1 files changed, 93 insertions, 0 deletions
diff --git a/src/rocksdb/util/log_buffer.cc b/src/rocksdb/util/log_buffer.cc
new file mode 100644
index 00000000..d09e0cb0
--- /dev/null
+++ b/src/rocksdb/util/log_buffer.cc
@@ -0,0 +1,93 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include "util/log_buffer.h"
+
+#include "port/sys_time.h"
+#include "port/port.h"
+
+namespace rocksdb {
+
+LogBuffer::LogBuffer(const InfoLogLevel log_level,
+                     Logger*info_log)
+    : log_level_(log_level), info_log_(info_log) {}
+
+void LogBuffer::AddLogToBuffer(size_t max_log_size, const char* format,
+                               va_list ap) {
+  if (!info_log_ || log_level_ < info_log_->GetInfoLogLevel()) {
+    // Skip the level because of its level.
+    return;
+  }
+
+  char* alloc_mem = arena_.AllocateAligned(max_log_size);
+  BufferedLog* buffered_log = new (alloc_mem) BufferedLog();
+  char* p = buffered_log->message;
+  char* limit = alloc_mem + max_log_size - 1;
+
+  // store the time
+  gettimeofday(&(buffered_log->now_tv), nullptr);
+
+  // Print the message
+  if (p < limit) {
+    va_list backup_ap;
+    va_copy(backup_ap, ap);
+    auto n = vsnprintf(p, limit - p, format, backup_ap);
+#ifndef OS_WIN
+    // MS reports -1 when the buffer is too short
+    assert(n >= 0);
+#endif
+    if (n > 0) {
+      p += n;
+    } else {
+      p = limit;
+    }
+    va_end(backup_ap);
+  }
+
+  if (p > limit) {
+    p = limit;
+  }
+
+  // Add '\0' to the end
+  *p = '\0';
+
+  logs_.push_back(buffered_log);
+}
+
+void LogBuffer::FlushBufferToLog() {
+  for (BufferedLog* log : logs_) {
+    const time_t seconds = log->now_tv.tv_sec;
+    struct tm t;
+    if (localtime_r(&seconds, &t) != nullptr) {
+      Log(log_level_, info_log_,
+          "(Original Log Time %04d/%02d/%02d-%02d:%02d:%02d.%06d) %s",
+          t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, t.tm_hour, t.tm_min,
+          t.tm_sec, static_cast<int>(log->now_tv.tv_usec), log->message);
+    }
+  }
+  logs_.clear();
+}
+
+void LogToBuffer(LogBuffer* log_buffer, size_t max_log_size, const char* format,
+                 ...) {
+  if (log_buffer != nullptr) {
+    va_list ap;
+    va_start(ap, format);
+    log_buffer->AddLogToBuffer(max_log_size, format, ap);
+    va_end(ap);
+  }
+}
+
+void LogToBuffer(LogBuffer* log_buffer, const char* format, ...) {
+  const size_t kDefaultMaxLogSize = 512;
+  if (log_buffer != nullptr) {
+    va_list ap;
+    va_start(ap, format);
+    log_buffer->AddLogToBuffer(kDefaultMaxLogSize, format, ap);
+    va_end(ap);
+  }
+}
+
+}  // namespace rocksdb