zhangsen · July 10, 2012 09:26 · Jul 10, 2012
diff --git a/gistfile1.py b/gistfile1.py
@@ -0,0 +1,72 @@
+import threading, sys
+import urlparse, httplib
+
+is_done = False
+
+class Downloader(threading.Thread):
+    def __init__(self, url, buf, n, semin, semout):
+        self.buf = buf
+        self.bufn = n
+        self.semin = semin
+        self.semout = semout
+        scheme, netloc, path, query, fragment = urlparse.urlsplit(url)
+        self.host, self.path = netloc, path
+        threading.Thread.__init__(self)
+
+    def run(self):
+        h = httplib.HTTPConnection(self.host)
+        h.request("GET", self.path)
+        r = h.getresponse()
+
+        global is_done
+        i = 0
+        while True:
+            self.semin.acquire()
+            self.buf[i] = r.read(1024)
+            ## when to stop???
+            if not self.buf[i]:
+                is_done = True
+                break
+            i = (i+1) % self.bufn
+            self.semout.release()
+        h.close()
+
+class Writer(threading.Thread):
+    def __init__(self, dest, buf, n, semin, semout):
+        self.dest = dest
+        self.buf = buf
+        self.bufn = n
+        self.semin = semin
+        self.semout = semout
+        threading.Thread.__init__(self)
+
+    def run(self):
+        global is_done
+
+        i = 0
+        f = open(self.dest, "w")
+        while True:
+            if is_done:
+                break
+            self.semout.acquire()
+            f.write(buf[i])
+            i = (i+1) % self.bufn
+            self.semin.release()
+        f.close()
+
+n = 100
+buf = [0 for i in range(n)]
+semin = threading.Semaphore(n)
+semout = threading.Semaphore(0)
+
+url="http://www.google.com"
+dest = "tmp"
+if len(sys.argv) > 1:
+    url = sys.argv[1]
+if len(sys.argv) > 2:
+    dest = sys.argv[2]
+
+dl = Downloader(url=url, buf=buf, n=n, semin=semin, semout=semout)
+wr = Writer(dest=dest, buf=buf, n=n, semin=semin, semout=semout)
+dl.start()
+wr.start()