From 600d7828a7733032b346e6f7b72825c4e914d0ce Mon Sep 17 00:00:00 2001 From: David Symonds Date: Wed, 8 Jul 2009 18:31:14 -0700 Subject: [PATCH] archive/tar cleanups: - rename untar{,_test}.go to reader{,_test}.go. - fix up some comments. - improve test output if it fails. R=rsc APPROVED=rsc DELTA=821 (400 added, 392 deleted, 29 changed) OCL=31376 CL=31378 --- src/pkg/Make.deps | 2 +- src/pkg/archive/tar/Makefile | 4 +- src/pkg/archive/tar/{untar.go => reader.go} | 9 ++-- .../tar/{untar_test.go => reader_test.go} | 0 src/pkg/archive/tar/writer.go | 28 ++++++------ src/pkg/archive/tar/writer_test.go | 43 +++++++++++-------- 6 files changed, 47 insertions(+), 39 deletions(-) rename src/pkg/archive/tar/{untar.go => reader.go} (97%) rename src/pkg/archive/tar/{untar_test.go => reader_test.go} (100%) diff --git a/src/pkg/Make.deps b/src/pkg/Make.deps index 088708fba5..9144ad40d9 100644 --- a/src/pkg/Make.deps +++ b/src/pkg/Make.deps @@ -1,4 +1,4 @@ -archive/tar.install: bufio.install bytes.install io.install os.install strconv.install +archive/tar.install: bytes.install io.install os.install strconv.install strings.install base64.install: bytes.install io.install os.install strconv.install bignum.install: fmt.install bufio.install: io.install os.install strconv.install utf8.install diff --git a/src/pkg/archive/tar/Makefile b/src/pkg/archive/tar/Makefile index 2689b30f6a..78734ef58a 100644 --- a/src/pkg/archive/tar/Makefile +++ b/src/pkg/archive/tar/Makefile @@ -36,7 +36,7 @@ O1=\ common.$O\ O2=\ - untar.$O\ + reader.$O\ writer.$O\ @@ -48,7 +48,7 @@ a1: $(O1) rm -f $(O1) a2: $(O2) - $(AR) grc _obj$D/tar.a untar.$O writer.$O + $(AR) grc _obj$D/tar.a reader.$O writer.$O rm -f $(O2) diff --git a/src/pkg/archive/tar/untar.go b/src/pkg/archive/tar/reader.go similarity index 97% rename from src/pkg/archive/tar/untar.go rename to src/pkg/archive/tar/reader.go index 87382d4f5c..7e8f617b00 100644 --- a/src/pkg/archive/tar/untar.go +++ b/src/pkg/archive/tar/reader.go @@ -6,7 +6,6 @@ package tar // TODO(dsymonds): // - pax extensions -// - rename this file to reader.go import ( "archive/tar"; @@ -20,13 +19,13 @@ var ( HeaderError os.Error = os.ErrorString("invalid tar header"); ) -// A tar archive consists of a sequence of files. // A Reader provides sequential access to the contents of a tar archive. +// A tar archive consists of a sequence of files. // The Next method advances to the next file in the archive (including the first), // and then it can be treated as an io.Reader to access the file's data. // // Example: -// tr := NewTarReader(r); +// tr := tar.NewReader(r); // for { // hdr, err := tr.Next(); // if err != nil { @@ -36,7 +35,7 @@ var ( // // end of tar archive // break // } -// io.Copy(tr, somewhere); +// io.Copy(tr, data); // } type Reader struct { r io.Reader; @@ -48,7 +47,7 @@ type Reader struct { func (tr *Reader) skipUnread() func (tr *Reader) readHeader() *Header -// NewReader creates a new Reader reading the given io.Reader. +// NewReader creates a new Reader reading from r. func NewReader(r io.Reader) *Reader { return &Reader{ r: r } } diff --git a/src/pkg/archive/tar/untar_test.go b/src/pkg/archive/tar/reader_test.go similarity index 100% rename from src/pkg/archive/tar/untar_test.go rename to src/pkg/archive/tar/reader_test.go diff --git a/src/pkg/archive/tar/writer.go b/src/pkg/archive/tar/writer.go index 57e9a4607c..fbb0031fc5 100644 --- a/src/pkg/archive/tar/writer.go +++ b/src/pkg/archive/tar/writer.go @@ -28,7 +28,7 @@ var ( // writing at most hdr.Size bytes in total. // // Example: -// tw := NewTarWriter(w); +// tw := tar.NewWriter(w); // hdr := new(Header); // hdr.Size = length of data in bytes; // // populate other hdr fields as desired @@ -112,19 +112,19 @@ func (tw *Writer) WriteHeader(hdr *Header) os.Error { // TODO(dsymonds): handle names longer than 100 chars nr := bytes.Copy(s.next(100), strings.Bytes(hdr.Name)); - tw.octal(s.next(8), hdr.Mode); - tw.octal(s.next(8), hdr.Uid); - tw.octal(s.next(8), hdr.Gid); - tw.octal(s.next(12), hdr.Size); - tw.octal(s.next(12), hdr.Mtime); - s.next(8); // chksum - s.next(1)[0] = hdr.Typeflag; - s.next(100); // linkname - bytes.Copy(s.next(8), strings.Bytes("ustar\x0000")); - tw.cString(s.next(32), hdr.Uname); - tw.cString(s.next(32), hdr.Gname); - tw.octal(s.next(8), hdr.Devmajor); - tw.octal(s.next(8), hdr.Devminor); + tw.octal(s.next(8), hdr.Mode); // 100:108 + tw.octal(s.next(8), hdr.Uid); // 108:116 + tw.octal(s.next(8), hdr.Gid); // 116:124 + tw.octal(s.next(12), hdr.Size); // 124:136 + tw.octal(s.next(12), hdr.Mtime); // 136:148 + s.next(8); // chksum (148:156) + s.next(1)[0] = hdr.Typeflag; // 156:157 + s.next(100); // linkname (157:257) + bytes.Copy(s.next(8), strings.Bytes("ustar\x0000")); // 257:265 + tw.cString(s.next(32), hdr.Uname); // 265:297 + tw.cString(s.next(32), hdr.Gname); // 297:329 + tw.octal(s.next(8), hdr.Devmajor); // 329:337 + tw.octal(s.next(8), hdr.Devminor); // 337:345 // The chksum field is terminated by a NUL and a space. // This is different from the other octal fields. diff --git a/src/pkg/archive/tar/writer_test.go b/src/pkg/archive/tar/writer_test.go index 202530a0f0..5ada36b530 100644 --- a/src/pkg/archive/tar/writer_test.go +++ b/src/pkg/archive/tar/writer_test.go @@ -62,30 +62,39 @@ var writerTests = []*writerTest{ } // Render byte array in a two-character hexadecimal string, spaced for easy visual inspection. -func bytestr(b []byte) string { - s := fmt.Sprintf("(%d bytes)\n", len(b)); +func bytestr(offset int, b []byte) string { const rowLen = 32; + s := fmt.Sprintf("%04x ", offset); for i, ch := range b { - if i % rowLen == 0 { - // start of line: hex offset - s += fmt.Sprintf("%04x", i); - } switch { case '0' <= ch && ch <= '9', 'A' <= ch && ch <= 'Z', 'a' <= ch && ch <= 'z': s += fmt.Sprintf(" %c", ch); default: s += fmt.Sprintf(" %02x", ch); } - if (i + 1) % rowLen == 0 { - // end of line - s += "\n"; - } else if (i + 1) % (rowLen / 2) == 0 { - // extra space - s += " "; - } } - if s[len(s)-1] != '\n' { - s += "\n" + return s +} + +// Render a pseudo-diff between two blocks of bytes. +func bytediff(a []byte, b []byte) string { + const rowLen = 32; + s := fmt.Sprintf("(%d bytes vs. %d bytes)\n", len(a), len(b)); + for offset := 0; len(a) + len(b) > 0; offset += rowLen { + na, nb := rowLen, rowLen; + if na > len(a) { + na = len(a); + } + if nb > len(b) { + nb = len(b); + } + sa := bytestr(offset, a[0:na]); + sb := bytestr(offset, b[0:nb]); + if sa != sb { + s += fmt.Sprintf("-%v\n+%v\n", sa, sb); + } + a = a[na:len(a)]; + b = b[nb:len(b)]; } return s } @@ -115,8 +124,8 @@ testLoop: actual := buf.Data(); if !bytes.Equal(expected, actual) { - t.Errorf("test %d: Incorrect result:\n%v\nwant:\n%v", - i, bytestr(actual), bytestr(expected)); + t.Errorf("test %d: Incorrect result: (-=expected, +=actual)\n%v", + i, bytediff(expected, actual)); } } }