spack/lib/spack/spack/database.py

852 lines
31 KiB
Python

##############################################################################
# Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
# Produced at the Lawrence Livermore National Laboratory.
#
# This file is part of Spack.
# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
# LLNL-CODE-647188
#
# For details, see https://github.com/llnl/spack
# Please also see the NOTICE and LICENSE files for our notice and the LGPL.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License (as
# published by the Free Software Foundation) version 2.1, February 1999.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
# conditions of the GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
##############################################################################
"""Spack's installation tracking database.
The database serves two purposes:
1. It implements a cache on top of a potentially very large Spack
directory hierarchy, speeding up many operations that would
otherwise require filesystem access.
2. It will allow us to track external installations as well as lost
packages and their dependencies.
Prior to the implementation of this store, a directory layout served
as the authoritative database of packages in Spack. This module
provides a cache and a sanity checking mechanism for what is in the
filesystem.
"""
import os
import sys
import socket
import contextlib
from six import string_types
from six import iteritems
from yaml.error import MarkedYAMLError, YAMLError
import llnl.util.tty as tty
from llnl.util.filesystem import *
from llnl.util.lock import *
import spack.store
import spack.repository
import spack.spec
import spack.util.spack_yaml as syaml
import spack.util.spack_json as sjson
from spack.util.crypto import bit_length
from spack.directory_layout import DirectoryLayoutError
from spack.error import SpackError
from spack.version import Version
# DB goes in this directory underneath the root
_db_dirname = '.spack-db'
# DB version. This is stuck in the DB file to track changes in format.
_db_version = Version('0.9.3')
# Timeout for spack database locks in seconds
_db_lock_timeout = 60
# Types of dependencies tracked by the database
_tracked_deps = ('link', 'run')
def _autospec(function):
"""Decorator that automatically converts the argument of a single-arg
function to a Spec."""
def converter(self, spec_like, *args, **kwargs):
if not isinstance(spec_like, spack.spec.Spec):
spec_like = spack.spec.Spec(spec_like)
return function(self, spec_like, *args, **kwargs)
return converter
class InstallRecord(object):
"""A record represents one installation in the DB.
The record keeps track of the spec for the installation, its
install path, AND whether or not it is installed. We need the
installed flag in case a user either:
a) blew away a directory, or
b) used spack uninstall -f to get rid of it
If, in either case, the package was removed but others still
depend on it, we still need to track its spec, so we don't
actually remove from the database until a spec has no installed
dependents left.
"""
def __init__(self, spec, path, installed, ref_count=0, explicit=False):
self.spec = spec
self.path = str(path)
self.installed = bool(installed)
self.ref_count = ref_count
self.explicit = explicit
def to_dict(self):
return {
'spec': self.spec.to_node_dict(),
'path': self.path,
'installed': self.installed,
'ref_count': self.ref_count,
'explicit': self.explicit
}
@classmethod
def from_dict(cls, spec, dictionary):
d = dictionary
return InstallRecord(spec, d['path'], d['installed'], d['ref_count'],
d.get('explicit', False))
class Database(object):
"""Per-process lock objects for each install prefix."""
_prefix_locks = {}
def __init__(self, root, db_dir=None):
"""Create a Database for Spack installations under ``root``.
A Database is a cache of Specs data from ``$prefix/spec.yaml``
files in Spack installation directories.
By default, Database files (data and lock files) are stored
under ``root/.spack-db``, which is created if it does not
exist. This is the ``db_dir``.
The Database will attempt to read an ``index.json`` file in
``db_dir``. If it does not find one, it will fall back to read
an ``index.yaml`` if one is present. If that does not exist, it
will create a database when needed by scanning the entire
Database root for ``spec.yaml`` files according to Spack's
``DirectoryLayout``.
Caller may optionally provide a custom ``db_dir`` parameter
where data will be stored. This is intended to be used for
testing the Database class.
"""
self.root = root
if db_dir is None:
# If the db_dir is not provided, default to within the db root.
self._db_dir = join_path(self.root, _db_dirname)
else:
# Allow customizing the database directory location for testing.
self._db_dir = db_dir
# Set up layout of database files within the db dir
self._old_yaml_index_path = join_path(self._db_dir, 'index.yaml')
self._index_path = join_path(self._db_dir, 'index.json')
self._lock_path = join_path(self._db_dir, 'lock')
# This is for other classes to use to lock prefix directories.
self.prefix_lock_path = join_path(self._db_dir, 'prefix_lock')
# Create needed directories and files
if not os.path.exists(self._db_dir):
mkdirp(self._db_dir)
# initialize rest of state.
self.lock = Lock(self._lock_path)
self._data = {}
# whether there was an error at the start of a read transaction
self._error = None
def write_transaction(self, timeout=_db_lock_timeout):
"""Get a write lock context manager for use in a `with` block."""
return WriteTransaction(self.lock, self._read, self._write, timeout)
def read_transaction(self, timeout=_db_lock_timeout):
"""Get a read lock context manager for use in a `with` block."""
return ReadTransaction(self.lock, self._read, timeout=timeout)
def prefix_lock(self, spec):
"""Get a lock on a particular spec's installation directory.
NOTE: The installation directory **does not** need to exist.
Prefix lock is a byte range lock on the nth byte of a file.
The lock file is ``spack.store.db.prefix_lock`` -- the DB
tells us what to call it and it lives alongside the install DB.
n is the sys.maxsize-bit prefix of the DAG hash. This makes
likelihood of collision is very low AND it gives us
readers-writer lock semantics with just a single lockfile, so no
cleanup required.
"""
prefix = spec.prefix
if prefix not in self._prefix_locks:
self._prefix_locks[prefix] = Lock(
self.prefix_lock_path,
spec.dag_hash_bit_prefix(bit_length(sys.maxsize)), 1)
return self._prefix_locks[prefix]
@contextlib.contextmanager
def prefix_read_lock(self, spec):
prefix_lock = self.prefix_lock(spec)
try:
prefix_lock.acquire_read(60)
yield self
finally:
prefix_lock.release_read()
@contextlib.contextmanager
def prefix_write_lock(self, spec):
prefix_lock = self.prefix_lock(spec)
try:
prefix_lock.acquire_write(60)
yield self
finally:
prefix_lock.release_write()
def _write_to_file(self, stream):
"""Write out the databsae to a JSON file.
This function does not do any locking or transactions.
"""
# map from per-spec hash code to installation record.
installs = dict((k, v.to_dict()) for k, v in self._data.items())
# database includes installation list and version.
# NOTE: this DB version does not handle multiple installs of
# the same spec well. If there are 2 identical specs with
# different paths, it can't differentiate.
# TODO: fix this before we support multiple install locations.
database = {
'database': {
'installs': installs,
'version': str(_db_version)
}
}
try:
sjson.dump(database, stream)
except YAMLError as e:
raise syaml.SpackYAMLError(
"error writing YAML database:", str(e))
def _read_spec_from_dict(self, hash_key, installs):
"""Recursively construct a spec from a hash in a YAML database.
Does not do any locking.
"""
spec_dict = installs[hash_key]['spec']
# Install records don't include hash with spec, so we add it in here
# to ensure it is read properly.
for name in spec_dict:
spec_dict[name]['hash'] = hash_key
# Build spec from dict first.
spec = spack.spec.Spec.from_node_dict(spec_dict)
return spec
def _assign_dependencies(self, hash_key, installs, data):
# Add dependencies from other records in the install DB to
# form a full spec.
spec = data[hash_key].spec
spec_dict = installs[hash_key]['spec']
if 'dependencies' in spec_dict[spec.name]:
yaml_deps = spec_dict[spec.name]['dependencies']
for dname, dhash, dtypes in spack.spec.Spec.read_yaml_dep_specs(
yaml_deps):
if dhash not in data:
tty.warn("Missing dependency not in database: ",
"%s needs %s-%s" % (
spec.cformat('$_$/'), dname, dhash[:7]))
continue
child = data[dhash].spec
spec._add_dependency(child, dtypes)
def _read_from_file(self, stream, format='json'):
"""
Fill database from file, do not maintain old data
Translate the spec portions from node-dict form to spec form
Does not do any locking.
"""
if format.lower() == 'json':
load = sjson.load
elif format.lower() == 'yaml':
load = syaml.load
else:
raise ValueError("Invalid database format: %s" % format)
try:
if isinstance(stream, string_types):
with open(stream, 'r') as f:
fdata = load(f)
else:
fdata = load(stream)
except MarkedYAMLError as e:
raise syaml.SpackYAMLError("error parsing YAML database:", str(e))
except Exception as e:
raise CorruptDatabaseError("error parsing database:", str(e))
if fdata is None:
return
def check(cond, msg):
if not cond:
raise CorruptDatabaseError(
"Spack database is corrupt: %s" % msg, self._index_path)
check('database' in fdata, "No 'database' attribute in YAML.")
# High-level file checks
db = fdata['database']
check('installs' in db, "No 'installs' in YAML DB.")
check('version' in db, "No 'version' in YAML DB.")
installs = db['installs']
# TODO: better version checking semantics.
version = Version(db['version'])
if version > _db_version:
raise InvalidDatabaseVersionError(_db_version, version)
elif version < _db_version:
self.reindex(spack.store.layout)
installs = dict((k, v.to_dict()) for k, v in self._data.items())
def invalid_record(hash_key, error):
msg = ("Invalid record in Spack database: "
"hash: %s, cause: %s: %s")
msg %= (hash_key, type(e).__name__, str(e))
raise CorruptDatabaseError(msg, self._index_path)
# Build up the database in three passes:
#
# 1. Read in all specs without dependencies.
# 2. Hook dependencies up among specs.
# 3. Mark all specs concrete.
#
# The database is built up so that ALL specs in it share nodes
# (i.e., its specs are a true Merkle DAG, unlike most specs.)
# Pass 1: Iterate through database and build specs w/o dependencies
data = {}
for hash_key, rec in installs.items():
try:
# This constructs a spec DAG from the list of all installs
spec = self._read_spec_from_dict(hash_key, installs)
# Insert the brand new spec in the database. Each
# spec has its own copies of its dependency specs.
# TODO: would a more immmutable spec implementation simplify
# this?
data[hash_key] = InstallRecord.from_dict(spec, rec)
except Exception as e:
invalid_record(hash_key, e)
# Pass 2: Assign dependencies once all specs are created.
for hash_key in data:
try:
self._assign_dependencies(hash_key, installs, data)
except Exception as e:
invalid_record(hash_key, e)
# Pass 3: Mark all specs concrete. Specs representing real
# installations must be explicitly marked.
# We do this *after* all dependencies are connected because if we
# do it *while* we're constructing specs,it causes hashes to be
# cached prematurely.
for hash_key, rec in data.items():
rec.spec._mark_concrete()
self._data = data
def reindex(self, directory_layout):
"""Build database index from scratch based on a directory layout.
Locks the DB if it isn't locked already.
"""
# Special transaction to avoid recursive reindex calls and to
# ignore errors if we need to rebuild a corrupt database.
def _read_suppress_error():
try:
if os.path.isfile(self._index_path):
self._read_from_file(self._index_path)
except CorruptDatabaseError as e:
self._error = e
self._data = {}
transaction = WriteTransaction(
self.lock, _read_suppress_error, self._write, _db_lock_timeout
)
with transaction:
if self._error:
tty.warn(
"Spack database was corrupt. Will rebuild. Error was:",
str(self._error)
)
self._error = None
# Read first the `spec.yaml` files in the prefixes. They should be
# considered authoritative with respect to DB reindexing, as
# entries in the DB may be corrupted in a way that still makes
# them readable. If we considered DB entries authoritative
# instead, we would perpetuate errors over a reindex.
old_data = self._data
try:
# Initialize data in the reconstructed DB
self._data = {}
# Start inspecting the installed prefixes
processed_specs = set()
for spec in directory_layout.all_specs():
# Try to recover explicit value from old DB, but
# default it to True if DB was corrupt. This is
# just to be conservative in case a command like
# "autoremove" is run by the user after a reindex.
tty.debug(
'RECONSTRUCTING FROM SPEC.YAML: {0}'.format(spec))
explicit = True
if old_data is not None:
old_info = old_data.get(spec.dag_hash())
if old_info is not None:
explicit = old_info.explicit
self._add(spec, directory_layout, explicit=explicit)
processed_specs.add(spec)
for key, entry in old_data.items():
# We already took care of this spec using
# `spec.yaml` from its prefix.
if entry.spec in processed_specs:
msg = 'SKIPPING RECONSTRUCTION FROM OLD DB: {0}'
msg += ' [already reconstructed from spec.yaml]'
tty.debug(msg.format(entry.spec))
continue
# If we arrived here it very likely means that
# we have external specs that are not dependencies
# of other specs. This may be the case for externally
# installed compilers or externally installed
# applications.
tty.debug(
'RECONSTRUCTING FROM OLD DB: {0}'.format(entry.spec))
try:
layout = spack.store.layout
if entry.spec.external:
layout = None
install_check = True
else:
install_check = layout.check_installed(entry.spec)
if install_check:
kwargs = {
'spec': entry.spec,
'directory_layout': layout,
'explicit': entry.explicit
}
self._add(**kwargs)
processed_specs.add(entry.spec)
except Exception as e:
# Something went wrong, so the spec was not restored
# from old data
tty.debug(e.message)
pass
self._check_ref_counts()
except:
# If anything explodes, restore old data, skip write.
self._data = old_data
raise
def _check_ref_counts(self):
"""Ensure consistency of reference counts in the DB.
Raise an AssertionError if something is amiss.
Does no locking.
"""
counts = {}
for key, rec in self._data.items():
counts.setdefault(key, 0)
for dep in rec.spec.dependencies(_tracked_deps):
dep_key = dep.dag_hash()
counts.setdefault(dep_key, 0)
counts[dep_key] += 1
for rec in self._data.values():
key = rec.spec.dag_hash()
expected = counts[key]
found = rec.ref_count
if not expected == found:
raise AssertionError(
"Invalid ref_count: %s: %d (expected %d), in DB %s" %
(key, found, expected, self._index_path))
def _write(self, type, value, traceback):
"""Write the in-memory database index to its file path.
This is a helper function called by the WriteTransaction context
manager. If there is an exception while the write lock is active,
nothing will be written to the database file, but the in-memory
database *may* be left in an inconsistent state. It will be consistent
after the start of the next transaction, when it read from disk again.
This routine does no locking.
"""
# Do not write if exceptions were raised
if type is not None:
return
temp_file = self._index_path + (
'.%s.%s.temp' % (socket.getfqdn(), os.getpid()))
# Write a temporary database file them move it into place
try:
with open(temp_file, 'w') as f:
self._write_to_file(f)
os.rename(temp_file, self._index_path)
except:
# Clean up temp file if something goes wrong.
if os.path.exists(temp_file):
os.remove(temp_file)
raise
def _read(self):
"""Re-read Database from the data in the set location.
This does no locking, with one exception: it will automatically
migrate an index.yaml to an index.json if possible. This requires
taking a write lock.
"""
if os.path.isfile(self._index_path):
# Read from JSON file if a JSON database exists
self._read_from_file(self._index_path, format='json')
elif os.path.isfile(self._old_yaml_index_path):
if os.access(self._db_dir, os.R_OK | os.W_OK):
# if we can write, then read AND write a JSON file.
self._read_from_file(self._old_yaml_index_path, format='yaml')
with WriteTransaction(self.lock, timeout=_db_lock_timeout):
self._write(None, None, None)
else:
# Read chck for a YAML file if we can't find JSON.
self._read_from_file(self._old_yaml_index_path, format='yaml')
else:
# The file doesn't exist, try to traverse the directory.
# reindex() takes its own write lock, so no lock here.
with WriteTransaction(self.lock, timeout=_db_lock_timeout):
self._write(None, None, None)
self.reindex(spack.store.layout)
def _add(self, spec, directory_layout=None, explicit=False):
"""Add an install record for this spec to the database.
Assumes spec is installed in ``layout.path_for_spec(spec)``.
Also ensures dependencies are present and updated in the DB as
either intsalled or missing.
"""
if not spec.concrete:
raise NonConcreteSpecAddError(
"Specs added to DB must be concrete.")
for dep in spec.dependencies(_tracked_deps):
dkey = dep.dag_hash()
if dkey not in self._data:
self._add(dep, directory_layout, explicit=False)
key = spec.dag_hash()
if key not in self._data:
installed = bool(spec.external)
path = None
if not spec.external and directory_layout:
path = directory_layout.path_for_spec(spec)
try:
directory_layout.check_installed(spec)
installed = True
except DirectoryLayoutError as e:
tty.warn(
'Dependency missing due to corrupt install directory:',
path, str(e))
# Create a new install record with no deps initially.
new_spec = spec.copy(deps=False)
self._data[key] = InstallRecord(
new_spec, path, installed, ref_count=0, explicit=explicit)
# Connect dependencies from the DB to the new copy.
for name, dep in iteritems(spec.dependencies_dict(_tracked_deps)):
dkey = dep.spec.dag_hash()
new_spec._add_dependency(self._data[dkey].spec, dep.deptypes)
self._data[dkey].ref_count += 1
# Mark concrete once everything is built, and preserve
# the original hash of concrete specs.
new_spec._mark_concrete()
new_spec._hash = key
else:
# If it is already there, mark it as installed.
self._data[key].installed = True
self._data[key].explicit = explicit
@_autospec
def add(self, spec, directory_layout, explicit=False):
"""Add spec at path to database, locking and reading DB to sync.
``add()`` will lock and read from the DB on disk.
"""
# TODO: ensure that spec is concrete?
# Entire add is transactional.
with self.write_transaction():
self._add(spec, directory_layout, explicit=explicit)
def _get_matching_spec_key(self, spec, **kwargs):
"""Get the exact spec OR get a single spec that matches."""
key = spec.dag_hash()
if key not in self._data:
match = self.query_one(spec, **kwargs)
if match:
return match.dag_hash()
raise KeyError("No such spec in database! %s" % spec)
return key
@_autospec
def get_record(self, spec, **kwargs):
key = self._get_matching_spec_key(spec, **kwargs)
return self._data[key]
def _decrement_ref_count(self, spec):
key = spec.dag_hash()
if key not in self._data:
# TODO: print something here? DB is corrupt, but
# not much we can do.
return
rec = self._data[key]
rec.ref_count -= 1
if rec.ref_count == 0 and not rec.installed:
del self._data[key]
for dep in spec.dependencies(_tracked_deps):
self._decrement_ref_count(dep)
def _remove(self, spec):
"""Non-locking version of remove(); does real work.
"""
key = self._get_matching_spec_key(spec)
rec = self._data[key]
if rec.ref_count > 0:
rec.installed = False
return rec.spec
del self._data[key]
for dep in rec.spec.dependencies(_tracked_deps):
self._decrement_ref_count(dep)
# Returns the concrete spec so we know it in the case where a
# query spec was passed in.
return rec.spec
@_autospec
def remove(self, spec):
"""Removes a spec from the database. To be called on uninstall.
Reads the database, then:
1. Marks the spec as not installed.
2. Removes the spec if it has no more dependents.
3. If removed, recursively updates dependencies' ref counts
and removes them if they are no longer needed.
"""
# Take a lock around the entire removal.
with self.write_transaction():
return self._remove(spec)
@_autospec
def installed_relatives(self, spec, direction='children', transitive=True):
"""Return installed specs related to this one."""
if direction not in ('parents', 'children'):
raise ValueError("Invalid direction: %s" % direction)
relatives = set()
for spec in self.query(spec):
if transitive:
to_add = spec.traverse(direction=direction, root=False)
elif direction == 'parents':
to_add = spec.dependents()
else: # direction == 'children'
to_add = spec.dependencies()
for relative in to_add:
hash_key = relative.dag_hash()
if hash_key not in self._data:
reltype = ('Dependent' if direction == 'parents'
else 'Dependency')
tty.warn("Inconsistent state! %s %s of %s not in DB"
% (reltype, hash_key, spec.dag_hash()))
continue
if not self._data[hash_key].installed:
continue
relatives.add(relative)
return relatives
@_autospec
def installed_extensions_for(self, extendee_spec):
"""
Return the specs of all packages that extend
the given spec
"""
for spec in self.query():
try:
spack.store.layout.check_activated(extendee_spec, spec)
yield spec.package
except spack.directory_layout.NoSuchExtensionError:
continue
# TODO: conditional way to do this instead of catching exceptions
def query(self, query_spec=any, known=any, installed=True, explicit=any):
"""Run a query on the database.
``query_spec``
Queries iterate through specs in the database and return
those that satisfy the supplied ``query_spec``. If
query_spec is `any`, This will match all specs in the
database. If it is a spec, we'll evaluate
``spec.satisfies(query_spec)``.
The query can be constrained by two additional attributes:
``known``
Possible values: True, False, any
Specs that are "known" are those for which Spack can
locate a ``package.py`` file -- i.e., Spack "knows" how to
install them. Specs that are unknown may represent
packages that existed in a previous version of Spack, but
have since either changed their name or been removed.
``installed``
Possible values: True, False, any
Specs for which a prefix exists are "installed". A spec
that is NOT installed will be in the database if some
other spec depends on it but its installation has gone
away since Spack installed it.
TODO: Specs are a lot like queries. Should there be a
wildcard spec object, and should specs have attributes
like installed and known that can be queried? Or are
these really special cases that only belong here?
"""
with self.read_transaction():
# Just look up concrete specs with hashes; no fancy search.
if (isinstance(query_spec, spack.spec.Spec) and
query_spec._concrete):
hash_key = query_spec.dag_hash()
if hash_key in self._data:
return [self._data[hash_key].spec]
else:
return []
# Abstract specs require more work -- currently we test
# against everything.
results = []
for key, rec in self._data.items():
if installed is not any and rec.installed != installed:
continue
if explicit is not any and rec.explicit != explicit:
continue
if known is not any and spack.repo.exists(
rec.spec.name) != known:
continue
if query_spec is any or rec.spec.satisfies(query_spec):
results.append(rec.spec)
return sorted(results)
def query_one(self, query_spec, known=any, installed=True):
"""Query for exactly one spec that matches the query spec.
Raises an assertion error if more than one spec matches the
query. Returns None if no installed package matches.
"""
concrete_specs = self.query(query_spec, known, installed)
assert len(concrete_specs) <= 1
return concrete_specs[0] if concrete_specs else None
def missing(self, spec):
with self.read_transaction():
key = spec.dag_hash()
return key in self._data and not self._data[key].installed
class CorruptDatabaseError(SpackError):
"""Raised when errors are found while reading the database."""
class NonConcreteSpecAddError(SpackError):
"""Raised when attemptint to add non-concrete spec to DB."""
class InvalidDatabaseVersionError(SpackError):
def __init__(self, expected, found):
super(InvalidDatabaseVersionError, self).__init__(
"Expected database version %s but found version %s."
% (expected, found),
"`spack reindex` may fix this, or you may need a newer "
"Spack version.")