dump1090/tools/vrs-basicaircraft-to-json.py
2015-02-25 13:16:54 +00:00

88 lines
3.1 KiB
Python
Executable file

#!/usr/bin/env python2
#
# Converts a Virtual Radar Server BasicAircraftLookup.sqb database
# into a bunch of json files suitable for use by the webmap
#
import sqlite3, json
from contextlib import closing
def extract(dbfile, todir, blocklimit, debug):
ac_count = 0
block_count = 0
blocks = {}
for i in xrange(16):
blocks['%01X' % i] = {}
print 'Reading', dbfile
with closing(sqlite3.connect(dbfile)) as db:
with closing(db.execute('SELECT a.Icao, a.Registration, m.Icao FROM Aircraft a, Model m WHERE a.ModelID = m.ModelID')) as c:
for icao24, reg, icaotype in c:
bkey = icao24[0:1].upper()
dkey = icao24[1:].upper()
blocks[bkey][dkey] = {}
if reg: blocks[bkey][dkey]['r'] = reg
if icaotype: blocks[bkey][dkey]['t'] = icaotype
ac_count += 1
print 'Read', ac_count, 'aircraft'
queue = list(blocks.keys())
while queue:
bkey = queue[0]
del queue[0]
blockdata = blocks[bkey]
if len(blockdata) > blocklimit:
if debug: print 'Splitting block', bkey, 'with', len(blockdata), 'entries..',
# split all children out
children = {}
for dkey in blockdata.keys():
new_bkey = bkey + dkey[0]
new_dkey = dkey[1:]
if new_bkey not in children: children[new_bkey] = {}
children[new_bkey][new_dkey] = blockdata[dkey]
# look for small children we can retain in the parent, to
# reduce the total number of files needed. This reduces the
# number of blocks needed from 150 to 61
blockdata = {}
children = list(children.items())
children.sort(lambda x,y: cmp(len(x[1]), len(y[1])))
retained = 1
while len(children[0][1]) + retained < blocklimit:
# move this child back to the parent
c_bkey, c_entries = children[0]
for c_dkey, entry in c_entries.items():
blockdata[c_bkey[-1] + c_dkey] = entry
retained += 1
del children[0]
if debug: print len(children), 'children created,', len(blockdata), 'entries retained in parent'
blockdata['children'] = sorted([x[0] for x in children])
blocks[bkey] = blockdata
for c_bkey, c_entries in children:
blocks[c_bkey] = c_entries
queue.append(c_bkey)
path = todir + '/' + bkey + '.json'
if debug: print 'Writing', len(blockdata), 'entries to', path
block_count += 1
with closing(open(path, 'w')) as f:
json.dump(obj=blockdata, fp=f, check_circular=False, separators=(',',':'), sort_keys=True)
print 'Wrote', block_count, 'blocks'
if __name__ == '__main__':
import sys
if len(sys.argv) < 3:
print 'Syntax: %s <path to BasicAircraftLookup.sqb> <path to DB dir>' % sys.argv[0]
sys.exit(1)
else:
extract(sys.argv[1], sys.argv[2], 1000, False)
sys.exit(0)