x/anvil
Code Issues Proposed changes

More comments + stable & defined op sorting order

Browse Source 
Add more comments to multipip explaining how the
ranking/scoring function works, and rename the logger
to denote that it's really a constant global value and
sort the operators (when versions are found to be
the same) in a explictly defined order (instead of the
more implicit sort order previously).

Change-Id: I948ee78367facbfcd1c593b1b0844ca5230a8bd5
This commit is contained in:
Joshua Harlow 2014-03-28 14:15:48 -07:00
parent d3e2377269
commit efcd5845fb
1 changed files with 33 additions and 7 deletions
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40
tools/multipip
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@ -16,9 +16,14 @@ import pip.req
import pkg_resources
# Use this for the sorting order of operators
OP_ORDER = ('!=', '==', '<', '<=', '>', '>=')
# Exit codes that are returned on various issues.
BAD_REQUIREMENTS = 2
INCOMPATIBLE_REQUIREMENTS = 3
logger = logging.getLogger()
LOGGER = logging.getLogger()
class RequirementException(Exception):
@ -69,8 +74,8 @@ def create_parser():
def setup_logging(options):
level = logging.DEBUG if options.debug else logging.WARNING
handler = logging.StreamHandler(sys.stderr)
logger.addHandler(handler)
logger.setLevel(level)
LOGGER.addHandler(handler)
LOGGER.setLevel(level)
def install_requirement_ensure_req_field(req):
@ -114,35 +119,54 @@ def iter_combinations(elements, include_empty=False):
def conflict_scorer(versioned):
"""Scores a list of (op, version) tuples, a higher score means more
conflicts while a lower score means less conflicts.
"""Scores a list of (op, version) tuples, a higher score means more likely
to cause conflicts while a lower score means less likely to cause
conflicts. A zero score means that no conflicts have been detected (aka
when installing no version issues will be encountered).
"""
if len(versioned) == 1:
# A single list has no capability to conflict with anything.
return 0
# Group by operator (and the versions that those operators are compatible
# with).
op_versions = collections.defaultdict(list)
for (op, version) in versioned:
op_versions[op].append(version)
score = 0
for version in sorted(op_versions.get("==", [])):
for (op, version2) in versioned:
# Any request for something not this version is a conflict.
if version != version2:
score += 1
# Any request for something is this version, but isn't '=='
# is also a conflict.
if version == version2 and op != "==":
score += 1
for version in sorted(op_versions.get("!=", [])):
for (op, version2) in versioned:
if op in ["!=", ">", "<"]:
continue
# Anything that is includes this version would be a conflict,
# thats why we exclude !=, <, and > from the above since
# those exclude versions.
if version2 == version:
score += 1
for version in sorted(op_versions.get(">", [])):
for (op, version2) in versioned:
if (op, version2) == (">", version):
continue
# A request for a lower version than the desired greater than
# version is a conflict.
if op in ["<", "<="] and version2 <= version:
score += 1
# A request for an inclusive version and matching with this
# version is also a conflict (since both can not be satisfied).
elif op in ["==", ">="] and version2 == version:
score += 1
# If another request asks for a version less than this version but
# also is asking for a greater than operator, that version spans
# a wider range of compatible versions and therefore we are in
# more of a conflict than that version.
elif op == ">" and version2 < version:
score += 1
elif op == ">=" and version2 <= version:
@ -244,11 +268,13 @@ def best_match(req_key, req_list):
return (req_list, [])
def spec_sort(spec1, spec2):
# Ensure there is always a well defined spec ordering so that the
# selection of matched specs is also well defined.
(op1, version1) = spec1
(op2, version2) = spec2
c = cmp(version1, version2)
if c == 0:
c = cmp(op1, op2)
c = cmp(OP_ORDER.index(op1), OP_ORDER.index(op2))
return c
def reform(specs, versions):
@ -405,7 +431,7 @@ def main():
try:
requirements, ignored_requirements = parse_requirements(options)
except RequirementException as ex:
logger.error("Requirement failure: %s", ex)
LOGGER.error("Requirement failure: %s", ex)
sys.exit(BAD_REQUIREMENTS)
else:
joined_requirements, incompatibles = join_requirements(requirements,