mirror metadata into mergd.mbtiles

still to do: treat bbox / vector_layers specially
hikeratlas · Oct 5, 2024 · 4c5abd8 · 4c5abd8
1 parent 427f2c1
commit 4c5abd8
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Showing 3 changed files with 30 additions and 6 deletions.
diff --git a/include/mbtiles.h b/include/mbtiles.h
@@ -48,6 +48,7 @@ class MBTiles {
 	virtual ~MBTiles();
 	void openForWriting(std::string &filename);
 	void writeMetadata(std::string key, std::string value);
+	std::vector<std::pair<std::string, std::string>> readMetadata();
 	void saveTile(int zoom, int x, int y, std::string *data, bool isMerge);
 	void closeForWriting();
 

diff --git a/src/mbtiles.cpp b/src/mbtiles.cpp
@@ -97,13 +97,23 @@ void MBTiles::openForWriting(string &filename) {
 }
 
 void MBTiles::writeMetadata(string key, string value) {
-	m.lock();
+	Flock lock(lockfd);
 	db << "REPLACE INTO metadata (name,value) VALUES (?,?);" << key << value;
-	m.unlock();
+}
+
+std::vector<std::pair<std::string, std::string>> MBTiles::readMetadata() {
+	Flock lock(lockfd);
+
+	std::vector<std::pair<std::string, std::string>> rv;
+	db << "SELECT name, value FROM metadata;" >> [&](std::string name, std::string value) {
+		rv.push_back(std::make_pair(name, value));
+	};
+
+	return rv;
 }
 
 void MBTiles::insertOrReplace(int zoom, int x, int y, const std::string& data, bool isMerge) {
-	// NB: assumes we have the `m` mutex
+	// NB: assumes we have n flock on lockfd
 	int tmsY = pow(2, zoom) - 1 - y;
 	int s = isMerge ? 1 : 0;
 	preparedStatements[s].reset();
@@ -113,7 +123,6 @@ void MBTiles::insertOrReplace(int zoom, int x, int y, const std::string& data, b
 
 void MBTiles::flushPendingStatements() {
 	Flock lock(lockfd);
-	// NB: assumes we have the `m` mutex
 
 	db << "BEGIN";
 

diff --git a/src/tilemaker.cpp b/src/tilemaker.cpp
@@ -202,8 +202,22 @@ int main(const int argc, const char* argv[]) {
 		}
 	}
 
-	// TODO: Populate the `metadata` table
-	// See https://github.com/mapbox/mbtiles-spec/blob/master/1.3/spec.md#content
+	if (shard == 0) {
+		// Populate the `metadata` table
+		// See https://github.com/mapbox/mbtiles-spec/blob/master/1.3/spec.md#content
+
+		std::map<std::string, std::string> metadata;
+		for (auto& input : inputs) {
+			for (const auto& entry : input->mbtiles.readMetadata()) {
+				metadata[entry.first] = entry.second;
+			}
+		}
+
+		// Dump the metadata into merged.mbtiles
+		for (auto const& entry : metadata) {
+			merged.writeMetadata(entry.first, entry.second);
+		}
+	}
 
 	merged.closeForWriting();