swh/model/exceptions.py

@@ -33,11 +33,12 @@
 # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
-NON_FIELD_ERRORS = '__all__'
+NON_FIELD_ERRORS = "__all__"
 
 
 class ValidationError(Exception):
     """An error while validating data."""
+
     def __init__(self, message, code=None, params=None):
         """
         The `message` argument can be a single error, a list of errors, or a
@@ -54,16 +55,15 @@ class ValidationError(Exception):
             message = message[0]
 
         if isinstance(message, ValidationError):
-            if hasattr(message, 'error_dict'):
+            if hasattr(message, "error_dict"):
                 message = message.error_dict
             # PY2 has a `message` property which is always there so we can't
             # duck-type on it. It was introduced in Python 2.5 and already
             # deprecated in Python 2.6.
-            elif not hasattr(message, 'message'):
+            elif not hasattr(message, "message"):
                 message = message.error_list
             else:
-                message, code, params = (message.message, message.code,
-                                         message.params)
+                message, code, params = (message.message, message.code, message.params)
 
         if isinstance(message, dict):
             self.error_dict = {}
@@ -78,9 +78,8 @@ class ValidationError(Exception):
                 # Normalize plain strings to instances of ValidationError.
                 if not isinstance(message, ValidationError):
                     message = ValidationError(message)
-                if hasattr(message, 'error_dict'):
-                    self.error_list.extend(sum(message.error_dict.values(),
-                                               []))
+                if hasattr(message, "error_dict"):
+                    self.error_list.extend(sum(message.error_dict.values(), []))
                 else:
                     self.error_list.extend(message.error_list)
 
@@ -94,18 +93,18 @@ class ValidationError(Exception):
     def message_dict(self):
         # Trigger an AttributeError if this ValidationError
         # doesn't have an error_dict.
-        getattr(self, 'error_dict')
+        getattr(self, "error_dict")
 
         return dict(self)
 
     @property
     def messages(self):
-        if hasattr(self, 'error_dict'):
+        if hasattr(self, "error_dict"):
             return sum(dict(self).values(), [])
         return list(self)
 
     def update_error_dict(self, error_dict):
-        if hasattr(self, 'error_dict'):
+        if hasattr(self, "error_dict"):
             for field, error_list in self.error_dict.items():
                 error_dict.setdefault(field, []).extend(error_list)
         else:
@@ -113,7 +112,7 @@ class ValidationError(Exception):
         return error_dict
 
     def __iter__(self):
-        if hasattr(self, 'error_dict'):
+        if hasattr(self, "error_dict"):
             for field, errors in self.error_dict.items():
                 yield field, list(ValidationError(errors))
         else:
@@ -124,9 +123,13 @@ class ValidationError(Exception):
                 yield message
 
     def __str__(self):
-        if hasattr(self, 'error_dict'):
+        if hasattr(self, "error_dict"):
             return repr(dict(self))
         return repr(list(self))
 
     def __repr__(self):
-        return 'ValidationError(%s)' % self
+        return "ValidationError(%s)" % self
+
+
+class InvalidDirectoryPath(Exception):
+    pass

swh/model/fields/__init__.py

@@ -6,8 +6,13 @@
 # We do our imports here but we don't use them, so flake8 complains
 # flake8: noqa
 
-from .simple import (validate_type, validate_int, validate_str, validate_bytes,
-                     validate_datetime, validate_enum)
-from .hashes import (validate_sha1, validate_sha1_git, validate_sha256)
-from .compound import (validate_against_schema, validate_all_keys,
-                       validate_any_key)
+from .compound import validate_against_schema, validate_all_keys, validate_any_key
+from .hashes import validate_sha1, validate_sha1_git, validate_sha256
+from .simple import (
+    validate_bytes,
+    validate_datetime,
+    validate_enum,
+    validate_int,
+    validate_str,
+    validate_type,
+)

swh/model/fields/compound.py

@@ -6,7 +6,7 @@
 from collections import defaultdict
 import itertools
 
-from ..exceptions import ValidationError, NON_FIELD_ERRORS
+from ..exceptions import NON_FIELD_ERRORS, ValidationError
 
 
 def validate_against_schema(model, schema, value):
@@ -26,19 +26,19 @@ def validate_against_schema(model, schema, value):
 
     if not isinstance(value, dict):
         raise ValidationError(
-            'Unexpected type %(type)s for %(model)s, expected dict',
+            "Unexpected type %(type)s for %(model)s, expected dict",
             params={
-                'model': model,
-                'type': value.__class__.__name__,
+                "model": model,
+                "type": value.__class__.__name__,
             },
-            code='model-unexpected-type',
+            code="model-unexpected-type",
         )
 
     errors = defaultdict(list)
 
     for key, (mandatory, validators) in itertools.chain(
         ((k, v) for k, v in schema.items() if k != NON_FIELD_ERRORS),
-        [(NON_FIELD_ERRORS, (False, schema.get(NON_FIELD_ERRORS, [])))]
+        [(NON_FIELD_ERRORS, (False, schema.get(NON_FIELD_ERRORS, [])))],
     ):
         if not validators:
             continue
@@ -54,9 +54,9 @@ def validate_against_schema(model, schema, value):
                 if mandatory:
                     errors[key].append(
                         ValidationError(
-                            'Field %(field)s is mandatory',
-                            params={'field': key},
-                            code='model-field-mandatory',
+                            "Field %(field)s is mandatory",
+                            params={"field": key},
+                            code="model-field-mandatory",
                         )
                     )
 
@@ -74,19 +74,21 @@ def validate_against_schema(model, schema, value):
             else:
                 if not valid:
                     errdata = {
-                        'validator': validator.__name__,
+                        "validator": validator.__name__,
                     }
 
                     if key == NON_FIELD_ERRORS:
-                        errmsg = 'Validation of model %(model)s failed in ' \
-                                 '%(validator)s'
-                        errdata['model'] = model
-                        errcode = 'model-validation-failed'
+                        errmsg = (
+                            "Validation of model %(model)s failed in " "%(validator)s"
+                        )
+                        errdata["model"] = model
+                        errcode = "model-validation-failed"
                     else:
-                        errmsg = 'Validation of field %(field)s failed in ' \
-                                 '%(validator)s'
-                        errdata['field'] = key
-                        errcode = 'field-validation-failed'
+                        errmsg = (
+                            "Validation of field %(field)s failed in " "%(validator)s"
+                        )
+                        errdata["field"] = key
+                        errcode = "field-validation-failed"
 
                     errors[key].append(
                         ValidationError(errmsg, params=errdata, code=errcode)
@@ -102,11 +104,11 @@ def validate_all_keys(value, keys):
     """Validate that all the given keys are present in value"""
     missing_keys = set(keys) - set(value)
     if missing_keys:
-        missing_fields = ', '.join(sorted(missing_keys))
+        missing_fields = ", ".join(sorted(missing_keys))
         raise ValidationError(
-            'Missing mandatory fields %(missing_fields)s',
-            params={'missing_fields': missing_fields},
-            code='missing-mandatory-field'
+            "Missing mandatory fields %(missing_fields)s",
+            params={"missing_fields": missing_fields},
+            code="missing-mandatory-field",
         )
 
     return True
@@ -116,11 +118,11 @@ def validate_any_key(value, keys):
     """Validate that any of the given keys is present in value"""
     present_keys = set(keys) & set(value)
     if not present_keys:
-        missing_fields = ', '.join(sorted(keys))
+        missing_fields = ", ".join(sorted(keys))
         raise ValidationError(
-            'Must contain one of the alternative fields %(missing_fields)s',
-            params={'missing_fields': missing_fields},
-            code='missing-alternative-field',
+            "Must contain one of the alternative fields %(missing_fields)s",
+            params={"missing_fields": missing_fields},
+            code="missing-alternative-field",
         )
 
     return True

swh/model/fields/hashes.py

@@ -4,6 +4,7 @@
 # See top-level LICENSE file for more information
 
 import string
+
 from ..exceptions import ValidationError
 
 
@@ -22,22 +23,22 @@ def validate_hash(value, hash_type):
     """
 
     hash_lengths = {
-        'sha1': 20,
-        'sha1_git': 20,
-        'sha256': 32,
+        "sha1": 20,
+        "sha1_git": 20,
+        "sha256": 32,
     }
 
     hex_digits = set(string.hexdigits)
 
     if hash_type not in hash_lengths:
         raise ValidationError(
-            'Unexpected hash type %(hash_type)s, expected one of'
-            ' %(hash_types)s',
+            "Unexpected hash type %(hash_type)s, expected one of" " %(hash_types)s",
             params={
-                'hash_type': hash_type,
-                'hash_types': ', '.join(sorted(hash_lengths)),
+                "hash_type": hash_type,
+                "hash_types": ", ".join(sorted(hash_lengths)),
             },
-            code='unexpected-hash-type')
+            code="unexpected-hash-type",
+        )
 
     if isinstance(value, str):
         errors = []
@@ -48,10 +49,10 @@ def validate_hash(value, hash_type):
                     "Unexpected characters `%(unexpected_chars)s' for hash "
                     "type %(hash_type)s",
                     params={
-                        'unexpected_chars': ', '.join(sorted(extra_chars)),
-                        'hash_type': hash_type,
+                        "unexpected_chars": ", ".join(sorted(extra_chars)),
+                        "hash_type": hash_type,
                     },
-                    code='unexpected-hash-contents',
+                    code="unexpected-hash-contents",
                 )
             )
 
@@ -60,14 +61,14 @@ def validate_hash(value, hash_type):
         if length != expected_length:
             errors.append(
                 ValidationError(
-                    'Unexpected length %(length)d for hash type '
-                    '%(hash_type)s, expected %(expected_length)d',
+                    "Unexpected length %(length)d for hash type "
+                    "%(hash_type)s, expected %(expected_length)d",
                     params={
-                        'length': length,
-                        'expected_length': expected_length,
-                        'hash_type': hash_type,
+                        "length": length,
+                        "expected_length": expected_length,
+                        "hash_type": hash_type,
                     },
-                    code='unexpected-hash-length',
+                    code="unexpected-hash-length",
                 )
             )
 
@@ -81,37 +82,37 @@ def validate_hash(value, hash_type):
         expected_length = hash_lengths[hash_type]
         if length != expected_length:
             raise ValidationError(
-                'Unexpected length %(length)d for hash type '
-                '%(hash_type)s, expected %(expected_length)d',
+                "Unexpected length %(length)d for hash type "
+                "%(hash_type)s, expected %(expected_length)d",
                 params={
-                    'length': length,
-                    'expected_length': expected_length,
-                    'hash_type': hash_type,
+                    "length": length,
+                    "expected_length": expected_length,
+                    "hash_type": hash_type,
                 },
-                code='unexpected-hash-length',
+                code="unexpected-hash-length",
             )
 
         return True
 
     raise ValidationError(
-        'Unexpected type %(type)s for hash, expected str or bytes',
+        "Unexpected type %(type)s for hash, expected str or bytes",
         params={
-            'type': value.__class__.__name__,
+            "type": value.__class__.__name__,
         },
-        code='unexpected-hash-value-type',
+        code="unexpected-hash-value-type",
     )
 
 
 def validate_sha1(sha1):
     """Validate that sha1 is a valid sha1 hash"""
-    return validate_hash(sha1, 'sha1')
+    return validate_hash(sha1, "sha1")
 
 
 def validate_sha1_git(sha1_git):
     """Validate that sha1_git is a valid sha1_git hash"""
-    return validate_hash(sha1_git, 'sha1_git')
+    return validate_hash(sha1_git, "sha1_git")
 
 
 def validate_sha256(sha256):
     """Validate that sha256 is a valid sha256 hash"""
-    return validate_hash(sha256, 'sha256')
+    return validate_hash(sha256, "sha256")

swh/model/fields/simple.py

@@ -13,16 +13,16 @@ def validate_type(value, type):
     """Validate that value is an integer"""
     if not isinstance(value, type):
         if isinstance(type, tuple):
-            typestr = 'one of %s' % ', '.join(typ.__name__ for typ in type)
+            typestr = "one of %s" % ", ".join(typ.__name__ for typ in type)
         else:
             typestr = type.__name__
         raise ValidationError(
-            'Unexpected type %(type)s, expected %(expected_type)s',
+            "Unexpected type %(type)s, expected %(expected_type)s",
             params={
-                'type': value.__class__.__name__,
-                'expected_type': typestr,
+                "type": value.__class__.__name__,
+                "expected_type": typestr,
             },
-            code='unexpected-type'
+            code="unexpected-type",
         )
 
     return True
@@ -54,10 +54,12 @@ def validate_datetime(value):
         errors.append(e)
 
     if isinstance(value, datetime.datetime) and value.tzinfo is None:
-        errors.append(ValidationError(
-            'Datetimes must be timezone-aware in swh',
-            code='datetime-without-tzinfo',
-        ))
+        errors.append(
+            ValidationError(
+                "Datetimes must be timezone-aware in swh",
+                code="datetime-without-tzinfo",
+            )
+        )
 
     if errors:
         raise ValidationError(errors)
@@ -69,12 +71,12 @@ def validate_enum(value, expected_values):
     """Validate that value is contained in expected_values"""
     if value not in expected_values:
         raise ValidationError(
-            'Unexpected value %(value)s, expected one of %(expected_values)s',
+            "Unexpected value %(value)s, expected one of %(expected_values)s",
             params={
-                'value': value,
-                'expected_values': ', '.join(sorted(expected_values)),
+                "value": value,
+                "expected_values": ", ".join(sorted(expected_values)),
             },
-            code='unexpected-value',
+            code="unexpected-value",
         )
 
     return True

swh/model/git.py

-# Copyright (C) 2015  The Software Heritage developers
-# See the AUTHORS file at the top-level directory of this distribution
-# License: GNU General Public License version 3, or any later version
-# See top-level LICENSE file for more information
-
-
-import os
-
-from enum import Enum
-
-from swh.model import hashutil, identifiers
-
-
-ROOT_TREE_KEY = b''
-
-
-class GitType(Enum):
-    BLOB = b'blob'
-    TREE = b'tree'
-    EXEC = b'exec'
-    LINK = b'link'
-    COMM = b'commit'
-    RELE = b'release'
-    REFS = b'ref'
-
-
-class GitPerm(Enum):
-    BLOB = b'100644'
-    TREE = b'40000'
-    EXEC = b'100755'
-    LINK = b'120000'
-
-
-def compute_directory_git_sha1(dirpath, hashes):
-    """Compute a directory git sha1 for a dirpath.
-
-    Args:
-        dirpath: the directory's absolute path
-        hashes: list of tree entries with keys:
-            - sha1_git: the tree entry's sha1
-            - name: file or subdir's name
-            - perms: the tree entry's sha1 permissions
-
-        Returns:
-            the binary sha1 of the dictionary's identifier
-
-        Assumes:
-            Every path exists in hashes.
-
-    """
-    directory = {
-        'entries':
-        [
-            {
-                'name': entry['name'],
-                'perms': int(entry['perms'].value, 8),
-                'target': entry['sha1_git'],
-                'type': 'dir' if entry['perms'] == GitPerm.TREE else 'file',
-            }
-            for entry in hashes[dirpath]
-        ]
-    }
-    return hashutil.hash_to_bytes(identifiers.directory_identifier(directory))
-
-
-def compute_revision_sha1_git(revision):
-    """Compute a revision sha1 git from its dict representation.
-
-    Args:
-        revision: Additional dictionary information needed to compute a
-        synthetic
-        revision. Following keys are expected:
-            - author
-            - date
-            - committer
-            - committer_date
-            - message
-            - type
-            - directory: binary form of the tree hash
-
-    Returns:
-        revision sha1 in bytes
-
-    # FIXME: beware, bytes output from storage api
-
-    """
-    return hashutil.hash_to_bytes(identifiers.revision_identifier(revision))
-
-
-def compute_release_sha1_git(release):
-    """Compute a release sha1 git from its dict representation.
-
-    Args:
-        release: Additional dictionary information needed to compute a
-        synthetic release. Following keys are expected:
-            - name
-            - message
-            - date
-            - author
-            - revision: binary form of the sha1_git revision targeted by this
-
-    Returns:
-        release sha1 in bytes
-
-    """
-    return hashutil.hash_to_bytes(identifiers.release_identifier(release))
-
-
-def compute_link_metadata(linkpath):
-    """Given a linkpath, compute the git metadata.
-
-    Args:
-        linkpath: absolute pathname of the link
-
-    Returns:
-        Dictionary of values:
-            - name: basename of the link
-            - perms: git permission for link
-            - type: git type for link
-    """
-    data = os.readlink(linkpath)
-    link_metadata = hashutil.hash_data(data)
-    link_metadata.update({
-        'data': data,
-        'length': len(data),
-        'name': os.path.basename(linkpath),
-        'perms': GitPerm.LINK,
-        'type': GitType.BLOB,
-        'path': linkpath
-    })
-
-    return link_metadata
-
-
-def compute_blob_metadata(filepath):
-    """Given a filepath, compute the git metadata.
-
-    Args:
-        filepath: absolute pathname of the file.
-
-    Returns:
-        Dictionary of values:
-            - name: basename of the file
-            - perms: git permission for file
-            - type: git type for file
-
-    """
-    blob_metadata = hashutil.hash_path(filepath)
-    perms = GitPerm.EXEC if os.access(filepath, os.X_OK) else GitPerm.BLOB
-    blob_metadata.update({
-        'name': os.path.basename(filepath),
-        'perms': perms,
-        'type': GitType.BLOB,
-        'path': filepath
-    })
-
-    return blob_metadata
-
-
-def compute_tree_metadata(dirname, ls_hashes):
-    """Given a dirname, compute the git metadata.
-
-    Args:
-        dirname: absolute pathname of the directory.
-
-    Returns:
-        Dictionary of values:
-            - name: basename of the directory
-            - perms: git permission for directory
-            - type: git type for directory
-
-    """
-    return {
-        'sha1_git': compute_directory_git_sha1(dirname, ls_hashes),
-        'name': os.path.basename(dirname),
-        'perms': GitPerm.TREE,
-        'type': GitType.TREE,
-        'path': dirname
-    }
-
-
-def walk_and_compute_sha1_from_directory(rootdir,
-                                         dir_ok_fn=lambda dirpath: True):
-    """Compute git sha1 from directory rootdir.
-
-    Args:
-        - rootdir: Root directory from which beginning the git hash computation
-
-        - dir_ok_fn: Filter function to filter directory according to rules
-        defined in the function. By default, all folders are ok.
-        Example override: dir_ok_fn = lambda dirpath: b'svn' not in dirpath
-
-    Returns:
-        Dictionary of entries with keys <path-name> and as values a list of
-        directory entries.
-        Those are list of dictionary with keys:
-          - 'perms'
-          - 'type'
-          - 'name'
-          - 'sha1_git'
-          - and specifically content: 'sha1', 'sha256', ...
-
-    Note:
-        One special key is ROOT_TREE_KEY to indicate the upper root of the
-        directory (this is the revision's directory).
-
-    Raises:
-        Nothing
-        If something is raised, this is a programmatic error.
-
-    """
-    ls_hashes = {}
-    all_links = set()
-
-    def filtfn(dirpath, dirnames):
-        return list(filter(lambda dirname: dir_ok_fn(os.path.join(dirpath,
-                                                                  dirname)),
-                           dirnames))
-
-    gen_dir = ((dp, filtfn(dp, dns), fns) for (dp, dns, fns)
-               in os.walk(rootdir, topdown=False)
-               if dir_ok_fn(dp))
-
-    for dirpath, dirnames, filenames in gen_dir:
-        hashes = []
-
-        links = (os.path.join(dirpath, file)
-                 for file in (filenames+dirnames)
-                 if os.path.islink(os.path.join(dirpath, file)))
-
-        for linkpath in links:
-            all_links.add(linkpath)
-            m_hashes = compute_link_metadata(linkpath)
-            hashes.append(m_hashes)
-
-        only_files = (os.path.join(dirpath, file)
-                      for file in filenames
-                      if os.path.join(dirpath, file) not in all_links)
-        for filepath in only_files:
-            m_hashes = compute_blob_metadata(filepath)
-            hashes.append(m_hashes)
-
-        ls_hashes[dirpath] = hashes
-
-        dir_hashes = []
-        subdirs = (os.path.join(dirpath, dir)
-                   for dir in dirnames
-                   if os.path.join(dirpath, dir)
-                   not in all_links)
-        for fulldirname in subdirs:
-            tree_hash = compute_tree_metadata(fulldirname, ls_hashes)
-            dir_hashes.append(tree_hash)
-
-        ls_hashes[dirpath].extend(dir_hashes)
-
-    # compute the current directory hashes
-    root_hash = {
-        'sha1_git': compute_directory_git_sha1(rootdir, ls_hashes),
-        'path': rootdir,
-        'name': os.path.basename(rootdir),
-        'perms': GitPerm.TREE,
-        'type': GitType.TREE
-    }
-    ls_hashes[ROOT_TREE_KEY] = [root_hash]
-
-    return ls_hashes

swh/model/hashutil.py

-# Copyright (C) 2015  The Software Heritage developers
+# Copyright (C) 2015-2018  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
+"""Module in charge of hashing function definitions. This is the base
+module use to compute swh's hashes.
+
+Only a subset of hashing algorithms is supported as defined in the
+ALGORITHMS set. Any provided algorithms not in that list will result
+in a ValueError explaining the error.
+
+This module defines a MultiHash class to ease the softwareheritage
+hashing algorithms computation. This allows to compute hashes from
+file object, path, data using a similar interface as what the standard
+hashlib module provides.
+
+Basic usage examples:
+
+- file object: MultiHash.from_file(
+                 file_object, hash_names=DEFAULT_ALGORITHMS).digest()
+
+- path (filepath): MultiHash.from_path(b'foo').hexdigest()
+
+- data (bytes): MultiHash.from_data(b'foo').bytehexdigest()
+
+
+"Complex" usage, defining a swh hashlib instance first:
+
+- To compute length, integrate the length to the set of algorithms to
+  compute, for example:
+
+  .. code-block:: python
+
+     h = MultiHash(hash_names=set({'length'}).union(DEFAULT_ALGORITHMS))
+     with open(filepath, 'rb') as f:
+         h.update(f.read(HASH_BLOCK_SIZE))
+     hashes = h.digest()  # returns a dict of {hash_algo_name: hash_in_bytes}
+
+- Write alongside computing hashing algorithms (from a stream), example:
+
+  .. code-block:: python
+
+     h = MultiHash(length=length)
+     with open(filepath, 'wb') as f:
+         for chunk in r.iter_content():  # r a stream of sort
+             h.update(chunk)
+             f.write(chunk)
+     hashes = h.hexdigest()  # returns a dict of {hash_algo_name: hash_in_hex}
+
+
+"""
+
 import binascii
 import functools
 import hashlib
 from io import BytesIO
 import os
+from typing import Callable, Dict, Optional, Union
+
+ALGORITHMS = set(
+    ["sha1", "sha256", "sha1_git", "blake2s256", "blake2b512", "md5", "sha512"]
+)
+"""Hashing algorithms supported by this module"""
+
+DEFAULT_ALGORITHMS = set(["sha1", "sha256", "sha1_git", "blake2s256"])
+"""Algorithms computed by default when calling the functions from this module.
 
-# supported hashing algorithms
-ALGORITHMS = set(['sha1', 'sha256', 'sha1_git'])
+Subset of :const:`ALGORITHMS`.
+"""
 
-# should be a multiple of 64 (sha1/sha256's block size)
-# FWIW coreutils' sha1sum uses 32768
 HASH_BLOCK_SIZE = 32768
+"""Block size for streaming hash computations made in this module"""
+
+_blake2_hash_cache: Dict[str, Callable] = {}
+
 
+class MultiHash:
+    """Hashutil class to support multiple hashes computation.
 
-def _new_git_hash(base_algo, git_type, length):
-    """Initialize a digest object (as returned by python's hashlib) for the
-    requested algorithm, and feed it with the header for a git object of the
-    given type and length.
+    Args:
+
+        hash_names (set): Set of hash algorithms (+ optionally length)
+                          to compute hashes (cf. DEFAULT_ALGORITHMS)
+        length (int): Length of the total sum of chunks to read
+
+    If the length is provided as algorithm, the length is also
+    computed and returned.
 
-    The header for hashing a git object consists of:
+    """
+
+    def __init__(self, hash_names=DEFAULT_ALGORITHMS, length=None):
+        self.state = {}
+        self.track_length = False
+        for name in hash_names:
+            if name == "length":
+                self.state["length"] = 0
+                self.track_length = True
+            else:
+                self.state[name] = _new_hash(name, length)
+
+    @classmethod
+    def from_state(cls, state, track_length):
+        ret = cls([])
+        ret.state = state
+        ret.track_length = track_length
+
+    @classmethod
+    def from_file(cls, fobj, hash_names=DEFAULT_ALGORITHMS, length=None):
+        ret = cls(length=length, hash_names=hash_names)
+        while True:
+            chunk = fobj.read(HASH_BLOCK_SIZE)
+            if not chunk:
+                break
+            ret.update(chunk)
+        return ret
+
+    @classmethod
+    def from_path(cls, path, hash_names=DEFAULT_ALGORITHMS):
+        length = os.path.getsize(path)
+        with open(path, "rb") as f:
+            ret = cls.from_file(f, hash_names=hash_names, length=length)
+        return ret
+
+    @classmethod
+    def from_data(cls, data, hash_names=DEFAULT_ALGORITHMS):
+        length = len(data)
+        fobj = BytesIO(data)
+        return cls.from_file(fobj, hash_names=hash_names, length=length)
+
+    def update(self, chunk):
+        for name, h in self.state.items():
+            if name == "length":
+                continue
+            h.update(chunk)
+        if self.track_length:
+            self.state["length"] += len(chunk)
+
+    def digest(self):
+        return {
+            name: h.digest() if name != "length" else h
+            for name, h in self.state.items()
+        }
+
+    def hexdigest(self):
+        return {
+            name: h.hexdigest() if name != "length" else h
+            for name, h in self.state.items()
+        }
+
+    def bytehexdigest(self):
+        return {
+            name: hash_to_bytehex(h.digest()) if name != "length" else h
+            for name, h in self.state.items()
+        }
+
+    def copy(self):
+        copied_state = {
+            name: h.copy() if name != "length" else h for name, h in self.state.items()
+        }
+        return self.from_state(copied_state, self.track_length)
+
+
+def _new_blake2_hash(algo):
+    """Return a function that initializes a blake2 hash."""
+    if algo in _blake2_hash_cache:
+        return _blake2_hash_cache[algo]()
+
+    lalgo = algo.lower()
+    if not lalgo.startswith("blake2"):
+        raise ValueError("Algorithm %s is not a blake2 hash" % algo)
+
+    blake_family = lalgo[:7]
+
+    digest_size = None
+    if lalgo[7:]:
+        try:
+            digest_size, remainder = divmod(int(lalgo[7:]), 8)
+        except ValueError:
+            raise ValueError("Unknown digest size for algo %s" % algo) from None
+        if remainder:
+            raise ValueError(
+                "Digest size for algorithm %s must be a multiple of 8" % algo
+            )
+
+    blake2 = getattr(hashlib, blake_family)
+    _blake2_hash_cache[algo] = lambda: blake2(digest_size=digest_size)
+
+    return _blake2_hash_cache[algo]()
+
+
+def _new_hashlib_hash(algo):
+    """Initialize a digest object from hashlib.
+
+    Handle the swh-specific names for the blake2-related algorithms
+    """
+    if algo.startswith("blake2"):
+        return _new_blake2_hash(algo)
+    else:
+        return hashlib.new(algo)
+
+
+def git_object_header(git_type: str, length: int) -> bytes:
+    """Returns the header for a git object of the given type and length.
+
+    The header of a git object consists of:
      - The type of the object (encoded in ASCII)
      - One ASCII space (\x20)
      - The length of the object (decimal encoded in ASCII)
      - One NUL byte
 
     Args:
-        base_algo: a hashlib-supported algorithm
+        base_algo (str from :const:`ALGORITHMS`): a hashlib-supported algorithm
         git_type: the type of the git object (supposedly one of 'blob',
                   'commit', 'tag', 'tree')
         length: the length of the git object you're encoding
@@ -37,25 +218,36 @@ def _new_git_hash(base_algo, git_type, length):
     Returns:
         a hashutil.hash object
     """
+    git_object_types = {
+        "blob",
+        "tree",
+        "commit",
+        "tag",
+        "snapshot",
+        "raw_extrinsic_metadata",
+        "extid",
+    }
 
-    h = hashlib.new(base_algo)
-    git_header = '%s %d\0' % (git_type, length)
-    h.update(git_header.encode('ascii'))
+    if git_type not in git_object_types:
+        raise ValueError(
+            "Unexpected git object type %s, expected one of %s"
+            % (git_type, ", ".join(sorted(git_object_types)))
+        )
 
-    return h
+    return ("%s %d\0" % (git_type, length)).encode("ascii")
 
 
-def _new_hash(algo, length=None):
-    """Initialize a digest object (as returned by python's hashlib) for the
-    requested algorithm. See the constant ALGORITHMS for the list of supported
-    algorithms. If a git-specific hashing algorithm is requested (e.g.,
-    "sha1_git"), the hashing object will be pre-fed with the needed header; for
-    this to work, length must be given.
+def _new_hash(algo: str, length: Optional[int] = None):
+    """Initialize a digest object (as returned by python's hashlib) for
+    the requested algorithm. See the constant ALGORITHMS for the list
+    of supported algorithms. If a git-specific hashing algorithm is
+    requested (e.g., "sha1_git"), the hashing object will be pre-fed
+    with the needed header; for this to work, length must be given.
 
     Args:
-        algo: a hashing algorithm (one of ALGORITHMS)
-        length: the length of the hashed payload (needed for git-specific
-                algorithms)
+        algo (str): a hashing algorithm (one of ALGORITHMS)
+        length (int): the length of the hashed payload (needed for
+          git-specific algorithms)
 
     Returns:
         a hashutil.hash object
@@ -63,125 +255,99 @@ def _new_hash(algo, length=None):
     Raises:
         ValueError if algo is unknown, or length is missing for a git-specific
         hash.
+
     """
     if algo not in ALGORITHMS:
-        raise ValueError('Unexpected hashing algorithm %s, '
-                         'expected one of %s' %
-                         (algo, ', '.join(sorted(ALGORITHMS))))
+        raise ValueError(
+            "Unexpected hashing algorithm %s, expected one of %s"
+            % (algo, ", ".join(sorted(ALGORITHMS)))
+        )
 
-    h = None
-    if algo.endswith('_git'):
+    if algo.endswith("_git"):
         if length is None:
-            raise ValueError('Missing length for git hashing algorithm')
+            raise ValueError("Missing length for git hashing algorithm")
         base_algo = algo[:-4]
-        h = _new_git_hash(base_algo, 'blob', length)
-    else:
-        h = hashlib.new(algo)
+        h = _new_hashlib_hash(base_algo)
+        h.update(git_object_header("blob", length))
+        return h
 
-    return h
+    return _new_hashlib_hash(algo)
 
 
-def hash_file(fobj, length=None, algorithms=ALGORITHMS, chunk_cb=None):
-    """Hash the contents of the given file object with the given algorithms.
+def hash_git_data(data, git_type, base_algo="sha1"):
+    """Hash the given data as a git object of type git_type.
 
     Args:
-        fobj: a file-like object
-        length: the length of the contents of the file-like object (for the
-                git-specific algorithms)
-        algorithms: the hashing algorithms used
+        data: a bytes object
+        git_type: the git object type
+        base_algo: the base hashing algorithm used (default: sha1)
 
-    Returns: a dict mapping each algorithm to a bytes digest.
+    Returns: a dict mapping each algorithm to a bytes digest
 
     Raises:
-        ValueError if algorithms contains an unknown hash algorithm.
+        ValueError if the git_type is unexpected.
     """
-    hashes = {algo: _new_hash(algo, length) for algo in algorithms}
-
-    while True:
-        chunk = fobj.read(HASH_BLOCK_SIZE)
-        if not chunk:
-            break
-        for hash in hashes.values():
-            hash.update(chunk)
-        if chunk_cb:
-            chunk_cb(chunk)
+    h = _new_hashlib_hash(base_algo)
+    h.update(git_object_header(git_type, len(data)))
+    h.update(data)
 
-    return {algo: hash.digest() for algo, hash in hashes.items()}
+    return h.digest()
 
 
-def hash_path(path, algorithms=ALGORITHMS, chunk_cb=None):
-    """Hash the contents of the file at the given path with the given algorithms.
+@functools.lru_cache()
+def hash_to_hex(hash: Union[str, bytes]) -> str:
+    """Converts a hash (in hex or bytes form) to its hexadecimal ascii form
 
     Args:
-        path: the path of the file to hash
-        algorithms: the hashing algorithms used
-        chunk_cb: a callback
-
-    Returns: a dict mapping each algorithm to a bytes digest.
+      hash (str or bytes): a :class:`bytes` hash or a :class:`str` containing
+        the hexadecimal form of the hash
 
-    Raises:
-        ValueError if algorithms contains an unknown hash algorithm.
-        OSError on file access error
+    Returns:
+      str: the hexadecimal form of the hash
     """
-    length = os.path.getsize(path)
-    with open(path, 'rb') as fobj:
-        return hash_file(fobj, length, algorithms, chunk_cb)
+    if isinstance(hash, str):
+        return hash
+    return binascii.hexlify(hash).decode("ascii")
 
 
-def hash_data(data, algorithms=ALGORITHMS):
-    """Hash the given binary blob with the given algorithms.
+@functools.lru_cache()
+def hash_to_bytehex(hash: bytes) -> bytes:
+    """Converts a hash to its hexadecimal bytes representation
 
     Args:
-        data: a bytes object
-        algorithms: the hashing algorithms used
-
-    Returns: a dict mapping each algorithm to a bytes digest
+      hash (bytes): a :class:`bytes` hash
 
-    Raises:
-        TypeError if data does not support the buffer interface.
-        ValueError if algorithms contains an unknown hash algorithm.
+    Returns:
+      bytes: the hexadecimal form of the hash, as :class:`bytes`
     """
-    fobj = BytesIO(data)
-    return hash_file(fobj, len(data), algorithms)
+    return binascii.hexlify(hash)
 
 
-def hash_git_data(data, git_type, base_algo='sha1'):
-    """Hash the given data as a git object of type git_type.
+@functools.lru_cache()
+def hash_to_bytes(hash: Union[str, bytes]) -> bytes:
+    """Converts a hash (in hex or bytes form) to its raw bytes form
 
     Args:
-        data: a bytes object
-        git_type: the git object type
-        base_algo: the base hashing algorithm used (default: sha1)
+      hash (str or bytes): a :class:`bytes` hash or a :class:`str` containing
+        the hexadecimal form of the hash
 
-    Returns: a dict mapping each algorithm to a bytes digest
-
-    Raises:
-        ValueError if the git_type is unexpected.
+    Returns:
+      bytes: the :class:`bytes` form of the hash
     """
-
-    git_object_types = {'blob', 'tree', 'commit', 'tag'}
-
-    if git_type not in git_object_types:
-        raise ValueError('Unexpected git object type %s, expected one of %s' %
-                         (git_type, ', '.join(sorted(git_object_types))))
-
-    h = _new_git_hash(base_algo, git_type, len(data))
-    h.update(data)
-
-    return h.digest()
+    if isinstance(hash, bytes):
+        return hash
+    return bytes.fromhex(hash)
 
 
 @functools.lru_cache()
-def hash_to_hex(hash):
-    """Converts a hash (in hex or bytes form) to its hexadecimal ascii form"""
-    if isinstance(hash, str):
-        return hash
-    return binascii.hexlify(hash).decode('ascii')
+def bytehex_to_hash(hex: bytes) -> bytes:
+    """Converts a hexadecimal bytes representation of a hash to that hash
 
+    Args:
+      hash (bytes): a :class:`bytes` containing the hexadecimal form of the
+        hash encoded in ascii
 
-@functools.lru_cache()
-def hash_to_bytes(hash):
-    """Converts a hash (in hex or bytes form) to its raw bytes form"""
-    if isinstance(hash, bytes):
-        return hash
-    return bytes.fromhex(hash)
+    Returns:
+      bytes: the :class:`bytes` form of the hash
+    """
+    return hash_to_bytes(hex.decode())

swh/model/identifiers.py

-# Copyright (C) 2015  The Software Heritage developers
-# See the AUTHORS file at the top-level directory of this distribution
-# License: GNU General Public License version 3, or any later version
-# See top-level LICENSE file for more information
-
-import binascii
-import datetime
-from functools import lru_cache
-
-from . import hashutil
-
-
-@lru_cache()
-def identifier_to_bytes(identifier):
-    """Convert a text identifier to bytes.
-
-    Args:
-        identifier: an identifier, either a 40-char hexadecimal string or a
-                    bytes object of length 20
-    Returns:
-        The length 20 bytestring corresponding to the given identifier
-
-    Raises:
-        ValueError if the identifier is of an unexpected type or length.
-    """
-
-    if isinstance(identifier, bytes):
-        if len(identifier) != 20:
-            raise ValueError(
-                'Wrong length for bytes identifier %s, expected 20' %
-                len(identifier))
-        return identifier
-
-    if isinstance(identifier, str):
-        if len(identifier) != 40:
-            raise ValueError(
-                'Wrong length for str identifier %s, expected 40' %
-                len(identifier))
-        return bytes.fromhex(identifier)
-
-    raise ValueError('Wrong type for identifier %s, expected bytes or str' %
-                     identifier.__class__.__name__)
-
-
-@lru_cache()
-def identifier_to_str(identifier):
-    """Convert an identifier to an hexadecimal string.
-
-    Args:
-        identifier: an identifier, either a 40-char hexadecimal string or a
-                    bytes object of length 20
-    Returns:
-        The length 40 string corresponding to the given identifier, hex encoded
-
-    Raises:
-        ValueError if the identifier is of an unexpected type or length.
-    """
-
-    if isinstance(identifier, str):
-        if len(identifier) != 40:
-            raise ValueError(
-                'Wrong length for str identifier %s, expected 40' %
-                len(identifier))
-        return identifier
-
-    if isinstance(identifier, bytes):
-        if len(identifier) != 20:
-            raise ValueError(
-                'Wrong length for bytes identifier %s, expected 20' %
-                len(identifier))
-        return binascii.hexlify(identifier).decode()
-
-    raise ValueError('Wrong type for identifier %s, expected bytes or str' %
-                     identifier.__class__.__name__)
-
-
-def content_identifier(content):
-    """Return the intrinsic identifier for a content.
-
-    A content's identifier is the sha1, sha1_git and sha256 checksums of its
-    data.
-
-    Args:
-        content: a content conforming to the Software Heritage schema
-
-    Returns:
-        A dictionary with all the hashes for the data
-
-    Raises:
-        KeyError if the content doesn't have a data member.
-
-    """
-
-    hashes = hashutil.hash_data(
-        content['data'],
-        {'sha1', 'sha1_git', 'sha256'},
-    )
-
-    return hashes
-
-
-def _sort_key(entry):
-    """The sorting key for tree entries"""
-    if entry['type'] == 'dir':
-        return entry['name'] + b'/'
-    else:
-        return entry['name']
-
-
-@lru_cache()
-def _perms_to_bytes(perms):
-    """Convert the perms value to its bytes representation"""
-    oc = oct(perms)[2:]
-    return oc.encode('ascii')
-
-
-def directory_identifier(directory):
-    """Return the intrinsic identifier for a directory.
-
-    A directory's identifier is the tree sha1 à la git of a directory listing,
-    using the following algorithm, which is equivalent to the git algorithm for
-    trees:
-
-    1. Entries of the directory are sorted using the name (or the name with '/'
-    appended for directory entries) as key, in bytes order.
-
-    2. For each entry of the directory, the following bytes are output:
-        - the octal representation of the permissions for the entry
-          (stored in the 'perms' member), which is a representation of the
-          entry type:
-            b'100644' (int 33188) for files
-            b'100755' (int 33261) for executable files
-            b'120000' (int 40960) for symbolic links
-            b'40000' (int 16384) for directories
-            b'160000' (int 57344) for references to revisions
-        - an ascii space (b'\x20')
-        - the entry's name (as raw bytes), stored in the 'name' member
-        - a null byte (b'\x00')
-        - the 20 byte long identifier of the object pointed at by the entry,
-          stored in the 'target' member:
-            for files or executable files: their blob sha1_git
-            for symbolic links: the blob sha1_git of a file containing the
-                                link destination
-            for directories: their intrinsic identifier
-            for revisions: their intrinsic identifier
-
-      (Note that there is no separator between entries)
-
-    """
-
-    components = []
-
-    for entry in sorted(directory['entries'], key=_sort_key):
-        components.extend([
-            _perms_to_bytes(entry['perms']),
-            b'\x20',
-            entry['name'],
-            b'\x00',
-            identifier_to_bytes(entry['target']),
-        ])
-
-    return identifier_to_str(hashutil.hash_git_data(b''.join(components),
-                                                    'tree'))
-
-
-def format_date(date):
-    """Convert a date object into an UTC timestamp encoded as ascii bytes.
-
-    Git stores timestamps as an integer number of seconds since the UNIX epoch.
-
-    However, Software Heritage stores timestamps as an integer number of
-    microseconds (postgres type "datetime with timezone").
-
-    Therefore, we print timestamps with no microseconds as integers, and
-    timestamps with microseconds as floating point values.
-
-    """
-    if isinstance(date, datetime.datetime):
-        if date.microsecond == 0:
-            date = int(date.timestamp())
-        else:
-            date = date.timestamp()
-        return str(date).encode()
-    else:
-        if date == int(date):
-            date = int(date)
-        return str(date).encode()
-
-
-@lru_cache()
-def format_offset(offset):
-    """Convert an integer number of minutes into an offset representation.
-
-    The offset representation is [+-]hhmm where:
-        hh is the number of hours;
-        mm is the number of minutes.
-
-    A null offset is represented as +0000.
-    """
-    if offset >= 0:
-        sign = '+'
-    else:
-        sign = '-'
-
-    hours = abs(offset) // 60
-    minutes = abs(offset) % 60
-
-    t = '%s%02d%02d' % (sign, hours, minutes)
-    return t.encode()
-
-
-def format_date_offset(date_offset):
-    """Format a date-compatible object with its timezone offset.
-
-    A date-compatible object is either:
-        - a dict with two members
-            timestamp: floating point number of seconds since the unix epoch
-            offset: (int) number of minutes representing the offset from UTC
-        - a datetime.datetime object with a timezone
-        - a numeric value (in which case the offset is hardcoded to 0)
-    """
-
-    # FIXME: move normalization to another module
-
-    if isinstance(date_offset, dict):
-        date = date_offset['timestamp']
-        offset = date_offset['offset']
-    elif isinstance(date_offset, datetime.datetime):
-        date = date_offset
-        utcoffset = date_offset.utcoffset()
-        if utcoffset is None:
-            raise ValueError('Received a datetime without a timezone')
-        seconds_offset = utcoffset.total_seconds()
-        if seconds_offset - int(seconds_offset) != 0 or seconds_offset % 60:
-            raise ValueError('Offset is not an integer number of minutes')
-        offset = int(seconds_offset) // 60
-    else:
-        date = date_offset
-        offset = 0
-
-    return b''.join([format_date(date), b' ', format_offset(offset)])
-
-
-def format_author(author):
-    return b''.join([author['name'], b' <', author['email'], b'>'])
-
-
-def revision_identifier(revision):
-    """Return the intrinsic identifier for a revision.
-    """
-    components = [
-        b'tree ', identifier_to_str(revision['directory']).encode(), b'\n',
-    ]
-    for parent in revision['parents']:
-        if parent:
-            components.extend([
-                b'parent ', identifier_to_str(parent).encode(), b'\n',
-            ])
-
-    components.extend([
-        b'author ', format_author(revision['author']),
-        b' ', format_date_offset(revision['date']), b'\n',
-        b'committer ', format_author(revision['committer']),
-        b' ', format_date_offset(revision['committer_date']), b'\n',
-        b'\n',
-        revision['message'],
-    ])
-
-    return identifier_to_str(hashutil.hash_git_data(b''.join(components),
-                                                    'commit'))
-
-
-def target_type_to_git(target_type):
-    """Convert a software heritage target type to a git object type"""
-    return {
-        'content': b'blob',
-        'directory': b'tree',
-        'revision': b'commit',
-        'release': b'tag',
-    }[target_type]
-
-
-def release_identifier(release):
-    """Return the intrinsic identifier for a release."""
-    components = [
-        b'object ', identifier_to_str(release['target']).encode(), b'\n',
-        b'type ', target_type_to_git(release['target_type']), b'\n',
-        b'tag ', release['name'], b'\n',
-    ]
-
-    if 'author' in release and release['author']:
-        components.extend([
-            b'tagger ', format_author(release['author']), b' ',
-            format_date_offset(release['date']), b'\n',
-        ])
-
-    components.extend([b'\n', release['message']])
-
-    return identifier_to_str(hashutil.hash_git_data(b''.join(components),
-                                                    'tag'))

swh/model/py.typed

+# Marker file for PEP 561.