Add porting.h

In preparation for MSVC compilation support

db-sqlite3.cpp

@@ -1,6 +1,6 @@
 #include "db-sqlite3.h"
 #include <stdexcept>
-#include <unistd.h> // for usleep
+#include "porting.h"
 #include "types.h"
 
 #define BLOCKPOSLIST_STATEMENT	"SELECT pos, rowid FROM blocks"
@@ -58,7 +58,7 @@ const DB::BlockPosList &DBSQLite3::getBlockPosList() {
 			sqlite3_int64 rowid = sqlite3_column_int64(m_blockPosListStatement, 1);
 			m_BlockPosList.push_back(BlockPos(blocknum, rowid));
 		} else if (result == SQLITE_BUSY) // Wait some time and try again
-			usleep(10000);
+			sleepMs(10);
 		else
 			break;
 	}
@@ -94,7 +94,7 @@ DB::Block DBSQLite3::getBlockOnPos(const BlockPos &pos)
 			m_blocksReadCount++;
 			break;
 		} else if (result == SQLITE_BUSY) { // Wait some time and try again
-			usleep(10000);
+			sleepMs(10);
 		} else {
 			break;
 		}

mapper.cpp

@@ -17,8 +17,8 @@
 #include <cstring>
 #include <stdexcept>
 #include <fcntl.h>
-#include <unistd.h>
 #include <sys/types.h>
+#include "porting.h"
 #include "TileGenerator.h"
 #include "PixelAttributes.h"
 #include "util.h"

porting.h

@@ -0,0 +1,22 @@
+#ifndef _PORTING_H
+#define _PORTING_H
+
+#ifdef _WIN32
+
+#include <windows.h>
+#define sleepMs(x) Sleep(x)
+
+#else
+
+#include <unistd.h>
+#define sleepMs(x) usleep(x*1000)
+
+#endif
+
+#ifdef _MSC_VER
+
+#define strcasecmp(a, b) _stricmp(a, b)
+
+#endif
+
+#endif // _PORTING_H