Source code for fsspec.implementations.http

from __future__ import absolute_import, division, print_function

import asyncio
import io
import logging
import re
import weakref
from copy import copy
from urllib.parse import urlparse

import aiohttp
import requests

from fsspec.asyn import AsyncFileSystem, sync, sync_wrapper
from fsspec.callbacks import _DEFAULT_CALLBACK
from fsspec.exceptions import FSTimeoutError
from fsspec.spec import AbstractBufferedFile
from fsspec.utils import DEFAULT_BLOCK_SIZE, nullcontext, tokenize

from ..caching import AllBytes

# https://stackoverflow.com/a/15926317/3821154
ex = re.compile(r"""<(a|A)\s+(?:[^>]*?\s+)?(href|HREF)=["'](?P<url>[^"']+)""")
ex2 = re.compile(r"""(?P<url>http[s]?://[-a-zA-Z0-9@:%_+.~#?&/=]+)""")
logger = logging.getLogger("fsspec.http")


async def get_client(**kwargs):
    return aiohttp.ClientSession(**kwargs)


class BlockSizeError(ValueError):
    """
    Helper class for exceptions raised in this module.
    """

    pass


[docs]class HTTPFileSystem(AsyncFileSystem): """ Simple File-System for fetching data via HTTP(S) ``ls()`` is implemented by loading the parent page and doing a regex match on the result. If simple_link=True, anything of the form "http(s)://server.com/stuff?thing=other"; otherwise only links within HTML href tags will be used. """ sep = "/"
[docs] def __init__( self, simple_links=True, block_size=None, same_scheme=True, size_policy=None, cache_type="bytes", cache_options=None, asynchronous=False, loop=None, client_kwargs=None, get_client=get_client, **storage_options, ): """ NB: if this is called async, you must await set_client Parameters ---------- block_size: int Blocks to read bytes; if 0, will default to raw requests file-like objects instead of HTTPFile instances simple_links: bool If True, will consider both HTML <a> tags and anything that looks like a URL; if False, will consider only the former. same_scheme: True When doing ls/glob, if this is True, only consider paths that have http/https matching the input URLs. size_policy: this argument is deprecated client_kwargs: dict Passed to aiohttp.ClientSession, see https://docs.aiohttp.org/en/stable/client_reference.html For example, ``{'auth': aiohttp.BasicAuth('user', 'pass')}`` get_client: Callable[..., aiohttp.ClientSession] A callable which takes keyword arguments and constructs an aiohttp.ClientSession. It's state will be managed by the HTTPFileSystem class. storage_options: key-value Any other parameters passed on to requests cache_type, cache_options: defaults used in open """ super().__init__(self, asynchronous=asynchronous, loop=loop, **storage_options) self.block_size = block_size if block_size is not None else DEFAULT_BLOCK_SIZE self.simple_links = simple_links self.same_schema = same_scheme self.cache_type = cache_type self.cache_options = cache_options self.client_kwargs = client_kwargs or {} self.get_client = get_client self.kwargs = storage_options self._session = None # Clean caching-related parameters from `storage_options` # before propagating them as `request_options` through `self.kwargs`. # TODO: Maybe rename `self.kwargs` to `self.request_options` to make # it clearer. request_options = copy(storage_options) self.use_listings_cache = request_options.pop("use_listings_cache", False) request_options.pop("listings_expiry_time", None) request_options.pop("max_paths", None) request_options.pop("skip_instance_cache", None) self.kwargs = request_options if not asynchronous: sync(self.loop, self.set_session)
@staticmethod def close_session(loop, session): if loop is not None and loop.is_running(): try: sync(loop, session.close, timeout=0.1) return except (TimeoutError, FSTimeoutError): pass connector = getattr(session, "_connector", None) if connector is not None: # close after loop is dead connector._close() async def set_session(self): if self._session is None: self._session = await self.get_client(loop=self.loop, **self.client_kwargs) if not self.asynchronous: weakref.finalize(self, self.close_session, self.loop, self._session) return self._session @classmethod def _strip_protocol(cls, path): """For HTTP, we always want to keep the full URL""" return path @classmethod def _parent(cls, path): # override, since _strip_protocol is different for URLs par = super()._parent(path) if len(par) > 7: # "http://..." return par return "" async def _ls_real(self, url, detail=True, **kwargs): # ignoring URL-encoded arguments kw = self.kwargs.copy() kw.update(kwargs) logger.debug(url) session = await self.set_session() async with session.get(url, **self.kwargs) as r: self._raise_not_found_for_status(r, url) text = await r.text() if self.simple_links: links = ex2.findall(text) + [u[2] for u in ex.findall(text)] else: links = [u[2] for u in ex.findall(text)] out = set() parts = urlparse(url) for l in links: if isinstance(l, tuple): l = l[1] if l.startswith("/") and len(l) > 1: # absolute URL on this server l = parts.scheme + "://" + parts.netloc + l if l.startswith("http"): if self.same_schema and l.startswith(url.rstrip("/") + "/"): out.add(l) elif l.replace("https", "http").startswith( url.replace("https", "http").rstrip("/") + "/" ): # allowed to cross http <-> https out.add(l) else: if l not in ["..", "../"]: # Ignore FTP-like "parent" out.add("/".join([url.rstrip("/"), l.lstrip("/")])) if not out and url.endswith("/"): out = await self._ls_real(url.rstrip("/"), detail=False) if detail: return [ { "name": u, "size": None, "type": "directory" if u.endswith("/") else "file", } for u in out ] else: return list(sorted(out)) return out async def _ls(self, url, detail=True, **kwargs): if self.use_listings_cache and url in self.dircache: out = self.dircache[url] else: out = await self._ls_real(url, detail=detail, **kwargs) self.dircache[url] = out return out ls = sync_wrapper(_ls) def _raise_not_found_for_status(self, response, url): """ Raises FileNotFoundError for 404s, otherwise uses raise_for_status. """ if response.status == 404: raise FileNotFoundError(url) response.raise_for_status() async def _cat_file(self, url, start=None, end=None, **kwargs): kw = self.kwargs.copy() kw.update(kwargs) logger.debug(url) # TODO: extract into testable utility function? if start is not None or end is not None: if start == end: return b"" headers = kw.pop("headers", {}).copy() headers["Range"] = await self._process_limits(url, start, end) kw["headers"] = headers session = await self.set_session() async with session.get(url, **kw) as r: out = await r.read() self._raise_not_found_for_status(r, url) return out async def _get_file( self, rpath, lpath, chunk_size=5 * 2 ** 20, callback=_DEFAULT_CALLBACK, **kwargs ): kw = self.kwargs.copy() kw.update(kwargs) logger.debug(rpath) session = await self.set_session() async with session.get(rpath, **self.kwargs) as r: try: size = int(r.headers["content-length"]) except (ValueError, KeyError): size = None callback.set_size(size) self._raise_not_found_for_status(r, rpath) with open(lpath, "wb") as fd: chunk = True while chunk: chunk = await r.content.read(chunk_size) fd.write(chunk) callback.relative_update(len(chunk)) async def _put_file( self, lpath, rpath, chunk_size=5 * 2 ** 20, callback=_DEFAULT_CALLBACK, method="post", **kwargs, ): async def gen_chunks(): # Support passing arbitrary file-like objects # and use them instead of streams. if isinstance(lpath, io.IOBase): context = nullcontext(lpath) use_seek = False # might not support seeking else: context = open(lpath, "rb") use_seek = True with context as f: if use_seek: callback.set_size(f.seek(0, 2)) f.seek(0) else: callback.set_size(getattr(f, "size", None)) chunk = f.read(64 * 1024) while chunk: yield chunk callback.relative_update(len(chunk)) chunk = f.read(64 * 1024) kw = self.kwargs.copy() kw.update(kwargs) session = await self.set_session() method = method.lower() if method not in ("post", "put"): raise ValueError( f"method has to be either 'post' or 'put', not: {method!r}" ) meth = getattr(session, method) async with meth(rpath, data=gen_chunks(), **kw) as resp: self._raise_not_found_for_status(resp, rpath) async def _exists(self, path, **kwargs): kw = self.kwargs.copy() kw.update(kwargs) try: logger.debug(path) session = await self.set_session() r = await session.get(path, **kw) async with r: return r.status < 400 except (requests.HTTPError, aiohttp.ClientError): return False async def _isfile(self, path, **kwargs): return await self._exists(path, **kwargs) def _open( self, path, mode="rb", block_size=None, autocommit=None, # XXX: This differs from the base class. cache_type=None, cache_options=None, size=None, **kwargs, ): """Make a file-like object Parameters ---------- path: str Full URL with protocol mode: string must be "rb" block_size: int or None Bytes to download in one request; use instance value if None. If zero, will return a streaming Requests file-like instance. kwargs: key-value Any other parameters, passed to requests calls """ if mode != "rb": raise NotImplementedError block_size = block_size if block_size is not None else self.block_size kw = self.kwargs.copy() kw["asynchronous"] = self.asynchronous kw.update(kwargs) size = size or self.info(path, **kwargs)["size"] session = sync(self.loop, self.set_session) if block_size and size: return HTTPFile( self, path, session=session, block_size=block_size, mode=mode, size=size, cache_type=cache_type or self.cache_type, cache_options=cache_options or self.cache_options, loop=self.loop, **kw, ) else: return HTTPStreamFile( self, path, mode=mode, loop=self.loop, session=session, **kw ) def ukey(self, url): """Unique identifier; assume HTTP files are static, unchanging""" return tokenize(url, self.kwargs, self.protocol) async def _info(self, url, **kwargs): """Get info of URL Tries to access location via HEAD, and then GET methods, but does not fetch the data. It is possible that the server does not supply any size information, in which case size will be given as None (and certain operations on the corresponding file will not work). """ info = {} session = await self.set_session() for policy in ["head", "get"]: try: info.update( await _file_info( url, size_policy=policy, session=session, **self.kwargs, **kwargs, ) ) if info.get("size") is not None: break except Exception as exc: if policy == "get": # If get failed, then raise a FileNotFoundError raise FileNotFoundError(url) from exc logger.debug(str(exc)) return {"name": url, "size": None, **info, "type": "file"} async def _glob(self, path, **kwargs): """ Find files by glob-matching. This implementation is idntical to the one in AbstractFileSystem, but "?" is not considered as a character for globbing, because it is so common in URLs, often identifying the "query" part. """ import re ends = path.endswith("/") path = self._strip_protocol(path) indstar = path.find("*") if path.find("*") >= 0 else len(path) indbrace = path.find("[") if path.find("[") >= 0 else len(path) ind = min(indstar, indbrace) detail = kwargs.pop("detail", False) if not has_magic(path): root = path depth = 1 if ends: path += "/*" elif await self._exists(path): if not detail: return [path] else: return {path: await self._info(path)} else: if not detail: return [] # glob of non-existent returns empty else: return {} elif "/" in path[:ind]: ind2 = path[:ind].rindex("/") root = path[: ind2 + 1] depth = None if "**" in path else path[ind2 + 1 :].count("/") + 1 else: root = "" depth = None if "**" in path else path[ind + 1 :].count("/") + 1 allpaths = await self._find( root, maxdepth=depth, withdirs=True, detail=True, **kwargs ) # Escape characters special to python regex, leaving our supported # special characters in place. # See https://www.gnu.org/software/bash/manual/html_node/Pattern-Matching.html # for shell globbing details. pattern = ( "^" + ( path.replace("\\", r"\\") .replace(".", r"\.") .replace("+", r"\+") .replace("//", "/") .replace("(", r"\(") .replace(")", r"\)") .replace("|", r"\|") .replace("^", r"\^") .replace("$", r"\$") .replace("{", r"\{") .replace("}", r"\}") .rstrip("/") ) + "$" ) pattern = re.sub("[*]{2}", "=PLACEHOLDER=", pattern) pattern = re.sub("[*]", "[^/]*", pattern) pattern = re.compile(pattern.replace("=PLACEHOLDER=", ".*")) out = { p: allpaths[p] for p in sorted(allpaths) if pattern.match(p.replace("//", "/").rstrip("/")) } if detail: return out else: return list(out) async def _isdir(self, path): # override, since all URLs are (also) files try: return bool(await self._ls(path)) except (FileNotFoundError, ValueError): return False
class HTTPFile(AbstractBufferedFile): """ A file-like object pointing to a remove HTTP(S) resource Supports only reading, with read-ahead of a predermined block-size. In the case that the server does not supply the filesize, only reading of the complete file in one go is supported. Parameters ---------- url: str Full URL of the remote resource, including the protocol session: requests.Session or None All calls will be made within this session, to avoid restarting connections where the server allows this block_size: int or None The amount of read-ahead to do, in bytes. Default is 5MB, or the value configured for the FileSystem creating this file size: None or int If given, this is the size of the file in bytes, and we don't attempt to call the server to find the value. kwargs: all other key-values are passed to requests calls. """ def __init__( self, fs, url, session=None, block_size=None, mode="rb", cache_type="bytes", cache_options=None, size=None, loop=None, asynchronous=False, **kwargs, ): if mode != "rb": raise NotImplementedError("File mode not supported") self.asynchronous = asynchronous self.url = url self.session = session self.details = {"name": url, "size": size, "type": "file"} super().__init__( fs=fs, path=url, mode=mode, block_size=block_size, cache_type=cache_type, cache_options=cache_options, **kwargs, ) self.loop = loop def read(self, length=-1): """Read bytes from file Parameters ---------- length: int Read up to this many bytes. If negative, read all content to end of file. If the server has not supplied the filesize, attempting to read only part of the data will raise a ValueError. """ if ( (length < 0 and self.loc == 0) # explicit read all # but not when the size is known and fits into a block anyways and not (self.size is not None and self.size <= self.blocksize) ): self._fetch_all() if self.size is None: if length < 0: self._fetch_all() else: length = min(self.size - self.loc, length) return super().read(length) async def async_fetch_all(self): """Read whole file in one shot, without caching This is only called when position is still at zero, and read() is called without a byte-count. """ logger.debug(f"Fetch all for {self}") if not isinstance(self.cache, AllBytes): r = await self.session.get(self.url, **self.kwargs) async with r: r.raise_for_status() out = await r.read() self.cache = AllBytes( size=len(out), fetcher=None, blocksize=None, data=out ) self.size = len(out) _fetch_all = sync_wrapper(async_fetch_all) async def async_fetch_range(self, start, end): """Download a block of data The expectation is that the server returns only the requested bytes, with HTTP code 206. If this is not the case, we first check the headers, and then stream the output - if the data size is bigger than we requested, an exception is raised. """ logger.debug(f"Fetch range for {self}: {start}-{end}") kwargs = self.kwargs.copy() headers = kwargs.pop("headers", {}).copy() headers["Range"] = "bytes=%i-%i" % (start, end - 1) logger.debug(self.url + " : " + headers["Range"]) r = await self.session.get(self.url, headers=headers, **kwargs) async with r: if r.status == 416: # range request outside file return b"" r.raise_for_status() if r.status == 206: # partial content, as expected out = await r.read() elif "Content-Length" in r.headers: cl = int(r.headers["Content-Length"]) if cl <= end - start: # data size OK out = await r.read() else: raise BlockSizeError( "Got more bytes so far (>%i) than requested (%i)" % (cl, end - start) ) else: cl = 0 out = [] while True: chunk = await r.content.read(2 ** 20) # data size unknown, let's see if it goes too big if chunk: out.append(chunk) cl += len(chunk) if cl > end - start: raise BlockSizeError( "Got more bytes so far (>%i) than requested (%i)" % (cl, end - start) ) else: break out = b"".join(out) return out _fetch_range = sync_wrapper(async_fetch_range) def close(self): pass def __reduce__(self): return ( reopen, ( self.fs, self.url, self.mode, self.blocksize, self.cache.name, self.size, ), ) def reopen(fs, url, mode, blocksize, cache_type, size=None): return fs.open( url, mode=mode, block_size=blocksize, cache_type=cache_type, size=size ) magic_check = re.compile("([*[])") def has_magic(s): match = magic_check.search(s) return match is not None class HTTPStreamFile(AbstractBufferedFile): def __init__(self, fs, url, mode="rb", loop=None, session=None, **kwargs): self.asynchronous = kwargs.pop("asynchronous", False) self.url = url self.loop = loop self.session = session if mode != "rb": raise ValueError self.details = {"name": url, "size": None} super().__init__(fs=fs, path=url, mode=mode, cache_type="none", **kwargs) async def cor(): r = await self.session.get(url, **kwargs).__aenter__() self.fs._raise_not_found_for_status(r, url) return r self.r = sync(self.loop, cor) def seek(self, *args, **kwargs): raise ValueError("Cannot seek streaming HTTP file") async def _read(self, num=-1): out = await self.r.content.read(num) self.loc += len(out) return out read = sync_wrapper(_read) async def _close(self): self.r.close() def close(self): asyncio.run_coroutine_threadsafe(self._close(), self.loop) def __reduce__(self): return reopen, (self.fs, self.url, self.mode, self.blocksize, self.cache.name) async def get_range(session, url, start, end, file=None, **kwargs): # explicit get a range when we know it must be safe kwargs = kwargs.copy() headers = kwargs.pop("headers", {}).copy() headers["Range"] = "bytes=%i-%i" % (start, end - 1) r = await session.get(url, headers=headers, **kwargs) r.raise_for_status() async with r: out = await r.read() if file: with open(file, "rb+") as f: f.seek(start) f.write(out) else: return out async def _file_info(url, session, size_policy="head", **kwargs): """Call HEAD on the server to get details about the file (size/checksum etc.) Default operation is to explicitly allow redirects and use encoding 'identity' (no compression) to get the true size of the target. """ logger.debug("Retrieve file size for %s" % url) kwargs = kwargs.copy() ar = kwargs.pop("allow_redirects", True) head = kwargs.get("headers", {}).copy() head["Accept-Encoding"] = "identity" kwargs["headers"] = head info = {} if size_policy == "head": r = await session.head(url, allow_redirects=ar, **kwargs) elif size_policy == "get": r = await session.get(url, allow_redirects=ar, **kwargs) else: raise TypeError('size_policy must be "head" or "get", got %s' "" % size_policy) async with r: r.raise_for_status() # TODO: # recognise lack of 'Accept-Ranges', # or 'Accept-Ranges': 'none' (not 'bytes') # to mean streaming only, no random access => return None if "Content-Length" in r.headers: info["size"] = int(r.headers["Content-Length"]) elif "Content-Range" in r.headers: info["size"] = int(r.headers["Content-Range"].split("/")[1]) for checksum_field in ["ETag", "Content-MD5", "Digest"]: if r.headers.get(checksum_field): info[checksum_field] = r.headers[checksum_field] return info async def _file_size(url, session=None, *args, **kwargs): if session is None: session = await get_client() info = await _file_info(url, session=session, *args, **kwargs) return info.get("size") file_size = sync_wrapper(_file_size)