def __init__(self,
py_client: types.ReverbClient,
table_name: Text,
max_sequence_length: int,
priority: Union[float, int] = 1,
bypass_partial_episodes: bool = False):
"""Creates an instance of the ReverbAddEpisodeObserver.
**Note**: This observer is designed to work with py_drivers only, and does
not support batches.
TODO(b/158865335): Optionally truncate long episodes and add to buffer.
Args:
py_client: Python client for the reverb replay server.
table_name: The table name where samples will be written to.
max_sequence_length: An integer. `max_sequence_length` used
to write to the replay buffer tables. This defines the size of the
internal buffer controlling the `upper` limit of the number of timesteps
which can be referenced in a single prioritized item. Note that this is
the maximum number of trajectories across all the cached episodes that
you are writing into the replay buffer (e.g. `number_of_episodes`).
`max_sequence_length` is not a limit of how many timesteps or
items that can be inserted into the replay buffer. Note that,
since `max_sequence_length` controls the size of internal buffer, it is
suggested not to set this value to a very large number. If the number of
steps in an episode is more than `max_sequence_length`, only items up to
`max_sequence_length` is written into the table.
priority: Initial priority for the table.
bypass_partial_episodes: If `False` (default) and an episode length is
greater than `max_sequence_length`, a `ValueError` is raised. If set to
`True`, the episodes with length more than `max_sequence_length` do not
cause a `ValueError`. These episodes are bypassed (will NOT be written
into the replay buffer) and an error message is shown to the user.
Note that in this case (`bypass_partial_episodes=True`), the steps for
episodes with length more than `max_sequence_length` are wasted and
thrown away. This decision is made to guarantee that the replay buffer
always has FULL episodes. Note that, `max_sequence_length` is just an
upper bound.
Raises:
ValueError: If `table_name` is not a string.
ValueError: If `priority` is not numeric.
ValueError: If max_sequence_length is not positive.
"""
if max_sequence_length <= 0:
raise ValueError(
"`max_sequence_length` must be an integer greater equal one.")
self._table_name = table_name
self._max_sequence_length = max_sequence_length
self._priority = priority
self._py_client = py_client
self._writer = py_client.writer(
max_sequence_length=self._max_sequence_length)
self._cached_steps = 0
self._bypass_partial_episodes = bypass_partial_episodes
self._overflow_episode = False
def __init__(self,
py_client: types.ReverbClient,
table_name: Union[Text, Sequence[Text]],
sequence_length: int,
stride_length: int = 1,
priority: Union[float, int] = 1,
pad_end_of_episodes: bool = False):
"""Creates an instance of the ReverbAddTrajectoryObserver.
If multiple table_names and sequence lengths are provided data will only be
stored once but be available for sampling with multiple sequence lengths
from the respective reverb tables.
**Note**: This observer is designed to work with py_drivers only, and does
not support batches.
Args:
py_client: Python client for the reverb replay server.
table_name: The table name(s) where samples will be written to.
sequence_length: The sequence_length used to write to the given table.
stride_length: The integer stride for the sliding window for overlapping
sequences. The default value of `1` creates an item for every window.
Using `L = sequence_length` this means items are created for times `{0,
1, .., L-1}, {1, 2, .., L}, ...`. In contrast, `stride_length = L` will
create an item only for disjoint windows `{0, 1, ..., L-1}, {L, ..., 2 *
L - 1}, ...`.
priority: Initial priority for new samples in the RB.
pad_end_of_episodes: At the end of an episode, the cache is dropped by
default. When `pad_end_of_episodes = True`, the cache gets padded with
boundary steps (last->first) with `0` values everywhere and padded items
of `sequence_length` are written to Reverb. The last padded item starts
with a boundary step from the episode. This ensures that the last few
steps are not less likely to get sampled compared to middle steps, this
is most useful for environments that have useful rewards at the end of
episodes. Note: because we do not pad at the beginning of an episode,
for `sequence_length = N > 1` scenarios, the first `N-1` steps in an
episode are sampled less frequently than all other steps. This generally
does not impact training performance. However, if you have an
environment where the only meaningful rewards are at the beginning of
the episodes, you may consider filing a feature request to support
padding in the front as well.
"""
if isinstance(table_name, Text):
self._table_names = [table_name]
else:
self._table_names = table_name
self._sequence_length = sequence_length
self._stride_length = stride_length
self._priority = priority
self._pad_end_of_episodes = pad_end_of_episodes
self._py_client = py_client
# TODO(b/153700282): Use a single writer with max_sequence_length=max(...)
# once Reverb Dataset with emit_timesteps=True returns properly shaped
# sequences.
self._writer = py_client.writer(max_sequence_length=sequence_length)
self._cached_steps = 0
self._last_trajectory = None
def __init__(self,
py_client: types.ReverbClient,
table_name: Text,
sequence_length: int,
stride_length: int = 1,
priority: Union[float, int] = 1):
"""Creates an instance of the ReverbAddTrajectoryObserver.
If multiple table_names and sequence lengths are provided data will only be
stored once but be available for sampling with multiple sequence lengths
from the respective reverb tables.
**Note**: This observer is designed to work with py_drivers only, and does
not support batches.
Args:
py_client: Python client for the reverb replay server.
table_name: The table name where samples will be written to.
sequence_length: The sequence_length used to write
to the given table.
stride_length: The integer stride for the sliding window for overlapping
sequences. The default value of `1` creates an item for every
window. Using `L = sequence_length` this means items are created for
times `{0, 1, .., L-1}, {1, 2, .., L}, ...`. In contrast,
`stride_length = L` will create an item only for disjoint windows
`{0, 1, ..., L-1}, {L, ..., 2 * L - 1}, ...`.
priority: Initial priority for new samples in the RB.
Raises:
ValueError: If table_names or sequence_lengths are not lists or their
lengths are not equal.
"""
self._table_name = table_name
self._sequence_length = sequence_length
self._stride_length = stride_length
self._priority = priority
self._py_client = py_client
# TODO(b/153700282): Use a single writer with max_sequence_length=max(...)
# once Reverb Dataset with emit_timesteps=True returns properly shaped
# sequences.
self._writer = py_client.writer(max_sequence_length=sequence_length)
self._cached_steps = 0
def __init__(self,
py_client: types.ReverbClient,
table_name: Union[Text, Sequence[Text]],
sequence_length: int,
stride_length: int = 1,
priority: Union[float, int] = 1,
pad_end_of_episodes: bool = False,
tile_end_of_episodes: bool = False):
"""Creates an instance of the ReverbAddTrajectoryObserver.
If multiple table_names and sequence lengths are provided data will only be
stored once but be available for sampling with multiple sequence lengths
from the respective reverb tables.
**Note**: This observer is designed to work with py_drivers only, and does
not support batches.
Args:
py_client: Python client for the reverb replay server.
table_name: The table name(s) where samples will be written to.
sequence_length: The sequence_length used to write to the given table.
stride_length: The integer stride for the sliding window for overlapping
sequences. The default value of `1` creates an item for every window.
Using `L = sequence_length` this means items are created for times `{0,
1, .., L-1}, {1, 2, .., L}, ...`. In contrast, `stride_length = L` will
create an item only for disjoint windows `{0, 1, ..., L-1}, {L, ..., 2 *
L - 1}, ...`.
priority: Initial priority for new samples in the RB.
pad_end_of_episodes: At the end of an episode, the cache is dropped by
default. When `pad_end_of_episodes = True`, the cache gets padded with
boundary steps (last->first) with `0` values everywhere and padded items
of `sequence_length` are written to Reverb.
tile_end_of_episodes: If `pad_end_of_episodes` is True then, the last
padded item starts with a boundary step from the episode.
When this option is True the following items will be generated:
F, M, L, P
M, L, P, P
L, P, P, P
If False, only a single one will be generated:
F, M, L, P
For training recurrent models on environments where required information
is only available at the start of the episode it is useful to set
`tile_end_of_episodes=False` and the `sequence_length` to be the length
of the longest episode.
Raises:
ValueError: If `tile_end_of_episodes` is set without
`pad_end_of_episodes`.
"""
if isinstance(table_name, Text):
self._table_names = [table_name]
else:
self._table_names = table_name
self._sequence_length = sequence_length
self._stride_length = stride_length
self._priority = priority
self._pad_end_of_episodes = pad_end_of_episodes
self._tile_end_of_episodes = tile_end_of_episodes
if tile_end_of_episodes and not pad_end_of_episodes:
raise ValueError("Must set `pad_end_of_episodes=True` when using "
"`tile_end_of_episodes`")
self._py_client = py_client
# TODO(b/153700282): Use a single writer with max_sequence_length=max(...)
# once Reverb Dataset with emit_timesteps=True returns properly shaped
# sequences.
self._writer = py_client.writer(max_sequence_length=sequence_length)
self._cached_steps = 0
self._last_trajectory = None
