Created
May 14, 2014 18:41
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| import os | |
| import shutil | |
| from bsddb.db import * | |
| DB_HOME = 'data' | |
| DB_FILENAME = 'queue.db' | |
| if os.path.isdir(DB_HOME): | |
| shutil.rmtree(DB_HOME) | |
| os.makedirs(DB_HOME) | |
| dbenv = DBEnv() | |
| dbenv.set_flags(DB_AUTO_COMMIT, 1) | |
| dbenv.open(DB_HOME, DB_CREATE|DB_INIT_MPOOL|DB_INIT_LOCK|DB_INIT_TXN|DB_REGISTER|DB_RECOVER) | |
| def open_db(): | |
| db = DB(dbenv) | |
| db.set_flags(DB_INORDER) | |
| db.set_re_len(768) | |
| db.set_pagesize(8192) | |
| db.set_q_extentsize(16 * 1024 * 1024 // 8192) | |
| db.open(DB_FILENAME, None, DB_QUEUE, DB_CREATE) | |
| return db | |
| def do_generate(db, count=256): | |
| data = 'x' * 768 | |
| for i in xrange(count): | |
| txn = dbenv.txn_begin() | |
| recid = db.append(data, txn) | |
| if i % 4 == 3: | |
| txn.abort() | |
| else: | |
| txn.commit() | |
| print 'Generated 0x%x' % (recid,) | |
| def do_consume(db): | |
| print 'Berkeley DB v%d.%d.%d' % version() | |
| while True: | |
| chunk = db.consume() | |
| if chunk is None: | |
| break | |
| print 'Consumed %r' % (chunk[0],) | |
| db = open_db() | |
| do_generate(db) | |
| do_consume(db) | |
| db.close() |
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