Create a bootstat library for external C and C++ programs

log_unit_tests.cc

Index: log_unit_tests.cc
diff --git a/log_unit_tests.cc b/log_unit_tests.cc
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+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "bootstat.h"
+
+#include <errno.h>
+#include <unistd.h>
+
+#include <string>
+#include <iostream>
+
+#include <gtest/gtest.h>
+
+namespace {
+
+using std::string;
+
+static const char kMostVoluminousEventName[] =
+  //             16              32              48              64
+  "event-6789abcdef_123456789ABCDEF.123456789abcdef0123456789abcdef" //  64
+  "event-6789abcdef_123456789ABCDEF.123456789abcdef0123456789abcdef" // 128
+  "event-6789abcdef_123456789ABCDEF.123456789abcdef0123456789abcdef" // 191
+  "event-6789abcdef_123456789ABCDEF.123456789abcdef0123456789abcdef" // 256
+  ;
+
+static const string kUptimeFileNamePrefix("/tmp/uptime-");
+static const string kDiskStatFileNamePrefix("/tmp/disk-");
+
+static void TestEventFileAccess(const string& file_name) {
+  int rv = access(file_name.c_str(), R_OK | W_OK);
+  EXPECT_EQ(rv, 0) << "access to " << file_name
+                   << " failed: " << strerror(errno);
+  (void) unlink(file_name.c_str());
+}
+
+static void TestEventByName(const string& event_name) {
+  bootstat_log(event_name.c_str());
+  string truncated_event(event_name.substr(0, BOOTSTAT_MAX_EVENT_LEN - 1));
+  TestEventFileAccess(kUptimeFileNamePrefix + truncated_event);
+  TestEventFileAccess(kDiskStatFileNamePrefix + truncated_event);
+}
+
+// Tests that name truncation of logged events works as advertised
+TEST(BoostatTest, EventNameTruncation) {
+  string very_long(kMostVoluminousEventName);
+
+  TestEventByName(very_long);
+  TestEventByName(very_long.substr(0, 1));
+  TestEventByName(very_long.substr(0, 16));
+  TestEventByName(very_long.substr(0, BOOTSTAT_MAX_EVENT_LEN - 1));
+  TestEventByName(very_long.substr(0, BOOTSTAT_MAX_EVENT_LEN));
+}
+
+}  // namespace
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}