Roman Shapovalov d2119c285f Serialising dynamic arrays in SQL; read-only SQLite connection in SQL Dataset
Summary:
1. We may need to store arrays of unknown shape in the database. It implements and tests serialisation.

2. Previously, when an inexisting metadata file was passed to SqlIndexDataset, it would try to open it and create an empty file, then crash. We now open the file in a read-only mode, so the error message is more intuitive. Note that the implementation is SQLite specific.

Reviewed By: bottler

Differential Revision: D46047857

fbshipit-source-id: 3064ae4f8122b4fc24ad3d6ab696572ebe8d0c26
2023-05-22 02:24:49 -07:00

742 lines
29 KiB
Python
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree.
import hashlib
import json
import logging
import os
from dataclasses import dataclass
from typing import (
Any,
ClassVar,
Dict,
Iterable,
Iterator,
List,
Optional,
Sequence,
Tuple,
Type,
Union,
)
import numpy as np
import pandas as pd
import sqlalchemy as sa
import torch
from pytorch3d.implicitron.dataset.dataset_base import DatasetBase
from pytorch3d.implicitron.dataset.frame_data import ( # noqa
FrameData,
FrameDataBuilder,
FrameDataBuilderBase,
)
from pytorch3d.implicitron.tools.config import (
registry,
ReplaceableBase,
run_auto_creation,
)
from sqlalchemy.orm import Session
from .orm_types import SqlFrameAnnotation, SqlSequenceAnnotation
logger = logging.getLogger(__name__)
_SET_LISTS_TABLE: str = "set_lists"
@registry.register
class SqlIndexDataset(DatasetBase, ReplaceableBase): # pyre-ignore
"""
A dataset with annotations stored as SQLite tables. This is an index-based dataset.
The length is returned after all sequence and frame filters are applied (see param
definitions below). Indices can either be ordinal in [0, len), or pairs of
(sequence_name, frame_number); with the performance of `dataset[i]` and
`dataset[sequence_name, frame_number]` being same. A faster way to get metadata only
(without blobs) is `dataset.meta[idx]` indexing; it requires box_crop==False.
With ordinal indexing, the sequences are NOT guaranteed to span contiguous index
ranges, and frame numbers are NOT guaranteed to be increasing within a sequence.
Sequence-aware batch samplers have to use `sequence_[frames|indices]_in_order`
iterators, which are efficient.
This functionality requires SQLAlchemy 2.0 or later.
Metadata-related args:
sqlite_metadata_file: A SQLite file containing frame and sequence annotation
tables (mapping to SqlFrameAnnotation and SqlSequenceAnnotation,
respectively).
dataset_root: A root directory to look for images, masks, etc. It can be
alternatively set in `frame_data_builder` args, but this takes precedence.
subset_lists_file: A JSON/sqlite file containing the lists of frames
corresponding to different subsets (e.g. train/val/test) of the dataset;
format: {subset: [(sequence_name, frame_id, file_path)]}. All entries
must be present in frame_annotation metadata table.
path_manager: a facade for non-POSIX filesystems.
subsets: Restrict frames/sequences only to the given list of subsets
as defined in subset_lists_file (see above). Applied before all other
filters.
remove_empty_masks: Removes the frames with no active foreground pixels
in the segmentation mask (needs frame_annotation.mask.mass to be set;
null values are retained).
pick_frames_sql_clause: SQL WHERE clause to constrain frame annotations
NOTE: This is a potential security risk! The string is passed to the SQL
engine verbatim. Dont expose it to end users of your application!
pick_categories: Restrict the dataset to the given list of categories.
pick_sequences: A Sequence of sequence names to restrict the dataset to.
exclude_sequences: A Sequence of the names of the sequences to exclude.
limit_sequences_to: Limit the dataset to the first `limit_sequences_to`
sequences (after other sequence filters have been applied but before
frame-based filters).
limit_to: Limit the dataset to the first #limit_to frames (after other
filters have been applied, except n_frames_per_sequence).
n_frames_per_sequence: If > 0, randomly samples `n_frames_per_sequence`
frames in each sequences uniformly without replacement if it has
more frames than that; applied after other frame-level filters.
seed: The seed of the random generator sampling `n_frames_per_sequence`
random frames per sequence.
"""
frame_annotations_type: ClassVar[Type[SqlFrameAnnotation]] = SqlFrameAnnotation
sqlite_metadata_file: str = ""
dataset_root: Optional[str] = None
subset_lists_file: str = ""
eval_batches_file: Optional[str] = None
path_manager: Any = None
subsets: Optional[List[str]] = None
remove_empty_masks: bool = True
pick_frames_sql_clause: Optional[str] = None
pick_categories: Tuple[str, ...] = ()
pick_sequences: Tuple[str, ...] = ()
exclude_sequences: Tuple[str, ...] = ()
limit_sequences_to: int = 0
limit_to: int = 0
n_frames_per_sequence: int = -1
seed: int = 0
remove_empty_masks_poll_whole_table_threshold: int = 300_000
# we set it manually in the constructor
# _index: pd.DataFrame = field(init=False)
frame_data_builder: FrameDataBuilderBase
frame_data_builder_class_type: str = "FrameDataBuilder"
def __post_init__(self) -> None:
if sa.__version__ < "2.0":
raise ImportError("This class requires SQL Alchemy 2.0 or later")
if not self.sqlite_metadata_file:
raise ValueError("sqlite_metadata_file must be set")
if self.dataset_root:
frame_builder_type = self.frame_data_builder_class_type
getattr(self, f"frame_data_builder_{frame_builder_type}_args")[
"dataset_root"
] = self.dataset_root
run_auto_creation(self)
self.frame_data_builder.path_manager = self.path_manager
# pyre-ignore # NOTE: sqlite-specific args (read-only mode).
self._sql_engine = sa.create_engine(
f"sqlite:///file:{self.sqlite_metadata_file}?mode=ro&uri=true"
)
sequences = self._get_filtered_sequences_if_any()
if self.subsets:
index = self._build_index_from_subset_lists(sequences)
else:
# TODO: if self.subset_lists_file and not self.subsets, it might be faster to
# still use the concatenated lists, assuming they cover the whole dataset
index = self._build_index_from_db(sequences)
if self.n_frames_per_sequence >= 0:
index = self._stratified_sample_index(index)
if len(index) == 0:
raise ValueError(f"There are no frames in the subsets: {self.subsets}!")
self._index = index.set_index(["sequence_name", "frame_number"]) # pyre-ignore
self.eval_batches = None # pyre-ignore
if self.eval_batches_file:
self.eval_batches = self._load_filter_eval_batches()
logger.info(str(self))
def __len__(self) -> int:
# pyre-ignore[16]
return len(self._index)
def __getitem__(self, frame_idx: Union[int, Tuple[str, int]]) -> FrameData:
"""
Fetches FrameData by either iloc in the index or by (sequence, frame_no) pair
"""
return self._get_item(frame_idx, True)
@property
def meta(self):
"""
Allows accessing metadata only without loading blobs using `dataset.meta[idx]`.
Requires box_crop==False, since in that case, cameras cannot be adjusted
without loading masks.
Returns:
FrameData objects with blob fields like `image_rgb` set to None.
Raises:
ValueError if dataset.box_crop is set.
"""
return SqlIndexDataset._MetadataAccessor(self)
@dataclass
class _MetadataAccessor:
dataset: "SqlIndexDataset"
def __getitem__(self, frame_idx: Union[int, Tuple[str, int]]) -> FrameData:
return self.dataset._get_item(frame_idx, False)
def _get_item(
self, frame_idx: Union[int, Tuple[str, int]], load_blobs: bool = True
) -> FrameData:
if isinstance(frame_idx, int):
if frame_idx >= len(self._index):
raise IndexError(f"index {frame_idx} out of range {len(self._index)}")
seq, frame = self._index.index[frame_idx]
else:
seq, frame, *rest = frame_idx
if isinstance(frame, torch.LongTensor):
frame = frame.item()
if (seq, frame) not in self._index.index:
raise IndexError(
f"Sequence-frame index {frame_idx} not found; was it filtered out?"
)
if rest and rest[0] != self._index.loc[(seq, frame), "_image_path"]:
raise IndexError(f"Non-matching image path in {frame_idx}.")
stmt = sa.select(self.frame_annotations_type).where(
self.frame_annotations_type.sequence_name == seq,
self.frame_annotations_type.frame_number
== int(frame), # cast from np.int64
)
seq_stmt = sa.select(SqlSequenceAnnotation).where(
SqlSequenceAnnotation.sequence_name == seq
)
with Session(self._sql_engine) as session:
entry = session.scalars(stmt).one()
seq_metadata = session.scalars(seq_stmt).one()
assert entry.image.path == self._index.loc[(seq, frame), "_image_path"]
frame_data = self.frame_data_builder.build(
entry, seq_metadata, load_blobs=load_blobs
)
# The rest of the fields are optional
frame_data.frame_type = self._get_frame_type(entry)
return frame_data
def __str__(self) -> str:
# pyre-ignore[16]
return f"SqlIndexDataset #frames={len(self._index)}"
def sequence_names(self) -> Iterable[str]:
"""Returns an iterator over sequence names in the dataset."""
return self._index.index.unique("sequence_name")
# override
def category_to_sequence_names(self) -> Dict[str, List[str]]:
stmt = sa.select(
SqlSequenceAnnotation.category, SqlSequenceAnnotation.sequence_name
).where( # we limit results to sequences that have frames after all filters
SqlSequenceAnnotation.sequence_name.in_(self.sequence_names())
)
with self._sql_engine.connect() as connection:
cat_to_seqs = pd.read_sql(stmt, connection)
return cat_to_seqs.groupby("category")["sequence_name"].apply(list).to_dict()
# override
def get_frame_numbers_and_timestamps(
self, idxs: Sequence[int], subset_filter: Optional[Sequence[str]] = None
) -> List[Tuple[int, float]]:
"""
Implements the DatasetBase method.
NOTE: Avoid this function as there are more efficient alternatives such as
querying `dataset[idx]` directly or getting all sequence frames with
`sequence_[frames|indices]_in_order`.
Return the index and timestamp in their videos of the frames whose
indices are given in `idxs`. They need to belong to the same sequence!
If timestamps are absent, they are replaced with zeros.
This is used for letting SceneBatchSampler identify consecutive
frames.
Args:
idxs: a sequence int frame index in the dataset (it can be a slice)
subset_filter: must remain None
Returns:
list of tuples of
- frame index in video
- timestamp of frame in video, coalesced with 0s
Raises:
ValueError if idxs belong to more than one sequence.
"""
if subset_filter is not None:
raise NotImplementedError(
"Subset filters are not supported in SQL Dataset. "
"We encourage creating a dataset per subset."
)
index_slice, _ = self._get_frame_no_coalesced_ts_by_row_indices(idxs)
# alternatively, we can use `.values.tolist()`, which may be faster
# but returns a list of lists
return list(index_slice.itertuples())
# override
def sequence_frames_in_order(
self, seq_name: str, subset_filter: Optional[Sequence[str]] = None
) -> Iterator[Tuple[float, int, int]]:
"""
Overrides the default DatasetBase implementation (we dont use `_seq_to_idx`).
Returns an iterator over the frame indices in a given sequence.
We attempt to first sort by timestamp (if they are available),
then by frame number.
Args:
seq_name: the name of the sequence.
subset_filter: subset names to filter to
Returns:
an iterator over triplets `(timestamp, frame_no, dataset_idx)`,
where `frame_no` is the index within the sequence, and
`dataset_idx` is the index within the dataset.
`None` timestamps are replaced with 0s.
"""
# TODO: implement sort_timestamp_first? (which would matter if the orders
# of frame numbers and timestamps are different)
rows = self._index.index.get_loc(seq_name)
if isinstance(rows, slice):
assert rows.stop is not None, "Unexpected result from pandas"
rows = range(rows.start or 0, rows.stop, rows.step or 1)
else:
rows = np.where(rows)[0]
index_slice, idx = self._get_frame_no_coalesced_ts_by_row_indices(
rows, seq_name, subset_filter
)
index_slice["idx"] = idx
yield from index_slice.itertuples(index=False)
# override
def get_eval_batches(self) -> Optional[List[Any]]:
"""
This class does not support eval batches with ordinal indices. You can pass
eval_batches as a batch_sampler to a data_loader since the dataset supports
`dataset[seq_name, frame_no]` indexing.
"""
return self.eval_batches
# override
def join(self, other_datasets: Iterable[DatasetBase]) -> None:
raise ValueError("Not supported! Preprocess the data by merging them instead.")
# override
@property
def frame_data_type(self) -> Type[FrameData]:
return self.frame_data_builder.frame_data_type
def is_filtered(self) -> bool:
"""
Returns `True` in case the dataset has been filtered and thus some frame
annotations stored on the disk might be missing in the dataset object.
Does not account for subsets.
Returns:
is_filtered: `True` if the dataset has been filtered, else `False`.
"""
return (
self.remove_empty_masks
or self.limit_to > 0
or self.limit_sequences_to > 0
or len(self.pick_sequences) > 0
or len(self.exclude_sequences) > 0
or len(self.pick_categories) > 0
or self.n_frames_per_sequence > 0
)
def _get_filtered_sequences_if_any(self) -> Optional[pd.Series]:
# maximum possible query: WHERE category IN 'self.pick_categories'
# AND sequence_name IN 'self.pick_sequences'
# AND sequence_name NOT IN 'self.exclude_sequences'
# LIMIT 'self.limit_sequence_to'
stmt = sa.select(SqlSequenceAnnotation.sequence_name)
where_conditions = [
*self._get_category_filters(),
*self._get_pick_filters(),
*self._get_exclude_filters(),
]
if where_conditions:
stmt = stmt.where(*where_conditions)
if self.limit_sequences_to > 0:
logger.info(
f"Limiting dataset to first {self.limit_sequences_to} sequences"
)
# NOTE: ROWID is SQLite-specific
stmt = stmt.order_by(sa.text("ROWID")).limit(self.limit_sequences_to)
if not where_conditions and self.limit_sequences_to <= 0:
# we will not need to filter by sequences
return None
with self._sql_engine.connect() as connection:
sequences = pd.read_sql_query(stmt, connection)["sequence_name"]
logger.info("... retained %d sequences" % len(sequences))
return sequences
def _get_category_filters(self) -> List[sa.ColumnElement]:
if not self.pick_categories:
return []
logger.info(f"Limiting dataset to categories: {self.pick_categories}")
return [SqlSequenceAnnotation.category.in_(self.pick_categories)]
def _get_pick_filters(self) -> List[sa.ColumnElement]:
if not self.pick_sequences:
return []
logger.info(f"Limiting dataset to sequences: {self.pick_sequences}")
return [SqlSequenceAnnotation.sequence_name.in_(self.pick_sequences)]
def _get_exclude_filters(self) -> List[sa.ColumnOperators]:
if not self.exclude_sequences:
return []
logger.info(f"Removing sequences from the dataset: {self.exclude_sequences}")
return [SqlSequenceAnnotation.sequence_name.notin_(self.exclude_sequences)]
def _load_subsets_from_json(self, subset_lists_path: str) -> pd.DataFrame:
assert self.subsets is not None
with open(subset_lists_path, "r") as f:
subset_to_seq_frame = json.load(f)
seq_frame_list = sum(
(
[(*row, subset) for row in subset_to_seq_frame[subset]]
for subset in self.subsets
),
[],
)
index = pd.DataFrame(
seq_frame_list,
columns=["sequence_name", "frame_number", "_image_path", "subset"],
)
return index
def _load_subsets_from_sql(self, subset_lists_path: str) -> pd.DataFrame:
subsets = self.subsets
assert subsets is not None
# we need a new engine since we store the subsets in a separate DB
engine = sa.create_engine(f"sqlite:///{subset_lists_path}")
table = sa.Table(_SET_LISTS_TABLE, sa.MetaData(), autoload_with=engine)
stmt = sa.select(table).where(table.c.subset.in_(subsets))
with engine.connect() as connection:
index = pd.read_sql(stmt, connection)
return index
def _build_index_from_subset_lists(
self, sequences: Optional[pd.Series]
) -> pd.DataFrame:
if not self.subset_lists_file:
raise ValueError("Requested subsets but subset_lists_file not given")
logger.info(f"Loading subset lists from {self.subset_lists_file}.")
subset_lists_path = self._local_path(self.subset_lists_file)
if subset_lists_path.lower().endswith(".json"):
index = self._load_subsets_from_json(subset_lists_path)
else:
index = self._load_subsets_from_sql(subset_lists_path)
index = index.set_index(["sequence_name", "frame_number"])
logger.info(f" -> loaded {len(index)} samples of {self.subsets}.")
if sequences is not None:
logger.info("Applying filtered sequences.")
sequence_values = index.index.get_level_values("sequence_name")
index = index.loc[sequence_values.isin(sequences)]
logger.info(f" -> retained {len(index)} samples.")
pick_frames_criteria = []
if self.remove_empty_masks:
logger.info("Culling samples with empty masks.")
if len(index) > self.remove_empty_masks_poll_whole_table_threshold:
# APPROACH 1: find empty masks and drop indices.
# dev load: 17s / 15 s (3.1M / 500K)
stmt = sa.select(
self.frame_annotations_type.sequence_name,
self.frame_annotations_type.frame_number,
).where(self.frame_annotations_type._mask_mass == 0)
with Session(self._sql_engine) as session:
to_remove = session.execute(stmt).all()
# Pandas uses np.int64 for integer types, so we have to case
# we might want to read it to pandas DataFrame directly to avoid the loop
to_remove = [(seq, np.int64(fr)) for seq, fr in to_remove]
index.drop(to_remove, errors="ignore", inplace=True)
else:
# APPROACH 3: load index into a temp table and join with annotations
# dev load: 94 s / 23 s (3.1M / 500K)
pick_frames_criteria.append(
sa.or_(
self.frame_annotations_type._mask_mass.is_(None),
self.frame_annotations_type._mask_mass != 0,
)
)
if self.pick_frames_sql_clause:
logger.info("Applying the custom SQL clause.")
pick_frames_criteria.append(sa.text(self.pick_frames_sql_clause))
if pick_frames_criteria:
index = self._pick_frames_by_criteria(index, pick_frames_criteria)
logger.info(f" -> retained {len(index)} samples.")
if self.limit_to > 0:
logger.info(f"Limiting dataset to first {self.limit_to} frames")
index = index.sort_index().iloc[: self.limit_to]
return index.reset_index()
def _pick_frames_by_criteria(self, index: pd.DataFrame, criteria) -> pd.DataFrame:
IndexTable = self._get_temp_index_table_instance()
with self._sql_engine.connect() as connection:
IndexTable.create(connection)
# we dont let pandass `to_sql` create the table automatically as
# the table would be permanent, so we create it and append with pandas
n_rows = index.to_sql(IndexTable.name, connection, if_exists="append")
assert n_rows == len(index)
sa_type = self.frame_annotations_type
stmt = (
sa.select(IndexTable)
.select_from(
IndexTable.join(
self.frame_annotations_type,
sa.and_(
sa_type.sequence_name == IndexTable.c.sequence_name,
sa_type.frame_number == IndexTable.c.frame_number,
),
)
)
.where(*criteria)
)
return pd.read_sql_query(stmt, connection).set_index(
["sequence_name", "frame_number"]
)
def _build_index_from_db(self, sequences: Optional[pd.Series]):
logger.info("Loading sequcence-frame index from the database")
stmt = sa.select(
self.frame_annotations_type.sequence_name,
self.frame_annotations_type.frame_number,
self.frame_annotations_type._image_path,
sa.null().label("subset"),
)
where_conditions = []
if sequences is not None:
logger.info(" applying filtered sequences")
where_conditions.append(
self.frame_annotations_type.sequence_name.in_(sequences.tolist())
)
if self.remove_empty_masks:
logger.info(" excluding samples with empty masks")
where_conditions.append(
sa.or_(
self.frame_annotations_type._mask_mass.is_(None),
self.frame_annotations_type._mask_mass != 0,
)
)
if self.pick_frames_sql_clause:
logger.info(" applying custom SQL clause")
where_conditions.append(sa.text(self.pick_frames_sql_clause))
if where_conditions:
stmt = stmt.where(*where_conditions)
if self.limit_to > 0:
logger.info(f"Limiting dataset to first {self.limit_to} frames")
stmt = stmt.order_by(
self.frame_annotations_type.sequence_name,
self.frame_annotations_type.frame_number,
).limit(self.limit_to)
with self._sql_engine.connect() as connection:
index = pd.read_sql_query(stmt, connection)
logger.info(f" -> loaded {len(index)} samples.")
return index
def _sort_index_(self, index):
logger.info("Sorting the index by sequence and frame number.")
index.sort_values(["sequence_name", "frame_number"], inplace=True)
logger.info(" -> Done.")
def _load_filter_eval_batches(self):
assert self.eval_batches_file
logger.info(f"Loading eval batches from {self.eval_batches_file}")
if not os.path.isfile(self.eval_batches_file):
# The batch indices file does not exist.
# Most probably the user has not specified the root folder.
raise ValueError(
f"Looking for dataset json file in {self.eval_batches_file}. "
+ "Please specify a correct dataset_root folder."
)
with open(self.eval_batches_file, "r") as f:
eval_batches = json.load(f)
# limit the dataset to sequences to allow multiple evaluations in one file
pick_sequences = set(self.pick_sequences)
if self.pick_categories:
cat_to_seq = self.category_to_sequence_names()
pick_sequences.update(
seq for cat in self.pick_categories for seq in cat_to_seq[cat]
)
if pick_sequences:
old_len = len(eval_batches)
eval_batches = [b for b in eval_batches if b[0][0] in pick_sequences]
logger.warn(
f"Picked eval batches by sequence/cat: {old_len} -> {len(eval_batches)}"
)
if self.exclude_sequences:
old_len = len(eval_batches)
exclude_sequences = set(self.exclude_sequences)
eval_batches = [b for b in eval_batches if b[0][0] not in exclude_sequences]
logger.warn(
f"Excluded eval batches by sequence: {old_len} -> {len(eval_batches)}"
)
return eval_batches
def _stratified_sample_index(self, index):
# NOTE this stratified sampling can be done more efficiently in
# the no-subset case above if it is added to the SQL query.
# We keep this generic implementation since no-subset case is uncommon
index = index.groupby("sequence_name", group_keys=False).apply(
lambda seq_frames: seq_frames.sample(
min(len(seq_frames), self.n_frames_per_sequence),
random_state=(
_seq_name_to_seed(seq_frames.iloc[0]["sequence_name"]) + self.seed
),
)
)
logger.info(f" -> retained {len(index)} samples aster stratified sampling.")
return index
def _get_frame_type(self, entry: SqlFrameAnnotation) -> Optional[str]:
return self._index.loc[(entry.sequence_name, entry.frame_number), "subset"]
def _get_frame_no_coalesced_ts_by_row_indices(
self,
idxs: Sequence[int],
seq_name: Optional[str] = None,
subset_filter: Union[Sequence[str], str, None] = None,
) -> Tuple[pd.DataFrame, Sequence[int]]:
"""
Loads timestamps for given index rows belonging to the same sequence.
If seq_name is known, it speeds up the computation.
Raises ValueError if `idxs` do not all belong to a single sequences .
"""
index_slice = self._index.iloc[idxs]
if subset_filter is not None:
if isinstance(subset_filter, str):
subset_filter = [subset_filter]
indicator = index_slice["subset"].isin(subset_filter)
index_slice = index_slice.loc[indicator]
idxs = [i for i, isin in zip(idxs, indicator) if isin]
frames = index_slice.index.get_level_values("frame_number").tolist()
if seq_name is None:
seq_name_list = index_slice.index.get_level_values("sequence_name").tolist()
seq_name_set = set(seq_name_list)
if len(seq_name_set) > 1:
raise ValueError("Given indices belong to more than one sequence.")
elif len(seq_name_set) == 1:
seq_name = seq_name_list[0]
coalesced_ts = sa.sql.functions.coalesce(
self.frame_annotations_type.frame_timestamp, 0
)
stmt = sa.select(
coalesced_ts.label("frame_timestamp"),
self.frame_annotations_type.frame_number,
).where(
self.frame_annotations_type.sequence_name == seq_name,
self.frame_annotations_type.frame_number.in_(frames),
)
with self._sql_engine.connect() as connection:
frame_no_ts = pd.read_sql_query(stmt, connection)
if len(frame_no_ts) != len(index_slice):
raise ValueError(
"Not all indices are found in the database; "
"do they belong to more than one sequence?"
)
return frame_no_ts, idxs
def _local_path(self, path: str) -> str:
if self.path_manager is None:
return path
return self.path_manager.get_local_path(path)
def _get_temp_index_table_instance(self, table_name: str = "__index"):
CachedTable = self.frame_annotations_type.metadata.tables.get(table_name)
if CachedTable is not None: # table definition is not idempotent
return CachedTable
return sa.Table(
table_name,
self.frame_annotations_type.metadata,
sa.Column("sequence_name", sa.String, primary_key=True),
sa.Column("frame_number", sa.Integer, primary_key=True),
sa.Column("_image_path", sa.String),
sa.Column("subset", sa.String),
prefixes=["TEMP"], # NOTE SQLite specific!
)
def _seq_name_to_seed(seq_name) -> int:
"""Generates numbers in [0, 2 ** 28)"""
return int(hashlib.sha1(seq_name.encode("utf-8")).hexdigest()[:7], 16)
def _safe_as_tensor(data, dtype):
return torch.tensor(data, dtype=dtype) if data is not None else None