/usr/lib/python2.7/dist-packages/TileStache/MBTiles.py is in tilestache 1.49.8-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 | """ Support for MBTiles file format, version 1.1.
MBTiles (http://mbtiles.org) is a specification for storing tiled map data in
SQLite databases for immediate use and for transfer. The files are designed for
portability of thousands, hundreds of thousands, or even millions of standard
map tile images in a single file.
This makes it easy to manage and share map tiles.
Read the spec:
https://github.com/mapbox/mbtiles-spec/blob/master/1.1/spec.md
MBTiles files generated by other applications such as Tilemill or Arc2Earth
can be used as data sources for the MBTiles Provider.
Example configuration:
{
"cache": { ... }.
"layers":
{
"roads":
{
"provider":
{
"name": "mbtiles",
"tileset": "collection.mbtiles"
}
}
}
}
MBTiles provider parameters:
tileset:
Required local file path to MBTiles tileset file, a SQLite 3 database file.
"""
from urlparse import urlparse, urljoin
from os.path import exists
# Heroku is missing standard python's sqlite3 package, so this will ImportError.
from sqlite3 import connect as _connect
from ModestMaps.Core import Coordinate
def create_tileset(filename, name, type, version, description, format, bounds=None):
""" Create a tileset 1.1 with the given filename and metadata.
From the specification:
The metadata table is used as a key/value store for settings.
Five keys are required:
name:
The plain-english name of the tileset.
type:
overlay or baselayer
version:
The version of the tileset, as a plain number.
description:
A description of the layer as plain text.
format:
The image file format of the tile data: png or jpg or json
One row in metadata is suggested and, if provided, may enhance performance:
bounds:
The maximum extent of the rendered map area. Bounds must define
an area covered by all zoom levels. The bounds are represented in
WGS:84 - latitude and longitude values, in the OpenLayers Bounds
format - left, bottom, right, top. Example of the full earth:
-180.0,-85,180,85.
"""
if format not in ('png', 'jpg',' json'):
raise Exception('Format must be one of "png" or "jpg" or "json", not "%s"' % format)
db = _connect(filename)
db.execute('CREATE TABLE metadata (name TEXT, value TEXT, PRIMARY KEY (name))')
db.execute('CREATE TABLE tiles (zoom_level INTEGER, tile_column INTEGER, tile_row INTEGER, tile_data BLOB)')
db.execute('CREATE UNIQUE INDEX coord ON tiles (zoom_level, tile_column, tile_row)')
db.execute('INSERT INTO metadata VALUES (?, ?)', ('name', name))
db.execute('INSERT INTO metadata VALUES (?, ?)', ('type', type))
db.execute('INSERT INTO metadata VALUES (?, ?)', ('version', version))
db.execute('INSERT INTO metadata VALUES (?, ?)', ('description', description))
db.execute('INSERT INTO metadata VALUES (?, ?)', ('format', format))
if bounds is not None:
db.execute('INSERT INTO metadata VALUES (?, ?)', ('bounds', bounds))
db.commit()
db.close()
def tileset_exists(filename):
""" Return true if the tileset exists and appears to have the right tables.
"""
if not exists(filename):
return False
# this always works
db = _connect(filename)
db.text_factory = bytes
try:
db.execute('SELECT name, value FROM metadata LIMIT 1')
db.execute('SELECT zoom_level, tile_column, tile_row, tile_data FROM tiles LIMIT 1')
except:
return False
return True
def tileset_info(filename):
""" Return name, type, version, description, format, and bounds for a tileset.
Returns None if tileset does not exist.
"""
if not tileset_exists(filename):
return None
db = _connect(filename)
db.text_factory = bytes
info = []
for key in ('name', 'type', 'version', 'description', 'format', 'bounds'):
value = db.execute('SELECT value FROM metadata WHERE name = ?', (key, )).fetchone()
info.append(value and value[0] or None)
return info
def list_tiles(filename):
""" Get a list of tile coordinates.
"""
db = _connect(filename)
db.text_factory = bytes
tiles = db.execute('SELECT tile_row, tile_column, zoom_level FROM tiles')
tiles = (((2**z - 1) - y, x, z) for (y, x, z) in tiles) # Hello, Paul Ramsey.
tiles = [Coordinate(row, column, zoom) for (row, column, zoom) in tiles]
return tiles
def get_tile(filename, coord):
""" Retrieve the mime-type and raw content of a tile by coordinate.
If the tile does not exist, None is returned for the content.
"""
db = _connect(filename)
db.text_factory = bytes
formats = {'png': 'image/png', 'jpg': 'image/jpeg', 'json': 'application/json', None: None}
format = db.execute("SELECT value FROM metadata WHERE name='format'").fetchone()
format = format and format[0] or None
mime_type = formats[format]
tile_row = (2**coord.zoom - 1) - coord.row # Hello, Paul Ramsey.
q = 'SELECT tile_data FROM tiles WHERE zoom_level=? AND tile_column=? AND tile_row=?'
content = db.execute(q, (coord.zoom, coord.column, tile_row)).fetchone()
content = content and content[0] or None
return mime_type, content
def delete_tile(filename, coord):
""" Delete a tile by coordinate.
"""
db = _connect(filename)
db.text_factory = bytes
tile_row = (2**coord.zoom - 1) - coord.row # Hello, Paul Ramsey.
q = 'DELETE FROM tiles WHERE zoom_level=? AND tile_column=? AND tile_row=?'
db.execute(q, (coord.zoom, coord.column, tile_row))
def put_tile(filename, coord, content):
"""
"""
db = _connect(filename)
db.text_factory = bytes
tile_row = (2**coord.zoom - 1) - coord.row # Hello, Paul Ramsey.
q = 'REPLACE INTO tiles (zoom_level, tile_column, tile_row, tile_data) VALUES (?, ?, ?, ?)'
db.execute(q, (coord.zoom, coord.column, tile_row, buffer(content)))
db.commit()
db.close()
class Provider:
""" MBTiles provider.
See module documentation for explanation of constructor arguments.
"""
def __init__(self, layer, tileset):
"""
"""
sethref = urljoin(layer.config.dirpath, tileset)
scheme, h, path, q, p, f = urlparse(sethref)
if scheme not in ('file', ''):
raise Exception('Bad scheme in MBTiles provider, must be local file: "%s"' % scheme)
self.tileset = path
self.layer = layer
@staticmethod
def prepareKeywordArgs(config_dict):
""" Convert configured parameters to keyword args for __init__().
"""
return {'tileset': config_dict['tileset']}
def renderTile(self, width, height, srs, coord):
""" Retrieve a single tile, return a TileResponse instance.
"""
mime_type, content = get_tile(self.tileset, coord)
formats = {'image/png': 'PNG', 'image/jpeg': 'JPEG', 'application/json': 'JSON', None: None}
return TileResponse(formats[mime_type], content)
def getTypeByExtension(self, extension):
""" Get mime-type and format by file extension.
This only accepts "png" or "jpg" or "json".
"""
if extension.lower() == 'json':
return 'application/json', 'JSON'
elif extension.lower() == 'png':
return 'image/png', 'PNG'
elif extension.lower() == 'jpg':
return 'image/jpg', 'JPEG'
else:
raise KnownUnknown('MBTiles only makes .png and .jpg and .json tiles, not "%s"' % extension)
class TileResponse:
""" Wrapper class for tile response that makes it behave like a PIL.Image object.
TileStache.getTile() expects to be able to save one of these to a buffer.
Constructor arguments:
- format: 'PNG' or 'JPEG'.
- content: Raw response bytes.
"""
def __init__(self, format, content):
self.format = format
self.content = content
def save(self, out, format):
if self.format is not None and format != self.format:
raise Exception('Requested format "%s" does not match tileset format "%s"' % (format, self.format))
out.write(self.content)
class Cache:
""" Cache provider for writing to MBTiles files.
This class is not exposed as a normal cache provider for TileStache,
because MBTiles has restrictions on file formats that aren't quite
compatible with some of the looser assumptions made by TileStache.
Instead, this cache provider is provided for use with the script
tilestache-seed.py, which can be called with --to-mbtiles option
to write cached tiles to a new tileset.
"""
def __init__(self, filename, format, name):
"""
"""
self.filename = filename
if not tileset_exists(filename):
create_tileset(filename, name, 'baselayer', '0', '', format.lower())
def lock(self, layer, coord, format):
return
def unlock(self, layer, coord, format):
return
def remove(self, layer, coord, format):
""" Remove a cached tile.
"""
delete_tile(self.filename, coord)
def read(self, layer, coord, format):
""" Return raw tile content from tileset.
"""
return get_tile(self.filename, coord)[1]
def save(self, body, layer, coord, format):
""" Write raw tile content to tileset.
"""
put_tile(self.filename, coord, body)
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