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Diffstat (limited to 'Lib/packaging/command/cmd.py')
| -rw-r--r-- | Lib/packaging/command/cmd.py | 440 |
1 files changed, 440 insertions, 0 deletions
diff --git a/Lib/packaging/command/cmd.py b/Lib/packaging/command/cmd.py new file mode 100644 index 0000000..fa56aa6 --- /dev/null +++ b/Lib/packaging/command/cmd.py @@ -0,0 +1,440 @@ +"""Base class for commands.""" + +import os +import re +from shutil import copyfile, move, make_archive +from packaging import util +from packaging import logger +from packaging.errors import PackagingOptionError + + +class Command: + """Abstract base class for defining command classes, the "worker bees" + of the Packaging. A useful analogy for command classes is to think of + them as subroutines with local variables called "options". The options + are "declared" in 'initialize_options()' and "defined" (given their + final values, aka "finalized") in 'finalize_options()', both of which + must be defined by every command class. The distinction between the + two is necessary because option values might come from the outside + world (command line, config file, ...), and any options dependent on + other options must be computed *after* these outside influences have + been processed -- hence 'finalize_options()'. The "body" of the + subroutine, where it does all its work based on the values of its + options, is the 'run()' method, which must also be implemented by every + command class. + """ + + # 'sub_commands' formalizes the notion of a "family" of commands, + # eg. "install_dist" as the parent with sub-commands "install_lib", + # "install_headers", etc. The parent of a family of commands + # defines 'sub_commands' as a class attribute; it's a list of + # (command_name : string, predicate : unbound_method | string | None) + # tuples, where 'predicate' is a method of the parent command that + # determines whether the corresponding command is applicable in the + # current situation. (Eg. we "install_headers" is only applicable if + # we have any C header files to install.) If 'predicate' is None, + # that command is always applicable. + # + # 'sub_commands' is usually defined at the *end* of a class, because + # predicates can be unbound methods, so they must already have been + # defined. The canonical example is the "install_dist" command. + sub_commands = [] + + # Pre and post command hooks are run just before or just after the command + # itself. They are simple functions that receive the command instance. They + # are specified as callable objects or dotted strings (for lazy loading). + pre_hook = None + post_hook = None + + # -- Creation/initialization methods ------------------------------- + + def __init__(self, dist): + """Create and initialize a new Command object. Most importantly, + invokes the 'initialize_options()' method, which is the real + initializer and depends on the actual command being instantiated. + """ + # late import because of mutual dependence between these classes + from packaging.dist import Distribution + + if not isinstance(dist, Distribution): + raise TypeError("dist must be a Distribution instance") + if self.__class__ is Command: + raise RuntimeError("Command is an abstract class") + + self.distribution = dist + self.initialize_options() + + # Per-command versions of the global flags, so that the user can + # customize Packaging' behaviour command-by-command and let some + # commands fall back on the Distribution's behaviour. None means + # "not defined, check self.distribution's copy", while 0 or 1 mean + # false and true (duh). Note that this means figuring out the real + # value of each flag is a touch complicated -- hence "self._dry_run" + # will be handled by a property, below. + # XXX This needs to be fixed. [I changed it to a property--does that + # "fix" it?] + self._dry_run = None + + # Some commands define a 'self.force' option to ignore file + # timestamps, but methods defined *here* assume that + # 'self.force' exists for all commands. So define it here + # just to be safe. + self.force = None + + # The 'help' flag is just used for command line parsing, so + # none of that complicated bureaucracy is needed. + self.help = False + + # 'finalized' records whether or not 'finalize_options()' has been + # called. 'finalize_options()' itself should not pay attention to + # this flag: it is the business of 'ensure_finalized()', which + # always calls 'finalize_options()', to respect/update it. + self.finalized = False + + # XXX A more explicit way to customize dry_run would be better. + @property + def dry_run(self): + if self._dry_run is None: + return getattr(self.distribution, 'dry_run') + else: + return self._dry_run + + def ensure_finalized(self): + if not self.finalized: + self.finalize_options() + self.finalized = True + + # Subclasses must define: + # initialize_options() + # provide default values for all options; may be customized by + # setup script, by options from config file(s), or by command-line + # options + # finalize_options() + # decide on the final values for all options; this is called + # after all possible intervention from the outside world + # (command line, option file, etc.) has been processed + # run() + # run the command: do whatever it is we're here to do, + # controlled by the command's various option values + + def initialize_options(self): + """Set default values for all the options that this command + supports. Note that these defaults may be overridden by other + commands, by the setup script, by config files, or by the + command line. Thus, this is not the place to code dependencies + between options; generally, 'initialize_options()' implementations + are just a bunch of "self.foo = None" assignments. + + This method must be implemented by all command classes. + """ + raise RuntimeError( + "abstract method -- subclass %s must override" % self.__class__) + + def finalize_options(self): + """Set final values for all the options that this command supports. + This is always called as late as possible, ie. after any option + assignments from the command line or from other commands have been + done. Thus, this is the place to code option dependencies: if + 'foo' depends on 'bar', then it is safe to set 'foo' from 'bar' as + long as 'foo' still has the same value it was assigned in + 'initialize_options()'. + + This method must be implemented by all command classes. + """ + raise RuntimeError( + "abstract method -- subclass %s must override" % self.__class__) + + def dump_options(self, header=None, indent=""): + if header is None: + header = "command options for '%s':" % self.get_command_name() + logger.info(indent + header) + indent = indent + " " + negative_opt = getattr(self, 'negative_opt', ()) + for option, _, _ in self.user_options: + if option in negative_opt: + continue + option = option.replace('-', '_') + if option[-1] == "=": + option = option[:-1] + value = getattr(self, option) + logger.info(indent + "%s = %s", option, value) + + def run(self): + """A command's raison d'etre: carry out the action it exists to + perform, controlled by the options initialized in + 'initialize_options()', customized by other commands, the setup + script, the command line and config files, and finalized in + 'finalize_options()'. All terminal output and filesystem + interaction should be done by 'run()'. + + This method must be implemented by all command classes. + """ + raise RuntimeError( + "abstract method -- subclass %s must override" % self.__class__) + + # -- External interface -------------------------------------------- + # (called by outsiders) + + def get_source_files(self): + """Return the list of files that are used as inputs to this command, + i.e. the files used to generate the output files. The result is used + by the `sdist` command in determining the set of default files. + + Command classes should implement this method if they operate on files + from the source tree. + """ + return [] + + def get_outputs(self): + """Return the list of files that would be produced if this command + were actually run. Not affected by the "dry-run" flag or whether + any other commands have been run. + + Command classes should implement this method if they produce any + output files that get consumed by another command. e.g., `build_ext` + returns the list of built extension modules, but not any temporary + files used in the compilation process. + """ + return [] + + # -- Option validation methods ------------------------------------- + # (these are very handy in writing the 'finalize_options()' method) + # + # NB. the general philosophy here is to ensure that a particular option + # value meets certain type and value constraints. If not, we try to + # force it into conformance (eg. if we expect a list but have a string, + # split the string on comma and/or whitespace). If we can't force the + # option into conformance, raise PackagingOptionError. Thus, command + # classes need do nothing more than (eg.) + # self.ensure_string_list('foo') + # and they can be guaranteed that thereafter, self.foo will be + # a list of strings. + + def _ensure_stringlike(self, option, what, default=None): + val = getattr(self, option) + if val is None: + setattr(self, option, default) + return default + elif not isinstance(val, str): + raise PackagingOptionError("'%s' must be a %s (got `%s`)" % + (option, what, val)) + return val + + def ensure_string(self, option, default=None): + """Ensure that 'option' is a string; if not defined, set it to + 'default'. + """ + self._ensure_stringlike(option, "string", default) + + def ensure_string_list(self, option): + r"""Ensure that 'option' is a list of strings. If 'option' is + currently a string, we split it either on /,\s*/ or /\s+/, so + "foo bar baz", "foo,bar,baz", and "foo, bar baz" all become + ["foo", "bar", "baz"]. + """ + val = getattr(self, option) + if val is None: + return + elif isinstance(val, str): + setattr(self, option, re.split(r',\s*|\s+', val)) + else: + if isinstance(val, list): + # checks if all elements are str + ok = True + for element in val: + if not isinstance(element, str): + ok = False + break + else: + ok = False + + if not ok: + raise PackagingOptionError( + "'%s' must be a list of strings (got %r)" % (option, val)) + + def _ensure_tested_string(self, option, tester, + what, error_fmt, default=None): + val = self._ensure_stringlike(option, what, default) + if val is not None and not tester(val): + raise PackagingOptionError( + ("error in '%s' option: " + error_fmt) % (option, val)) + + def ensure_filename(self, option): + """Ensure that 'option' is the name of an existing file.""" + self._ensure_tested_string(option, os.path.isfile, + "filename", + "'%s' does not exist or is not a file") + + def ensure_dirname(self, option): + self._ensure_tested_string(option, os.path.isdir, + "directory name", + "'%s' does not exist or is not a directory") + + # -- Convenience methods for commands ------------------------------ + + @classmethod + def get_command_name(cls): + if hasattr(cls, 'command_name'): + return cls.command_name + else: + return cls.__name__ + + def set_undefined_options(self, src_cmd, *options): + """Set values of undefined options from another command. + + Undefined options are options set to None, which is the convention + used to indicate that an option has not been changed between + 'initialize_options()' and 'finalize_options()'. This method is + usually called from 'finalize_options()' for options that depend on + some other command rather than another option of the same command, + typically subcommands. + + The 'src_cmd' argument is the other command from which option values + will be taken (a command object will be created for it if necessary); + the remaining positional arguments are strings that give the name of + the option to set. If the name is different on the source and target + command, you can pass a tuple with '(name_on_source, name_on_dest)' so + that 'self.name_on_dest' will be set from 'src_cmd.name_on_source'. + """ + src_cmd_obj = self.distribution.get_command_obj(src_cmd) + src_cmd_obj.ensure_finalized() + for obj in options: + if isinstance(obj, tuple): + src_option, dst_option = obj + else: + src_option, dst_option = obj, obj + if getattr(self, dst_option) is None: + setattr(self, dst_option, + getattr(src_cmd_obj, src_option)) + + def get_finalized_command(self, command, create=True): + """Wrapper around Distribution's 'get_command_obj()' method: find + (create if necessary and 'create' is true) the command object for + 'command', call its 'ensure_finalized()' method, and return the + finalized command object. + """ + cmd_obj = self.distribution.get_command_obj(command, create) + cmd_obj.ensure_finalized() + return cmd_obj + + def get_reinitialized_command(self, command, reinit_subcommands=False): + return self.distribution.get_reinitialized_command( + command, reinit_subcommands) + + def run_command(self, command): + """Run some other command: uses the 'run_command()' method of + Distribution, which creates and finalizes the command object if + necessary and then invokes its 'run()' method. + """ + self.distribution.run_command(command) + + def get_sub_commands(self): + """Determine the sub-commands that are relevant in the current + distribution (ie., that need to be run). This is based on the + 'sub_commands' class attribute: each tuple in that list may include + a method that we call to determine if the subcommand needs to be + run for the current distribution. Return a list of command names. + """ + commands = [] + for sub_command in self.sub_commands: + if len(sub_command) == 2: + cmd_name, method = sub_command + if method is None or method(self): + commands.append(cmd_name) + else: + commands.append(sub_command) + return commands + + # -- External world manipulation ----------------------------------- + + def execute(self, func, args, msg=None, level=1): + util.execute(func, args, msg, dry_run=self.dry_run) + + def mkpath(self, name, mode=0o777, dry_run=None, verbose=0): + if dry_run is None: + dry_run = self.dry_run + name = os.path.normpath(name) + if os.path.isdir(name) or name == '': + return + if dry_run: + head = '' + for part in name.split(os.sep): + logger.info("created directory %s%s", head, part) + head += part + os.sep + return + os.makedirs(name, mode) + + def copy_file(self, infile, outfile, + preserve_mode=True, preserve_times=True, link=None, level=1): + """Copy a file respecting verbose, dry-run and force flags. (The + former two default to whatever is in the Distribution object, and + the latter defaults to false for commands that don't define it.)""" + if self.dry_run: + # XXX add a comment + return + if os.path.isdir(outfile): + outfile = os.path.join(outfile, os.path.split(infile)[-1]) + copyfile(infile, outfile) + return outfile, None # XXX + + def copy_tree(self, infile, outfile, preserve_mode=True, + preserve_times=True, preserve_symlinks=False, level=1): + """Copy an entire directory tree respecting verbose, dry-run, + and force flags. + """ + if self.dry_run: + return # see if we want to display something + + + return util.copy_tree(infile, outfile, preserve_mode, preserve_times, + preserve_symlinks, not self.force, dry_run=self.dry_run) + + def move_file(self, src, dst, level=1): + """Move a file respecting the dry-run flag.""" + if self.dry_run: + return # XXX log ? + return move(src, dst) + + def spawn(self, cmd, search_path=True, level=1): + """Spawn an external command respecting dry-run flag.""" + from packaging.util import spawn + spawn(cmd, search_path, dry_run=self.dry_run) + + def make_archive(self, base_name, format, root_dir=None, base_dir=None, + owner=None, group=None): + return make_archive(base_name, format, root_dir, + base_dir, dry_run=self.dry_run, + owner=owner, group=group) + + def make_file(self, infiles, outfile, func, args, + exec_msg=None, skip_msg=None, level=1): + """Special case of 'execute()' for operations that process one or + more input files and generate one output file. Works just like + 'execute()', except the operation is skipped and a different + message printed if 'outfile' already exists and is newer than all + files listed in 'infiles'. If the command defined 'self.force', + and it is true, then the command is unconditionally run -- does no + timestamp checks. + """ + if skip_msg is None: + skip_msg = "skipping %s (inputs unchanged)" % outfile + + # Allow 'infiles' to be a single string + if isinstance(infiles, str): + infiles = (infiles,) + elif not isinstance(infiles, (list, tuple)): + raise TypeError( + "'infiles' must be a string, or a list or tuple of strings") + + if exec_msg is None: + exec_msg = "generating %s from %s" % (outfile, ', '.join(infiles)) + + # If 'outfile' must be regenerated (either because it doesn't + # exist, is out-of-date, or the 'force' flag is true) then + # perform the action that presumably regenerates it + if self.force or util.newer_group(infiles, outfile): + self.execute(func, args, exec_msg, level) + + # Otherwise, print the "skip" message + else: + logger.debug(skip_msg) |