"""SCons.Sig The Signature package for the scons software construction utility. """ # # __COPYRIGHT__ # # Permission is hereby granted, free of charge, to any person obtaining # a copy of this software and associated documentation files (the # "Software"), to deal in the Software without restriction, including # without limitation the rights to use, copy, modify, merge, publish, # distribute, sublicense, and/or sell copies of the Software, and to # permit persons to whom the Software is furnished to do so, subject to # the following conditions: # # The above copyright notice and this permission notice shall be included # in all copies or substantial portions of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. # __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__" import cPickle import os import os.path import time import SCons.Node import SCons.Warnings try: import MD5 default_module = MD5 except ImportError: import TimeStamp default_module = TimeStamp #XXX Get rid of the global array so this becomes re-entrant. sig_files = [] # 1 means use build signature for derived source files # 0 means use content signature for derived source files build_signature = 1 def write(): global sig_files for sig_file in sig_files: sig_file.write() class SConsignEntry: """Objects of this type are pickled to the .sconsign file, so it should only contain simple builtin Python datatypes and no methods. This class is used to store cache information about nodes between scons runs for efficiency, and to store the build signature for nodes so that scons can determine if they are out of date. """ # setup the default value for various attributes: # (We make the class variables so the default values won't get pickled # with the instances, which would waste a lot of space) timestamp = None bsig = None csig = None implicit = None class SConsignFile: """ Encapsulates reading and writing a .sconsign file. """ def __init__(self, dir, module=None): """ dir - the directory for the file module - the signature module being used """ self.dir = dir if module is None: self.module = default_calc.module else: self.module = module self.sconsign = os.path.join(dir.path, '.sconsign') self.entries = {} self.dirty = 0 try: file = open(self.sconsign, 'rb') except: pass else: try: self.entries = cPickle.load(file) if type(self.entries) is not type({}): self.entries = {} raise TypeError except: SCons.Warnings.warn(SCons.Warnings.CorruptSConsignWarning, "Ignoring corrupt .sconsign file: %s"%self.sconsign) global sig_files sig_files.append(self) def get(self, filename): """ Get the .sconsign entry for a file filename - the filename whose signature will be returned returns - (timestamp, bsig, csig) """ entry = self.get_entry(filename) return (entry.timestamp, entry.bsig, entry.csig) def get_entry(self, filename): """ Create an entry for the filename and return it, or if one already exists, then return it. """ try: return self.entries[filename] except: return SConsignEntry() def set_entry(self, filename, entry): """ Set the entry. """ self.entries[filename] = entry self.dirty = 1 def set_csig(self, filename, csig): """ Set the csig .sconsign entry for a file filename - the filename whose signature will be set csig - the file's content signature """ entry = self.get_entry(filename) entry.csig = csig self.set_entry(filename, entry) def set_bsig(self, filename, bsig): """ Set the csig .sconsign entry for a file filename - the filename whose signature will be set bsig - the file's built signature """ entry = self.get_entry(filename) entry.bsig = bsig self.set_entry(filename, entry) def set_timestamp(self, filename, timestamp): """ Set the csig .sconsign entry for a file filename - the filename whose signature will be set timestamp - the file's timestamp """ entry = self.get_entry(filename) entry.timestamp = timestamp self.set_entry(filename, entry) def get_implicit(self, filename): """Fetch the cached implicit dependencies for 'filename'""" entry = self.get_entry(filename) return entry.implicit def set_implicit(self, filename, implicit): """Cache the implicit dependencies for 'filename'.""" entry = self.get_entry(filename) if SCons.Util.is_String(implicit): implicit = [implicit] implicit = map(str, implicit) entry.implicit = implicit self.set_entry(filename, entry) def write(self): """ 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 self.dirty: temp = os.path.join(self.dir.path, '.scons%d' % os.getpid()) try: file = open(temp, 'wb') fname = temp except: try: file = open(self.sconsign, 'wb') fname = self.sconsign except: return cPickle.dump(self.entries, file, 1) file.close() if fname != self.sconsign: try: mode = os.stat(self.sconsign)[0] os.chmod(self.sconsign, 0666) os.unlink(self.sconsign) except: pass try: os.rename(fname, self.sconsign) except: open(self.sconsign, 'wb').write(open(fname, 'rb').read()) os.chmod(self.sconsign, mode) try: os.unlink(temp) except: pass class Calculator: """ Encapsulates signature calculations and .sconsign file generating for the build engine. """ def __init__(self, module=default_module, max_drift=2*24*60*60): """ Initialize the calculator. module - the signature module to use for signature calculations max_drift - the maximum system clock drift used to determine when to cache content signatures. A negative value means to never cache content signatures. (defaults to 2 days) """ self.module = module self.max_drift = max_drift def bsig(self, node): """ Generate a node's build signature, the digested signatures of its dependency files and build information. node - the node whose sources will be collected returns - the build signature This no longer handles the recursive descent of the node's children's signatures. We expect that they're already built and updated by someone else, if that's what's wanted. """ sigs = map(lambda n, c=self: n.calc_signature(c), node.children()) if node.has_builder(): sigs.append(self.module.signature(node.builder_sig_adapter())) bsig = self.module.collect(filter(lambda x: not x is None, sigs)) node.set_bsig(bsig) # don't store the bsig here, because it isn't accurate until # the node is actually built. return bsig def csig(self, node): """ Generate a node's content signature, the digested signature of its content. node - the node returns - the content signature """ if self.max_drift >= 0: info = node.get_prevsiginfo() else: info = None mtime = node.get_timestamp() if (info and info[0] and info[2] and info[0] == mtime): # use the signature stored in the .sconsign file csig = info[2] # Set the csig here so it doesn't get recalculated unnecessarily # and so it's set when the .sconsign file gets written node.set_csig(csig) else: csig = self.module.signature(node) # Set the csig here so it doesn't get recalculated unnecessarily # and so it's set when the .sconsign file gets written node.set_csig(csig) if self.max_drift >= 0 and (time.time() - mtime) > self.max_drift: node.store_csig() node.store_timestamp() return csig def current(self, node, newsig): """ Check if a signature is up to date with respect to a node. node - the node whose signature will be checked newsig - the (presumably current) signature of the file returns - 1 if the file is current with the specified signature, 0 if it isn't """ oldtime, oldbsig, oldcsig = node.get_prevsiginfo() if not node.has_builder() and node.get_timestamp() == oldtime: return 1 return self.module.current(newsig, oldbsig) default_calc = Calculator()