Added more tests, and more sample files. In the process fixed a few e…

…dge cases (mainly in how the tests were written).

packages/pmtiles/lib/pmtiles.dart

@@ -6,8 +6,9 @@ import 'package:meta/meta.dart';
 
 export 'src/archive.dart';
 export 'src/exceptions.dart';
-export 'src/types.dart';
+export 'src/header.dart';
 export 'src/tile.dart';
+export 'src/types.dart';
 export 'src/zxy.dart';
 
 @visibleForTesting

packages/pmtiles/lib/src/archive.dart

@@ -86,7 +86,10 @@ class PmTilesArchive {
     return null;
   }
 
-  /// Return the tile data for a single tile [tileId].
+  /// Returns a handle to a single tile [tileId].
+  ///
+  /// The returned tile may not exist, or be corrupt. This will be discovered
+  /// when Tile.bytes() or Tile.compressedBytes() is called.
   Future<Tile> tile(int tileId) async {
     final entry = await lookup(tileId);
     if (entry == null || entry.isLeaf) {
@@ -186,7 +189,7 @@ class PmTilesArchive {
     );
   }
 
-  /// Returns a stream of tiles for the given [tildIds]. The tiles my be return
+  /// Returns a stream of tiles for the given [tileIds]. The tiles my be return
   /// out of order. This tries to batch the fetching of tiles together to reduce
   /// the calls to the underlying archive.
   Stream<Tile> tiles(List<int> tileIds) {
@@ -205,21 +208,21 @@ class PmTilesArchive {
           (key1, key2) => key1.offset.compareTo(key2.offset),
         );
         for (var i = 0; i < tileIds.length; i++) {
-          final tildId = tileIds[i];
+          final tileId = tileIds[i];
           final entry = entries[i];
 
           if (entry == null) {
             controller.add(Tile(
-              tildId,
-              exception: TileNotFoundException(tildId),
+              tileId,
+              exception: TileNotFoundException(tileId),
             ));
             continue;
           }
 
           if (entriesMap.containsKey(entry)) {
-            entriesMap[entry]!.add(tildId);
+            entriesMap[entry]!.add(tileId);
           } else {
-            entriesMap[entry] = [tildId];
+            entriesMap[entry] = [tileId];
           }
         }
 

packages/pmtiles/lib/src/zxy.dart

@@ -10,18 +10,20 @@ class ZXY {
   final int x;
   final int y;
 
+  /// The maximum supported zoom level.
+  ///
+  /// Only allow up to (and including) 26, so that this library works in places
+  /// where doubles are used to represent ints, such as JavaScript.
+  ///    tileID = 2^53 + 1 = ZXY(27, 67108861, 67108863)
+  static const maxAllowedZoom = 26;
+
   const ZXY(this.z, this.x, this.y)
       : assert(z >= 0 && z < 27),
         assert(x >= 0 && x < (1 << z)),
         assert(y >= 0 && x < (1 << z));
 
   /// Maps a tileId to the appropriate Zoom, X and Y coordinate.
   factory ZXY.fromTileId(int tileId) {
-    const maxAllowedZoom = 26;
-    // Only allow up to 27, so that this library works in places where
-    // doubles are used to represent ints, such as JavaScript.
-    // tildID = 2^53 + 1 = ZXY(27, 67108861, 67108863)
-
     // We search each zoom level finding which one the tile belongs to
     // Then we use a Hilbert curve to map the ID into the X and Y coordinates.
     //

packages/pmtiles_tests/samples/headers.dart

@@ -0,0 +1,204 @@
+/// The headers from each sample file, formatted in the Header.toString() format.
+// TODO Consider turning this into a more sensible encoding, e.g JSON.
+const sampleHeaders = <String, String>{
+  'countries-leaf.pmtiles': '''
+    magic: PMTiles,
+    version: 3,
+    rootDirectoryOffset: 127,
+    rootDirectoryLength: 30,
+    metadataOffset: 157,
+    metadataLength: 463,
+    leafDirectoriesOffset: 620,
+    leafDirectoriesLength: 8388,
+    tileDataOffset: 9008,
+    tileDataLength: 7910833,
+    numberOfAddressedTiles: 4099,
+    numberOfTileEntries: 3963,
+    numberOfTileContents: 3474,
+    clustered: Clustered.clustered,
+    internalCompression: Compression.gzip,
+    tileCompression: Compression.gzip,
+    tileType: TileType.mvt,
+    minZoom: 0,
+    maxZoom: 6,
+    minPosition: LatLng(latitude:-85.0, longitude:-180.0),
+    maxPosition: LatLng(latitude:85.0, longitude:180.0),
+    centerZoom: 0,
+    centerPosition: LatLng(latitude:7.0137, longitude:0.0),
+''',
+  'countries-leafs.pmtiles': '''
+    magic: PMTiles,
+    version: 3,
+    rootDirectoryOffset: 127,
+    rootDirectoryLength: 145,
+    metadataOffset: 272,
+    metadataLength: 463,
+    leafDirectoriesOffset: 735,
+    leafDirectoriesLength: 10888,
+    tileDataOffset: 11623,
+    tileDataLength: 7910833,
+    numberOfAddressedTiles: 4099,
+    numberOfTileEntries: 3963,
+    numberOfTileContents: 3474,
+    clustered: Clustered.clustered,
+    internalCompression: Compression.gzip,
+    tileCompression: Compression.gzip,
+    tileType: TileType.mvt,
+    minZoom: 0,
+    maxZoom: 6,
+    minPosition: LatLng(latitude:-85.0, longitude:-180.0),
+    maxPosition: LatLng(latitude:85.0, longitude:180.0),
+    centerZoom: 0,
+    centerPosition: LatLng(latitude:7.0137, longitude:0.0),
+    ''',
+  'countries-raster.pmtiles': ''' 
+    magic: PMTiles,
+    version: 3,
+    rootDirectoryOffset: 127,
+    rootDirectoryLength: 8227,
+    metadataOffset: 8354,
+    metadataLength: 100,
+    leafDirectoriesOffset: 8454,
+    leafDirectoriesLength: 0,
+    tileDataOffset: 8454,
+    tileDataLength: 7423783,
+    numberOfAddressedTiles: 5461,
+    numberOfTileEntries: 2883,
+    numberOfTileContents: 2204,
+    clustered: Clustered.clustered,
+    internalCompression: Compression.gzip,
+    tileCompression: Compression.none,
+    tileType: TileType.png,
+    minZoom: 0,
+    maxZoom: 6,
+    minPosition: LatLng(latitude:-85.738076, longitude:-180.0),
+    maxPosition: LatLng(latitude:84.798428, longitude:180.0),
+    centerZoom: 2,
+    centerPosition: LatLng(latitude:0.0, longitude:0.0),
+''',
+  'countries.pmtiles': '''
+    magic: PMTiles,
+    version: 3,
+    rootDirectoryOffset: 127,
+    rootDirectoryLength: 8388,
+    metadataOffset: 8515,
+    metadataLength: 463,
+    leafDirectoriesOffset: 8978,
+    leafDirectoriesLength: 0,
+    tileDataOffset: 8978,
+    tileDataLength: 7910833,
+    numberOfAddressedTiles: 4099,
+    numberOfTileEntries: 3963,
+    numberOfTileContents: 3474,
+    clustered: Clustered.clustered,
+    internalCompression: Compression.gzip,
+    tileCompression: Compression.gzip,
+    tileType: TileType.mvt,
+    minZoom: 0,
+    maxZoom: 6,
+    minPosition: LatLng(latitude:-85.0, longitude:-180.0),
+    maxPosition: LatLng(latitude:85.0, longitude:180.0),
+    centerZoom: 0,
+    centerPosition: LatLng(latitude:7.0137, longitude:0.0),
+''',
+  'protomaps(vector)ODbL_firenze.pmtiles': '''
+    magic: PMTiles,
+    version: 3,
+    rootDirectoryOffset: 127,
+    rootDirectoryLength: 406,
+    metadataOffset: 533,
+    metadataLength: 575,
+    leafDirectoriesOffset: 1108,
+    leafDirectoriesLength: 0,
+    tileDataOffset: 1108,
+    tileDataLength: 3958871,
+    numberOfAddressedTiles: 108,
+    numberOfTileEntries: 108,
+    numberOfTileContents: 106,
+    clustered: Clustered.clustered,
+    internalCompression: Compression.gzip,
+    tileCompression: Compression.gzip,
+    tileType: TileType.mvt,
+    minZoom: 0,
+    maxZoom: 14,
+    minPosition: LatLng(latitude:43.727013, longitude:11.154026),
+    maxPosition: LatLng(latitude:43.832546, longitude:11.32894),
+    centerZoom: 0,
+    centerPosition: LatLng(latitude:43.779779, longitude:11.241483),
+''',
+  'stamen_toner(raster)CC-BY+ODbL_z3.pmtiles': '''
+    magic: PMTiles,
+    version: 3,
+    rootDirectoryOffset: 127,
+    rootDirectoryLength: 246,
+    metadataOffset: 373,
+    metadataLength: 22,
+    leafDirectoriesOffset: 395,
+    leafDirectoriesLength: 0,
+    tileDataOffset: 395,
+    tileDataLength: 715657,
+    numberOfAddressedTiles: 85,
+    numberOfTileEntries: 84,
+    numberOfTileContents: 80,
+    clustered: Clustered.clustered,
+    internalCompression: Compression.gzip,
+    tileCompression: Compression.none,
+    tileType: TileType.png,
+    minZoom: 0,
+    maxZoom: 3,
+    minPosition: LatLng(latitude:-85.0, longitude:-180.0),
+    maxPosition: LatLng(latitude:85.0, longitude:180.0),
+    centerZoom: 0,
+    centerPosition: LatLng(latitude:0.0, longitude:0.0),
+''',
+  'trails.pmtiles': '''
+    magic: PMTiles,
+    version: 3,
+    rootDirectoryOffset: 127,
+    rootDirectoryLength: 2417,
+    metadataOffset: 2544,
+    metadataLength: 311,
+    leafDirectoriesOffset: 2855,
+    leafDirectoriesLength: 0,
+    tileDataOffset: 2855,
+    tileDataLength: 969515,
+    numberOfAddressedTiles: 1201,
+    numberOfTileEntries: 1201,
+    numberOfTileContents: 1201,
+    clustered: Clustered.clustered,
+    internalCompression: Compression.gzip,
+    tileCompression: Compression.gzip,
+    tileType: TileType.mvt,
+    minZoom: 0,
+    maxZoom: 14,
+    minPosition: LatLng(latitude:48.253941, longitude:-114.477539),
+    maxPosition: LatLng(latitude:49.009051, longitude:-113.225098),
+    centerZoom: 14,
+    centerPosition: LatLng(latitude:48.6402, longitude:-113.8348),
+''',
+  'usgs-mt-whitney-8-15-webp-512.pmtiles': '''
+    magic: PMTiles,
+    version: 3,
+    rootDirectoryOffset: 127,
+    rootDirectoryLength: 232,
+    metadataOffset: 359,
+    metadataLength: 210,
+    leafDirectoriesOffset: 569,
+    leafDirectoriesLength: 0,
+    tileDataOffset: 569,
+    tileDataLength: 1964030,
+    numberOfAddressedTiles: 50,
+    numberOfTileEntries: 50,
+    numberOfTileContents: 50,
+    clustered: Clustered.clustered,
+    internalCompression: Compression.gzip,
+    tileCompression: Compression.none,
+    tileType: TileType.webp,
+    minZoom: 8,
+    maxZoom: 15,
+    minPosition: LatLng(latitude:36.56109, longitude:-118.31982),
+    maxPosition: LatLng(latitude:36.59301, longitude:-118.26069),
+    centerZoom: 12,
+    centerPosition: LatLng(latitude:36.577, longitude:-118.2903),
+'''
+};