89 lines
1.7 KiB
Go
89 lines
1.7 KiB
Go
package parser
|
|
|
|
import (
|
|
"bytes"
|
|
"code.google.com/p/goprotobuf/proto"
|
|
"compress/zlib"
|
|
structs "encoding/binary"
|
|
"goposm/parser/osmpbf"
|
|
"io"
|
|
"log"
|
|
"os"
|
|
)
|
|
|
|
func ReadPrimitiveBlock(pos BlockPosition) *osmpbf.PrimitiveBlock {
|
|
file, err := os.Open(pos.Filename)
|
|
if err != nil {
|
|
log.Panic(err)
|
|
}
|
|
defer file.Close()
|
|
|
|
var block = &osmpbf.PrimitiveBlock{}
|
|
var blob = &osmpbf.Blob{}
|
|
|
|
blobData := make([]byte, pos.Size)
|
|
file.Seek(pos.Offset, 0)
|
|
io.ReadFull(file, blobData)
|
|
err = proto.Unmarshal(blobData, blob)
|
|
if err != nil {
|
|
log.Panic("unmarshaling error blob: ", err)
|
|
}
|
|
|
|
buf := bytes.NewBuffer(blob.GetZlibData())
|
|
r, err := zlib.NewReader(buf)
|
|
if err != nil {
|
|
log.Panic("zlib error: ", err)
|
|
}
|
|
raw := make([]byte, blob.GetRawSize())
|
|
io.ReadFull(r, raw)
|
|
|
|
err = proto.Unmarshal(raw, block)
|
|
if err != nil {
|
|
log.Panic("unmarshaling error: ", err)
|
|
}
|
|
|
|
return block
|
|
}
|
|
|
|
func (pbf *PBF) BlockPositions() (positions chan BlockPosition) {
|
|
positions = make(chan BlockPosition, 8)
|
|
go func() {
|
|
for {
|
|
offset, size := pbf.NextDataPosition()
|
|
if size == 0 {
|
|
close(positions)
|
|
pbf.Close()
|
|
return
|
|
}
|
|
positions <- BlockPosition{pbf.filename, offset, size}
|
|
}
|
|
}()
|
|
return
|
|
}
|
|
|
|
func (pbf *PBF) nextBlobHeaderSize() (size int32) {
|
|
pbf.offset += 4
|
|
structs.Read(pbf.file, structs.BigEndian, &size)
|
|
return
|
|
}
|
|
|
|
func (pbf *PBF) nextBlobHeader() *osmpbf.BlobHeader {
|
|
var blobHeader = &osmpbf.BlobHeader{}
|
|
|
|
size := pbf.nextBlobHeaderSize()
|
|
if size == 0 {
|
|
return blobHeader
|
|
}
|
|
|
|
data := make([]byte, size)
|
|
io.ReadFull(pbf.file, data)
|
|
|
|
err := proto.Unmarshal(data, blobHeader)
|
|
if err != nil {
|
|
log.Fatal("unmarshaling error (header): ", err)
|
|
}
|
|
|
|
pbf.offset += int64(size)
|
|
return blobHeader
|
|
}
|