ircd::db: Add interface to count cache entries.

modules/console: Add count column to db cache cmd.

include/ircd/db/cache.h

@@ -41,6 +41,10 @@ namespace ircd::db
 	size_t pinned(const rocksdb::Cache &);
 	size_t pinned(const rocksdb::Cache *const &);
 
+	// Get number of entries
+	size_t count(const rocksdb::Cache &);
+	size_t count(const rocksdb::Cache *const &);
+
 	// Test if key exists
 	bool exists(const rocksdb::Cache &, const string_view &key);
 	bool exists(const rocksdb::Cache *const &, const string_view &key);
@@ -133,6 +137,14 @@ ircd::db::exists(const rocksdb::Cache *const &cache,
 		false;
 }
 
+inline size_t
+ircd::db::count(const rocksdb::Cache *const &cache)
+{
+	return cache?
+		count(*cache):
+		0UL;
+}
+
 inline size_t
 ircd::db::pinned(const rocksdb::Cache *const &cache)
 {

ircd/db.cc

@@ -7569,6 +7569,19 @@ ircd::db::exists(const rocksdb::Cache &cache_,
 	return bool(handle);
 }
 
+size_t
+ircd::db::count(const rocksdb::Cache &cache)
+{
+	size_t ret(0);
+	for_each(cache, [&ret]
+	(const const_buffer &)
+	{
+		++ret;
+	});
+
+	return ret;
+}
+
 size_t
 ircd::db::pinned(const rocksdb::Cache &cache)
 {

modules/console.cc

@@ -3728,6 +3728,7 @@ try
 
 	struct stats
 	{
+		size_t count;
 		size_t usage;
 		size_t pinned;
 		size_t capacity;
@@ -3738,6 +3739,7 @@ try
 
 		stats &operator+=(const stats &b)
 		{
+			count += b.count;
 			usage += b.usage;
 			pinned += b.pinned;
 			capacity += b.capacity;
@@ -3751,6 +3753,7 @@ try
 
 	if(!colname)
 	{
+		const auto count(db::count(cache(database)));
 		const auto usage(db::usage(cache(database)));
 		const auto pinned(db::pinned(cache(database)));
 		const auto capacity(db::capacity(cache(database)));
@@ -3778,6 +3781,11 @@ try
 			inserts > 0.0? (double(hits) / double(inserts)) : 0.0L
 		};
 
+		const auto ins_cnt_rat
+		{
+			count > 0.0? (double(inserts) / double(count)) : 0.0L
+		};
+
 		out << std::left
 		    << std::setw(24) << "ROW"
 		    << std::right
@@ -3802,6 +3810,10 @@ try
 		    << " "
 		    << std::setw(9) << "INSERT%"
 		    << "  "
+		    << std::setw(8) << "COUNT"
+		    << " "
+		    << std::setw(10) << "INS:CNT"
+		    << "  "
 		    << std::setw(20) << "LOCKED"
 		    << " "
 		    << std::endl;
@@ -3834,6 +3846,11 @@ try
 		    << std::setw(8) << std::right << std::fixed << std::setprecision(2) << (ins_miss_pct * 100)
 		    << "%"
 		    << "  "
+		    << std::setw(8) << std::right << count
+		    << " "
+		    << std::setw(8) << std::right << std::fixed << std::setprecision(0) << ins_cnt_rat
+		    << ":1"
+		    << "  "
 		    << std::setw(20) << std::right << pretty(iec(pinned))
 		    << " "
 		    << std::endl
@@ -3868,6 +3885,10 @@ try
 	    << " "
 	    << std::setw(9) << "INSERT%"
 	    << "  "
+	    << std::setw(8) << "COUNT"
+	    << " "
+	    << std::setw(10) << "INS:CNT"
+	    << "  "
 	    << std::setw(20) << "LOCKED"
 	    << " "
 	    << std::endl;
@@ -3895,6 +3916,11 @@ try
 			s.inserts > 0.0? (double(s.hits) / double(s.inserts)) : 0.0L
 		};
 
+		const auto ins_cnt_rat
+		{
+			s.count > 0.0? (double(s.inserts) / double(s.count)) : 0.0L
+		};
+
 		out << std::setw(24) << std::left << column_name
 		    << std::right
 		    << " "
@@ -3922,6 +3948,11 @@ try
 		    << std::setw(8) << std::right << std::fixed << std::setprecision(2) << (ins_miss_pct * 100)
 		    << '%'
 		    << "  "
+		    << std::setw(8) << std::right << s.count
+		    << " "
+		    << std::setw(8) << std::right << std::fixed << std::setprecision(0) << ins_cnt_rat
+		    << ":1"
+		    << "  "
 		    << std::setw(20) << std::right << pretty(iec(s.pinned))
 		    << " "
 		    << std::endl;
@@ -3955,6 +3986,7 @@ try
 
 		const stats uncompressed
 		{
+			db::count(cache(column)),
 			db::usage(cache(column)),
 			db::pinned(cache(column)),
 			db::capacity(cache(column)),
@@ -3966,6 +3998,7 @@ try
 
 		const stats compressed
 		{
+			db::count(cache_compressed(column)),
 			db::usage(cache_compressed(column)),
 			0,
 			db::capacity(cache_compressed(column)),