PEL: Capture the journal in UserData sections

If a PEL message registry entry has a 'JournalCapture' section, capture
the listed portions of the journal in UserData sections for that error.

If the JSON looks like:

"JournalCapture": {
    "NumLines": 30
}

Then the code will capture the previous 30 lines from the journal into a
single UserData section.

If the JSON looks like:

"JournalCapture":
{
    "Sections": [
        {
            "SyslogID": "phosphor-bmc-state-manager",
            "NumLines": 20
        },
        {
            "SyslogID": "phosphor-log-manager",
            "NumLines": 15
        }
    ]
}

Then the code will create two UserData sections, the first with the most
recent 20 lines from phosphor-bmc-state-manager, and the second with 15
lines from phosphor-log-manager.

If a section would cause the PEL to exceed its maximum size of 16KB, it
will be dropped.  While the UserData class does have a shrink() method,
it prunes data from the end, which would cause the most recent journal
entries to be removed, which could be misleading.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I2ecbd8002b0e7087eb166a1219c6ab9da14a122a
diff --git a/extensions/openpower-pels/journal.cpp b/extensions/openpower-pels/journal.cpp
index 0a728f0..18359fd 100644
--- a/extensions/openpower-pels/journal.cpp
+++ b/extensions/openpower-pels/journal.cpp
@@ -15,10 +15,11 @@
  */
 #include "journal.hpp"
 
-#include <phosphor-logging/log.hpp>
+#include "util.hpp"
 
-#include <stdexcept>
-#include <thread>
+#include <fmt/format.h>
+
+#include <phosphor-logging/log.hpp>
 
 namespace openpower::pels
 {
@@ -50,6 +51,23 @@
     sd_journal* journal{nullptr};
 };
 
+void Journal::sync() const
+{
+    auto start = std::chrono::steady_clock::now();
+
+    util::journalSync();
+
+    auto end = std::chrono::steady_clock::now();
+    auto duration =
+        std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
+
+    if (duration.count() > 100)
+    {
+        log<level::INFO>(
+            fmt::format("Journal sync took {}ms", duration.count()).c_str());
+    }
+}
+
 std::vector<std::string> Journal::getMessages(const std::string& syslogID,
                                               size_t maxMessages) const
 {