22617d335c
A new redo-stamp program takes whatever you give it as stdin and uses it to calculate a checksum for the current target. If that checksum is the same as last time, then we consider the target to be unchanged, and we set checked_runid and stamp, but leave changed_runid alone. That will make future callers of redo-ifchange see this target as unmodified. However, this is only "half" support because by the time we run the .do script that calls redo-stamp, it's too late; the caller is a dependant of the stamped program, which is already being rebuilt, even if redo-stamp turns out to say that this target is unchanged. The other half is coming up.
43 lines
1.1 KiB
Python
Executable file
43 lines
1.1 KiB
Python
Executable file
#!/usr/bin/python
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import sys, os
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import vars, state
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from helpers import err, debug2
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if len(sys.argv) > 1:
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err('%s: no arguments expected.\n' % sys.argv[0])
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sys.exit(1)
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# hashlib is only available in python 2.5 or higher, but the 'sha' module
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# produces a DeprecationWarning in python 2.6 or higher. We want to support
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# python 2.4 and above without any stupid warnings, so let's try using hashlib
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# first, and downgrade if it fails.
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try:
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import hashlib
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except ImportError:
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import sha
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sh = sha.sha()
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else:
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sh = hashlib.sha1()
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while 1:
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b = os.read(0, 4096)
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sh.update(b)
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if not b: break
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f = state.File(name=vars.TARGET)
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csum = sh.hexdigest()
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changed = (csum != f.csum)
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debug2('%s: old = %s\n' % (f.name, f.csum))
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debug2('%s: sum = %s (%s)\n' % (f.name, csum,
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changed and 'changed' or 'unchanged'))
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f.is_generated = True
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f.is_override = False
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f.failed_runid = None
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if changed:
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f.set_changed() # update_stamp might not do this if the mtime is identical
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f.csum = csum
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else:
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# unchanged
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f.set_checked()
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f.save()
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state.commit()
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