Gcc-7 buffer size insufficient

Summary:
Bunch of commits related to insufficient buffer size. Errors in individual commits.
Closes https://github.com/facebook/rocksdb/pull/1673

Differential Revision: D4332127

Pulled By: IslamAbdelRahman

fbshipit-source-id: 878f73c

tools/db_bench_tool.cc

@@ -2615,7 +2615,7 @@ class Benchmark {
     if (!ok) {
       thread->stats.AddMessage("(compression failure)");
     } else {
-      char buf[100];
+      char buf[340];
       snprintf(buf, sizeof(buf), "(output: %.1f%%)",
                (produced * 100.0) / bytes);
       thread->stats.AddMessage(buf);

util/transaction_test_util.cc

@@ -190,7 +190,7 @@ Status RandomTransactionInserter::Verify(DB* db, uint16_t num_sets) {
 
   // For each set of keys with the same prefix, sum all the values
   for (uint32_t i = 0; i < num_sets; i++) {
-    char prefix_buf[5];
+    char prefix_buf[6];
     snprintf(prefix_buf, sizeof(prefix_buf), "%.4u", i + 1);
     uint64_t total = 0;
 

utilities/simulator_cache/sim_cache.cc

@@ -136,7 +136,7 @@ class SimCacheImpl : public SimCache {
     std::string res;
     res.append("SimCache MISSes: " + std::to_string(get_miss_counter()) + "\n");
     res.append("SimCache HITs:    " + std::to_string(get_hit_counter()) + "\n");
-    char buff[100];
+    char buff[350];
     auto lookups = get_miss_counter() + get_hit_counter();
     snprintf(buff, sizeof(buff), "SimCache HITRATE: %.2f%%\n",
              (lookups == 0 ? 0 : get_hit_counter() * 100.0f / lookups));

utilities/transactions/transaction_util.cc

@@ -81,7 +81,7 @@ Status TransactionUtil::CheckKey(DBImpl* db_impl, SuperVersion* sv,
     if (cache_only) {
       // The age of this memtable is too new to use to check for recent
       // writes.
-      char msg[255];
+      char msg[300];
       snprintf(msg, sizeof(msg),
                "Transaction could not check for conflicts for operation at "
                "SequenceNumber %" PRIu64