Added debug_toolbar app to project.

[wolnelektury.git] / apps / debug_toolbar / panels / cache.py

diff --git a/apps/debug_toolbar/panels/cache.py b/apps/debug_toolbar/panels/cache.py
new file mode 100644 (file)
index 0000000..4fef6bf
--- /dev/null
+++ b/apps/debug_toolbar/panels/cache.py
@@ -0,0 +1,102 @@
+from debug_toolbar.panels import DebugPanel
+try: from cStringIO import StringIO
+except ImportError: import StringIO
+from django.core import cache
+from django.core.cache.backends.base import BaseCache
+import time
+import inspect
+import os.path
+from django.template.loader import render_to_string
+
+class CacheStatTracker(BaseCache):
+    """A small class used to track cache calls."""
+    def __init__(self, cache):
+        self.cache = cache
+        self.reset()
+
+    def reset(self):
+        self.calls = []
+        self.hits = 0
+        self.misses = 0
+        self.sets = 0
+        self.gets = 0
+        self.get_many = 0
+        self.deletes = 0
+        self.total_time = 0
+
+    def _get_func_info(self):
+        stack = inspect.stack()[2]
+        return (os.path.basename(stack[1]), stack[2], stack[3], stack[4])
+    
+    def get(self, key, default=None):
+        t = time.time()
+        value = self.cache.get(key, default)
+        this_time = time.time()-t
+        self.total_time += this_time*1000
+        if value is None:
+            self.misses += 1
+        else:
+            self.hits += 1
+        self.gets += 1
+        self.calls.append((this_time, 'get', (key,), self._get_func_info()))
+        return value
+
+    def set(self, key, value, timeout=None):
+        t = time.time()
+        self.cache.set(key, value, timeout)
+        this_time = time.time()-t
+        self.total_time += this_time*1000
+        self.sets += 1
+        self.calls.append((this_time, 'set', (key, value, timeout), self._get_func_info()))
+
+    def delete(self, key):
+        t = time.time()
+        self.instance.delete(key, value)
+        this_time = time.time()-t
+        self.total_time += this_time*1000
+        self.deletes += 1
+        self.calls.append((this_time, 'delete', (key,), self._get_func_info()))
+
+    def get_many(self, keys):
+        t = time.time()
+        results = self.cache.get_many(keys)
+        this_time = time.time()-t
+        self.total_time += this_time*1000
+        self.get_many += 1
+        for key, value in results.iteritems():
+            if value is None:
+                self.misses += 1
+            else:
+                self.hits += 1
+        self.calls.append((this_time, 'get_many', (keys,), self._get_func_info()))
+
+class CacheDebugPanel(DebugPanel):
+    """
+    Panel that displays the cache statistics.
+    """
+    name = 'Cache'
+
+    def __init__(self, request):
+        # This is hackish but to prevent threading issues
+        # is somewhat needed
+        if isinstance(cache.cache, CacheStatTracker):
+            cache.cache.reset()
+            self.cache = cache.cache
+        else:
+            self.cache = CacheStatTracker(cache.cache)
+            cache.cache = self.cache
+        super(CacheDebugPanel, self).__init__(request)
+
+    def title(self):
+        return 'Cache: %.2fms' % self.cache.total_time
+
+    def url(self):
+        return ''
+
+    def content(self):
+        context = dict(
+            cache_calls = len(self.cache.calls),
+            cache_time = self.cache.total_time,
+            cache = self.cache,
+        )
+        return render_to_string('debug_toolbar/panels/cache.html', context)
\ No newline at end of file