dbcampaign: select multiple variants/benchmark pairs

The variant/benchmark selection now can use SQL LIKE syntax, all unfinished
pilots from all selected variants are sent to the clients. E.g.:

./cored-voter-server  -v x86-cored-voter -b simple-% -p basic

Will select the fsppilots in the variants:

- x86-cored-voter/simple-ip/basic
- x86-cored-voter/simple-instr/basic

The variant and benchmark information is now sent within the
fsppilot.

Change-Id: I287bfcddc478d0b79d89e156d6f5bf8188674532

src/core/util/Database.cc

@@ -74,36 +74,56 @@ my_ulonglong Database::affected_rows()
 }
 
 
-int Database::get_variant_id(const std::string &variant, const std::string &benchmark)
-{
+std::vector<Database::Variant> Database::get_variants(const std::string &variant, const std::string &benchmark) {
+	std::vector<Variant> result;
+
 	if (!query("CREATE TABLE IF NOT EXISTS variant ("
 		  "	 id int(11) NOT NULL AUTO_INCREMENT,"
 		  "	 variant varchar(255) NOT NULL,"
 		  "	 benchmark varchar(255) NOT NULL,"
 		  "	 PRIMARY KEY (id),"
 		  "UNIQUE KEY variant (variant,benchmark))")) {
-		return 0;
+		return result;
 	}
 
-	int variant_id;
 	std::stringstream ss;
 	// FIXME SQL injection possible
-	ss << "SELECT id FROM variant WHERE variant LIKE '" << variant << "' AND benchmark LIKE '" << benchmark << "'";
+	ss << "SELECT id, variant, benchmark FROM variant WHERE variant LIKE '" << variant << "' AND benchmark LIKE '" << benchmark << "'";
 	MYSQL_RES *variant_id_res = query(ss.str().c_str(), true);
+
 	if (!variant_id_res) {
-		return 0;
+		return result;
 	} else if (mysql_num_rows(variant_id_res)) {
-		MYSQL_ROW row = mysql_fetch_row(variant_id_res);
-		variant_id = atoi(row[0]);
-	} else {
-		ss.str("");
+		for (unsigned int i = 0; i < mysql_num_rows(variant_id_res); ++i) {
+			MYSQL_ROW row = mysql_fetch_row(variant_id_res);
+			Variant var;
+			var.id = atoi(row[0]);
+			var.variant = std::string(row[1]);
+			var.benchmark = std::string(row[2]);
+			result.push_back(var);
+		}
+	}
+
+	return result;
+}
+
+int Database::get_variant_id(const std::string &variant, const std::string &benchmark)
+{
+	std::vector<Variant> variants = get_variants(variant, benchmark);
+	if (variants.size() == 0) {
+		// Insert a new variant
+		std::stringstream ss;
 		ss << "INSERT INTO variant (variant, benchmark) VALUES ('" << variant << "', '" << benchmark << "')";
 		if (!query(ss.str().c_str())) {
 			return 0;
 		}
-		variant_id = mysql_insert_id(handle);
+		return mysql_insert_id(handle);
+	} else if (variants.size() == 1) {
+		return variants[0].id;
+	} else {
+		LOG << "Variant identifier " << variant << "/" << benchmark << " is ambigious!" << std::endl;
+		return 0;
 	}
-	return variant_id;
 }
 
 int Database::get_fspmethod_id(const std::string &method)

src/core/util/Database.hpp

@@ -5,6 +5,7 @@
 #include <boost/thread.hpp>
 #endif
 
+#include <vector>
 #include <mysql/mysql.h>
 #include <iostream>
 #include <string>
@@ -31,6 +32,12 @@ namespace fail {
 		Database(const std::string &username, const std::string &host, const std::string &database);
 		~Database() { mysql_close(handle); }
 
+		struct Variant {
+			int id;
+			std::string variant;
+			std::string benchmark;
+		};
+
 		/**
 		 * Get the variant id for a specific variant/benchmark pair,
 		 * if it isn't defined in the database (variant table), it is
@@ -38,6 +45,13 @@ namespace fail {
 		 */
 		int get_variant_id(const std::string &variant, const std::string &benchmark);
 
+		/**
+		 * Get all variants that fit the given patterns (will be
+		 * queried with SQL LIKE).
+		 */
+		std::vector<Variant> get_variants(const std::string &variant, const std::string &benchmark);
+
+
 		/**
 		 * Get the fault space pruning method id for a specific
 		 * pruning method, if it isn't defined in the database