Source code for SCons.SConsign

"""SCons.SConsign

Writing and reading information to the .sconsign file or files.

"""

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import SCons.compat

import os
import pickle

import SCons.dblite
import SCons.Warnings

from SCons.compat import PICKLE_PROTOCOL


[docs]def corrupt_dblite_warning(filename): SCons.Warnings.warn(SCons.Warnings.CorruptSConsignWarning, "Ignoring corrupt .sconsign file: %s"%filename)
SCons.dblite.ignore_corrupt_dbfiles = 1 SCons.dblite.corruption_warning = corrupt_dblite_warning # XXX Get rid of the global array so this becomes re-entrant. sig_files = [] # Info for the database SConsign implementation (now the default): # "DataBase" is a dictionary that maps top-level SConstruct directories # to open database handles. # "DB_Module" is the Python database module to create the handles. # "DB_Name" is the base name of the database file (minus any # extension the underlying DB module will add). DataBase = {} DB_Module = SCons.dblite DB_Name = ".sconsign" DB_sync_list = []
[docs]def Get_DataBase(dir): global DataBase, DB_Module, DB_Name top = dir.fs.Top if not os.path.isabs(DB_Name) and top.repositories: mode = "c" for d in [top] + top.repositories: if dir.is_under(d): try: return DataBase[d], mode except KeyError: path = d.entry_abspath(DB_Name) try: db = DataBase[d] = DB_Module.open(path, mode) except (IOError, OSError): pass else: if mode != "r": DB_sync_list.append(db) return db, mode mode = "r" try: return DataBase[top], "c" except KeyError: db = DataBase[top] = DB_Module.open(DB_Name, "c") DB_sync_list.append(db) return db, "c" except TypeError: print("DataBase =", DataBase) raise
[docs]def Reset(): """Reset global state. Used by unit tests that end up using SConsign multiple times to get a clean slate for each test.""" global sig_files, DB_sync_list sig_files = [] DB_sync_list = []
normcase = os.path.normcase
[docs]def write(): global sig_files for sig_file in sig_files: sig_file.write(sync=0) for db in DB_sync_list: try: syncmethod = db.sync except AttributeError: pass # Not all dbm modules have sync() methods. else: syncmethod() try: closemethod = db.close except AttributeError: pass # Not all dbm modules have close() methods. else: closemethod()
[docs]class SConsignEntry: """ Wrapper class for the generic entry in a .sconsign file. The Node subclass populates it with attributes as it pleases. XXX As coded below, we do expect a '.binfo' attribute to be added, but we'll probably generalize this in the next refactorings. """ __slots__ = ("binfo", "ninfo", "__weakref__") current_version_id = 2 def __init__(self): # Create an object attribute from the class attribute so it ends up # in the pickled data in the .sconsign file. #_version_id = self.current_version_id pass
[docs] def convert_to_sconsign(self): self.binfo.convert_to_sconsign()
[docs] def convert_from_sconsign(self, dir, name): self.binfo.convert_from_sconsign(dir, name)
def __getstate__(self): state = getattr(self, '__dict__', {}).copy() for obj in type(self).mro(): for name in getattr(obj,'__slots__',()): if hasattr(self, name): state[name] = getattr(self, name) state['_version_id'] = self.current_version_id try: del state['__weakref__'] except KeyError: pass return state def __setstate__(self, state): for key, value in state.items(): if key not in ('_version_id','__weakref__'): setattr(self, key, value)
[docs]class Base: """ This is the controlling class for the signatures for the collection of entries associated with a specific directory. The actual directory association will be maintained by a subclass that is specific to the underlying storage method. This class provides a common set of methods for fetching and storing the individual bits of information that make up signature entry. """ def __init__(self): self.entries = {} self.dirty = False self.to_be_merged = {}
[docs] def get_entry(self, filename): """ Fetch the specified entry attribute. """ return self.entries[filename]
[docs] def set_entry(self, filename, obj): """ Set the entry. """ self.entries[filename] = obj self.dirty = True
[docs] def do_not_set_entry(self, filename, obj): pass
[docs] def store_info(self, filename, node): entry = node.get_stored_info() entry.binfo.merge(node.get_binfo()) self.to_be_merged[filename] = node self.dirty = True
[docs] def do_not_store_info(self, filename, node): pass
[docs] def merge(self): for key, node in self.to_be_merged.items(): entry = node.get_stored_info() try: ninfo = entry.ninfo except AttributeError: # This happens with SConf Nodes, because the configuration # subsystem takes direct control over how the build decision # is made and its information stored. pass else: ninfo.merge(node.get_ninfo()) self.entries[key] = entry self.to_be_merged = {}
[docs]class DB(Base): """ A Base subclass that reads and writes signature information from a global .sconsign.db* file--the actual file suffix is determined by the database module. """ def __init__(self, dir): Base.__init__(self) self.dir = dir db, mode = Get_DataBase(dir) # Read using the path relative to the top of the Repository # (self.dir.tpath) from which we're fetching the signature # information. path = normcase(dir.get_tpath()) try: rawentries = db[path] except KeyError: pass else: try: self.entries = pickle.loads(rawentries) if not isinstance(self.entries, dict): self.entries = {} raise TypeError except KeyboardInterrupt: raise except Exception as e: SCons.Warnings.warn(SCons.Warnings.CorruptSConsignWarning, "Ignoring corrupt sconsign entry : %s (%s)\n"%(self.dir.get_tpath(), e)) for key, entry in self.entries.items(): entry.convert_from_sconsign(dir, key) if mode == "r": # This directory is actually under a repository, which means # likely they're reaching in directly for a dependency on # a file there. Don't actually set any entry info, so we # won't try to write to that .sconsign.dblite file. self.set_entry = self.do_not_set_entry self.store_info = self.do_not_store_info global sig_files sig_files.append(self)
[docs] def write(self, sync=1): if not self.dirty: return self.merge() db, mode = Get_DataBase(self.dir) # Write using the path relative to the top of the SConstruct # directory (self.dir.path), not relative to the top of # the Repository; we only write to our own .sconsign file, # not to .sconsign files in Repositories. path = normcase(self.dir.get_internal_path()) for key, entry in self.entries.items(): entry.convert_to_sconsign() db[path] = pickle.dumps(self.entries, PICKLE_PROTOCOL) if sync: try: syncmethod = db.sync except AttributeError: # Not all anydbm modules have sync() methods. pass else: syncmethod()
[docs]class Dir(Base): def __init__(self, fp=None, dir=None): """ fp - file pointer to read entries from """ Base.__init__(self) if not fp: return self.entries = pickle.load(fp) if not isinstance(self.entries, dict): self.entries = {} raise TypeError if dir: for key, entry in self.entries.items(): entry.convert_from_sconsign(dir, key)
[docs]class DirFile(Dir): """ Encapsulates reading and writing a per-directory .sconsign file. """ def __init__(self, dir): """ dir - the directory for the file """ self.dir = dir self.sconsign = os.path.join(dir.get_internal_path(), '.sconsign') try: fp = open(self.sconsign, 'rb') except IOError: fp = None try: Dir.__init__(self, fp, dir) except KeyboardInterrupt: raise except Exception: SCons.Warnings.warn(SCons.Warnings.CorruptSConsignWarning, "Ignoring corrupt .sconsign file: %s"%self.sconsign) try: fp.close() except AttributeError: pass global sig_files sig_files.append(self)
[docs] def write(self, sync=1): """ Write the .sconsign file to disk. Try to write to a temporary file first, and rename it if we succeed. If we can't write to the temporary file, it's probably because the directory isn't writable (and if so, how did we build anything in this directory, anyway?), so try to write directly to the .sconsign file as a backup. If we can't rename, try to copy the temporary contents back to the .sconsign file. Either way, always try to remove the temporary file at the end. """ if not self.dirty: return self.merge() temp = os.path.join(self.dir.get_internal_path(), '.scons%d' % os.getpid()) try: file = open(temp, 'wb') fname = temp except IOError: try: file = open(self.sconsign, 'wb') fname = self.sconsign except IOError: return for key, entry in self.entries.items(): entry.convert_to_sconsign() pickle.dump(self.entries, file, PICKLE_PROTOCOL) file.close() if fname != self.sconsign: try: mode = os.stat(self.sconsign)[0] os.chmod(self.sconsign, 0o666) os.unlink(self.sconsign) except (IOError, OSError): # Try to carry on in the face of either OSError # (things like permission issues) or IOError (disk # or network issues). If there's a really dangerous # issue, it should get re-raised by the calls below. pass try: os.rename(fname, self.sconsign) except OSError: # An OSError failure to rename may indicate something # like the directory has no write permission, but # the .sconsign file itself might still be writable, # so try writing on top of it directly. An IOError # here, or in any of the following calls, would get # raised, indicating something like a potentially # serious disk or network issue. with open(self.sconsign, 'wb') as f, open(fname, 'rb') as f2: f.write(f2.read()) os.chmod(self.sconsign, mode) try: os.unlink(temp) except (IOError, OSError): pass
ForDirectory = DB
[docs]def File(name, dbm_module=None): """ Arrange for all signatures to be stored in a global .sconsign.db* file. """ global ForDirectory, DB_Name, DB_Module if name is None: ForDirectory = DirFile DB_Module = None else: ForDirectory = DB DB_Name = name if dbm_module is not None: DB_Module = dbm_module
# Local Variables: # tab-width:4 # indent-tabs-mode:nil # End: # vim: set expandtab tabstop=4 shiftwidth=4: