move client info into base for all samples

Summary:
I added client logging to the Watchman `dispatch_command` event.

Watchman has a few different types of scuba events:
- query_execute
- sync_to_now
- full_crawl
- clock_test
- saved_state
- dropped
- age_out

Some of these events are associated with a specific client request, so I would
like to include client information there as well. There are a few that are not
related to a specific client event:
- full_crawl
- clock_test
- dropped
- age_out

So I only intend to add client information to
- query_execute
- sync_to_now
- saved_state

Going to move these client attributes to the more generically used
MetadataEventData instead of being on the event types for each event to avoid
copy paste.

Reviewed By: genevievehelsel

Differential Revision: D61684457

fbshipit-source-id: bf4765780cfd09c7ff5a0a3f0ef56dcc10f58dfd

eden/common/utils/ProcessInfoCache.cpp

@@ -8,6 +8,7 @@
 #include "eden/common/utils/ProcessInfoCache.h"
 
 #include <folly/MapUtil.h>
+#include <folly/String.h>
 #include <folly/container/EvictingCacheMap.h>
 #include <folly/futures/SharedPromise.h>
 #include <folly/logging/xlog.h>
@@ -418,4 +419,10 @@ std::optional<ProcessName> ProcessInfoCache::getProcessName(pid_t pid) {
       readProcessSimpleName(pid)};
 }
 
+/*static*/ std::string ProcessInfoCache::cleanProcessCommandline(
+    std::string processName) {
+  std::replace(processName.begin(), processName.end(), '\0', ' ');
+  return folly::rtrimWhitespace(processName).str();
+}
+
 } // namespace facebook::eden

eden/common/utils/ProcessInfoCache.h

@@ -163,6 +163,14 @@ class ProcessInfoCache {
    */
   std::optional<ProcessName> getProcessName(pid_t pid);
 
+  /**
+   * Commandlines (on linux anyways) use \0 instead of spaces to separate
+   * arguments. sl is often a command we are interested in. and sl also
+   * doed some funky commandline manipulation that causes a bunch of \0 to be
+   * on the end of their commandline. This will clean those off.
+   */
+  static std::string cleanProcessCommandline(std::string process);
+
  private:
   struct State {
     std::unordered_map<pid_t, std::shared_ptr<detail::ProcessInfoNode>> infos;

eden/common/utils/test/ProcessInfoCacheTest.cpp

@@ -208,4 +208,37 @@ TEST(ProcessInfoCache, multipleLookups) {
   thread1.join();
   thread2.join();
 }
+
+TEST(ProcessInfoCache, testSlCommandlineCleaning) {
+  // Sapling does some commandline manipulation to name the background processes
+  // something like pfc[worker/XXXXXXXX]. But this causes the commanline to be
+  // full of null bytes. This is something we want to be filtered out in
+  // telemetry.
+
+  // note to editor: we use the char *, size_t variant of the string constructor
+  // o.w the \0 will be interpreted as the end of the string!
+  auto sl_worker_raw_cmdline = std::string{
+      "pfc[worker/663504]\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000",
+      112};
+
+  EXPECT_EQ(
+      "pfc[worker/663504]",
+      ProcessInfoCache::cleanProcessCommandline(sl_worker_raw_cmdline));
+}
+
+TEST(ProcessInfoCache, testBuckCommandlineCleaning) {
+  // Commandlines are \0 byte separated. We should turn those null bytes into
+  // spaces to make the commandlines easier to read in telemetry.
+
+  // note to editor: we use the char *, size_t variant of the string constructor
+  // o.w the \0 will be interpreted as the end of the string!
+  auto buck2_raw_cmdline = std::string{
+      "buck2d[fbsource]\u0000--isolation-dir\u0000v2\u0000daemon\u0000{\"buck_config\":\"somevalue\"}\u0000",
+      70};
+
+  EXPECT_EQ(
+      "buck2d[fbsource] --isolation-dir v2 daemon {\"buck_config\":\"somevalue\"}",
+      ProcessInfoCache::cleanProcessCommandline(buck2_raw_cmdline));
+}
+
 } // namespace facebook::eden