/// <summary>
/// Dekodiert die Werte aus einem PBF-Stream
/// </summary>
/// <param name="buf">Buffer, worraus die Werte gelesen werden sollen</param>
/// <param name="ofs">Startposition innerhalb des Buffers</param>
/// <param name="headerBlock">HeaderBlock-Struktur mit den ausgelesenen Werten</param>
/// <returns>Anzahl der gelesenen Bytes aus dem Buffer</returns>
public static int Decode(byte[] buf, int ofs, out HeaderBlock headerBlock)
{
/*****
* message HeaderBlock
* {
* optional HeaderBBox bbox = 1;
*
* // Additional tags to aid in parsing this dataset
* repeated string required_features = 4;
* repeated string optional_features = 5;
*
* optional string writingprogram = 16;
*
* optional string source = 17; // From the bbox field.
*
* // Tags that allow continuing an Osmosis replication
* // replication timestamp, expressed in seconds since the epoch,
* // otherwise the same value as in the "timestamp=..." field
* // in the state.txt file used by Osmosis
* optional int64 osmosis_replication_timestamp = 32;
*
* // replication sequence number (sequenceNumber in state.txt)
* optional int64 osmosis_replication_sequence_number = 33;
*
* // replication base URL (from Osmosis' configuration.txt file)
* optional string osmosis_replication_base_url = 34;
* }
*****/
int len = 0;
ulong tmp;
var tmps = new List <string>();
headerBlock = new HeaderBlock();
// --- optional HeaderBBox bbox = 1; ---
if (buf[ofs + len] == (1 << 3 | 2))
{
len++;
len += HeaderBBox.Decode(buf, ofs + len, out headerBlock.bbox);
}
// --- repeated string required_features = 4; ---
tmps.Clear();
while (buf[ofs + len] == (4 << 3 | 2))
{
len++;
string feature;
len += ProtoBuf.ReadString(buf, ofs + len, out feature);
tmps.Add(feature);
switch (feature)
{
case "OsmSchema-V0.6": break;
case "DenseNodes": break;
default: throw new PbfParseException("required feature not supported: \"" + feature + "\"");
}
}
headerBlock.requiredFeatures = tmps.ToArray();
// --- repeated string optional_features = 5; ---
tmps.Clear();
while (buf[ofs + len] == (5 << 3 | 2))
{
len++;
string feature;
len += ProtoBuf.ReadString(buf, ofs + len, out feature);
tmps.Add(feature);
switch (feature)
{
case "Has_Metadata": break;
case "Sort.Type_then_ID": break;
default: throw new PbfParseException("optional feature not supported: \"" + feature + "\"");
}
}
headerBlock.optionalFeatures = tmps.ToArray();
// --- optional string writingprogram = 16; ---
if (ProtoBuf.PeekVarInt(buf, ofs + len) == (16 << 3 | 2))
{
len += 2;
len += ProtoBuf.ReadString(buf, ofs + len, out headerBlock.writingprogram);
}
else
{
headerBlock.writingprogram = "";
}
// --- optional string source = 17; ---
if (ProtoBuf.PeekVarInt(buf, ofs + len) == (17 << 3 | 2))
{
len += 2;
len += ProtoBuf.ReadString(buf, ofs + len, out headerBlock.source);
}
else
{
headerBlock.source = "";
}
// --- optional int64 osmosis_replication_timestamp = 32; ---
if (ProtoBuf.PeekVarInt(buf, ofs + len) == (32 << 3 | 0))
{
len += 2;
len += ProtoBuf.ReadVarInt(buf, ofs + len, out tmp);
headerBlock.replicationTimestamp = (long)tmp;
}
// --- optional int64 osmosis_replication_sequence_number = 33; ---
if (ProtoBuf.PeekVarInt(buf, ofs + len) == (33 << 3 | 0))
{
len += 2;
len += ProtoBuf.ReadVarInt(buf, ofs + len, out tmp);
headerBlock.replicationSequenceNumber = (long)tmp;
}
// --- optional string osmosis_replication_base_url = 34; ---
if (ProtoBuf.PeekVarInt(buf, ofs + len) == (34 << 3 | 2))
{
len += 2;
len += ProtoBuf.ReadString(buf, ofs + len, out headerBlock.replicationBaseUrl);
}
else
{
headerBlock.replicationBaseUrl = "";
}
return(len);
}