update docs for cpp http api

api/http/cpp/client.cpp

@@ -124,6 +124,7 @@ int CHttpClient::Get(const std::string &strUrl, const std::string &filename, boo
 		curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);
 		curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION, OnDebug);
 	}
+    curl_easy_setopt(curl, CURLOPT_BUFFERSIZE, 4096);
 	curl_easy_setopt(curl, CURLOPT_URL, UrlEncode(strUrl).c_str());
 	curl_easy_setopt(curl, CURLOPT_READFUNCTION, NULL);
 	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, NULL);

api/http/cpp/example/Benchmark.cpp

@@ -14,6 +14,8 @@ bool correctness = true;
 bool lcorrectness = true;
 bool ucorrectness = true;
 
+// before you run this example, make sure that you have started up ghttp service (using bin/ghttp db_name port)
+
 pthread_mutex_t mutex;
 
 string int2string(int n)

api/http/cpp/example/Benchmark1.cpp

@@ -14,6 +14,8 @@ bool correctness = true;
 bool lcorrectness = true;
 bool ucorrectness = true;
 
+// before you run this example, make sure that you have started up ghttp service (using bin/ghttp db_name port)
+
 pthread_mutex_t mutex;
 
 string int2string(int n)

api/http/cpp/example/CppAPIExample.cpp

@@ -10,7 +10,7 @@
 #include <string>
 #include <iostream>
 using namespace std;
-// before run this example, you must start up the GStore server at first (use command ./gserver).
+// before you run this example, make sure that you have started up ghttp service (using bin/ghttp db_name port)
 int main(int argc, char * argv[])
 {
     // initialize the GStore server's IP address and port.

api/http/cpp/example/example.cpp

@@ -7,7 +7,7 @@
 #include "client.h"
 
 using namespace std;
-
+// before you run this example, make sure that you have started up ghttp service (using bin/ghttp db_name port)
 int main()
 {