"""SCons.Sig The Signature package for the scons software construction utility. """ # # Copyright (c) 2001, 2002 Steven Knight # # 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 os import os.path import string import SCons.Node import time #XXX Get rid of the global array so this becomes re-entrant. sig_files = [] def write(): global sig_files for sig_file in sig_files: sig_file.write() class SConsignEntry: def __init__(self, module, entry=None): self.timestamp = self.csig = self.bsig = self.implicit = None if not entry is None: arr = map(string.strip, string.split(entry, " ", 3)) try: if arr[0] == '-': self.timestamp = None else: self.timestamp = int(arr[0]) if arr[1] == '-': self.bsig = None else: self.bsig = module.from_string(arr[1]) if arr[2] == '-': self.csig = None else: self.csig = module.from_string(arr[2]) if arr[3] == '-': self.implicit = None else: self.implicit = arr[3] except IndexError: pass def render(self, module): if self.timestamp is None: timestamp = '-' else: timestamp = "%d"%self.timestamp if self.bsig is None: bsig = '-' else: bsig = module.to_string(self.bsig) if self.csig is None: csig = '-' else: csig = module.to_string(self.csig) if self.implicit is None: implicit = '-' else: implicit = self.implicit return '%s %s %s %s' % (timestamp, bsig, csig, implicit) def get_implicit(self): if self.implicit is None: return None else: return string.split(self.implicit, '\0') def set_implicit(self, implicit): if implicit is None: self.implicit = None else: self.implicit = string.join(map(str, implicit), '\0') 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 = None try: file = open(self.sconsign, 'rt') except: pass else: for line in file.readlines(): filename, rest = map(string.strip, string.split(line, ":", 1)) self.entries[filename] = SConsignEntry(self.module, rest) 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, implicit) """ try: entry = self.entries[filename] return (entry.timestamp, entry.bsig, entry.csig) except KeyError: return (None, None, None) def set(self, filename, timestamp, bsig = None, csig = None): """ Set the .sconsign entry for a file filename - the filename whose signature will be set timestamp - the timestamp module - the signature module being used bsig - the file's build signature csig - the file's content signature """ try: entry = self.entries[filename] except KeyError: entry = SConsignEntry(self.module) self.entries[filename] = entry entry.timestamp = timestamp entry.bsig = bsig entry.csig = csig self.dirty = 1 def get_implicit(self, filename): """Fetch the cached implicit dependencies for 'filename'""" try: entry = self.entries[filename] return entry.get_implicit() except KeyError: return None def set_implicit(self, filename, implicit): """Cache the implicit dependencies for 'filename'.""" try: entry = self.entries[filename] except KeyError: entry = SConsignEntry(self.module) self.entries[filename] = entry entry.set_implicit(implicit) 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, 'wt') fname = temp except: try: file = open(self.sconsign, 'wt') fname = self.sconsign except: return keys = self.entries.keys() keys.sort() for name in keys: file.write("%s: %s\n" % (name, self.entries[name].render(self.module))) 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=None, 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) """ if module is None: import MD5 self.module = MD5 else: 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. """ if not node.use_signature: return None bsig = node.get_bsig() if not bsig is None: return bsig sigs = map(self.get_signature, node.children()) if node.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 not node.use_signature: return None csig = node.get_csig() if not csig is None: return csig 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() return csig def get_signature(self, node): """ Get the appropriate signature for a node. node - the node returns - the signature or None if the signature could not be computed. This method does not store the signature in the node and in the .sconsign file. """ if not node.use_signature: # This node type doesn't use a signature (e.g. a # directory) so bail right away. return None elif node.builder: return self.bsig(node) elif not node.exists(): return None else: return self.csig(node) 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 """ c = node.current() if not c is None: # The node itself has told us whether or not it's # current without checking the signature. The # canonical uses here are a "0" return for a file # that doesn't exist, or a directory. return c oldtime, oldbsig, oldcsig = node.get_prevsiginfo() if not node.builder and node.get_timestamp() == oldtime: return 1 return self.module.current(newsig, oldbsig) default_calc = Calculator()