Files
node-mbtiles/lib/mbtiles.js
2011-06-28 16:47:23 +02:00

465 lines
16 KiB
JavaScript

var _ = require('underscore'),
fs = require('fs'),
Step = require('step'),
crypto = require('crypto'),
zlib = require('zlib'),
path = require('path'),
url = require('url'),
sm = new (require('sphericalmercator')),
sqlite3 = require('sqlite3');
function noop(err) {
if (err) throw err;
}
// MBTiles
// -------
// MBTiles class for doing common operations (schema setup, tile reading,
// insertion, etc.)
module.exports = MBTiles;
MBTiles.utils = require('./utils');
// Provides access to an mbtiles database file.
// - uri: A parsed URL hash, the only relevant part is `pathname`.
// - callback: Will be called when the resources have been acquired
// or acquisition failed.
function MBTiles(uri, callback) {
var mbtiles = this;
if (typeof callback !== 'function') callback = noop;
if (typeof uri === 'string') uri = url.parse(uri);
this.filename = uri.pathname;
this.db = new sqlite3.cached.Database(mbtiles.filename, function(err) {
if (err) return callback(err);
else fs.stat(mbtiles.filename, function(err, stat) {
if (err) return callback(err);
mbtiles.stat = stat;
callback(null, mbtiles);
});
});
};
// Finds all mbtiles file in the filepath and returns their tilesource URI.
MBTiles.list = function(filepath, callback) {
if (typeof callback !== 'function') callback = noop;
filepath = path.resolve(filepath);
fs.readdir(filepath, function(err, files) {
if (err) return callback(err);
for (var result = {}, i = 0; i < files.length; i++) {
var name = files[i].match(/^([\w-]+)\.mbtiles$/);
if (name) result[name[1]] = 'mbtiles://' + path.join(filepath, name[0]);
}
callback(null, result);
});
};
// Finds an mbtiles file with the given ID in the filepath and returns a
// tilesource URI.
MBTiles.findID = function(filepath, id, callback) {
if (typeof callback !== 'function') callback = noop;
filepath = path.resolve(filepath);
var file = path.join(filepath, id + '.mbtiles');
fs.stat(file, function(err, stats) {
if (err) callback(err);
else callback(null, 'mbtiles://' + file);
});
};
// Retrieve the schema of the current mbtiles database and inform the caller of
// whether the specified table exists.
MBTiles.prototype.exists = function(table, callback) {
if (typeof callback !== 'function') callback = noop;
if (this.schema) {
return callback(null, _(this.schema).include(table));
} else {
this.schema = [];
this.db.all(
'SELECT name FROM sqlite_master WHERE type IN (?, ?)',
'table',
'view',
function(err, rows) {
if (err) return callback(err);
this.schema = _(rows).pluck('name');
this.exists(table, callback);
}.bind(this)
);
}
};
// DB integrity check.
MBTiles.prototype.integrity = function(callback) {
if (typeof callback !== 'function') callback = noop;
this.db.get('PRAGMA quick_check(1)', function(err, row) {
if (!(row && row.integrity_check && row.integrity_check === 'ok')) {
callback(new Error('Corrupted database.'));
} else {
callback(null, true);
}
});
};
// Setup schema, indices, views for a new mbtiles database.
// Sets the synchronous flag to OFF for (much) faster inserts.
// See http://www.sqlite3.org/pragma.html#pragma_synchronous
MBTiles.prototype.setup = function(callback) {
if (typeof callback !== 'function') callback = noop;
fs.readFile(__dirname + '/schema.sql', 'utf8', function(err, sql) {
if (err) return callback(err);
this.db.serialize(function() {
this.db.run('PRAGMA synchronous = 0');
this.db.exec(sql, callback);
}.bind(this));
}.bind(this));
};
// Generic object insert.
//
// - `table` String. The table to which objects should be inserted.
// - `objects` Array. Objects to be inserted, where each object attribute
// has key/value pairs as a hash corresponding to column name and row value.
// - `callback` Function.
MBTiles.prototype.insert = function(table, objects, callback) {
if (typeof callback !== 'function') callback = noop;
if (!objects.length) return callback(null);
var keys = _(objects[0]).keys();
var placeholders = [];
_(keys).each(function(k) { placeholders.push('?'); });
var stmt = this.db.prepare(
'INSERT OR IGNORE INTO ' + table + ' ' +
'(' + keys.join(',') + ') ' +
'VALUES (' + placeholders.join(',') + ')'
);
for (var i = 0; i < objects.length; i++) {
stmt.run.apply(stmt, _(objects[i]).values());
}
stmt.finalize(callback);
};
// Insert metadata into the mbtiles database.
//
// - @param {Object} metadata key, value hash of metadata to be inserted.
// - @param {Function} callback
MBTiles.prototype.insertMetadata = function(data, callback) {
if (typeof callback !== 'function') callback = noop;
var metadata = _(data).map(function(value, key) {
return { name: key, value: value};
});
this.insert('metadata', metadata, callback);
};
// Insert a set of tiles into an mbtiles database.
//
// - @param {Array} renders array of images to be inserted. Each item should
// be an object of the form { z: z, x: x, y: y, data: [Image buffer] }.
// - @param {Function} callback
MBTiles.prototype.insertTiles = function(data, callback) {
var that = this,
map = [],
images = [],
ids = [];
for (var i = 0; i < data.length; i++) {
var tile_id = crypto
.createHash('md5')
.update(data[i].data)
.digest('hex');
!_(ids).include(tile_id) && ids.push(tile_id) && images.push({
tile_id: tile_id,
tile_data: data[i].data
});
map.push({
tile_id: tile_id,
zoom_level: data[i].z,
tile_column: data[i].x,
tile_row: data[i].y
});
}
Step(
function() {
var group = this.group();
that.insert('images', images, group());
that.insert('map', map, group());
},
callback
);
};
// Insert a set of grids into an mbtiles database.
//
// - @param {Array} renders array of grids to be inserted. Each item should
// be an object of the form { z: z, x: x, y: y, data: [Image buffer], keys: [] }.
// - @param {Function} callback
MBTiles.prototype.insertGrids = function(data, callback) {
if (typeof callback !== 'function') callback = noop;
var that = this,
map = [],
grids = [],
grid_keys = [],
features = {},
ids = [];
for (var i = 0; i < data.length; i++) {
var json = JSON.stringify({
grid: data[i].grid,
keys: data[i].keys
});
var grid_id = crypto
.createHash('md5')
.update(json)
.digest('hex');
!_(ids).include(grid_id) && ids.push(grid_id) && grids.push({
grid_id: grid_id,
grid_utfgrid: zlib.deflate(new Buffer(json, 'utf8'))
});
data[i].keys.forEach(function(k) {
grid_keys.push({
grid_id: grid_id,
key_name: k
});
});
map.push({
grid_id: grid_id,
zoom_level: data[i].z,
tile_column: data[i].x,
tile_row: data[i].y
});
_(features).extend(data[i].data);
}
features = _(features).map(function(value, key) {
return { key_name: key, key_json: JSON.stringify(value) };
});
Step(
function() {
var group = this.group();
that.insert('grid_utfgrid', grids, group());
that.insert('grid_key', grid_keys, group());
that.insert('keymap', features, group());
that.insertGridTiles(map, group());
},
callback
);
};
// Insert grids into the mbtiles database.
//
// - @param {Object} tile tile object to be inserted.
// - @param {Function} callback
MBTiles.prototype.insertGridTiles = function(map, callback) {
if (typeof callback !== 'function') callback = noop;
var stmt = this.db.prepare('UPDATE OR REPLACE map SET grid_id = ? WHERE ' +
' zoom_level = ? AND tile_column = ? AND tile_row = ?');
for (var i = 0; i < map.length; i++) {
stmt.run(
map[i].grid_id,
map[i].zoom_level,
map[i].tile_column,
map[i].tile_row
);
}
stmt.finalize(callback);
};
// Select a tile from an mbtiles database.
//
// - @param {Number} x tile x coordinate.
// - @param {Number} y tile y coordinate.
// - @param {Number} z tile z coordinate.
// - @param {Function} callback
MBTiles.prototype.getTile = function(z, x, y, callback) {
if (typeof callback !== 'function') callback = noop;
var mbtiles = this;
this.db.get('SELECT tile_data FROM tiles WHERE ' +
'zoom_level = ? AND tile_column = ? AND tile_row = ?',
z, x, y,
function(err, row) {
if (!row || (err && err.errno == 1)) callback(new Error('Tile does not exist'));
else if (err) callback(err);
else {
var options = {
'Content-Type': MBTiles.utils.getMimeType(row.tile_data),
'Last-Modified': mbtiles.stat.mtime,
'E-Tag': mbtiles.stat.size + '-' + Number(mbtiles.stat.mtime)
};
callback(null, row.tile_data, options);
}
});
};
// Select a grid and its data from an mbtiles database.
//
// - @param {Number} x tile x coordinate
// - @param {Number} y tile y coordinate
// - @param {Number} z tile z coordinate
// - @param {Function} callback
MBTiles.prototype.getGrid = function(z, x, y, callback) {
if (typeof callback !== 'function') callback = noop;
var that = this;
Step(
function() {
that.db.get('SELECT grid FROM grids WHERE ' +
'zoom_level = ? AND tile_column = ? AND tile_row = ?',
z, x, y,
this.parallel()
);
that.db.all('SELECT key_name, key_json FROM grid_data WHERE ' +
'zoom_level = ? AND tile_column = ? AND tile_row = ?',
z, x, y,
this.parallel()
);
},
function(err, row, rows) {
if ((!row || !row.grid) || (err && err.errno == 1)) {
return callback(new Error('Grid does not exist'));
}
if (err) return callback(err);
try {
var grid = zlib.inflate(
!Buffer.isBuffer(row.grid)
? new Buffer(row.grid, 'binary')
: row.grid
).toString();
var data = rows.reduce(function(memo, r) {
memo[r.key_name] = JSON.parse(r.key_json);
return memo;
}, {});
callback(null, _(JSON.parse(grid)).extend({ data: data }));
} catch (err) {
callback(new Error('Grid is invalid'));
}
}
);
};
// Select a metadata value from the database.
//
// - @param {Function} callback
MBTiles.prototype.metadata = function(key, callback) {
if (typeof callback !== 'function') callback = noop;
this.db.get('SELECT value FROM metadata WHERE name = ?',
key,
function(err, row) {
if (!row || (err && err.errno == 1)) callback(new Error('Key does not exist'));
else if (err) callback(err);
else callback(null, row.value);
});
};
// Extend `MBTiles` class with an `info` method for retrieving metadata and
// performing fallback queries if certain keys (like `bounds`, `minzoom`,
// `maxzoom`) have not been provided.
MBTiles.prototype.getInfo = function(callback) {
if (typeof callback !== 'function') callback = noop;
var that = this;
var info = {};
info.basename = path.basename(that.filename);
info.id = info.basename.replace(path.extname(that.filename), '');
Step(function() {
var end = this;
that.db.all('SELECT name, value FROM metadata', function(err, rows) {
if (rows) for (var i = 0; i < rows.length; i++) {
info[rows[i].name] = rows[i].value;
}
end(err);
});
},
// Determine min/max zoom if needed
function(err) {
if (err && err.errno !== 1) return callback(err);
if (info.maxzoom !== undefined
&& info.minzoom !== undefined) return this();
var step = this;
var zoomquery = that.db.prepare('SELECT zoom_level FROM tiles ' +
'WHERE zoom_level = ? LIMIT 1', function(err) {
if (err) {
if (err.errno === 1) step();
else throw new Error(err);
} else {
var group = step.group();
for (var i = 0; i < 30; i++) {
zoomquery.get(i, group());
}
zoomquery.finalize();
}
});
},
function(err, rows) {
if (err) return callback(err);
if (rows) {
var zooms = _(rows).chain()
.reject(_.isUndefined)
.pluck('zoom_level')
.value();
info.minzoom = zooms.shift();
info.maxzoom = zooms.length ? zooms.pop() : info.minzoom;
}
this();
},
// Determine bounds if needed
function(err) {
if (err) return callback(err);
if (info.bounds) return this();
if (typeof info.minzoom === 'undefined') return this();
var next = this;
Step(
function() {
that.db.get(
'SELECT MAX(tile_column) AS maxx, ' +
'MIN(tile_column) AS minx, MAX(tile_row) AS maxy, ' +
'MIN(tile_row) AS miny FROM tiles ' +
'WHERE zoom_level = ?',
info.minzoom,
this
);
},
function(err, row) {
if (!err && row) {
// @TODO this breaks a little at zoom level zero
var urTile = sm.bbox(row.maxx, row.maxy, info.minzoom, true);
var llTile = sm.bbox(row.minx, row.miny, info.minzoom, true);
// @TODO bounds are limited to "sensible" values here
// as sometimes tilesets are rendered with "negative"
// and/or other extremity tiles. Revisit this if there
// are actual use cases for out-of-bounds bounds.
info.bounds = [
llTile[0] > -180 ? llTile[0] : -180,
llTile[1] > -90 ? llTile[1] : -90,
urTile[2] < 180 ? urTile[2] : 180,
urTile[3] < 90 ? urTile[3] : 90
].join(',');
}
next();
}
);
},
// Return info
function(err) {
if (err) return callback(err);
var range = parseInt(info.maxzoom, 10) - parseInt(info.minzoom, 10);
info.minzoom = parseInt(info.minzoom, 10);
info.maxzoom = parseInt(info.maxzoom, 10);
info.bounds = _((info.bounds || '').split(',')).map(parseFloat);
info.center = [
(info.bounds[2] - info.bounds[0]) / 2 + info.bounds[0],
(info.bounds[3] - info.bounds[1]) / 2 + info.bounds[1],
(range <= 1) ? info.maxzoom : Math.floor(range * 0.5) + info.minzoom
];
callback(null, info);
});
};