1 files changed, 104 insertions, 0 deletions
diff --git a/paste/util/dateinterval.py b/paste/util/dateinterval.py
new file mode 100644
index 0000000..023bce4
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+++ b/paste/util/dateinterval.py
@@ -0,0 +1,104 @@
+"""
+DateInterval.py
+
+Convert interval strings (in the form of 1w2d, etc) to
+seconds, and back again.  Is not exactly about months or
+years (leap years in particular).
+
+Accepts (y)ear, (b)month, (w)eek, (d)ay, (h)our, (m)inute, (s)econd.
+
+Exports only timeEncode and timeDecode functions.
+"""
+
+import re
+
+__all__ = ['interval_decode', 'interval_encode']
+
+second = 1
+minute = second*60
+hour = minute*60
+day = hour*24
+week = day*7
+month = day*30
+year = day*365
+timeValues = {
+    'y': year,
+    'b': month,
+    'w': week,
+    'd': day,
+    'h': hour,
+    'm': minute,
+    's': second,
+    }
+timeOrdered = list(timeValues.items())
+timeOrdered.sort(key=lambda x: x[1], reverse=True)
+
+
+def interval_encode(seconds, include_sign=False):
+    """Encodes a number of seconds (representing a time interval)
+    into a form like 1h2d3s.
+
+    >>> interval_encode(10)
+    '10s'
+    >>> interval_encode(493939)
+    '5d17h12m19s'
+    """
+    s = ''
+    orig = seconds
+    seconds = abs(seconds)
+    for char, amount in timeOrdered:
+        if seconds >= amount:
+            i, seconds = divmod(seconds, amount)
+            s += '%i%s' % (i, char)
+    if orig < 0:
+        s = '-' + s
+    elif not orig:
+        return '0'
+    elif include_sign:
+        s = '+' + s
+    return s
+
+_timeRE = re.compile(r'[0-9]+[a-zA-Z]')
+def interval_decode(s):
+    """Decodes a number in the format 1h4d3m (1 hour, 3 days, 3 minutes)
+    into a number of seconds
+
+    >>> interval_decode('40s')
+    40
+    >>> interval_decode('10000s')
+    10000
+    >>> interval_decode('3d1w45s')
+    864045
+    """
+    time = 0
+    sign = 1
+    s = s.strip()
+    if s.startswith('-'):
+        s = s[1:]
+        sign = -1
+    elif s.startswith('+'):
+        s = s[1:]
+    for match in allMatches(s, _timeRE):
+        char = match.group(0)[-1].lower()
+        if char not in timeValues:
+            # @@: should signal error
+            continue
+        time += int(match.group(0)[:-1]) * timeValues[char]
+    return time
+
+# @@-sgd 2002-12-23 - this function does not belong in this module, find a better place.
+def allMatches(source, regex):
+    """Return a list of matches for regex in source
+    """
+    pos = 0
+    end = len(source)
+    rv = []
+    match = regex.search(source, pos)
+    while match:
+        rv.append(match)
+        match = regex.search(source, match.end() )
+    return rv
+
+if __name__ == '__main__':
+    import doctest
+    doctest.testmod()