Merge pull request #168 from addtheice/mysql_fetch_lengths_interface

Mysql fetch lengths interface

common/MySQLRequestResult.cpp

@@ -32,6 +32,11 @@ MySQLRequestResult::MySQLRequestResult(MYSQL_RES* result, uint32 rowsAffected, u
 	m_RowsAffected = rowsAffected;
 	m_RowCount = rowCount;
 	m_ColumnCount = columnCount;
+	// If we actually need the column length / fields it will be 
+	// requested at that time, no need to pull it in just to cache it. 
+	// Normal usage would have it as nullptr most likely anyways.
+	m_ColumnLengths = nullptr; 
+	m_Fields = nullptr;
 	m_LastInsertedID = lastInsertedID;
 	m_ErrorNumber = errorNumber;
 }
@@ -51,6 +56,8 @@ void MySQLRequestResult::ZeroOut()
 	m_Success = false;
 	m_Result = nullptr;
 	m_ErrorBuffer = nullptr;
+	m_ColumnLengths = nullptr;
+	m_Fields = nullptr;
 	m_RowCount = 0;
 	m_RowsAffected = 0;
 	m_LastInsertedID = 0;
@@ -61,6 +68,39 @@ MySQLRequestResult::~MySQLRequestResult()
 	FreeInternals();
 }
 
+uint32 MySQLRequestResult::LengthOfColumn(int columnIndex)
+{
+	if (m_ColumnLengths == nullptr && m_Result != nullptr)
+		m_ColumnLengths = mysql_fetch_lengths(m_Result);
+
+	// If someone screws up and tries to get the length of a
+	// column when no result occured (check Success! argh!)
+	// then we always return 0. Also applies if mysql screws
+	// up and can't get the column lengths for whatever reason.
+	if (m_ColumnLengths == nullptr)
+		return 0;
+
+	// Want to index check to be sure we don't read passed
+	// the end of the array. Just default to 0 in that case.
+	// We *shouldn't* need this or the previous checks if all
+	// interface code is correctly written.
+	if (columnIndex >= m_ColumnCount)
+		return 0;
+
+	return m_ColumnLengths[columnIndex];
+}
+
+const std::string MySQLRequestResult::FieldName(int columnIndex)
+{
+	if (columnIndex >= m_ColumnCount || m_Result == nullptr)
+		return std::string();
+
+	if (m_Fields == nullptr)
+		m_Fields = mysql_fetch_fields(m_Result);
+
+	return std::string(m_Fields[columnIndex].name);
+}
+
 MySQLRequestResult::MySQLRequestResult(MySQLRequestResult&& moveItem)
 	: m_CurrentRow(moveItem.m_CurrentRow), m_OneBeyondRow()
 {
@@ -70,6 +110,8 @@ MySQLRequestResult::MySQLRequestResult(MySQLRequestResult&& moveItem)
 	m_RowCount = moveItem.m_RowCount;
 	m_RowsAffected = moveItem.m_RowsAffected;
 	m_LastInsertedID = moveItem.m_LastInsertedID;
+	m_ColumnLengths = moveItem.m_ColumnLengths;
+	m_Fields = moveItem.m_Fields;
 
 	// Keeps deconstructor from double freeing 
 	// pre move instance.
@@ -95,7 +137,9 @@ MySQLRequestResult& MySQLRequestResult::operator=(MySQLRequestResult&& other)
 	m_LastInsertedID = other.m_LastInsertedID;
 	m_CurrentRow = other.m_CurrentRow;
 	m_OneBeyondRow = other.m_OneBeyondRow;
-	
+	m_ColumnLengths = other.m_ColumnLengths;
+	m_Fields = other.m_Fields;
+
 	// Keeps deconstructor from double freeing 
 	// pre move instance.
 	other.ZeroOut();

common/MySQLRequestResult.h

@@ -16,7 +16,9 @@
 class MySQLRequestResult {
 private:
 	MYSQL_RES* m_Result;
+	MYSQL_FIELD* m_Fields;
 	char* m_ErrorBuffer;
+	unsigned long* m_ColumnLengths;
 	MySQLRequestRow m_CurrentRow;
 	MySQLRequestRow m_OneBeyondRow;
 
@@ -44,6 +46,9 @@ public:
 	uint32 RowCount() const {return m_RowCount;}
 	uint32 ColumnCount() const {return m_ColumnCount;}
 	uint32 LastInsertedID() const {return m_LastInsertedID;}
+	// default to 0 index since we mostly use it that way anyways.
+	uint32 LengthOfColumn(int columnIndex = 0); 
+	const std::string FieldName(int columnIndex);
 
 	MySQLRequestRow& begin() { return m_CurrentRow; }
 	MySQLRequestRow& end() { return m_OneBeyondRow;}

common/dbcore.cpp

@@ -58,6 +58,11 @@ void DBcore::ping() {
 	MDatabase.unlock();
 }
 
+MySQLRequestResult DBcore::QueryDatabase(std::string query, bool retryOnFailureOnce)
+{
+	return QueryDatabase(query.c_str(), query.length(), retryOnFailureOnce);
+}
+
 MySQLRequestResult DBcore::QueryDatabase(const char* query, uint32 querylen, bool retryOnFailureOnce)
 {
 	LockMutex lock(&MDatabase);

common/dbcore.h

@@ -7,6 +7,7 @@
 #endif
 
 #include <mysql.h>
+#include <string.h>
 #include "../common/types.h"
 #include "../common/Mutex.h"
 #include "../common/linked_list.h"
@@ -24,6 +25,7 @@ public:
 	eStatus	GetStatus() { return pStatus; }
 	bool	RunQuery(const char* query, uint32 querylen, char* errbuf = 0, MYSQL_RES** result = 0, uint32* affected_rows = 0, uint32* last_insert_id = 0, uint32* errnum = 0, bool retry = true);
 	MySQLRequestResult	QueryDatabase(const char* query, uint32 querylen, bool retryOnFailureOnce = true);
+	MySQLRequestResult	QueryDatabase(std::string query, bool retryOnFailureOnce = true);
 	uint32	DoEscapeString(char* tobuf, const char* frombuf, uint32 fromlen);
 	void	ping();
 	MYSQL*	getMySQL(){ return &mysql; }