Initial commit of tilelive-mbtiles

This commit is contained in:
Young Hahn
2011-05-06 21:11:30 -04:00
commit 03d2d4eb47
4 changed files with 511 additions and 0 deletions

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index.js Normal file
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var MBTiles = require('./lib/mbtiles'),
zlib = require('zlib'),
Buffer = require('buffer').Buffer,
Step = require('step');
module.exports = {
MBTiles: MBTiles,
pool: function(datasource, options) {
return {
create: function(callback) {
var resource = new MBTiles(
datasource,
options,
function() { callback(resource); }
);
},
destroy: function(resource) {
resource.db.close(function() {});
}
}
},
serve: function(resource, options, callback) {
switch (options.format) {
case 'layer.json':
Step(
function() {
resource.metadata('formatter', this.parallel());
resource.metadata('legend', this.parallel());
},
function(err, f, l) {
var layer = {};
f && (layer.formatter = f);
l && (layer.legend = l);
callback(null, layer);
}
);
break;
case 'grid.json':
var grid;
Step(
function() {
resource.grid(options.x, options.y, options.z, this);
},
function(err, buf) {
if (err) throw err;
if (!Buffer.isBuffer(buf))
buf = new Buffer(buf, 'binary');
var inflated = zlib.inflate(buf);
this(null,inflated);
},
function(err, buf) {
if (err) throw err;
grid = buf.toString();
resource.grid_data(options.x, options.y, options.z, this);
},
function(err, gd) {
if (err) return callback(err);
// Manually append grid data as a string to the grid buffer.
// Ideally we would
//
// JSON.stringify(_.extend(JSON.parse(grid), { data: gd }))
//
// But calling JSON stringify will escape UTF8 characters of a
// high enough ordinal making the grid data unusable. Instead,
// manipulate the JSON string directly, popping the trailing }
// off and splicing the grid data in at the "data" key.
grid = grid.substr(0, grid.length - 1)
+ ', "data":'
+ JSON.stringify(gd)
+ '}';
callback(err, grid);
}
);
break;
default:
resource.tile(options.x, options.y, options.z, function(err, image) {
callback(err, [image, { 'Content-Type': 'image/png' }]);
});
break;
}
},
store: function(step, resource, data, callback) {
switch (step) {
case 'setup':
resource.setup(callback);
break;
case 'tiles':
resource.insertTiles(data, callback);
break;
case 'grids':
resource.insertGrids(data, callback);
break;
case 'finish':
callback();
break;
}
}
};

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lib/mbtiles.js Normal file
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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;

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lib/schema.sql Normal file
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-- MBTiles schema
CREATE TABLE IF NOT EXISTS map (
zoom_level INTEGER,
tile_column INTEGER,
tile_row INTEGER,
tile_id TEXT,
grid_id TEXT
);
CREATE TABLE IF NOT EXISTS grid_key (
grid_id TEXT,
key_name TEXT
);
CREATE TABLE IF NOT EXISTS keymap (
key_name TEXT,
key_json TEXT
);
CREATE TABLE IF NOT EXISTS grid_utfgrid (
grid_id TEXT,
grid_utfgrid BLOB
);
CREATE TABLE IF NOT EXISTS images (
tile_data blob,
tile_id text
);
CREATE TABLE IF NOT EXISTS metadata (
name text,
value text
);
CREATE UNIQUE INDEX IF NOT EXISTS map_index ON map (zoom_level, tile_column, tile_row);
CREATE UNIQUE INDEX IF NOT EXISTS grid_key_lookup ON grid_key (grid_id, key_name);
CREATE UNIQUE INDEX IF NOT EXISTS keymap_lookup ON keymap (key_name);
CREATE UNIQUE INDEX IF NOT EXISTS grid_utfgrid_lookup ON grid_utfgrid (grid_id);
CREATE UNIQUE INDEX IF NOT EXISTS images_id ON images (tile_id);
CREATE UNIQUE INDEX IF NOT EXISTS name ON metadata (name);
CREATE VIEW IF NOT EXISTS tiles AS
SELECT
map.zoom_level AS zoom_level,
map.tile_column AS tile_column,
map.tile_row AS tile_row,
images.tile_data AS tile_data
FROM map
JOIN images ON images.tile_id = map.tile_id;
CREATE VIEW IF NOT EXISTS grids AS
SELECT
map.zoom_level AS zoom_level,
map.tile_column AS tile_column,
map.tile_row AS tile_row,
grid_utfgrid.grid_utfgrid AS grid
FROM map
JOIN grid_utfgrid ON grid_utfgrid.grid_id = map.grid_id;
CREATE VIEW IF NOT EXISTS grid_data AS
SELECT
map.zoom_level AS zoom_level,
map.tile_column AS tile_column,
map.tile_row AS tile_row,
keymap.key_name AS key_name,
keymap.key_json AS key_json
FROM map
JOIN grid_key ON map.grid_id = grid_key.grid_id
JOIN keymap ON grid_key.key_name = keymap.key_name;

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package.json Normal file
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{
"name" : "tilelive-mbtiles",
"main" : "./index",
"description" : "mbtiles backend for tilelive",
"url" : "http://github.com/mapbox/tilelive-mbtiles",
"keywords" : ["map", "server", "mbtiles", "tms"],
"licenses" : [{
"type": "BSD"
}],
"repositories": [{
"type": "git",
"url": "http://github.com/mapbox/tilelive-mbtiles.git"
}],
"contributors": [
"Tom MacWright <tmcw>",
"Will White <willwhite>",
"Dane Springmeyer <springmeyer>",
"Young Hahn <yhahn>"
],
"dependencies": {
"sqlite3" : ">= 2.0.8 < 2.1.0",
"step" : ">= 0.0.4 < 0.1.0",
"underscore" : ">= 1.1.1 < 1.2.0",
"zlib" : ">= 1.0.3 < 1.1.0"
},
"engines": {
"node": ">= 0.2.6"
},
"version" : "0.0.1"
}