ray/rllib/offline/dataset_reader.py

277 lines
11 KiB
Python

import logging
import math
from pathlib import Path
import re
from typing import List, Tuple, Optional
import zipfile
import ray.data
from ray.rllib.offline.input_reader import InputReader
from ray.rllib.offline.io_context import IOContext
from ray.rllib.offline.json_reader import from_json_data, postprocess_actions
from ray.rllib.policy.sample_batch import concat_samples, SampleBatch, DEFAULT_POLICY_ID
from ray.rllib.utils.annotations import override, PublicAPI
from ray.rllib.utils.typing import SampleBatchType, AlgorithmConfigDict
logger = logging.getLogger(__name__)
DEFAULT_NUM_CPUS_PER_TASK = 0.5
# TODO: @avnishn what is the use of this function anymore?
def _get_resource_bundles(config: AlgorithmConfigDict):
input_config = config.get("input_config", {})
parallelism = input_config.get("parallelism", config.get("num_workers", 1))
cpus_per_task = input_config.get(
"num_cpus_per_read_task", DEFAULT_NUM_CPUS_PER_TASK
)
return [{"CPU": math.ceil(parallelism * cpus_per_task)}]
def _unzip_this_path(fpath: Path, extract_path: str):
with zipfile.ZipFile(str(fpath), "r") as zip_ref:
zip_ref.extractall(extract_path)
def _unzip_if_needed(paths: List[str], format: str):
"""If a path in paths is a zip file, unzip it and use path of the unzipped file"""
ret_paths = []
for path in paths:
if re.search("\\.zip$", str(path)):
# TODO: We need to add unzip support for s3
if str(path).startswith("s3://"):
raise ValueError(
"unzip_if_needed currently does not support remote paths from s3"
)
extract_path = "./"
try:
_unzip_this_path(str(path), extract_path)
except FileNotFoundError:
# intrepreted as a relative path to rllib folder
try:
# TODO: remove this later when we replace all tests with s3 paths
_unzip_this_path(Path(__file__).parent.parent / path, extract_path)
except FileNotFoundError:
raise FileNotFoundError(f"File not found: {path}")
unzipped_path = str(
Path(extract_path).absolute() / f"{Path(path).stem}.{format}"
)
ret_paths.append(unzipped_path)
else:
# TODO: We can get rid of this logic when we replace all tests with s3 paths
if str(path).startswith("s3://"):
ret_paths.append(path)
else:
if not Path(path).exists():
relative_path = str(Path(__file__).parent.parent / path)
if not Path(relative_path).exists():
raise FileNotFoundError(f"File not found: {path}")
path = relative_path
ret_paths.append(path)
return ret_paths
@PublicAPI
def get_dataset_and_shards(
config: AlgorithmConfigDict, num_workers: int = 0
) -> Tuple[ray.data.dataset.Dataset, List[ray.data.dataset.Dataset]]:
"""Returns a dataset and a list of shards.
This function uses algorithm configs to create a dataset and a list of shards.
The following config keys are used to create the dataset:
input: The input type should be "dataset".
input_config: A dict containing the following key and values:
`format`: str, speciifies the format of the input data. This will be the
format that ray dataset supports. See ray.data.dataset.Dataset for
supported formats. Only "parquet" or "json" are supported for now.
`paths`: str, a single string or a list of strings. Each string is a path
to a file or a directory holding the dataset. It can be either a local path
or a remote path (e.g. to an s3 bucket).
`loader_fn`: Callable[None, ray.data.dataset.Dataset], Instead of
specifying paths and format, you can specify a function to load the dataset.
`parallelism`: int, The number of tasks to use for loading the dataset.
If not specified, it will be set to the number of workers.
`num_cpus_per_read_task`: float, The number of CPUs to use for each read
task. If not specified, it will be set to 0.5.
Args:
config: The config dict for the algorithm.
num_workers: The number of shards to create for remote workers.
Returns:
dataset: The dataset object.
shards: A list of dataset shards. For num_workers > 0 the first returned
shared would be a dummy None shard for local_worker.
"""
# check input and input config keys
assert config["input"] == "dataset", (
f"Must specify input as dataset if"
f" calling `get_dataset_and_shards`. Got {config['input']}"
)
assert (
"input_config" in config
), "Must specify input_config dict if using Dataset input."
# check input config format
input_config = config["input_config"]
format = input_config.get("format")
supported_fmts = ["json", "parquet"]
if format is not None and format not in supported_fmts:
raise ValueError(
f"Unsupported format {format}. Supported formats are {supported_fmts}"
)
# check paths and loader_fn since only one of them is required.
paths = input_config.get("paths")
loader_fn = input_config.get("loader_fn")
if loader_fn and (format or paths):
raise ValueError(
"When using a `loader_fn`, you cannot specify a `format` or `path`."
)
# check if at least loader_fn or format + path is specified.
if not (format and paths) and not loader_fn:
raise ValueError(
f"If using a loader_fn: {loader_fn} that constructs a dataset, "
"neither format: {format} and paths: {paths} must not be specified. If "
"format and paths are specified, a loader_fn must not be specified."
)
# check paths to be a str or list[str] if not None
if paths is not None:
if isinstance(paths, str):
paths = [paths]
elif isinstance(paths, list):
assert isinstance(paths[0], str), "Paths must be a list of path strings."
else:
raise ValueError("Paths must be a path string or a list of path strings.")
paths = _unzip_if_needed(paths, format)
parallelism = input_config.get("parallelism", num_workers or 1)
cpus_per_task = input_config.get(
"num_cpus_per_read_task", DEFAULT_NUM_CPUS_PER_TASK
)
if loader_fn:
dataset = loader_fn()
elif format == "json":
dataset = ray.data.read_json(
paths, parallelism=parallelism, ray_remote_args={"num_cpus": cpus_per_task}
)
elif format == "parquet":
dataset = ray.data.read_parquet(
paths, parallelism=parallelism, ray_remote_args={"num_cpus": cpus_per_task}
)
else:
raise ValueError("Un-supported Ray dataset format: ", format)
# Local worker will be responsible for sampling.
if num_workers == 0:
# Dataset is the only shard we need.
return dataset, [dataset]
# Remote workers are responsible for sampling:
else:
# Each remote worker gets 1 shard.
remote_shards = dataset.repartition(
num_blocks=num_workers, shuffle=False
).split(num_workers)
# The first None shard is for the local worker, which
# shouldn't be doing rollout work anyways.
return dataset, [None] + remote_shards
@PublicAPI
class DatasetReader(InputReader):
"""Reader object that loads data from Ray Dataset.
Examples:
config = {
"input": "dataset",
"input_config": {
"format": "json",
# A single data file, a directory, or anything
# that ray.data.dataset recognizes.
"paths": "/tmp/sample_batches/",
# By default, parallelism=num_workers.
"parallelism": 3,
# Dataset allocates 0.5 CPU for each reader by default.
# Adjust this value based on the size of your offline dataset.
"num_cpus_per_read_task": 0.5,
}
}
"""
@PublicAPI
def __init__(self, ds: ray.data.Dataset, ioctx: Optional[IOContext] = None):
"""Initializes a DatasetReader instance.
Args:
ds: Ray dataset to sample from.
"""
self._ioctx = ioctx or IOContext()
self._default_policy = self.policy_map = None
self._dataset = ds
self.count = None if not self._dataset else self._dataset.count()
# do this to disable the ray data stdout logging
ray.data.set_progress_bars(enabled=False)
# the number of steps to return per call to next()
self.batch_size = self._ioctx.config.get("train_batch_size", 1)
num_workers = self._ioctx.config.get("num_workers", 0)
seed = self._ioctx.config.get("seed", None)
if num_workers:
self.batch_size = max(math.ceil(self.batch_size / num_workers), 1)
# We allow the creation of a non-functioning None DatasetReader.
# It's useful for example for a non-rollout local worker.
if ds:
if self._ioctx.worker is not None:
self._policy_map = self._ioctx.worker.policy_map
self._default_policy = self._policy_map.get(DEFAULT_POLICY_ID)
self._dataset.random_shuffle(seed=seed)
print(
f"DatasetReader {self._ioctx.worker_index} has {ds.count()}, samples."
)
# TODO: @avnishn make this call seeded.
# calling random_shuffle_each_window shuffles the dataset after
# each time the whole dataset has been read.
self._iter = self._dataset.repeat().random_shuffle_each_window().iter_rows()
else:
self._iter = None
@override(InputReader)
def next(self) -> SampleBatchType:
# next() should not get called on None DatasetReader.
assert self._iter is not None
ret = []
count = 0
while count < self.batch_size:
d = next(self._iter).as_pydict()
# Columns like obs are compressed when written by DatasetWriter.
d = from_json_data(d, self._ioctx.worker)
d = postprocess_actions(d, self._ioctx)
count += d.count
ret.append(self._postprocess_if_needed(d))
ret = concat_samples(ret)
return ret
def _postprocess_if_needed(self, batch: SampleBatchType) -> SampleBatchType:
if not self._ioctx.config.get("postprocess_inputs"):
return batch
if isinstance(batch, SampleBatch):
out = []
for sub_batch in batch.split_by_episode():
if self._default_policy is not None:
out.append(self._default_policy.postprocess_trajectory(sub_batch))
else:
out.append(sub_batch)
return concat_samples(out)
else:
# TODO(ekl) this is trickier since the alignments between agent
# trajectories in the episode are not available any more.
raise NotImplementedError(
"Postprocessing of multi-agent data not implemented yet."
)