Index: zlib.py
===================================================================
RCS file: /cvsroot/jython/jython/Lib/zlib.py,v
retrieving revision 1.2
diff -u -r1.2 zlib.py
--- zlib.py	6 Oct 2001 20:36:45 -0000	1.2
+++ zlib.py	27 Feb 2004 21:08:49 -0000
@@ -24,6 +24,7 @@
 # Z_SYNC_FLUSH = 2
 # Z_FULL_FLUSH = 3
 Z_FINISH = 4
+_valid_flush_modes = (Z_FINISH,)
 
 def adler32(string, value=1):
     if value != 1: 
@@ -51,6 +52,7 @@
     
 
 class compressobj:
+    # all jython uses wbits for is deciding whether to skip the header if it's negative
     def __init__(self, level=6, method=DEFLATED, wbits=MAX_WBITS,
                        memLevel=0, strategy=0):
         if abs(wbits) > MAX_WBITS or abs(wbits) < 8:
@@ -59,34 +61,68 @@
         self.deflater.setStrategy(strategy)
         if wbits < 0:
             _get_deflate_data(self.deflater)
+        self._ended = False
 
     def compress(self, string):
+        if self._ended:
+            raise error("compressobj may not be used after flush(Z_FINISH)")
         self.deflater.setInput(string, 0, len(string))
         return _get_deflate_data(self.deflater)
         
     def flush(self, mode=Z_FINISH):
-        if mode != Z_FINISH:
+        if self._ended:
+            raise error("compressobj may not be used after flush(Z_FINISH)")
+        if mode not in _valid_flush_modes:
             raise ValueError, "Invalid flush option"
         self.deflater.finish()
-        return _get_deflate_data(self.deflater)
+        last = _get_deflate_data(self.deflater)
+        if mode == Z_FINISH:
+            self.deflater.end()
+            self._ended = True
+        return last
 
 class decompressobj:
-    def __init__(self, wbits=0):
+    # all jython uses wbits for is deciding whether to skip the header if it's negative
+    def __init__(self, wbits=MAX_WBITS):
         if abs(wbits) > MAX_WBITS or abs(wbits) < 8:
             raise ValueError, "Invalid initialization option"
         self.inflater = util.zip.Inflater(wbits < 0)
         self.unused_data = ""
+        self._ended = False
+
+    def decompress(self, string, max_length=0):
+        if self._ended:
+            raise error("decompressobj may not be used after flush()")
+        
+        # unused_data is always "" until inflation is finished; then it is
+        # the unused bytes of the input;
+        # unconsumed_tail is whatever input was not used because max_length
+        # was exceeded before inflation finished.
+        # Thus, at most one of {unused_data, unconsumed_tail} may be non-empty.
+        self.unused_data = ""
+        self.unconsumed_tail = ""
+
+        if max_length < 0:
+            raise ValueError("max_length must be a positive integer")
 
-    def decompress(self, string):
         self.inflater.setInput(string)
-        r = _get_inflate_data(self.inflater)
-        # Arrgh. This suck.
-        self.unused_data = " " * self.inflater.getRemaining()
-        return r
+        inflated = _get_inflate_data(self.inflater, max_length)
+
+        r = self.inflater.getRemaining()
+        if r:
+            if max_length:
+                self.unconsumed_tail = string[-r:]
+            else:
+                self.unused_data = string[-r:]
+        
+        return inflated
 
     def flush(self):
-        #self.inflater.finish()
-        return _get_inflate_data(self.inflater)
+        if self._ended:
+            raise error("decompressobj may not be used after flush()")
+        last = _get_inflate_data(self.inflater)
+        self.inflater.end()
+        return last
 
 
 def _get_deflate_data(deflater):
@@ -100,13 +136,20 @@
     return sb.toString()
 
         
-def _get_inflate_data(inflater):
+def _get_inflate_data(inflater, max_length=0):
     buf = jarray.zeros(1024, 'b')
     sb = lang.StringBuffer()
+    total = 0
     while not inflater.finished():
-        l = inflater.inflate(buf)
+        if max_length:
+            l = inflater.inflate(buf, 0, min(1024, max_length - total))
+        else:
+            l = inflater.inflate(buf)
         if l == 0:
             break
+
+        total += l
         sb.append(lang.String(buf, 0, 0, l))
+        if max_length and total == max_length:
+            break
     return sb.toString()
-