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Robustify geocoder indexing of legacy MBTiles sources.

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This commit is contained in:
Young Hahn
2014-01-21 23:55:30 -05:00
parent c2d71be2d7
commit 0ed1500ac1
2 changed files with 161 additions and 38 deletions
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153
lib/mbtiles.js
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@@ -588,21 +588,19 @@ MBTiles.prototype.getIndexableDocs = function(pointer, callback) {
pointer.offset = pointer.offset || 0;
pointer.nogrids = 'nogrids' in pointer ? pointer.nogrids : false;
// Converts MBTiles native TMS coords to ZXY.
function tms2zxy(zxys) {
return zxys.split(',').map(function(tms) {
var zxy = tms.split('/').map(function(v) { return parseInt(v, 10); });
zxy[2] = (1 << zxy[0]) - 1 - zxy[2];
return zxy.join('/');
});
}
// If 'carmen' option is passed in initial pointer, retrieve indexables from
// carmen table. This option can be used to access the previously indexed
// documents from an MBTiles database without having to know what search
// field was used in the past (see comment below).
if (pointer.table === 'carmen') {
return this._db.all('SELECT c.id AS id, c.text AS text, c.zxy, k.key_json FROM carmen c JOIN keymap k ON c.id = k.key_name LIMIT ? OFFSET ?', pointer.limit, pointer.offset, makedocs);
return this._db.all('SELECT c.id AS id, c.text AS text, c.zxy, k.key_json FROM carmen c JOIN keymap k ON c.id = k.key_name LIMIT ? OFFSET ?', pointer.limit, pointer.offset, function(err, rows) {
if (err) return callback(err);
this.geocoderMigrateDocs(rows, function(err, docs) {
if (err) return callback(err);
pointer.offset += pointer.limit;
return callback(null, docs, pointer);
});
}.bind(this));
}
// By default the keymap table contains all indexable documents.
@@ -616,32 +614,115 @@ MBTiles.prototype.getIndexableDocs = function(pointer, callback) {
sql = "SELECT k.key_name AS id, k.key_json, GROUP_CONCAT(zoom_level||'/'||tile_column ||'/'||tile_row,',') AS zxy FROM keymap k JOIN grid_key g ON k.key_name = g.key_name JOIN map m ON g.grid_id = m.grid_id WHERE m.zoom_level=? GROUP BY k.key_name LIMIT ? OFFSET ?;";
args = [info.maxzoom, pointer.limit, pointer.offset];
}
this._db.all(sql, args, makedocs);
this._db.all(sql, args, function(err, rows) {
if (err) return callback(err);
this.geocoderMigrateDocs(rows, function(err, docs) {
if (err) return callback(err);
pointer.offset += pointer.limit;
return callback(null, docs, pointer);
});
}.bind(this));
}.bind(this));
function makedocs(err, rows) {
if (err) return callback(err);
var docs = [];
for (var i = 0; i < rows.length; i++) {
var row = rows[i];
var doc = JSON.parse(row.key_json);
var text = row.text || doc.search || doc.name || '';
if (!('lon' in doc) || !('lat' in doc)) continue;
if (!text) continue;
doc._id = row.id;
doc._text = text;
doc._zxy = row.zxy ? tms2zxy(row.zxy) : [];
doc._center = [doc.lon, doc.lat];
if (doc.score) doc._score = parseFloat(doc.score);
if (doc.bounds) doc._bbox = doc.bounds.split(',').map(function(v) { return parseFloat(v) });
delete doc.lon;
delete doc.lat;
delete doc.score;
delete doc.bounds;
docs.push(doc);
}
pointer.offset += pointer.limit;
return callback(null, docs, pointer);
};
};
MBTiles.prototype.geocoderMigrateDocs = function(rows, callback) {
// Store docs state on callback.
callback.docs = callback.docs || [];
var docs = callback.docs;
var source = this;
// Done.
if (!rows.length) return callback(null, docs);
// Converts MBTiles native TMS coords to ZXY.
function tms2zxy(zxys) {
return zxys.split(',').map(function(tms) {
var zxy = tms.split('/').map(function(v) { return parseInt(v, 10); });
zxy[2] = (1 << zxy[0]) - 1 - zxy[2];
return zxy.join('/');
});
}
var row = rows.shift();
var doc = JSON.parse(row.key_json);
var text = row.text || doc.search || doc.name || '';
if ('zxy' in row && text) {
doc._id = parseInt(row.id,10).toString() === row.id ?
parseInt(row.id,10) :
parseInt(crypto.createHash('md5').update(row.id).digest('hex').substr(0,8), 16);
doc._text = text;
doc._zxy = row.zxy ? tms2zxy(row.zxy) : [];
if (doc.score) doc._score = parseFloat(doc.score);
if (doc.bounds) doc._bbox = doc.bounds.split(',').map(function(v) { return parseFloat(v) });
delete doc.score;
delete doc.bounds;
if ('lon' in doc && 'lat' in doc) {
doc._center = [ doc.lon, doc.lat ];
delete doc.lon;
delete doc.lat;
docs.push(doc);
source.geocoderMigrateDocs(rows, callback);
} else {
source.geocoderCentroid(row.id, doc._zxy, function(err, center) {
if (err) return callback(err);
doc._center = center;
docs.push(doc);
source.geocoderMigrateDocs(rows, callback);
});
}
} else {
source.geocoderMigrateDocs(rows, callback);
}
};
// Get the [lon,lat] of a feature given an array of xyz tiles.
// Looks up a point in the feature geometry using a point from a central grid.
MBTiles.prototype.geocoderCentroid = function(id, zxy, callback) {
var coords = [];
for (var i = 0; i < zxy.length; i++) {
var parts = zxy[i].split('/');
parts[0] = parts[0] | 0;
parts[1] = parts[1] | 0;
parts[2] = parts[2] | 0;
coords.push(parts);
}
coords.sort(function(a, b) {
if (a[1] < b[1]) return -1;
if (a[1] > b[1]) return 1;
if (a[2] < b[2]) return -1;
if (a[2] > b[2]) return 1;
return -1;
});
var mid = coords[Math.floor(coords.length * 0.5)];
this.getGrid(mid[0],mid[1],mid[2],function(err, grid) {
if (err) return callback(err);
if (!grid) return callback(new Error('Grid does not exist'));
// Convert id local index in utfgrid to charactercode.
var key = grid.keys.indexOf(id)
key += 32;
if (key >= 34) key++;
if (key >= 92) key++;
var chr = String.fromCharCode(key);
var xy = [];
for (var y = 0; y < grid.grid.length; y++) {
if (grid.grid[y].indexOf(chr) === -1) continue;
for (var x = 0; x < 64; x++) {
if (grid.grid[y][x] === chr) xy.push([x,y]);
}
}
xy.sort(function(a, b) {
if (a[0] < b[0]) return -1;
if (a[0] > b[0]) return 1;
if (a[1] < b[1]) return -1;
if (a[1] > b[1]) return 1;
return -1;
});
var cxy = xy[Math.floor(xy.length * 0.5)];
callback(null, sm.ll([
(256*mid[1]) + (cxy[0]*4),
(256*mid[2]) + (cxy[1]*4)
], mid[0]));
});
};