1 files changed, 46 insertions, 0 deletions
diff --git a/testlib/lazycache/lazycache.py b/testlib/lazycache/lazycache.py
new file mode 100644
index 0000000..1e52f3c
--- /dev/null
+++ b/testlib/lazycache/lazycache.py
@@ -0,0 +1,46 @@
+import scraperwiki, urllib2, datetime, base64,time, logging
+
+# TODO: Implement time-based cache removal (some stubs in, 'age' and 'date'
+
+def lazycache(url,age=datetime.timedelta(1), verbose=False, delay=0):
+    # html is the data from the webpage; it might not be html.
+
+    def scrapesave(url):
+        if verbose: print "Downloading %s"%url
+        try:
+            html=urllib2.urlopen(url).read()
+        except:
+            html=urllib2.urlopen(url).read()
+        scraperwiki.sqlite.save(table_name='__lazycache', data={'url':url,'payload':base64.b64encode(html),'date':datetime.datetime.now()}, unique_keys=['url'], verbose=0)
+        return html
+
+    if ' ' in url:
+        logging.warn('URL "%s" contains spaces.'%url)
+        url=url.replace(' ','%20')
+        logging.warn('Using "%s"'%url)
+    try:
+        r=scraperwiki.sqlite.select("* from __lazycache where url=?", url, verbose=0) # attempt grab from database.
+    except scraperwiki.sqlite.SqliteError, e: # if table doesn't exist, don't bother checking
+        if 'no such table: __lazycache' not in str(e):
+            raise
+        return scrapesave(url)
+    if len(r)>0:
+        if verbose: print "Cache hit for %s"%url
+        return base64.b64decode(r[0]['payload'])
+    else:
+        if verbose: print "No cache held for %s"%url
+        if delay:
+            if verbose: print "sleeping"
+            time.sleep(delay)
+        return scrapesave(url)
+
+
+
+
+#scraperwiki.sqlite.execute("drop table __lazycache;") # reset to new condition
+#html=lazycache('http://placekitten.com/g/200/300')
+#html=lazycache('http://www.everything2.net')
+#print html
+#html=lazycache('http://www.everything2.net')
+#print html
+