func runRevlog(cmd *Command, w io.Writer, args []string) {
if len(args) == 0 {
fatalf("missing argument: revlog index file")
}
index, err := revlog.Open(storeName(args[0]))
if err != nil {
fatalf("%s", err)
}
if *revlogR == -1 {
index.Dump(w)
return
}
r, err := revlog.FileRevSpec(*revlogR).Lookup(index)
if err != nil {
fatalf("%s", err)
}
if !*revlogBuild {
dh := &dataHelper{}
d, err := r.GetData(dh)
if dh.file != nil {
dh.file.Close()
}
if err != nil {
fatalf("%s", err)
}
if r.IsBase() {
w.Write(d)
} else {
hunks, err := patch.Parse(d)
if err != nil {
fatalf("%s", err)
}
for _, h := range hunks {
h.Dump(w)
}
}
} else {
fb := revlog.NewFileBuilder()
err = fb.BuildWrite(w, r)
if err != nil {
fatalf("%s", err)
}
}
}
func (p *FileBuilder) PreparePatch(r *Rec) (f *FilePatch, err error) {
var prevPatch []patch.Hunk
rsav := r
dc := p.dataCache
if dc == nil {
dc = noCache{}
}
if !p.data.keepOpen {
defer p.CloseData()
}
for {
d := dc.Get(r.i)
if d == nil {
d, err = r.GetData(&p.data)
if err != nil {
err = fmt.Errorf("rev %d: get data: %v", r.i, err)
return
}
dc.Store(r.i, d)
}
if r.IsBase() {
f = new(FilePatch)
if rsav.IsStartOfBranch() {
if r == rsav {
// The normal case, rsav is a base revision, the
// complete meta header is at the top of the data
f.MetaData = scanMetaData(d)
f.MetaSkip = len(f.MetaData)
} else if len(prevPatch) > 0 {
baseMeta := scanMetaData(d)
skipFirst := false
prevPatch[0].Adjust(func(begin, end int, data []byte) []byte {
if n := len(baseMeta); n > 0 && begin >= 2 && end <= n-2 {
// A rare case: There is a meta header at the top of the
// data of the base revision (already parsed into tmp), but
// there's also the first patch that modifies some content of the
// meta header. (For a more robust solution the patches
// following the first one would need to be checked too
// whether they are located within the original meta header.)
// An example is:
// hgo revlog $GOROOT/.hg/store/data/test/fixedbugs/bug136.go.i
// file revision 1
b := &p.metaBuf
b.Reset()
b.Write(baseMeta[:begin])
b.Write(data)
b.Write(baseMeta[end:])
f.MetaSkip = n
f.MetaData = b.Bytes()
skipFirst = true
return data[:0]
}
// Another rare case, rsav is an incremental revision, the
// meta header is at the top of the first hunk.
// Example: hgo revlog -r 1 $PLAN9/.hg/store/data/src/cmd/dd.c.i
if begin > 0 {
return data
}
f.MetaData = scanMetaData(data)
return data[len(f.MetaData):]
})
if skipFirst {
prevPatch = prevPatch[1:]
}
}
}
f.baseData = d
f.patch = prevPatch
f.rev = rsav
f.fb = p
return
}
hunks, err1 := patch.Parse(d)
if err1 != nil {
err = err1
return
}
if prevPatch == nil {
prevPatch = hunks
} else {
prevPatch = p.w.JoinPatches(hunks, prevPatch)
p.swap()
}
r = r.Prev()
}
panic("not reached")
}