Switch to klauspost/compress/gzip package

The "github.com/klauspost/compress/gzip" package is about 8x faster when
compressing using gzip.

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/google/subcommands v1.2.0
 	github.com/gorilla/handlers v1.5.1
 	github.com/gorilla/mux v1.8.0
+	github.com/klauspost/compress v1.15.12
 	github.com/prometheus/client_golang v1.14.0
 	github.com/prometheus/common v0.37.0
 	go.uber.org/multierr v1.8.0

go.sum

@@ -149,6 +149,8 @@ github.com/jstemmer/go-junit-report v0.9.1/go.mod h1:Brl9GWCQeLvo8nXZwPNNblvFj/X
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/klauspost/compress v1.15.12 h1:YClS/PImqYbn+UILDnqxQCZ3RehC9N318SU3kElDUEM=
+github.com/klauspost/compress v1.15.12/go.mod h1:QPwzmACJjUTFsnSHH934V6woptycfrDDJnH7hvFVbGM=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=

internal/snapshotstream/stream.go

@@ -1,7 +1,6 @@
 package snapshotstream
 
 import (
-	"compress/gzip"
 	"crypto/sha256"
 	"encoding/hex"
 	"errors"
@@ -12,8 +11,10 @@ import (
 	"path/filepath"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/hansmi/prombackup/api"
+	"github.com/klauspost/compress/gzip"
 	"go.uber.org/multierr"
 )