http://codereview.chromium.org/147084

Implements unique client ID generation for Posix.

Client ID generation happens once-per-install of Chromium (...well, this is
mostly true, at least).  On Windows, the code currently uses some system library
code that generates a GUID.  We don't ACTUALLY need a GUID, something that's
quite random and in the same format will work.  Since we don't want to add a
dependency on libuuid for POSIX, I created a less-random-but-still-good-enough
version.

BUG=15418
TEST=none

Review URL: http://codereview.chromium.org/149343

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@20184 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 63 insertions, 4 deletions

diff --git a/chrome/browser/metrics/metrics_service.cc b/chrome/browser/metrics/metrics_service.cc
index 30e1628..aaffb64 100644
--- a/chrome/browser/metrics/metrics_service.cc
+++ b/chrome/browser/metrics/metrics_service.cc
@@ -166,6 +166,7 @@
 #include "base/histogram.h"
 #include "base/path_service.h"
 #include "base/platform_thread.h"
+#include "base/rand_util.h"
 #include "base/string_util.h"
 #include "base/task.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
@@ -762,16 +763,29 @@ std::string MetricsService::GenerateClientID() {
   DCHECK(result == kGUIDSize);
 
   return WideToUTF8(guid_string.substr(1, guid_string.length() - 2));
+#elif defined(LINUX2)
+  uint64 sixteen_bytes[2] = { base::RandUint64(), base::RandUint64() };
+  return RandomBytesToGUIDString(sixteen_bytes);
 #else
-  // TODO(port): Implement for Mac and linux.
-  // Rather than actually implementing a random source, might this be a good
-  // time to implement http://code.google.com/p/chromium/issues/detail?id=2278
-  // ?  I think so!
+  // TODO(cmasone): enable the above for all OS_POSIX platforms once the
+  // first-run dialog text is all up to date.
   NOTIMPLEMENTED();
   return std::string();
 #endif
 }
 
+#if defined(OS_POSIX)
+// TODO(cmasone): Once we're comfortable this works, migrate Windows code to
+// use this as well.
+std::string MetricsService::RandomBytesToGUIDString(const uint64 bytes[2]) {
+  return StringPrintf("%08llX-%04llX-%04llX-%04llX-%012llX",
+                      bytes[0] >> 32,
+                      (bytes[0] >> 16) & 0x0000ffff,
+                      bytes[0] & 0x0000ffff,
+                      bytes[1] >> 48,
+                      bytes[1] & 0x0000ffffffffffffULL);
+}
+#endif
 
 //------------------------------------------------------------------------------
 // State save methods
diff --git a/chrome/browser/metrics/metrics_service.h b/chrome/browser/metrics/metrics_service.h
index a955da1..e173915 100644
--- a/chrome/browser/metrics/metrics_service.h
+++ b/chrome/browser/metrics/metrics_service.h
@@ -22,6 +22,7 @@
 #include "chrome/browser/net/url_fetcher.h"
 #include "chrome/common/notification_registrar.h"
 #include "webkit/glue/webplugin.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"
 
 class BookmarkModel;
 class BookmarkNode;
@@ -160,6 +161,12 @@ class MetricsService : public NotificationObserver,
   // Generates a new client ID to use to identify self to metrics server.
   static std::string GenerateClientID();
 
+#if defined(OS_POSIX)
+  // Generates a new client ID to use to identify self to metrics server,
+  // given 128 bits of randomness.
+  static std::string RandomBytesToGUIDString(const uint64 bytes[2]);
+#endif
+
   // Schedule the next save of LocalState information.  This is called
   // automatically by the task that performs each save to schedule the next one.
   void ScheduleNextStateSave();
@@ -475,6 +482,9 @@ class MetricsService : public NotificationObserver,
   // Indicate that a timer for sending the next log has already been queued.
   bool timer_pending_;
 
+  FRIEND_TEST(MetricsServiceTest, ClientIdGeneratesAllZeroes);
+  FRIEND_TEST(MetricsServiceTest, ClientIdGeneratesCorrectly);
+  FRIEND_TEST(MetricsServiceTest, ClientIdCorrectlyFormatted);
   DISALLOW_COPY_AND_ASSIGN(MetricsService);
 };
 
diff --git a/chrome/browser/metrics/metrics_service_unittest.cc b/chrome/browser/metrics/metrics_service_unittest.cc
new file mode 100644
index 0000000..1bd5c77a
--- /dev/null
+++ b/chrome/browser/metrics/metrics_service_unittest.cc
@@ -0,0 +1,35 @@
+// Copyright (c) 2009 The Chromium 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 "chrome/browser/metrics/metrics_service.h"
+
+#include <string>
+#include "testing/gtest/include/gtest/gtest.h"
+
+#if defined(OS_POSIX) && defined(LINUX2)
+TEST(MetricsServiceTest, ClientIdGeneratesAllZeroes) {
+  uint64 bytes[] = { 0, 0 };
+  std::string clientid = MetricsService::RandomBytesToGUIDString(bytes);
+  EXPECT_EQ("00000000-0000-0000-0000-000000000000", clientid);
+}
+TEST(MetricsServiceTest, ClientIdGeneratesCorrectly) {
+  uint64 bytes[] = { 0x0123456789ABCDEFULL, 0xFEDCBA9876543210ULL };
+  std::string clientid = MetricsService::RandomBytesToGUIDString(bytes);
+  EXPECT_EQ("01234567-89AB-CDEF-FEDC-BA9876543210", clientid);
+}
+
+TEST(MetricsServiceTest, ClientIdCorrectlyFormatted) {
+  std::string clientid = MetricsService::GenerateClientID();
+  EXPECT_EQ(36U, clientid.length());
+  std::string hexchars = "0123456789ABCDEF";
+  for (uint32 i = 0; i < clientid.length(); i++) {
+    char current = clientid.at(i);
+    if (i == 8 || i == 13 || i == 18 || i == 23) {
+      EXPECT_EQ('-', current);
+    } else {
+      EXPECT_TRUE(std::string::npos != hexchars.find(current));
+    }
+  }
+}
+#endif