From: Brad Fitzpatrick <bradfitz@golang.org>
Date: Tue, 13 Aug 2013 23:29:51 +0000 (-0700)
Subject: archive/zip: add File.DataOffset
X-Git-Tag: go1.2rc2~603
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=a2599cf50e8f45a19c91c2180468ba0c9d96af0e;p=gostls13.git

archive/zip: add File.DataOffset

Accessor to find where the bytes of a file start.

R=golang-dev, rsc, dsymonds, adg
CC=golang-dev
https://golang.org/cl/12784045
---

diff --git a/src/pkg/archive/zip/reader.go b/src/pkg/archive/zip/reader.go
index 499215328f..116737337f 100644
--- a/src/pkg/archive/zip/reader.go
+++ b/src/pkg/archive/zip/reader.go
@@ -114,6 +114,19 @@ func (rc *ReadCloser) Close() error {
 	return rc.f.Close()
 }
 
+// DataOffset returns the offset of the file's possibly-compressed
+// data, relative to the beginning of the zip file.
+//
+// Most callers should instead use Open, which transparently
+// decompresses data and verifies checksums.
+func (f *File) DataOffset() (offset int64, err error) {
+	bodyOffset, err := f.findBodyOffset()
+	if err != nil {
+		return
+	}
+	return f.headerOffset + bodyOffset, nil
+}
+
 // Open returns a ReadCloser that provides access to the File's contents.
 // Multiple files may be read concurrently.
 func (f *File) Open() (rc io.ReadCloser, err error) {