mirror of
https://github.com/peridotbuild/peridot.git
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95 lines
2.4 KiB
Go
Vendored
95 lines
2.4 KiB
Go
Vendored
/*
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* Copyright (c) SAS Institute, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package rpmutils
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import (
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"bytes"
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"compress/bzip2"
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"compress/gzip"
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"fmt"
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"io"
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"github.com/ulikunitz/xz/lzma"
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"github.com/xi2/xz"
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)
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// Wrap RPM payload with uncompress reader, assumes that header has
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// already been read.
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func uncompressRpmPayloadReader(r io.Reader, hdr *RpmHeader) (io.Reader, error) {
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// Check to make sure payload format is a cpio archive. If the tag does
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// not exist, assume archive is cpio.
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if hdr.HasTag(PAYLOADFORMAT) {
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val, err := hdr.GetString(PAYLOADFORMAT)
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if err != nil {
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return nil, err
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}
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if val != "cpio" {
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return nil, fmt.Errorf("Unknown payload format %s", val)
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}
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}
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// Check to see how the payload was compressed. If the tag does not
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// exist, check if it is gzip, if not it is uncompressed.
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var compression string
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if hdr.HasTag(PAYLOADCOMPRESSOR) {
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val, err := hdr.GetString(PAYLOADCOMPRESSOR)
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if err != nil {
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return nil, err
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}
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compression = val
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} else {
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// peek at the start of the payload to see if it's compressed
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b := make([]byte, 2)
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_, err := io.ReadFull(r, b)
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if err != nil {
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return nil, err
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}
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if b[0] == 0x1f && b[1] == 0x8b {
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compression = "gzip"
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} else {
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compression = "uncompressed"
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}
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// splice the peeked bytes back in
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r = io.MultiReader(bytes.NewReader(b), r)
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}
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switch compression {
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case "zstd":
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return newZstdReader(r)
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case "gzip":
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return gzip.NewReader(r)
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case "bzip2":
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return bzip2.NewReader(r), nil
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case "lzma":
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return lzma.NewReader(r)
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case "xz":
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return xz.NewReader(r, 0)
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case "uncompressed":
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// prevent ExpandPayload from closing the underlying file
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return noCloseWrapper{r}, nil
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default:
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return nil, fmt.Errorf("Unknown compression type %s", compression)
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}
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}
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type noCloseWrapper struct {
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r io.Reader
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}
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func (w noCloseWrapper) Read(d []byte) (int, error) {
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return w.r.Read(d)
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}
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