compressor: Allow to optionally use zlib-ng

bazel/BUILD

@@ -243,6 +243,14 @@ config_setting(
     values = {"define": "boringssl=disabled"},
 )
 
+config_setting(
+    name = "zlib_ng",
+    constraint_values = [
+        "@bazel_tools//platforms:linux",
+    ],
+    values = {"define": "zlib=ng"},
+)
+
 config_setting(
     name = "enable_quiche",
     values = {"define": "quiche=enabled"},

bazel/README.md

@@ -606,6 +606,8 @@ The following optional features can be enabled on the Bazel build command-line:
 * Process logging for Android applications can be enabled with `--define logger=android`.
 * Excluding assertions for known issues with `--define disable_known_issue_asserts=true`.
   A KNOWN_ISSUE_ASSERT is an assertion that should pass (like all assertions), but sometimes fails for some as-yet unidentified or unresolved reason. Because it is known to potentially fail, it can be compiled out even when DEBUG is true, when this flag is set. This allows Envoy to be run in production with assertions generally enabled, without crashing for known issues. KNOWN_ISSUE_ASSERT should only be used for newly-discovered issues that represent benign violations of expectations.
+* Envoy can be linked to [`zlib-ng`](https://github.com/zlib-ng/zlib-ng) instead of
+  [`zlib`](https://zlib.net) with `--define zlib=ng`.
 
 ## Disabling extensions
 

bazel/foreign_cc/BUILD

@@ -218,8 +218,32 @@ envoy_cmake_external(
         "CMAKE_CXX_COMPILER_FORCED": "on",
         "CMAKE_C_COMPILER_FORCED": "on",
         "SKIP_BUILD_EXAMPLES": "on",
+
+        # The following entries are for zlib-ng. Since zlib and zlib-ng are compatible source
+        # codes and CMake ignores unknown cache entries, it is fine to combine it into one
+        # dictionary.
+        #
+        # Reference: https://github.com/zlib-ng/zlib-ng#build-options.
+        "ZLIB_COMPAT": "on",
+        "ZLIB_ENABLE_TESTS": "off",
+
+        # Warning: Turning WITH_OPTIM to "on" doesn't pass ZlibCompressorImplTest.CallingChecksum.
+        "WITH_OPTIM": "on",
+        # However turning off SSE4 fixes it.
+        "WITH_SSE4": "off",
+
+        # Warning: Turning WITH_NEW_STRATEGIES to "on" doesn't pass gzip compressor fuzz test.
+        # Turning this off means falling into NO_QUICK_STRATEGY route.
+        "WITH_NEW_STRATEGIES": "off",
+
+        # Only allow aligned address.
+        # Reference: https://github.com/zlib-ng/zlib-ng#advanced-build-options.
+        "UNALIGNED_OK": "off",
     },
-    lib_source = "@net_zlib//:all",
+    lib_source = select({
+        "//bazel:zlib_ng": "@com_github_zlib_ng_zlib_ng//:all",
+        "//conditions:default": "@net_zlib//:all",
+    }),
     static_libraries = select({
         "//bazel:windows_x86_64": ["zlibstatic.lib"],
         "//conditions:default": ["libz.a"],

bazel/repositories.bzl

@@ -213,6 +213,7 @@ def envoy_dependencies(skip_targets = []):
     _com_lightstep_tracer_cpp()
     _io_opentracing_cpp()
     _net_zlib()
+    _com_github_zlib_ng_zlib_ng()
     _upb()
     _proxy_wasm_cpp_sdk()
     _proxy_wasm_cpp_host()
@@ -401,6 +402,12 @@ def _net_zlib():
         actual = "@envoy//bazel/foreign_cc:zlib",
     )
 
+def _com_github_zlib_ng_zlib_ng():
+    _repository_impl(
+        name = "com_github_zlib_ng_zlib_ng",
+        build_file_content = BUILD_ALL_CONTENT,
+    )
+
 def _com_google_cel_cpp():
     _repository_impl("com_google_cel_cpp")
     _repository_impl("rules_antlr")

bazel/repository_locations.bzl

@@ -344,6 +344,17 @@ DEPENDENCY_REPOSITORIES_SPEC = dict(
         use_category = ["dataplane"],
         cpe = "cpe:2.3:a:gnu:zlib:*",
     ),
+    com_github_zlib_ng_zlib_ng = dict(
+        project_name = "zlib-ng",
+        project_url = "https://github.com/zlib-ng/zlib-ng",
+        version = "193d8fd7dfb7927facab7a3034daa27ad5b9df1c",
+        sha256 = "5fe543e8d007b9e7b729f3d6b3a5ee1f9b68d0eef5f6af1393745a4dcd472a98",
+        strip_prefix = "zlib-ng-193d8fd7dfb7927facab7a3034daa27ad5b9df1c",
+        # 2020-08-16 develop branch.
+        urls = ["https://github.com/zlib-ng/zlib-ng/archive/193d8fd7dfb7927facab7a3034daa27ad5b9df1c.tar.gz"],
+        use_category = ["dataplane"],
+        cpe = "N/A",
+    ),
     com_github_jbeder_yaml_cpp = dict(
         project_name = "yaml-cpp",
         project_url = "https://github.com/jbeder/yaml-cpp",

ci/do_ci.sh

@@ -263,6 +263,7 @@ elif [[ "$CI_TARGET" == "bazel.compile_time_options" ]]; then
     --define path_normalization_by_default=true \
     --define deprecated_features=disabled \
     --define use_new_codecs_in_integration_tests=true \
+    --define zlib=ng \
   "
   ENVOY_STDLIB="${ENVOY_STDLIB:-libstdc++}"
   setup_clang_toolchain

docs/root/extending/extending.rst

@@ -23,6 +23,7 @@ types including:
 * BoringSSL private key methods
 * :ref:`Watchdog action <envoy_v3_api_msg_config.bootstrap.v3.Watchdog.WatchdogAction>`
 * :ref:`Internal redirect policy <envoy_v3_api_field_config.route.v3.InternalRedirectPolicy.predicates>`
+* :ref:`Compression libraries <arch_overview_compression_libraries>`
 
 As of this writing there is no high level extension developer documentation. The
 :repo:`existing extensions <source/extensions>` are a good way to learn what is possible.

docs/root/intro/arch_overview/arch_overview.rst

@@ -11,6 +11,7 @@ Architecture overview
   observability/observability
   security/security
   operations/operations
+  compression/libraries
   other_features/other_features
   other_protocols/other_protocols
   advanced/advanced

docs/root/intro/arch_overview/compression/libraries.rst

@@ -0,0 +1,19 @@
+.. _arch_overview_compression_libraries:
+
+Compression Libraries
+=====================
+
+Underlying implementation
+-------------------------
+
+Currently Envoy uses `zlib <http://zlib.net>`_ as a compression library.
+
+.. note::
+
+  `zlib-ng <https://github.com/zlib-ng/zlib-ng>`_ is a fork that hosts several 3rd-party
+  contributions containing new optimizations. Those optimizations are considered useful for
+  `improving compression performance <https://github.com/envoyproxy/envoy/issues/8448#issuecomment-667152013>`_.
+  Envoy can be built to use `zlib-ng <https://github.com/zlib-ng/zlib-ng>`_ instead of regular
+  `zlib <http://zlib.net>`_ by using ``--define zlib=ng`` Bazel option. The relevant build options
+  used to build `zlib-ng <https://github.com/zlib-ng/zlib-ng>`_ can be evaluated in :repo:`here
+  <bazel/foreign_cc/BUILD>`. Currently, this option is only available on Linux.

docs/root/version_history/current.rst

@@ -96,6 +96,7 @@ New Features
 * watchdog: support randomizing the watchdog's kill timeout to prevent synchronized kills via a maximium jitter parameter :ref:`max_kill_timeout_jitter<envoy_v3_api_field_config.bootstrap.v3.Watchdog.max_kill_timeout_jitter>`.
 * watchdog: supports an extension point where actions can be registered to fire on watchdog events such as miss, megamiss, kill and multikill. See ref:`watchdog actions<envoy_v3_api_field_config.bootstrap.v3.Watchdog.actions>`.
 * xds: added :ref:`extension config discovery<envoy_v3_api_msg_config.core.v3.ExtensionConfigSource>` support for HTTP filters.
+* zlib: added option to use `zlib-ng <https://github.com/zlib-ng/zlib-ng>`_ as zlib library.
 
 Deprecated
 ----------