persolijn

Blob.java (2490B)

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 package osm.message;
 
 import java.util.zip.Inflater;
 
 import protobuf.Message;
 import protobuf.ProtobufReader;
 
 import java.io.UnsupportedEncodingException;
 import java.util.Iterator;
 import java.util.List;
 import java.util.zip.DataFormatException;
 
 // optional bytes raw = 1; // No compression
 // optional int32 raw_size = 2; // When compressed, the uncompressed size
 // optional bytes zlib_data = 3;
 // optional bytes lzma_data = 4;
 // optional bytes OBSOLETE_bzip2_data = 5 [deprecated=true]; // Don't reuse this tag number.
 public class Blob implements Message<Blob> {
     public final String headerType;
     public int size = 0;
 
     public HeaderBlock header = null;
     public List<Entity> primitive = null;
 
     public Blob(String headerType) {
         this.headerType = headerType;
     }
 
     @Override
     public Blob parse(Iterator<ProtobufReader> tags) {
         while (tags.hasNext()) {
             ProtobufReader message = tags.next();
             switch (message.tag()) {
                 case 1 -> {
                     switch (headerType) {
                         case "OSMHeader" -> header = message.message(new HeaderBlock());
                         case "OSMData" -> primitive = message.message(new PrimitiveBlock());
                     }
                 }
                 case 2 -> size = message.varint32();
                 case 3 -> {
                     switch (headerType) {
                         case "OSMHeader" -> message.delayed(new HeaderBlock(), this::decompress, this::setHeader);
                         case "OSMData" -> message.delayed(new PrimitiveBlock(), this::decompress, this::setPrimitive);
                     }
                 }
                 default -> message.throwUnexpected();
             }
         }
 
         return this;
     }
 
     private void setHeader(HeaderBlock header) {
         this.header = header;
     }
 
     private void setPrimitive(List<Entity> primitive) {
         this.primitive = primitive;
     }
 
     private byte[] decompress(byte[] block) {
         Inflater decompresser = new Inflater();
         decompresser.setInput(block);
 
         try {
             byte[] buffer = new byte[size];
             int uncompressedSize = decompresser.inflate(buffer);
 
             if (uncompressedSize != size) {
                 throw new RuntimeException("Invalid blob payload size");
             }
 
             return buffer;
         } catch (DataFormatException exc) {
             throw new RuntimeException(exc);
         }
     }
 }