async def read_version(tx):
fdb_future = lib.fdb_transaction_get_read_version(tx.pointer)
aio_future = _loop.create_future()
handle = ffi.new_handle(aio_future)
lib.fdb_future_set_callback(fdb_future, _on_transaction_get_read_version,
handle)
out = await aio_future
return out
async def query(tx, key, other, *, limit=0, mode=STREAMING_MODE_ITERATOR):
key = key if isinstance(key, KeySelector) else gte(key)
other = other if isinstance(other, KeySelector) else gte(other)
if key.key < other.key:
begin = key
end = other
reverse = False
else:
begin = other
end = key
reverse = True
# the first read was fired off when the FDBRange was initialized
iteration = 1
snapshot = tx.snapshot
while True:
fdb_future = lib.fdb_transaction_get_range(
tx.pointer,
begin.key,
len(begin.key),
begin.or_equal,
begin.offset,
end.key,
len(end.key),
end.or_equal,
end.offset,
limit,
0,
mode,
iteration,
snapshot,
reverse,
)
aio_future = _loop.create_future()
handle = ffi.new_handle(aio_future)
lib.fdb_future_set_callback(fdb_future, on_transaction_get_range,
handle)
kvs, count, more = await aio_future
index = 0
if count == 0:
return
for kv in kvs:
yield kv
index += 1
if index == count:
if not more or limit == count:
return
iteration += 1
if limit > 0:
limit -= count
if reverse:
end = gte(kv[0])
else:
begin = gt(kv[0])
async def estimated_size_bytes(tx, begin, end):
fdb_future = lib.fdb_transaction_get_estimated_range_size_bytes(
tx.pointer, begin, len(begin), end, len(end))
aio_future = _loop.create_future()
handle = ffi.new_handle(aio_future)
lib.fdb_future_set_callback(fdb_future, _estimated_size_bytes_callback,
handle)
size = await aio_future
return size
async def get(tx, key):
assert isinstance(tx, Transaction)
assert isinstance(key, bytes)
fdb_future = lib.fdb_transaction_get(tx.pointer, key, len(key),
tx.snapshot)
aio_future = _loop.create_future()
handle = ffi.new_handle(aio_future)
lib.fdb_future_set_callback(fdb_future, _on_transaction_get, handle)
out = await aio_future
return out
async def transactional(db, func, *args, snapshot=False, **kwargs):
tx = _make_transaction(db, snapshot)
while True:
try:
out = await func(tx, *args, **kwargs)
await _commit(tx)
except FoundException as exc:
fdb_future = lib.fdb_transaction_on_error(tx.pointer, exc.code)
aio_future = _loop.create_future()
handle = ffi.new_handle(aio_future)
lib.fdb_future_set_callback(fdb_future, _on_error_callback, handle)
await aio_future # may raise an exception
else:
return out
async def _commit(tx):
fdb_future = lib.fdb_transaction_commit(tx.pointer)
aio_future = _loop.create_future()
handle = ffi.new_handle(aio_future)
lib.fdb_future_set_callback(fdb_future, on_transaction_commit, handle)
await aio_future