_compressBound(in_len);
+}
+
+static ssize_t nxt_zstd_compress(nxt_http_comp_compressor_ctx_t *ctx,
+                                 const uint8_t *in_buf, size_t in_len,
+                                 uint8_t *out_buf, size_t out_len, bool last)
+{
+    size_t ret;
+    ZSTD_CStream *zstd = ctx->zstd_ctx;
+    ZSTD_inBuffer zinb = { .src = in_buf, .size = in_len };
+    ZSTD_outBuffer zoutb = { .dst = out_buf, .size = out_len };
+
+    printf("%s: in_len [%lu] out_len [%lu]\n", __func__, in_len, out_len);
+
+    ret = ZSTD_compressStream(zstd, &zoutb, &zinb);
+
+    if (zinb.pos < zinb.size) {
+        printf("%s: short by [%d]\n", __func__, zinb.pos < zinb.size);
+        ret = ZSTD_flushStream(zstd, &zoutb);
+    }
+
+    if (last) {
+        ret = ZSTD_endStream(zstd, &zoutb);
+        nxt_zstd_free(ctx);
+    }
+
+    printf("%s: ret [%lu]\n", __func__, ret);
+    if (ZSTD_isError(ret)) {
+        printf("%s: [%s]\n", __func__, ZSTD_getErrorName(ret));
+        return -1;
+    }
+
+    return zoutb.pos;
+}
+
+const nxt_http_comp_operations_t  nxt_comp_zstd_ops = {
+    .init               = nxt_zstd_init,
+    .compressed_size    = nxt_zstd_compressed_size,
+    .deflate            = nxt_zstd_compress,
+    .free_ctx           = nxt_zstd_free,
+};