Tile-join had not been compressing its tiles.

decode.cpp

@@ -54,9 +54,10 @@ struct lonlat {
 void handle(std::string message, int z, unsigned x, unsigned y, int describe, std::set<std::string> const &to_decode) {
 	int within = 0;
 	mvt_tile tile;
+	bool was_compressed;
 
 	try {
-		if (!tile.decode(message)) {
+		if (!tile.decode(message, was_compressed)) {
 			fprintf(stderr, "Couldn't parse tile %d/%u/%u\n", z, x, y);
 			exit(EXIT_FAILURE);
 		}
@@ -68,7 +69,12 @@ void handle(std::string message, int z, unsigned x, unsigned y, int describe, st
 	printf("{ \"type\": \"FeatureCollection\"");
 
 	if (describe) {
-		printf(", \"properties\": { \"zoom\": %d, \"x\": %d, \"y\": %d }", z, x, y);
+		printf(", \"properties\": { \"zoom\": %d, \"x\": %d, \"y\": %d", z, x, y);
+		if (!was_compressed) {
+			printf(", \"compressed\": false");
+		}
+
+		printf(" }");
 
 		if (projection != projections) {
 			printf(", \"crs\": { \"type\": \"name\", \"properties\": { \"name\": ");

mvt.cpp

@@ -79,7 +79,7 @@ int compress(std::string const &input, std::string &output) {
 	return 0;
 }
 
-bool mvt_tile::decode(std::string &message) {
+bool mvt_tile::decode(std::string &message, bool &was_compressed) {
 	layers.clear();
 	std::string src;
 
@@ -87,8 +87,10 @@ bool mvt_tile::decode(std::string &message) {
 		std::string uncompressed;
 		decompress(message, uncompressed);
 		src = uncompressed;
+		was_compressed = true;
 	} else {
 		src = message;
+		was_compressed = false;
 	}
 
 	protozero::pbf_reader reader(src);

mvt.hpp

@@ -91,7 +91,7 @@ struct mvt_tile {
 	std::vector<mvt_layer> layers;
 
 	std::string encode();
-	bool decode(std::string &message);
+	bool decode(std::string &message, bool &was_compressed);
 };
 
 bool is_compressed(std::string const &data);

tile-join.cpp

@@ -32,8 +32,9 @@ struct stats {
 void handle(std::string message, int z, unsigned x, unsigned y, std::map<std::string, layermap_entry> &layermap, std::vector<std::string> &header, std::map<std::string, std::vector<std::string>> &mapping, std::set<std::string> &exclude, std::set<std::string> &keep_layers, std::set<std::string> &remove_layers, int ifmatched, mvt_tile &outtile) {
 	mvt_tile tile;
 	int features_added = 0;
+	bool was_compressed;
 
-	if (!tile.decode(message)) {
+	if (!tile.decode(message, was_compressed)) {
 		fprintf(stderr, "Couldn't decompress tile %d/%u/%u\n", z, x, y);
 		exit(EXIT_FAILURE);
 	}
@@ -402,7 +403,9 @@ void *join_worker(void *v) {
 		}
 
 		if (anything) {
-			std::string compressed = tile.encode();
+			std::string pbf = tile.encode();
+			std::string compressed;
+			compress(pbf, compressed);
 
 			if (!pk && compressed.size() > 500000) {
 				fprintf(stderr, "Tile %lld/%lld/%lld size is %lld, >500000. Skipping this tile\n.", ai->first.z, ai->first.x, ai->first.y, (long long) compressed.size());