add s3path

s3torchconnector/pyproject.toml

@@ -24,6 +24,7 @@ classifiers = [
 dependencies = [
     "torch >= 2.0.1, != 2.5.0",
     "s3torchconnectorclient >= 1.3.0",
+    "pathlib_abc >= 0.3.1"
 ]
 
 [project.optional-dependencies]

s3torchconnector/src/s3torchconnector/__init__.py

@@ -10,6 +10,7 @@
 from .s3iterable_dataset import S3IterableDataset
 from .s3map_dataset import S3MapDataset
 from .s3checkpoint import S3Checkpoint
+from .s3path import S3Path
 from ._version import __version__
 from ._s3client import S3ClientConfig
 
@@ -21,5 +22,6 @@
     "S3Writer",
     "S3Exception",
     "S3ClientConfig",
+    "S3Path",
     "__version__",
 ]

s3torchconnector/src/s3torchconnector/s3path.py

@@ -0,0 +1,305 @@
+#  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#  // SPDX-License-Identifier: BSD
+import errno
+import io
+import logging
+import os
+import posixpath
+import stat
+import time
+from types import SimpleNamespace
+from typing import Optional
+
+from pathlib import PurePosixPath
+from pathlib_abc import ParserBase, PathBase, UnsupportedOperation
+from urllib.parse import urlparse
+
+from s3torchconnectorclient._mountpoint_s3_client import S3Exception
+from ._s3client import S3Client, S3ClientConfig
+
+logger = logging.getLogger(__name__)
+
+ENV_S3_TORCH_CONNECTOR_REGION = "S3_TORCH_CONNECTOR_REGION"
+ENV_S3_TORCH_CONNECTOR_THROUGHPUT_TARGET_GPBS = (
+    "S3_TORCH_CONNECTOR_THROUGHPUT_TARGET_GPBS"
+)
+ENV_S3_TORCH_CONNECTOR_PART_SIZE_MB = "S3_TORCH_CONNECTOR_PART_SIZE_MB"
+DRIVE = "s3://"
+
+
+def _get_default_bucket_region():
+    for var in [
+        ENV_S3_TORCH_CONNECTOR_REGION,
+        "AWS_DEFAULT_REGION",
+        "AWS_REGION",
+        "REGION",
+    ]:
+        if var in os.environ:
+            return os.environ[var]
+
+
+def _get_default_throughput_target_gbps():
+    if ENV_S3_TORCH_CONNECTOR_THROUGHPUT_TARGET_GPBS in os.environ:
+        return float(os.environ[ENV_S3_TORCH_CONNECTOR_THROUGHPUT_TARGET_GPBS])
+
+
+def _get_default_part_size():
+    if ENV_S3_TORCH_CONNECTOR_PART_SIZE_MB in os.environ:
+        return int(os.environ[ENV_S3_TORCH_CONNECTOR_PART_SIZE_MB]) * 1024 * 1024
+
+
+class S3Parser(ParserBase):
+    @classmethod
+    def _unsupported_msg(cls, attribute):
+        return f"{cls.__name__}.{attribute} is unsupported"
+
+    @property
+    def sep(self):
+        return "/"
+
+    def join(self, path, *paths):
+        return posixpath.join(path, *paths)
+
+    def split(self, path):
+        scheme, bucket, prefix, _, _, _ = urlparse(path)
+        parent, _, name = prefix.lstrip("/").rpartition("/")
+        if not bucket:
+            return bucket, name
+        return (scheme + "://" + bucket + "/" + parent, name)
+
+    def splitdrive(self, path):
+        scheme, bucket, prefix, _, _, _ = urlparse(path)
+        drive = f"{scheme}://{bucket}"
+        return drive, prefix.lstrip("/")
+
+    def splitext(self, path):
+        return posixpath.splitext(path)
+
+    def normcase(self, path):
+        return posixpath.normcase(path)
+
+    def isabs(self, path):
+        s = os.fspath(path)
+        scheme_tail = s.split("://", 1)
+        return len(scheme_tail) == 2
+
+
+class S3Path(PathBase):
+    __slots__ = ("_region", "_s3_client_config", "_client", "_raw_path")
+    parser = S3Parser()
+    _stat_cache_ttl_seconds = 1
+    _stat_cache_size = 1024
+    _stat_cache = {}
+
+    def __init__(
+        self,
+        *pathsegments,
+        client: Optional[S3Client] = None,
+        region=None,
+        s3_client_config=None,
+    ):
+        super().__init__(*pathsegments)
+        if not self.drive.startswith(DRIVE):
+            raise ValueError("Should pass in S3 uri")
+        self._region = region or _get_default_bucket_region()
+        self._s3_client_config = s3_client_config or S3ClientConfig(
+            throughput_target_gbps=_get_default_throughput_target_gbps(),
+            part_size=_get_default_part_size(),
+        )
+        self._client = client or S3Client(
+            region=self._region,
+            s3client_config=self._s3_client_config,
+        )
+
+    def __repr__(self):
+        return f"{type(self).__name__}({str(self)!r})"
+
+    def __hash__(self):
+        return hash(str(self))
+
+    def __eq__(self, other):
+        if not isinstance(other, S3Path):
+            return NotImplemented
+        return str(self) == str(other)
+
+    def with_segments(self, *pathsegments):
+        path = str("/".join(pathsegments)).lstrip("/")
+        if not path.startswith(self.anchor):
+            path = f"{self.anchor}{path}"
+        return type(self)(
+            path,
+            client=self._client,
+            region=self._region,
+            s3_client_config=self._s3_client_config,
+        )
+
+    @property
+    def bucket(self):
+        if self.is_absolute() and self.drive.startswith(DRIVE):
+            return self.drive[5:]
+        return ""
+
+    @property
+    def key(self):
+        if self.is_absolute() and len(self.parts) > 1:
+            return self.parser.sep.join(self.parts[1:])
+        return ""
+
+    def open(self, mode="r", buffering=-1, encoding=None, errors=None, newline=None):
+        if buffering != -1:
+            raise ValueError("Only default buffering (-1) is supported.")
+        if not self.is_absolute():
+            raise ValueError("S3Path must be absolute.")
+        action = "".join(c for c in mode if c not in "btU")
+        if action == "r":
+            try:
+                fileobj = self._client.get_object(self.bucket, self.key)
+            except S3Exception:
+                raise FileNotFoundError(errno.ENOENT, "Not found", str(self)) from None
+            except:
+                raise
+        elif action == "w":
+            try:
+                fileobj = self._client.put_object(self.bucket, self.key)
+            except S3Exception:
+                raise
+            except:
+                raise
+        else:
+            raise UnsupportedOperation()
+        if "b" not in mode:
+            fileobj = io.TextIOWrapper(fileobj, encoding, errors, newline)
+        return fileobj
+
+    def stat(self, *, follow_symlinks=True):
+        cache_key = (self.bucket, self.key.rstrip("/"))
+        cached_result = self._stat_cache.get(cache_key)
+        if cached_result:
+            result, timestamp = cached_result
+            if time.time() - timestamp < self._stat_cache_ttl_seconds:
+                return result
+            del self._stat_cache[cache_key]
+        try:
+            info = self._client.head_object(self.bucket, self.key.rstrip("/"))
+            mode = stat.S_IFREG
+        except S3Exception as e:
+            listobj = next(self._list_objects(max_keys=2))
+
+            if len(listobj.object_info) > 0 or len(listobj.common_prefixes) > 0:
+                info = SimpleNamespace(size=0, last_modified=None)
+                mode = stat.S_IFDIR
+            else:
+                error_msg = f"No stats available for {self}; it may not exist."
+                raise FileNotFoundError(error_msg) from e
+
+        result = os.stat_result(
+            (
+                mode,  # mode
+                None,  # ino
+                DRIVE,  # dev
+                None,  # nlink
+                None,  # uid
+                None,  # gid
+                info.size,  # size
+                None,  # atime
+                info.last_modified or 0,  # mtime
+                None,  # ctime
+            )
+        )
+        if len(self._stat_cache) >= self._stat_cache_size:
+            self._stat_cache.pop(next(iter(self._stat_cache)))
+
+        self._stat_cache[cache_key] = (result, time.time())
+        return result
+
+    def iterdir(self):
+        if not self.is_dir():
+            raise NotADirectoryError("not a s3 folder")
+        key = "" if not self.key else self.key.rstrip("/") + "/"
+        for page in self._list_objects():
+            for prefix in page.common_prefixes:
+                # yield directories first
+                yield self.with_segments(prefix.rstrip("/"))
+            for info in page.object_info:
+                if info.key != key:
+                    yield self.with_segments(info.key)
+
+    def mkdir(self, mode=0o777, parents=False, exist_ok=False):
+        if self.is_dir():
+            if exist_ok:
+                return
+            raise FileExistsError(f"S3 folder {self} already exists.")
+        with self._client.put_object(self.bucket, self.key.rstrip("/") + "/"):
+            pass
+
+    def unlink(self, missing_ok=False):
+        if self.is_dir():
+            if missing_ok:
+                return
+            raise IsADirectoryError(
+                f"Path {self} is a directory; call rmdir instead of unlink."
+            )
+        self._client.delete_object(self.bucket, self.key)
+
+    def rmdir(self):
+        if not self.is_dir():
+            raise NotADirectoryError(f"{self} is not an s3 folder")
+        listobj = next(self._list_objects(max_keys=2))
+        if len(listobj.object_info) > 1:
+            raise Exception(f"{self} is not empty")
+        self._client.delete_object(self.bucket, self.key.rstrip("/") + "/")
+
+    def glob(self, pattern, *, case_sensitive=None, recurse_symlinks=True):
+        if ".." in pattern:
+            raise NotImplementedError(
+                "Relative paths with '..' not supported in glob patterns"
+            )
+        if pattern.startswith(self.anchor) or pattern.startswith("/"):
+            raise NotImplementedError("Non-relative patterns are unsupported")
+
+        parts = list(PurePosixPath(pattern).parts)
+        select = self._glob_selector(parts, case_sensitive, recurse_symlinks)
+        return select(self)
+
+    def with_name(self, name):
+        """Return a new path with the file name changed."""
+        split = self.parser.split
+        if split(name)[0]:
+            # Ensure that the provided name does not contain any path separators
+            raise ValueError(f"Invalid name {name!r}")
+        return self.with_segments(str(self.parent), name)
+
+    def _list_objects(self, max_keys: int = 1000):
+        try:
+            key = "" if not self.key else self.key.rstrip("/") + "/"
+            pages = iter(
+                self._client.list_objects(
+                    self.bucket, key, delimiter="/", max_keys=max_keys
+                )
+            )
+            for page in pages:
+                yield page
+        except S3Exception as e:
+            raise RuntimeError(f"Failed to list contents of {self}") from e
+
+    def __getstate__(self):
+        state = {
+            slot: getattr(self, slot, None)
+            for cls in self.__class__.__mro__
+            for slot in getattr(cls, "__slots__", [])
+            if slot
+            not in [
+                "_client",
+            ]
+        }
+        return (None, state)
+
+    def __setstate__(self, state):
+        _, state_dict = state
+        for slot, value in state_dict.items():
+            if slot not in ["_client"]:
+                setattr(self, slot, value)
+        self._client = S3Client(
+            region=self._region,
+            s3client_config=self._s3_client_config,
+        )