Utilities and Configuration

def infer_storage_options(urlpath, inherit_storage_options=None):
    """
    Infer storage options from URL parameters.
    
    Parameters:
    - urlpath: str, URL with potential query parameters
    - inherit_storage_options: dict, existing options to inherit/override
    
    Returns:
    dict, storage options extracted from URL
    """

def get_protocol(url):
    """
    Extract protocol from URL.
    
    Parameters:
    - url: str, URL to parse
    
    Returns:
    str, protocol name (e.g., 's3', 'gcs', 'file')
    """

def stringify_path(filepath):
    """
    Convert path object to string.
    
    Parameters:
    - filepath: str or Path-like, file path
    
    Returns:
    str, string representation of path
    """

def infer_compression(filename):
    """
    Infer compression format from filename.
    
    Parameters:
    - filename: str, file name or path
    
    Returns:
    str or None, compression format name or None if uncompressed
    """

def tokenize(*args, **kwargs):
    """
    Generate hash token from arguments.
    
    Parameters:
    - *args: positional arguments to hash
    - **kwargs: keyword arguments to hash
    
    Returns:
    str, hash token string
    """

def read_block(file, offset, length, delimiter=None):
    """
    Read a block of data from file.
    
    Parameters:
    - file: file-like object, source file
    - offset: int, byte offset to start reading
    - length: int, maximum bytes to read
    - delimiter: bytes, delimiter to read until (optional)
    
    Returns:
    bytes, block data
    """

def build_name_function(max_int):
    """
    Build function for generating sequential filenames.
    
    Parameters:
    - max_int: int, maximum number to generate names for
    
    Returns:
    callable, function that takes int and returns filename string
    """

def atomic_write(path, mode='wb'):
    """
    Context manager for atomic file writing.
    
    Parameters:
    - path: str, target file path
    - mode: str, file opening mode
    
    Returns:
    context manager, yields temporary file object
    """

def glob_translate(pat):
    """
    Translate glob pattern to regular expression.
    
    Parameters:
    - pat: str, glob pattern
    
    Returns:
    str, regular expression pattern
    """

conf: dict
    """Global configuration dictionary with fsspec settings"""

conf_dir: str
    """Configuration directory path"""

def set_conf_env(conf_dict, envdict=os.environ):
    """
    Set configuration from environment variables.
    
    Parameters:
    - conf_dict: dict, configuration dictionary to update
    - envdict: dict, environment variables dictionary
    """

def apply_config(cls, kwargs):
    """
    Apply configuration to class constructor arguments.
    
    Parameters:
    - cls: type, class to configure
    - kwargs: dict, keyword arguments to modify
    
    Returns:
    dict, modified keyword arguments with config applied
    """

# Extract storage options from URL query parameters
url = 's3://bucket/path?key=ACCESS_KEY&secret=SECRET_KEY&region=us-west-2'
storage_options = fsspec.utils.infer_storage_options(url)
print(storage_options)
# {'key': 'ACCESS_KEY', 'secret': 'SECRET_KEY', 'region': 'us-west-2'}

# Use extracted options
fs = fsspec.filesystem('s3', **storage_options)

# Inherit and override options
base_options = {'key': 'BASE_KEY', 'timeout': 30}
url = 's3://bucket/path?secret=SECRET_KEY'
final_options = fsspec.utils.infer_storage_options(url, base_options)
# Result: {'key': 'BASE_KEY', 'timeout': 30, 'secret': 'SECRET_KEY'}

# Extract protocol from various URL formats
urls = [
    's3://bucket/file.txt',
    'gcs://bucket/file.txt', 
    'https://example.com/api',
    '/local/path/file.txt',
    'file:///absolute/path'
]

for url in urls:
    protocol = fsspec.utils.get_protocol(url)
    print(f"{url} -> {protocol}")

# s3://bucket/file.txt -> s3
# gcs://bucket/file.txt -> gcs  
# https://example.com/api -> https
# /local/path/file.txt -> file
# file:///absolute/path -> file

# Automatically detect compression from filenames
filenames = [
    'data.csv.gz',
    'archive.tar.bz2',
    'logs.txt.xz',
    'config.json',
    'model.pkl.lz4'
]

for filename in filenames:
    compression = fsspec.utils.infer_compression(filename)
    print(f"{filename} -> {compression}")

# data.csv.gz -> gzip
# archive.tar.bz2 -> bz2
# logs.txt.xz -> lzma
# config.json -> None
# model.pkl.lz4 -> lz4

import pathlib

# Convert various path types to strings
paths = [
    '/local/file.txt',
    pathlib.Path('/local/file.txt'),
    pathlib.PurePosixPath('/local/file.txt')
]

for path in paths:
    str_path = fsspec.utils.stringify_path(path)
    print(f"{type(path)} -> {str_path}")

# Generate consistent tokens for caching
token1 = fsspec.utils.tokenize('s3', 'bucket', 'file.txt', region='us-east-1')
token2 = fsspec.utils.tokenize('s3', 'bucket', 'file.txt', region='us-east-1')
token3 = fsspec.utils.tokenize('s3', 'bucket', 'file.txt', region='us-west-2')

print(token1 == token2)  # True - same parameters
print(token1 == token3)  # False - different region

# Use for cache keys
cache_key = fsspec.utils.tokenize(protocol, path, **storage_options)

# Read file in blocks with line boundaries
with open('large_file.txt', 'rb') as f:
    offset = 0
    block_size = 1024 * 1024  # 1MB blocks
    
    while True:
        # Read block ending at line boundary
        block = fsspec.utils.read_block(f, offset, block_size, delimiter=b'\n')
        if not block:
            break
            
        # Process complete lines
        lines = block.split(b'\n')
        for line in lines:
            if line:  # Skip empty lines
                process_line(line)
                
        offset += len(block)

# Generate systematic filenames for batch output
name_func = fsspec.utils.build_name_function(1000)

filenames = [name_func(i) for i in range(5)]
print(filenames)
# ['000', '001', '002', '003', '004']

# Use with fsspec.open_files for multiple outputs
output_files = fsspec.open_files(
    'output-*.json',
    'w',
    num=10,
    name_function=name_func
)

# Ensure atomic writes to prevent corruption
with fsspec.utils.atomic_write('/important/file.txt', 'w') as f:
    f.write('Critical data that must be written atomically\n')
    f.write('If this fails, the original file remains unchanged\n')
    # File is only moved to final location if all writes succeed

# Works with binary mode too
with fsspec.utils.atomic_write('/data/model.pkl', 'wb') as f:
    pickle.dump(model, f)

# Convert glob patterns to regex for custom matching
patterns = ['*.txt', 'data_*.csv', 'logs/*/error.log']

for pattern in patterns:
    regex = fsspec.utils.glob_translate(pattern)
    print(f"{pattern} -> {regex}")

# Use compiled regex for matching
import re
regex_pattern = fsspec.utils.glob_translate('data_*.csv')
compiled = re.compile(regex_pattern)

files = ['data_1.csv', 'data_2.csv', 'config.json', 'data_old.csv']
matches = [f for f in files if compiled.match(f)]
print(matches)  # ['data_1.csv', 'data_2.csv', 'data_old.csv']

# Check current configuration
print("Current fsspec config:", fsspec.config.conf)

# Set configuration options
fsspec.config.conf['default_cache_type'] = 'blockcache'
fsspec.config.conf['default_block_size'] = 1024 * 1024

# Configuration from environment variables
import os
os.environ['FSSPEC_CACHE_TYPE'] = 'readahead'
os.environ['FSSPEC_BLOCK_SIZE'] = '2097152'

fsspec.utils.set_conf_env(fsspec.config.conf)
print("Updated config:", fsspec.config.conf)

def get_file_info(url):
    """Get comprehensive file information from URL."""
    protocol = fsspec.utils.get_protocol(url)
    compression = fsspec.utils.infer_compression(url)
    storage_options = fsspec.utils.infer_storage_options(url)
    
    return {
        'protocol': protocol,
        'compression': compression,
        'storage_options': storage_options,
        'token': fsspec.utils.tokenize(url, **storage_options)
    }

# Use custom utility
info = get_file_info('s3://bucket/data.csv.gz?region=us-west-2')
print(info)

def safe_infer_compression(filename):
    """Safely infer compression with fallback."""
    try:
        return fsspec.utils.infer_compression(filename)
    except Exception:
        # Return None if compression inference fails
        return None

def safe_get_protocol(url):
    """Safely extract protocol with fallback."""
    try:
        return fsspec.utils.get_protocol(url)
    except Exception:
        # Default to file protocol
        return 'file'

# Cache tokenization results for repeated operations
from functools import lru_cache

@lru_cache(maxsize=1000)
def cached_tokenize(*args, **kwargs):
    """Cached version of tokenize for performance."""
    # Sort kwargs for consistent hashing
    sorted_kwargs = tuple(sorted(kwargs.items()))
    return fsspec.utils.tokenize(*args, *sorted_kwargs)

# Use cached tokenization
token = cached_tokenize('s3', 'bucket', 'file.txt', region='us-east-1')

# Common configuration options in fsspec.config.conf
{
    'default_cache_type': 'readahead',      # Default cache strategy
    'default_block_size': 1024 * 1024,     # Default block size (1MB)  
    'connect_timeout': 10,                  # Connection timeout seconds
    'read_timeout': 30,                     # Read timeout seconds
    'max_connections': 100,                 # Max concurrent connections
    'cache_dir': '/tmp/fsspec',             # Cache directory
    'logging_level': 'INFO'                 # Logging verbosity
}

# Environment variables that affect fsspec behavior
FSSPEC_CACHE_TYPE -> conf['default_cache_type']
FSSPEC_BLOCK_SIZE -> conf['default_block_size']  
FSSPEC_TIMEOUT -> conf['connect_timeout']
FSSPEC_CACHE_DIR -> conf['cache_dir']

# Apply configuration to specific filesystem instances
config_overrides = {
    's3': {'default_cache_type': 'mmap'},
    'gcs': {'default_block_size': 2*1024*1024},
    'http': {'connect_timeout': 5}
}

# Configuration is applied when creating filesystem instances
for protocol, overrides in config_overrides.items():
    fsspec.utils.apply_config(fsspec.get_filesystem_class(protocol), overrides)