Fix bug in handling null string and freeing redis reply

Author: Jinglei Ren

db/redis_db.cc

@@ -31,8 +31,8 @@ int RedisDB::Read(const string &table, const string &key,
  assert(reply->type == REDIS_REPLY_ARRAY);
  assert(fields->size() == reply->elements);
  for (size_t i = 0; i < reply->elements; ++i) {
- result.push_back(make_pair(
-  fields->at(i), string(reply->element[i]->str)));
+ const char *value = reply->element[i]->str;
+ result.push_back(make_pair(fields->at(i), string(value ? value : "")));
  }
  freeReplyObject(reply);
  } else {

redis/Makefile

@@ -6,9 +6,10 @@ LDFLAGS=-lhiredis
 
 all: hiredis sample
 
-sample:	sample.cc $(HEADERS)
+sample:	sample.cc ../db/redis_db.o $(HEADERS)
 $(MAKE) -C ./hiredis
-$(CC) $(CFLAGS) $(INCLUDES) $< $(LDFLAGS) -o $@
+$(MAKE) -C ../db
+$(CC) $(CFLAGS) $(INCLUDES) $< ../db/redis_db.o $(LDFLAGS) -o $@
 
 clean:
 $(RM) sample

redis/redis_client.h

@@ -59,10 +59,12 @@ inline int RedisClient::Command(std::string cmd, int n, int t) {
  HandleError(reply, cmd.c_str());
  }
  freeReplyObject(reply);
- if (sync_ && redisGetReply(context_, (void **)&reply) == REDIS_ERR) {
- HandleError(reply, "WAIT");
+ if (sync_) {
+ if (redisGetReply(context_, (void **)&reply) == REDIS_ERR) {
+ HandleError(reply, "WAIT");
+ }
+ freeReplyObject(reply);
  }
- freeReplyObject(reply);
  return 0;
 }
 

redis/run_sample.sh

@@ -1,10 +1,6 @@
 #! /bin/bash
 
-REDIS=~/redis
-
 export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
 
 ./sample
 
-$REDIS/src/redis-cli hmget Ren field1 field2
-

redis/sample.cc

@@ -1,5 +1,10 @@
-#include "redis_client.h"
+#include <iostream>
+#include <string>
+#include <vector>
+#include "redis/redis_client.h"
+#include "db/redis_db.h"
 
+using namespace std;
 using namespace ycsbc;
 
 int main(int argc, const char *argv[]) {
@@ -10,5 +15,31 @@ int main(int argc, const char *argv[]) {
 
  client.Command("HMSET Ren field1 jinglei@ren.systems field2 Jinglei");
 
+ RedisDB db(host, port, false);
+ db.Init();
+ string key = "Ren";
+ vector<string> fields;
+ fields.push_back("field1");
+ fields.push_back("field3");
+ vector<DB::KVPair> result;
+
+ db.Read(key, key, &fields, result);
+ for (auto &p : result) {
+ cout << p.first << '\t' << p.second << endl;
+ }
+
+ result[1].second = "HelloWorld!";
+ db.Update(key, key, result);
+
+ result.clear();
+ db.Read(key, key, nullptr, result);
+ for (auto &p : result) {
+ cout << p.first << '\t' << p.second << endl;
+ }
+
+ db.Delete(key, key);
+ result.clear();
+ db.Read(key, key, nullptr, result);
+ cout << "After delete: " << result.size() << endl;
  return 0;
 }