Disable lite build/testing for persistent read cache

Summary:
Persistent read cache isn't very applicable for lite builds. Wrapping
the code with #ifndef ROCKSDB_LITE .. #endif

Test Plan: Run unit, lite, lite_test

Reviewers: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D58563

utilities/persistent_cache/hash_table.h

@@ -5,6 +5,8 @@
 //
 #pragma once
 
+#ifndef ROCKSDB_LITE
+
 #include <assert.h>
 #include <sys/mman.h>
 #include <list>
@@ -224,3 +226,5 @@ class HashTable {
 };
 
 }  // namespace rocksdb
+
+#endif

utilities/persistent_cache/hash_table_bench.cc

@@ -4,6 +4,8 @@
 //  of patent rights can be found in the PATENTS file in the same directory.
 //
 
+#ifndef ROCKSDB_LITE
+
 #include <gflags/gflags.h>
 #include <sys/time.h>
 #include <unistd.h>
@@ -292,3 +294,6 @@ int main(int argc, char** argv) {
 
   return 0;
 }
+#else
+int main(int /*argc*/, char** /*argv*/) { return 0; }
+#endif

utilities/persistent_cache/hash_table_evictable.h

@@ -5,6 +5,8 @@
 //
 #pragma once
 
+#ifndef ROCKSDB_LITE
+
 #include "utilities/persistent_cache/hash_table.h"
 #include "utilities/persistent_cache/lrulist.h"
 
@@ -158,3 +160,5 @@ class EvictableHashTable : private HashTable<T*, Hash, Equal> {
 };
 
 }  // namespace rocksdb
+
+#endif

utilities/persistent_cache/hash_table_test.cc

@@ -13,6 +13,8 @@
 #include "utilities/persistent_cache/hash_table.h"
 #include "utilities/persistent_cache/hash_table_evictable.h"
 
+#ifndef ROCKSDB_LITE
+
 namespace rocksdb {
 
 struct HashTableTest : public testing::Test {
@@ -145,6 +147,7 @@ TEST_F(EvictableHashTableTest, TestEvict) {
 }
 
 }  // namespace rocksdb
+#endif
 
 int main(int argc, char** argv) {
   ::testing::InitGoogleTest(&argc, argv);

utilities/persistent_cache/lrulist.h

@@ -5,6 +5,8 @@
 //
 #pragma once
 
+#ifndef ROCKSDB_LITE
+
 #include <atomic>
 
 #include "util/mutexlock.h"
@@ -168,3 +170,5 @@ class LRUList {
 };
 
 }  // namespace rocksdb
+
+#endif