Better file close and err handling

Signed-off-by: Mario Loriedo <mario.loriedo@gmail.com>

pkg/machine/compression/compression_test.go

@@ -111,11 +111,17 @@ func Test_Decompress(t *testing.T) {
 		want want
 	}{
 		{name: "zip", args: args{src: "./testdata/sample.zip", dst: "./testdata/hellozip"}, want: "zip\n"},
+		{name: "zip with trailing zeros", args: args{src: "./testdata/sample-withzeros.zip", dst: "./testdata/hellozip-withzeros"}, want: "zip\n\x00\x00\x00\x00\x00\x00"},
 		{name: "xz", args: args{src: "./testdata/sample.xz", dst: "./testdata/helloxz"}, want: "xz\n"},
+		{name: "xz with trailing zeros", args: args{src: "./testdata/sample-withzeros.xz", dst: "./testdata/helloxz-withzeros"}, want: "xz\n\x00\x00\x00\x00\x00\x00\x00"},
 		{name: "gzip", args: args{src: "./testdata/sample.gz", dst: "./testdata/hellogz"}, want: "gzip\n"},
+		{name: "gzip with trailing zeros", args: args{src: "./testdata/sample-withzeros.gz", dst: "./testdata/hellogzip-withzeros"}, want: "gzip\n\x00\x00\x00\x00\x00"},
 		{name: "bzip2", args: args{src: "./testdata/sample.bz2", dst: "./testdata/hellobz2"}, want: "bzip2\n"},
+		{name: "bzip2 with trailing zeros", args: args{src: "./testdata/sample-withzeros.bz2", dst: "./testdata/hellobz2-withzeros"}, want: "bzip2\n\x00\x00\x00\x00"},
 		{name: "zstd", args: args{src: "./testdata/sample.zst", dst: "./testdata/hellozstd"}, want: "zstd\n"},
-		{name: "uncompressed", args: args{src: "./testdata/sample.uncompressed", dst: "./testdata/hellozuncompressed"}, want: "uncompressed\n"},
+		{name: "zstd with trailing zeros", args: args{src: "./testdata/sample-withzeros.zst", dst: "./testdata/hellozstd-withzeros"}, want: "zstd\n\x00\x00\x00\x00\x00"},
+		{name: "uncompressed", args: args{src: "./testdata/sample.uncompressed", dst: "./testdata/hellouncompressed"}, want: "uncompressed\n"},
+		{name: "uncompressed with trailing zeros", args: args{src: "./testdata/sample-withzeros.uncompressed", dst: "./testdata/hellozuncompressed-withzeros"}, want: "uncompressed\n\x00\x00\x00\x00\x00\x00\x00"},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

pkg/machine/compression/generic.go

@@ -10,10 +10,9 @@ import (
 )
 
 type genericDecompressor struct {
-	compressedFilePath     string
-	compressedFile         *os.File
-	decompressedFileReader io.ReadCloser
-	compressedFileInfo     os.FileInfo
+	compressedFilePath string
+	compressedFile     *os.File
+	compressedFileInfo os.FileInfo
 }
 
 func newGenericDecompressor(compressedFilePath string) (*genericDecompressor, error) {
@@ -49,7 +48,11 @@ func (d *genericDecompressor) decompress(w WriteSeekCloser, r io.Reader) error {
 	if err != nil {
 		return err
 	}
-	d.decompressedFileReader = decompressedFileReader
+	defer func() {
+		if err := decompressedFileReader.Close(); err != nil {
+			logrus.Errorf("Unable to close gz file: %q", err)
+		}
+	}()
 
 	_, err = io.Copy(w, decompressedFileReader)
 	return err
@@ -59,10 +62,4 @@ func (d *genericDecompressor) close() {
 	if err := d.compressedFile.Close(); err != nil {
 		logrus.Errorf("Unable to close compressed file: %q", err)
 	}
-
-	if d.decompressedFileReader != nil {
-		if err := d.decompressedFileReader.Close(); err != nil {
-			logrus.Errorf("Unable to close uncompressed stream: %q", err)
-		}
-	}
 }

pkg/machine/compression/gzip.go

@@ -9,12 +9,11 @@ import (
 
 type gzipDecompressor struct {
 	genericDecompressor
-	gzReader io.ReadCloser
 }
 
 func newGzipDecompressor(compressedFilePath string) (*gzipDecompressor, error) {
 	d, err := newGenericDecompressor(compressedFilePath)
-	return &gzipDecompressor{*d, nil}, err
+	return &gzipDecompressor{*d}, err
 }
 
 func (d *gzipDecompressor) decompress(w WriteSeekCloser, r io.Reader) error {
@@ -22,16 +21,19 @@ func (d *gzipDecompressor) decompress(w WriteSeekCloser, r io.Reader) error {
 	if err != nil {
 		return err
 	}
-	d.gzReader = gzReader
+	defer func() {
+		if err := gzReader.Close(); err != nil {
+			logrus.Errorf("Unable to close gz file: %q", err)
+		}
+	}()
 
 	sparseWriter := NewSparseWriter(w)
+	defer func() {
+		if err := sparseWriter.Close(); err != nil {
+			logrus.Errorf("Unable to close uncompressed file: %q", err)
+		}
+	}()
+
 	_, err = io.Copy(sparseWriter, gzReader)
 	return err
 }
-
-func (d *gzipDecompressor) close() {
-	if err := d.gzReader.Close(); err != nil {
-		logrus.Errorf("Unable to close gz file: %q", err)
-	}
-	d.genericDecompressor.close()
-}

pkg/machine/compression/testdata/gen-testdata.sh

@@ -0,0 +1,51 @@
+#!/bin/bash
+
+echo "zstd" > hellozstd-withzeros && \
+truncate -c -s 10 hellozstd-withzeros && \
+zstd -f --sparse hellozstd-withzeros -o sample-withzeros.zst && \
+rm hellozstd-withzeros
+
+echo "zstd" > hellozstd && \
+zstd -f --sparse hellozstd -o sample.zst && \
+rm hellozstd
+
+echo "gzip" > hellogzip-withzeros && \
+truncate -c -s 10 hellogzip-withzeros && \
+gzip -f -c hellogzip-withzeros > sample-withzeros.gz && \
+rm hellogzip-withzeros
+
+echo "gzip" > hellogzip && \
+gzip -f -c hellogzip > sample.gz && \
+rm hellogzip
+
+echo "bzip2" > hellobzip2-withzeros && \
+truncate -c -s 10 hellobzip2-withzeros && \
+bzip2 -f -c hellobzip2-withzeros > sample-withzeros.bz2 && \
+rm hellobzip2-withzeros
+
+echo "bzip2" > hellobzip2 && \
+bzip2 -f -c hellobzip2 > sample.bz2 && \
+rm hellobzip2
+
+echo "uncompressed" > sample-withzeros.uncompressed && \
+truncate -c -s 20 sample-withzeros.uncompressed
+
+echo "uncompressed" > sample.uncompressed
+
+echo "xz" > helloxz-withzeros && \
+truncate -c -s 10 helloxz-withzeros && \
+xz -f -z -c helloxz-withzeros > sample-withzeros.xz && \
+rm helloxz-withzeros
+
+echo "xz" > helloxz && \
+xz -f -z -c helloxz > sample.xz && \
+rm helloxz
+
+echo "zip" > hellozip-withzeros && \
+truncate -c -s 10 hellozip-withzeros && \
+zip sample-withzeros.zip hellozip-withzeros && \
+rm hellozip-withzeros
+
+echo "zip" > hellozip && \
+zip sample.zip hellozip && \
+rm hellozip

pkg/machine/compression/uncompressed.go

@@ -2,6 +2,8 @@ package compression
 
 import (
 	"io"
+
+	"github.com/sirupsen/logrus"
 )
 
 type uncompressedDecompressor struct {
@@ -15,6 +17,12 @@ func newUncompressedDecompressor(compressedFilePath string) (*uncompressedDecomp
 
 func (d *uncompressedDecompressor) decompress(w WriteSeekCloser, r io.Reader) error {
 	sparseWriter := NewSparseWriter(w)
+	defer func() {
+		if err := sparseWriter.Close(); err != nil {
+			logrus.Errorf("Unable to close uncompressed file: %q", err)
+		}
+	}()
+
 	_, err := io.Copy(sparseWriter, r)
 	return err
 }

pkg/machine/compression/zstd.go

@@ -4,16 +4,16 @@ import (
 	"io"
 
 	"github.com/klauspost/compress/zstd"
+	"github.com/sirupsen/logrus"
 )
 
 type zstdDecompressor struct {
 	genericDecompressor
-	zstdReader *zstd.Decoder
 }
 
 func newZstdDecompressor(compressedFilePath string) (*zstdDecompressor, error) {
 	d, err := newGenericDecompressor(compressedFilePath)
-	return &zstdDecompressor{*d, nil}, err
+	return &zstdDecompressor{*d}, err
 }
 
 func (d *zstdDecompressor) decompress(w WriteSeekCloser, r io.Reader) error {
@@ -21,14 +21,15 @@ func (d *zstdDecompressor) decompress(w WriteSeekCloser, r io.Reader) error {
 	if err != nil {
 		return err
 	}
-	d.zstdReader = zstdReader
+	defer zstdReader.Close()
 
 	sparseWriter := NewSparseWriter(w)
+	defer func() {
+		if err := sparseWriter.Close(); err != nil {
+			logrus.Errorf("Unable to close uncompressed file: %q", err)
+		}
+	}()
+
 	_, err = io.Copy(sparseWriter, zstdReader)
 	return err
 }
-
-func (d *zstdDecompressor) close() {
-	d.zstdReader.Close()
-	d.genericDecompressor.close()
-}