Files
node-mbtiles/lib/mbtiles.js
2011-05-06 21:11:30 -04:00

311 lines
9.8 KiB
JavaScript

var fs = require('fs');
var Step = require('step');
var crypto = require('crypto');
var sys = require('sys');
var Buffer = require('buffer').Buffer;
var zlib = require('zlib');
var sqlite3 = require('sqlite3');
// MBTiles
// -------
// MBTiles class for doing common operations (schema setup, tile reading,
// insertion, etc.)
function MBTiles(filename, options, callback) {
this.options = options || {};
this.filename = filename;
this.compress = true; // @TODO
this.db = new sqlite3.Database(filename, callback);
}
// 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 (this.schema) {
if (this.schema.indexOf(table) !== -1) {
return callback(null, true);
} else {
return callback(null, false);
}
}
var that = this;
that.schema = [];
this.db.all('SELECT name FROM sqlite_master WHERE type IN (?, ?)',
'table',
'view',
function(err, rows) {
if (err) return callback(err);
for (var i = 0; i < rows.length; i++) {
that.schema.push(rows[i].name);
}
that.exists(table, callback);
});
}
// Setup schema, indices, views for a new mbtiles database.
MBTiles.prototype.setup = function(callback) {
var db = this.db;
fs.readFile(__dirname + '/schema.sql', 'utf8', function(err, sql) {
if (err) return callback(err);
db.serialize(function() {
// Set the synchronous flag to OFF for (much) faster inserts.
// See http://www.sqlite3.org/pragma.html#pragma_synchronous
db.run('PRAGMA synchronous = 0');
db.exec(sql, 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 { tile: [z, x, 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++) {
// Generate ID from MD5 hash of actual image data.
// Generate ID from tile coordinates (unique).
var tile_id = this.compress
? crypto.createHash('md5').update(data[i].data).digest('hex')
: data[i].tile.join('.');
if (ids.indexOf(tile_id) === -1) {
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].tile[0],
tile_column: data[i].tile[1],
tile_row: data[i].tile[2]
});
}
Step(
function() {
var group = this.group();
for (var i = 0; i < images.length; i++) {
that.insertImage(images[i], group());
}
for (var i = 0; i < map.length; i++) {
that.insertTile(map[i], 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 { tile: [z, x, y], data: [Grid data] }.
// - @param {Function} callback
MBTiles.prototype.insertGrids = function(data, callback) {
var that = this,
map = [],
grids = [],
grid_keys = [],
ids = [];
for (var i = 0; i < tiles.length; i++) {
var grid_id;
// Generate ID from MD5 hash of grid data.
// Generate ID from tile coordinates (unique).
var grid_id = this.compress
? crypto.createHash('md5').update(data[i].data[0]).digest('hex')
: data[i].tile.join('.');
if (ids.indexOf(grid_id) === -1) {
ids.push(grid_id);
grids.push({ grid_id: grid_id, grid_utfgrid: renders[i][0] });
}
data[i].data[2].keys.forEach(function(k) {
grid_keys.push({ grid_id: grid_id, key_name: k });
});
map.push({
grid_id: grid_id,
zoom_level: data[i].tile[0],
tile_column: data[i].tile[1],
tile_row: data[i].tile[2]
});
}
Step(
function() {
var group = this.group();
that.insertUTFGrids(grids, group());
that.insertGridKeys(grid_keys, group());
that.insertGridTiles(map, group());
},
callback
);
};
// Given an array of mappings of grid_id to key_name, insert
// them all into the `grid_key` table.
MBTiles.prototype.insertGridKeys = function(grid_keys, callback) {
var stmt = this.db.prepare('INSERT OR IGNORE INTO grid_key' +
' (grid_id, key_name) VALUES (?, ?)');
for (var i = 0; i < grid_keys.length; i++) {
stmt.run(
grid_keys[i].grid_id,
grid_keys[i].key_name
);
}
stmt.finalize(callback);
};
// Insert a single feature into the grid_data table,
// with the key/axis of `key`
MBTiles.prototype.insertGridData = function(data, key_name, callback) {
this.db.run(
'INSERT OR IGNORE INTO keymap (key_name, key_json) VALUES (?, ?)',
data[key_name],
JSON.stringify(data),
callback
);
};
// Insert a single tile into the mbtiles database.
//
// - @param {Object} tile tile object to be inserted.
// - @param {Function} callback
MBTiles.prototype.insertTile = function(tile, callback) {
this.db.run(
'INSERT INTO map (tile_id, zoom_level, tile_column, tile_row) VALUES (?, ?, ?, ?)',
tile.tile_id,
tile.zoom_level,
tile.tile_column,
tile.tile_row,
callback
);
};
// Insert a single tile into the mbtiles database.
//
// - @param {Object} tile tile object to be inserted.
// - @param {Function} callback
MBTiles.prototype.insertGridTiles = function(map, callback) {
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);
};
// Insert a single grid into the mbtiles database.
//
// - @param {Object} image object to be inserted.
// - @param {Function} callback
MBTiles.prototype.insertUTFGrids = function(grids, callback) {
var stmt = this.db.prepare('INSERT OR IGNORE INTO grid_utfgrid'
+ ' (grid_id, grid_utfgrid) VALUES (?, ?)');
var total = grids.length, ran = 0;
grids.forEach(function(grid) {
var buf = zlib.deflate(grid.grid_utfgrid);
stmt.run(grid.grid_id, buf);
if (++ran === total) stmt.finalize(callback);
});
};
// Insert a single image into the mbtiles database.
//
// - @param {Object} image object to be inserted.
// - @param {Function} callback
MBTiles.prototype.insertImage = function(image, callback) {
this.db.run(
'INSERT OR IGNORE INTO images (tile_id, tile_data) VALUES (?, ?)',
image.tile_id,
image.tile_data,
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(metadata, callback) {
var stmt = this.db.prepare('INSERT INTO metadata (name, value) VALUES (?, ?)');
for (var name in metadata) {
stmt.run(name, metadata[name]);
}
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.tile = function(x, y, z, callback) {
this.db.get('SELECT tile_data FROM tiles WHERE ' +
'zoom_level = ? AND tile_column = ? AND tile_row = ?',
z, x, y,
function(err, row) {
if (err) callback(err);
else if (!row || !row.tile_data) callback('Tile does not exist');
else callback(null, row.tile_data);
});
};
// Get grid data at a certain `x, y, z` coordinate, calling
// back with an error argument if the grid is not found.
MBTiles.prototype.grid_data = function(x, y, z, callback) {
this.db.all('SELECT key_name, key_json FROM grid_data WHERE ' +
'zoom_level = ? AND tile_column = ? AND tile_row = ?',
z, x, y,
function(err, rows) {
if (err) callback(err);
else if (!rows.length) callback('Grid data does not exist');
else callback(null, rows.reduce(function(memo, r) {
memo[r.key_name] = JSON.parse(r.key_json);
return memo;
}, {}));
});
};
// 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.grid = function(x, y, z, callback) {
this.db.get('SELECT grid FROM grids WHERE ' +
'zoom_level = ? AND tile_column = ? AND tile_row = ?',
z, x, y,
function(err, row) {
if (err) callback(err);
else if (!row || !row.grid) callback('Grid does not exist');
else callback(null, row.grid);
});
};
// Select a metadata value from the database.
//
// - @param {Function} callback
MBTiles.prototype.metadata = function(key, callback) {
this.db.get('SELECT value FROM metadata WHERE name = ?',
key,
function(err, row) {
if (err) callback(err);
else if (!row) callback('Key does not exist');
else callback(null, row.value);
});
};
module.exports = MBTiles;