Package: src:golang Severity: important >From upstream[1]: > "archive/tar: reuse temporary buffer in writeHeader" introduced a > change which was supposed to help lower the number of allocations from > 512 bytes for every call to writeHeader. This change broke the writing > of PAX headers. > > writeHeader calls writePAXHeader and writePAXHeader calls writeHeader > again. writeHeader will end up writing the PAX header twice. > > ... > > This commit adds a dedicated buffer for pax headers to the Writer > struct. This change increases the size of the struct by 512 bytes, but > allows tar/writer to avoid allocating 512 bytes for all written > headers and it avoids allocating 512 more bytes for pax headers.
I've attached a patch for the package to include this to complement our previous patches. :) ♥, - Tianon [1]: https://code.google.com/p/go/source/detail?r=1b17b3426e3c281a973d2d7bbf235b936d6a0942
>From c386aa0db324f7180338c3863b380a1e3e64afdf Mon Sep 17 00:00:00 2001 From: Tianon Gravi <admwig...@gmail.com> Date: Tue, 29 Jul 2014 07:59:28 -0600 Subject: [PATCH 2/2] backport archive/tar patch to fix PAX headers --- ...04-archive-tar-fix-writing-of-pax-headers.patch | 82 ++++++++++++++++++++++ debian/patches/series | 1 + 2 files changed, 83 insertions(+) create mode 100644 debian/patches/0004-archive-tar-fix-writing-of-pax-headers.patch diff --git a/debian/patches/0004-archive-tar-fix-writing-of-pax-headers.patch b/debian/patches/0004-archive-tar-fix-writing-of-pax-headers.patch new file mode 100644 index 0000000..4b0634d --- /dev/null +++ b/debian/patches/0004-archive-tar-fix-writing-of-pax-headers.patch @@ -0,0 +1,82 @@ +Description: archive/tar: fix writing of pax headers +Author: Cristian Staretu <unclejacks...@gmail.com> +Last-Update: 2014-07-16 +Forwarded: not-needed +Origin: vendor, https://code.google.com/p/go/source/detail?r=1b17b3426e3c281a973d2d7bbf235b936d6a0942 + +--- + +diff -r 278365dff593 -r 1b17b3426e3c src/pkg/archive/tar/writer.go +--- a/src/pkg/archive/tar/writer.go ++++ b/src/pkg/archive/tar/writer.go +@@ -39,7 +39,8 @@ + closed bool + usedBinary bool // whether the binary numeric field extension was used + preferPax bool // use pax header instead of binary numeric header +- hdrBuff [blockSize]byte // buffer to use in writeHeader ++ hdrBuff [blockSize]byte // buffer to use in writeHeader when writing a regular header ++ paxHdrBuff [blockSize]byte // buffer to use in writeHeader when writing a pax header + } + + // NewWriter creates a new Writer writing to w. +@@ -161,7 +162,17 @@ + // subsecond time resolution, but for now let's just capture + // too long fields or non ascii characters + +- header := tw.hdrBuff[:] ++ var header []byte ++ ++ // We need to select which scratch buffer to use carefully, ++ // since this method is called recursively to write PAX headers. ++ // If allowPax is true, this is the non-recursive call, and we will use hdrBuff. ++ // If allowPax is false, we are being called by writePAXHeader, and hdrBuff is ++ // already being used by the non-recursive call, so we must use paxHdrBuff. ++ header = tw.hdrBuff[:] ++ if !allowPax { ++ header = tw.paxHdrBuff[:] ++ } + copy(header, zeroBlock) + s := slicer(header) + +diff -r 278365dff593 -r 1b17b3426e3c src/pkg/archive/tar/writer_test.go +--- a/src/pkg/archive/tar/writer_test.go ++++ b/src/pkg/archive/tar/writer_test.go +@@ -454,3 +454,38 @@ + t.Fatal("Couldn't recover long name") + } + } ++ ++func TestValidTypeflagWithPAXHeader(t *testing.T) { ++ var buffer bytes.Buffer ++ tw := NewWriter(&buffer) ++ ++ fileName := strings.Repeat("ab", 100) ++ ++ hdr := &Header{ ++ Name: fileName, ++ Size: 4, ++ Typeflag: 0, ++ } ++ if err := tw.WriteHeader(hdr); err != nil { ++ t.Fatalf("Failed to write header: %s", err) ++ } ++ if _, err := tw.Write([]byte("fooo")); err != nil { ++ t.Fatalf("Failed to write the file's data: %s", err) ++ } ++ tw.Close() ++ ++ tr := NewReader(&buffer) ++ ++ for { ++ header, err := tr.Next() ++ if err == io.EOF { ++ break ++ } ++ if err != nil { ++ t.Fatalf("Failed to read header: %s", err) ++ } ++ if header.Typeflag != 0 { ++ t.Fatalf("Typeflag should've been 0, found %d", header.Typeflag) ++ } ++ } ++} diff --git a/debian/patches/series b/debian/patches/series index 0267a2a..027d486 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -1,3 +1,4 @@ 0001-backport-delete-whole-line.patch 0002-archive-tar-reuse-temporary-buffer-in-writeHeader.patch 0003-archive-tar-reuse-temporary-buffer-in-readHeader.patch +0004-archive-tar-fix-writing-of-pax-headers.patch -- 1.8.5.5
