perf: accelerate backend gzip decoding with zlib-ng

.gitignore

@@ -1,6 +1,7 @@
 # Program binaries
 /carbonapi
 /carbonzipper
+/.build/
 
 # Booking.com internals
 .deploy

Makefile

@@ -14,7 +14,7 @@ debug: GCFLAGS += -gcflags=all='-l -N'
 
 LDFLAGS = -ldflags '-X main.BuildVersion=$(VERSION)'
 
-TAGS := -tags cairo,nativegzip
+TAGS := -tags cairo,nativegzip,zlibng
 nocairo: TAGS =
 
 ### Targets ###
@@ -29,7 +29,7 @@ nocairo: build
 debug: build
 
 .PHONY: build
-build:
+build: native-deps
 	$(PKGCONF) go build $(TAGS) $(LDFLAGS) $(GCFLAGS) $(PKG_CARBONAPI)
 
 .PHONY: check
@@ -41,8 +41,15 @@ lint:
 	GOMEMLIMIT=1024MiB golangci-lint run -v
 
 .PHONY: test
-test:
+test: native-deps
 	$(PKGCONF) go test $(TAGS) -timeout 10s -race ./...
+	@case '$(TAGS)' in *zlibng*) \
+		go test -tags nativegzip -timeout 10s -race ./pkg/backend/net && \
+		go test -timeout 10s -race ./pkg/backend/net ;; esac
+
+.PHONY: native-deps
+native-deps:
+	@case '$(TAGS)' in *zlibng*) ./scripts/build-zlib-ng.sh ;; esac
 
 .PHONY: test-e2e
 test-e2e:
@@ -55,6 +62,7 @@ test-hurl:
 .PHONY: clean
 clean:
 	rm -f carbonapi carbonzipper
+	rm -rf .build/zlib-ng
 
 .PHONY: authors
 authors:

README.md

@@ -23,6 +23,18 @@ To build both the `carbonapi` and `carbonzipper` binaries, run:
 make
 ```
 
+The default build links a pinned zlib-ng 2.3.3 static library for backend gzip
+decoding. The first build needs a C compiler, Make, curl, tar and internet access;
+the source archive is verified by SHA-256 and its tests run before installation
+under `.build/zlib-ng`. No system libraries are installed or replaced. The native
+`zng_*` API leaves response compression and Cairo/libpng on their existing paths.
+Remove `.build/zlib-ng` (or run `make clean`) to rebuild the dependency.
+
+`make build TAGS='-tags cairo,nativegzip'` retains system-zlib decoding.
+`make nocairo` retains the portable Go decoder without either native dependency.
+The existing `CARBONAPI_NATIVE_GZIP` and `CARBONAPI_STREAM_RENDER` startup flags
+still control use of native backend decoding.
+
 To build the binaries with debug symbols, run:
 
 ```

docker/carbonapi/Dockerfile

@@ -1,7 +1,7 @@
 FROM golang:1.26
 
 RUN apt-get update
-RUN apt-get install -y libcairo2-dev
+RUN apt-get install -y libcairo2-dev curl
 
 WORKDIR /go/src/github.com/bookingcom/carbonapi
 COPY . .

pkg/backend/net/native_gzip.go

@@ -3,19 +3,32 @@
 package net
 
 /*
-#cgo LDFLAGS: -lz
+#cgo !zlibng LDFLAGS: -lz
+#cgo zlibng CFLAGS: -DCARBONAPI_ZLIBNG -I${SRCDIR}/../../../.build/zlib-ng/include
+#cgo zlibng LDFLAGS: ${SRCDIR}/../../../.build/zlib-ng/lib/libz-ng.a
 #include <stdlib.h>
+#ifdef CARBONAPI_ZLIBNG
+// The native API has separate symbols: Cairo/libpng continue using system zlib.
+#include <zlib-ng.h>
+typedef zng_stream carbonapi_z_stream;
+#define inflateInit2 zng_inflateInit2
+#define inflateReset2 zng_inflateReset2
+#define inflateEnd zng_inflateEnd
+#define inflate zng_inflate
+#else
 #include <zlib.h>
+typedef z_stream carbonapi_z_stream;
+#endif
 
 typedef struct { unsigned int used, produced; int code; } carbonapi_inflate_result;
-static z_stream *carbonapi_inflate_new(void) {
-    z_stream *s = (z_stream *)calloc(1, sizeof(z_stream));
+static carbonapi_z_stream *carbonapi_inflate_new(void) {
+    carbonapi_z_stream *s = (carbonapi_z_stream *)calloc(1, sizeof(carbonapi_z_stream));
     if (s && inflateInit2(s, 15 + 16) != Z_OK) { free(s); return NULL; }
     return s;
 }
-static int carbonapi_inflate_reset(z_stream *s) { return inflateReset2(s, 15 + 16); }
-static void carbonapi_inflate_free(z_stream *s) { if (s) { inflateEnd(s); free(s); } }
-static carbonapi_inflate_result carbonapi_inflate_step(z_stream *s, unsigned char *in,
+static int carbonapi_inflate_reset(carbonapi_z_stream *s) { return inflateReset2(s, 15 + 16); }
+static void carbonapi_inflate_free(carbonapi_z_stream *s) { if (s) { inflateEnd(s); free(s); } }
+static carbonapi_inflate_result carbonapi_inflate_step(carbonapi_z_stream *s, unsigned char *in,
         unsigned int input_size, unsigned char *out, unsigned int output_size) {
     s->next_in = in; s->avail_in = input_size;
     s->next_out = out; s->avail_out = output_size;
@@ -38,7 +51,7 @@ import (
 )
 
 type nativeGzipReader struct {
-	state                 *C.z_stream
+	state                 *C.carbonapi_z_stream
 	src                   io.Reader
 	input                 []byte
 	pos, end              int

pkg/backend/net/stream_render_test.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"math/rand"
 	"net/http"
 	"net/http/httptest"
 	"reflect"
@@ -41,6 +42,46 @@ func gzipData(t testing.TB, body []byte) []byte {
 	return b.Bytes()
 }
 
+func TestNativeInflaterCompressionVariants(t *testing.T) {
+	noise := make([]byte, 65537)
+	_, _ = rand.New(rand.NewSource(42)).Read(noise)
+	for _, level := range []int{gzip.NoCompression, gzip.BestSpeed, gzip.BestCompression, gzip.HuffmanOnly} {
+		for _, body := range [][]byte{noise, bytes.Repeat([]byte("repeated backend points\x00\xff"), 4096)} {
+			var encoded bytes.Buffer
+			w, err := gzip.NewWriterLevel(&encoded, level)
+			if err != nil {
+				t.Fatal(err)
+			}
+			w.Name, w.Comment, w.Extra = "backend", "optional gzip header", []byte{0, 1, 255}
+			if _, err := w.Write(body); err != nil {
+				t.Fatal(err)
+			}
+			if err := w.Close(); err != nil {
+				t.Fatal(err)
+			}
+			for _, chunk := range []int{1, 37, 32768} {
+				base, err := gzip.NewReader(bytes.NewReader(encoded.Bytes()))
+				if err != nil {
+					t.Fatal(err)
+				}
+				want, err := io.ReadAll(base)
+				if err != nil {
+					t.Fatal(err)
+				}
+				r, err := newNativeInflater(&gzipFragments{data: encoded.Bytes(), chunk: chunk})
+				if err != nil {
+					t.Fatal(err)
+				}
+				got, err := io.ReadAll(r)
+				_ = r.Close()
+				if err != nil || !bytes.Equal(got, want) {
+					t.Fatalf("level=%d chunk=%d: %v; bytes=%d/%d", level, chunk, err, len(got), len(want))
+				}
+			}
+		}
+	}
+}
+
 func TestNativeInflaterDifferential(t *testing.T) {
 	for _, size := range []int{0, 1, 31, 4096, 65536, 1 << 20} {
 		body := bytes.Repeat([]byte("some repeated protobuf-like bytes\x00\x01\xff"), (size+38)/39)

scripts/build-zlib-ng.sh

@@ -0,0 +1,34 @@
+#!/bin/sh
+set -eu
+
+# zlib-ng 2.3.3. Use its native, namespaced API, never replace system zlib.
+revision=12731092979c6d07f42da27da673a9f6c7b13586
+checksum=a0d2a5d122c84b56a793a1553a9c3327fb2eb7469bf7a86b79e3c7be5d92e8d6
+root=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
+prefix="$root/.build/zlib-ng"
+if test -f "$prefix/revision" && test "$(cat "$prefix/revision")" = "$revision" &&
+    test -f "$prefix/lib/libz-ng.a" && test -f "$prefix/include/zlib-ng.h"; then
+    exit 0
+fi
+
+mkdir -p "$root/.build"
+work=$(mktemp -d "$root/.build/zlib-ng-build.XXXXXX")
+trap 'rm -rf "$work"' EXIT HUP INT TERM
+curl --fail --location --retry 3 --connect-timeout 10 --max-time 120 --output "$work/source.tar.gz" \
+    "https://codeload.github.com/zlib-ng/zlib-ng/tar.gz/$revision"
+if command -v sha256sum >/dev/null 2>&1; then
+    actual=$(sha256sum "$work/source.tar.gz" | cut -d ' ' -f 1)
+else
+    actual=$(shasum -a 256 "$work/source.tar.gz" | cut -d ' ' -f 1)
+fi
+test "$actual" = "$checksum" || { echo 'zlib-ng source checksum mismatch' >&2; exit 1; }
+mkdir "$work/source"
+tar -xzf "$work/source.tar.gz" -C "$work/source" --strip-components=1
+cd "$work/source"
+# Upstream's default build uses runtime CPU dispatch, not -march=native.
+./configure --static --prefix="$prefix"
+make -j "${ZLIBNG_JOBS:-2}"
+make check
+make install
+cp LICENSE.md "$prefix/LICENSE.md"
+printf '%s\n' "$revision" > "$prefix/revision"