1 files changed, 42 insertions, 0 deletions
diff --git a/lab/gendata.py b/lab/gendata.py
new file mode 100644
index 00000000..27ad4fda
--- /dev/null
+++ b/lab/gendata.py
@@ -0,0 +1,42 @@
+# Run some timing tests of JsonData vs SqliteData.
+
+import random
+import time
+
+from coverage.data import CoverageJsonData
+from coverage.sqldata import CoverageSqliteData
+
+NUM_FILES = 1000
+NUM_LINES = 1000
+
+def gen_data(cdata):
+    rnd = random.Random()
+    rnd.seed(17)
+
+    def linenos(num_lines, prob):
+        return (n for n in range(num_lines) if random.random() < prob)
+
+    start = time.time()
+    for i in range(NUM_FILES):
+        filename = "/src/foo/project/file{i}.py".format(i=i)
+        line_data = { filename: dict.fromkeys(linenos(NUM_LINES, .6)) }
+        cdata.add_lines(line_data)
+
+    cdata.write()
+    end = time.time()
+    delta = end - start
+    return delta
+
+class DummyData:
+    def add_lines(self, line_data):
+        return
+    def write(self):
+        return
+
+overhead = gen_data(DummyData())
+jtime = gen_data(CoverageJsonData("gendata.json")) - overhead
+stime = gen_data(CoverageSqliteData("gendata.db")) - overhead
+print("Overhead: {overhead:.3f}s".format(overhead=overhead))
+print("JSON: {jtime:.3f}s".format(jtime=jtime))
+print("SQLite: {stime:.3f}s".format(stime=stime))
+print("{slower:.3f}x slower".format(slower=stime/jtime))