Mercurial > gemma
changeset 4646:89a72e0e2f9b stree-experiment
Add a method to serialize an STRTree.
| author | Sascha L. Teichmann <sascha.teichmann@intevation.de> |
|---|---|
| date | Sun, 13 Oct 2019 15:45:39 +0200 |
| parents | a1a9b1eab57c |
| children | 18331577a251 |
| files | go.mod go.sum pkg/imports/sr.go pkg/octree/strtree.go |
| diffstat | 4 files changed, 112 insertions(+), 0 deletions(-) [+] |
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--- a/go.mod Fri Oct 11 23:46:35 2019 +0200 +++ b/go.mod Sun Oct 13 15:45:39 2019 +0200 @@ -16,6 +16,7 @@ github.com/magiconair/properties v1.8.1 // indirect github.com/mitchellh/go-homedir v1.1.0 github.com/pelletier/go-toml v1.4.0 // indirect + github.com/pierrec/lz4 v2.3.0+incompatible github.com/pkg/errors v0.8.1 // indirect github.com/rs/cors v1.7.0 github.com/sergi/go-diff v1.0.0
--- a/go.sum Fri Oct 11 23:46:35 2019 +0200 +++ b/go.sum Sun Oct 13 15:45:39 2019 +0200 @@ -95,6 +95,8 @@ github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic= github.com/pelletier/go-toml v1.4.0 h1:u3Z1r+oOXJIkxqw34zVhyPgjBsm6X2wn21NWs/HfSeg= github.com/pelletier/go-toml v1.4.0/go.mod h1:PN7xzY2wHTK0K9p34ErDQMlFxa51Fk0OUruD3k1mMwo= +github.com/pierrec/lz4 v2.3.0+incompatible h1:CZzRn4Ut9GbUkHlQ7jqBXeZQV41ZSKWFc302ZU6lUTk= +github.com/pierrec/lz4 v2.3.0+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi+IEE17M5jbnwPHcY= github.com/pkg/errors v0.8.0 h1:WdK/asTD0HN+q6hsWO3/vpuAkAr+tw6aNJNDFFf0+qw= github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0= github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
--- a/pkg/imports/sr.go Fri Oct 11 23:46:35 2019 +0200 +++ b/pkg/imports/sr.go Sun Oct 13 15:45:39 2019 +0200 @@ -24,6 +24,7 @@ "errors" "fmt" "io" + "log" "math" "os" "path" @@ -565,6 +566,16 @@ feedback.Info("Clipping STR tree took %v.", time.Since(start)) feedback.Info("Number of triangles to clip %d.", len(removed)) + start = time.Now() + s := octree.STRTree{Entries: 16} + s.BuildWithout(tin, removed) + if _, err2 := s.Bytes(); err2 != nil { + log.Printf("serializing STRTree failed: %v\n", err2) + } + log.Printf("Building strtree took: %v.\n", time.Since(start)) + + // return nil, UnchangedError("nothing to do") + feedback.Info("Build final octree index") builder := octree.NewBuilder(tin)
--- a/pkg/octree/strtree.go Fri Oct 11 23:46:35 2019 +0200 +++ b/pkg/octree/strtree.go Sun Oct 13 15:45:39 2019 +0200 @@ -14,8 +14,14 @@ package octree import ( + "bytes" + "encoding/binary" + "io" + "log" "math" "sort" + + "github.com/pierrec/lz4" ) const STRTreeDefaultEntries = 8 @@ -44,6 +50,9 @@ } } else { // leaf top = -top - 1 + if !s.bbox(top).Contains(x, y) { + continue + } for i, n := int32(0), s.index[top+1]; i < n; i++ { idx := s.index[top+2+i] ti := s.tin.Triangles[idx] @@ -150,6 +159,95 @@ return removed } +func (s *STRTree) serializeIndex(w io.Writer) error { + + if err := binary.Write(w, binary.LittleEndian, int32(len(s.index))); err != nil { + return err + } + + if err := binary.Write(w, binary.LittleEndian, s.index[0]); err != nil { + return err + } + + var buf [binary.MaxVarintLen32]byte + + var last int32 + var written int + + for _, x := range s.index[1:] { + delta := x - last + n := binary.PutVarint(buf[:], int64(delta)) + for p := buf[:n]; len(p) > 0; p = p[n:] { + var err error + if n, err = w.Write(p); err != nil { + return err + } + written += n + } + + last = x + } + log.Printf("info: compressed index in bytes: %d %.2f (%d %.2f)\n", + written, + float64(written)/(1024*1024), + 4*len(s.index), + float64(4*len(s.index))/(1024*1024), + ) + + return nil +} + +func (s *STRTree) serializeBBoxes(w io.Writer) (rr error) { + + if err := binary.Write(w, binary.LittleEndian, int32(len(s.bboxes))); err != nil { + return err + } + + var err error + + write := func(v float64) { + if err == nil { + err = binary.Write(w, binary.LittleEndian, math.Float64bits(v)) + } + } + for _, box := range s.bboxes { + write(box.X1) + write(box.Y1) + write(box.X2) + write(box.Y2) + } + + return err +} + +func (s *STRTree) Bytes() ([]byte, error) { + + var buf bytes.Buffer + w := lz4.NewWriter(&buf) + + if err := s.tin.serialize(w); err != nil { + return nil, err + } + + if err := binary.Write(w, binary.LittleEndian, uint8(s.Entries)); err != nil { + return nil, err + } + + if err := s.serializeIndex(w); err != nil { + return nil, err + } + + if err := s.serializeBBoxes(w); err != nil { + return nil, err + } + + if err := w.Flush(); err != nil { + return nil, err + } + + return buf.Bytes(), nil +} + func (s *STRTree) allTriangles(pos int32, tris map[int32]struct{}) { stack := []int32{pos} for len(stack) > 0 {