ProgramVersionDatabase.py

import os.path
import pygit2
import yaml
 
class ProgramVersionDatabase:
    """
    Provides information on the versions of the OpenMPCD program.
    """
 
    def __init__(self):
        """
        The constructor.
 
        This will require a file `.OpenMPCD/config/ProgramVersionDatabase.yaml`
        to be readable, and contain in `repositoryPath` the path to the git
        repository of the `OpenMPCD` project. The path may contain an initial '~'
        character, which will be expanded to the user's home directory.
        """
 
        configPath = \
            os.path.expanduser("~/.OpenMPCD/config/ProgramVersionDatabase.yaml")
 
        config = yaml.safe_load(open(configPath, "r"))
 
        repoPath = os.path.expanduser(config["repositoryPath"])
 
        self.repository = pygit2.Repository(repoPath)
 
        self.knownBugs = {
            1: "ee7ec551c6f6d038d2a1195f35e4da8264f7f8e5",
            8: "62e287cb9d60906bf4b514291f42fc882d2d4f90",
            15: "9daa26741fb622759b4b32bef542441b693c7e22",
            18: "28b668cdf97e4a478c31bd17702bfacfddd2ed07",
            19: "53af091fd877cb52dcbe150aeaa5a8e03ebb67ca",
            }
 
 
    def returnCurrentRepositoryDescription(self):
        """
        Returns the current commit SHA1 id, with the string "+MODIFICATIONS"
        appended if any of the currently tracked files have been modified, and
        with the string "+UNTRACKED" appended if there are files which are not
        tracked.
        """
 
        modificationsString = "+MODIFICATIONS"
        untrackedString = "+UNTRACKED"
 
        description = \
            self.repository.describe(
                describe_strategy = pygit2.GIT_DESCRIBE_ALL,
                abbreviated_size = 100,
                dirty_suffix = modificationsString)
 
        modified = False
 
 
        if description.endswith(modificationsString):
            modified = True
            description = description[:-len(modificationsString)]
 
        commit = str(self.repository.revparse_single(description).id)
 
        ret = commit
        if modified:
            ret += modificationsString
 
        for path, flags in self.repository.status().items():
            if flags & pygit2.GIT_STATUS_WT_NEW:
                if not self.repository.path_is_ignored(path):
                    ret += untrackedString
                    break
 
        return ret
 
 
    def commitContainsNoKnownBugs(self, commit):
        """
        Returns whether the specified `commit` contains no known bugs.
        """
 
        for bugID, fixingCommit in self.knownBugs.items():
            if fixingCommit is None:
                return False
 
            if not self._gitCommitAContainsCommitB(commit, fixingCommit):
                return False
 
        return True
 
 
    def currentCommitContainsNoKnownBugs(self):
        """
        Returns whether the current commit contains no known bugs.
 
        Untracked and unstaged changes are ignored for this function.
        """
 
        return self.commitContainsNoKnownBugs(self._getCurrentGitCommit())
 
 
    def _getCurrentGitCommit(self):
        """
        Returns the commit ID of the current commit.
 
        Untracked and unstaged changes have no influence on the returned value.
        """
 
        description = \
            self.repository.describe(
                describe_strategy = pygit2.GIT_DESCRIBE_ALL,
                abbreviated_size = 100)
 
        return self.repository.revparse_single(description).id
 
 
    def _gitCommitAContainsCommitB(self, commitA, commitB):
        """
        Returns whether the commit specified in `commitA` contains in its
        history the commit specified in `commitB`.
        """
 
        if not isinstance(commitB, pygit2.Oid):
            commitB = pygit2.Oid(hex = commitB)
 
        for commit in self.repository.walk(commitA):
            if commit.id == commitB:
                return True
 
        return False
 
 
    def _currentCommitContainsCommitB(self, commitB):
        """
        Returns whether the current commit conatins in its history `commitB`.
        """
 
        return \
            self._gitCommitAContainsCommitB(
                self._getCurrentGitCommit(), commitB)