Source code for farm.file_utils

Utilities for working with the local dataset cache.
This file is adapted from the AllenNLP library at
Copyright by the AllenNLP authors.
from __future__ import absolute_import, division, print_function, unicode_literals
from pathlib import Path
import fnmatch
import json
import logging
import os
import shutil
import sys
import tempfile
from functools import wraps
from hashlib import sha256
from io import open

import boto3
import numpy as np
import requests
from botocore.exceptions import ClientError
from dotmap import DotMap
from tqdm import tqdm

    from torch.hub import _get_torch_home

    torch_cache_home = Path(_get_torch_home())
except ImportError:
    torch_cache_home = Path(os.path.expanduser(
            "TORCH_HOME", Path(os.getenv("XDG_CACHE_HOME", "~/.cache")) / "torch"
default_cache_path = torch_cache_home / "farm"

    from urllib.parse import urlparse
except ImportError:
    from urlparse import urlparse

    from pathlib import Path

    FARM_CACHE = Path(os.getenv("FARM_CACHE", default_cache_path))
except (AttributeError, ImportError):
    FARM_CACHE = os.getenv("FARM_CACHE", default_cache_path)

logger = logging.getLogger(__name__)  # pylint: disable=invalid-name

[docs]def url_to_filename(url, etag=None): """ Convert `url` into a hashed filename in a repeatable way. If `etag` is specified, append its hash to the url's, delimited by a period. """ url_bytes = url.encode("utf-8") url_hash = sha256(url_bytes) filename = url_hash.hexdigest() if etag: etag_bytes = etag.encode("utf-8") etag_hash = sha256(etag_bytes) filename += "." + etag_hash.hexdigest() return filename
[docs]def filename_to_url(filename, cache_dir=None): """ Return the url and etag (which may be ``None``) stored for `filename`. Raise ``EnvironmentError`` if `filename` or its stored metadata do not exist. """ if cache_dir is None: cache_dir = FARM_CACHE cache_path = cache_dir / filename if not os.path.exists(cache_path): raise EnvironmentError("file {} not found".format(cache_path)) meta_path = cache_path + ".json" if not os.path.exists(meta_path): raise EnvironmentError("file {} not found".format(meta_path)) with open(meta_path, encoding="utf-8") as meta_file: metadata = json.load(meta_file) url = metadata["url"] etag = metadata["etag"] return url, etag
[docs]def cached_path(url_or_filename, cache_dir=None): """ Given something that might be a URL (or might be a local path), determine which. If it's a URL, download the file and cache it, and return the path to the cached file. If it's already a local path, make sure the file exists and then return the path. """ if cache_dir is None: cache_dir = FARM_CACHE if sys.version_info[0] == 3 and isinstance(url_or_filename, Path): url_or_filename = str(url_or_filename) if sys.version_info[0] == 3 and isinstance(cache_dir, Path): cache_dir = str(cache_dir) parsed = urlparse(url_or_filename) if parsed.scheme in ("http", "https", "s3"): # URL, so get it from the cache (downloading if necessary) return get_from_cache(url_or_filename, cache_dir) elif os.path.exists(url_or_filename): # File, and it exists. return url_or_filename elif parsed.scheme == "": # File, but it doesn't exist. raise EnvironmentError("file {} not found".format(url_or_filename)) else: # Something unknown raise ValueError( "unable to parse {} as a URL or as a local path".format(url_or_filename) )
[docs]def split_s3_path(url): """Split a full s3 path into the bucket name and path.""" parsed = urlparse(url) if not parsed.netloc or not parsed.path: raise ValueError("bad s3 path {}".format(url)) bucket_name = parsed.netloc s3_path = parsed.path # Remove '/' at beginning of path. if s3_path.startswith("/"): s3_path = s3_path[1:] return bucket_name, s3_path
[docs]def s3_request(func): """ Wrapper function for s3 requests in order to create more helpful error messages. """ @wraps(func) def wrapper(url, *args, **kwargs): try: return func(url, *args, **kwargs) except ClientError as exc: if int(exc.response["Error"]["Code"]) == 404: raise EnvironmentError("file {} not found".format(url)) else: raise return wrapper
[docs]@s3_request def s3_etag(url): """Check ETag on S3 object.""" s3_resource = boto3.resource("s3") bucket_name, s3_path = split_s3_path(url) s3_object = s3_resource.Object(bucket_name, s3_path) return s3_object.e_tag
[docs]@s3_request def s3_get(url, temp_file): """Pull a file directly from S3.""" s3_resource = boto3.resource("s3") bucket_name, s3_path = split_s3_path(url) s3_resource.Bucket(bucket_name).download_fileobj(s3_path, temp_file)
[docs]def http_get(url, temp_file, proxies=None): req = requests.get(url, stream=True, proxies=proxies) content_length = req.headers.get("Content-Length") total = int(content_length) if content_length is not None else None progress = tqdm(unit="B", total=total) for chunk in req.iter_content(chunk_size=1024): if chunk: # filter out keep-alive new chunks progress.update(len(chunk)) temp_file.write(chunk) progress.close()
[docs]def get_from_cache(url, cache_dir=None): """ Given a URL, look for the corresponding dataset in the local cache. If it's not there, download it. Then return the path to the cached file. """ if cache_dir is None: cache_dir = FARM_CACHE if sys.version_info[0] == 3 and isinstance(cache_dir, Path): cache_dir = str(cache_dir) if not os.path.exists(cache_dir): os.makedirs(cache_dir) # Get eTag to add to filename, if it exists. if url.startswith("s3://"): etag = s3_etag(url) else: try: response = requests.head(url, allow_redirects=True) if response.status_code != 200: etag = None else: etag = response.headers.get("ETag") except EnvironmentError: etag = None if sys.version_info[0] == 2 and etag is not None: etag = etag.decode("utf-8") filename = url_to_filename(url, etag) # get cache path to put the file cache_path = cache_dir / filename # If we don't have a connection (etag is None) and can't identify the file # try to get the last downloaded one if not os.path.exists(cache_path) and etag is None: matching_files = fnmatch.filter(os.listdir(cache_dir), filename + ".*") matching_files = list(filter(lambda s: not s.endswith(".json"), matching_files)) if matching_files: cache_path = cache_dir / matching_files[-1] if not os.path.exists(cache_path): # Download to temporary file, then copy to cache dir once finished. # Otherwise you get corrupt cache entries if the download gets interrupted. with tempfile.NamedTemporaryFile() as temp_file:"%s not found in cache, downloading to %s", url, # GET file object if url.startswith("s3://"): s3_get(url, temp_file) else: http_get(url, temp_file) # we are copying the file before closing it, so flush to avoid truncation temp_file.flush() # shutil.copyfileobj() starts at the current position, so go to the start"copying %s to cache at %s",, cache_path) with open(cache_path, "wb") as cache_file: shutil.copyfileobj(temp_file, cache_file)"creating metadata file for %s", cache_path) meta = {"url": url, "etag": etag} meta_path = cache_path + ".json" with open(meta_path, "w") as meta_file: output_string = json.dumps(meta) if sys.version_info[0] == 2 and isinstance(output_string, str): output_string = unicode( output_string, "utf-8" ) # The beauty of python 2 meta_file.write(output_string)"removing temp file %s", return cache_path
[docs]def read_set_from_file(filename): """ Extract a de-duped collection (set) of text from a file. Expected file format is one item per line. """ collection = set() with open(filename, "r", encoding="utf-8") as file_: for line in file_: collection.add(line.rstrip()) return collection
[docs]def get_file_extension(path, dot=True, lower=True): ext = os.path.splitext(path)[1] ext = ext if dot else ext[1:] return ext.lower() if lower else ext
[docs]def read_config(path): if path: with open(path) as json_data_file: conf_args = json.load(json_data_file) else: raise ValueError("No config provided for classifier") # flatten last part of config, take either value or default as value for gk, gv in conf_args.items(): for k, v in gv.items(): conf_args[gk][k] = v["value"] if (v["value"] is not None) else v["default"] # DotMap for making nested dictionary accessible through dot notation args = DotMap(conf_args, _dynamic=False) return args
[docs]def unnestConfig(config): """ This function creates a list of config files for evaluating parameters with different values. If a config parameter is of type list this list is iterated over and a config object without lists is returned. Can handle lists inside any number of parameters. Can handle nested (one level) configs """ nestedKeys = [] nestedVals = [] for gk, gv in config.items(): if(gk != "task"): for k, v in gv.items(): if isinstance(v, list): if ( k != "layer_dims" ): # exclude layer dims, since it is already a list nestedKeys.append([gk, k]) nestedVals.append(v) elif isinstance(v, dict): logger.warning("Config too deep! Working on %s" %(str(v))) if len(nestedKeys) == 0: unnestedConfig = [config] else: "Nested config at parameters: %s" % (", ".join(".".join(x) for x in nestedKeys)) ) unnestedConfig = [] mesh = np.meshgrid( *nestedVals ) # get all combinations, each dimension corresponds to one parameter type # flatten mesh into shape: [num_parameters, num_combinations] so we can iterate in 2d over any paramter combinations mesh = [x.flatten() for x in mesh] # loop over all combinations for i in range(len(mesh[0])): tempconfig = config.copy() for j, k in enumerate(nestedKeys): if isinstance(k, str): tempconfig[k] = mesh[j][ i ] # get ith val of correct param value and overwrite original config elif len(k) == 2: tempconfig[k[0]][k[1]] = mesh[j][i] # set nested dictionary keys else: logger.warning("Config too deep! Working on %s" %(str(k))) unnestedConfig.append(tempconfig) return unnestedConfig