Reduce includes of <platform/histogram.h>

Forward-declare the types in <platform/histogram.h> where possible.

Change-Id: Ib8d84f14687ed0bdcbc3529afc5b702fbe61a619
Reviewed-on: http://review.couchbase.org/110225
Reviewed-by: Richard de Mellow <[email protected]>
Tested-by: Build Bot <[email protected]>

Author: daverigby

daemon/subdocument.cc

@@ -39,6 +39,7 @@
 #include <memcached/durability_spec.h>
 #include <memcached/protocol_binary.h>
 #include <memcached/types.h>
+#include <platform/histogram.h>
 #include <xattr/blob.h>
 #include <gsl/gsl>
 

engines/ep/src/couch-kvstore/couch-fs-stats.cc

@@ -15,9 +15,10 @@
  *   limitations under the License.
  */
 
-#include "common.h"
 #include "couch-kvstore/couch-fs-stats.h"
+#include "common.h"
 #include "kvstore.h"
+#include <platform/histogram.h>
 
 std::unique_ptr<FileOpsInterface> getCouchstoreStatsOps(
     FileStats& stats, FileOpsInterface& base_ops) {

engines/ep/src/stats.h

@@ -27,6 +27,7 @@
 #include <platform/platform_time.h>
 #include <relaxed_atomic.h>
 
+#include <platform/histogram.h>
 #include <algorithm>
 #include <atomic>
 

utilities/hdrhistogram.h

@@ -19,7 +19,6 @@
 
 #include <boost/optional/optional_fwd.hpp>
 #include <nlohmann/json_fwd.hpp>
-#include <platform/histogram.h>
 #include <chrono>
 #include <memory>
 #include <utility>
@@ -35,6 +34,11 @@
 #pragma warning(pop)
 #endif
 
+template <typename HISTOGRAM, uint64_t THRESHOLD_MS>
+class GenericBlockTimer;
+template <typename T>
+class MicrosecondStopwatch;
+
 /**
  * A container for the c hdr_histogram data structure.
  *