From 3bbb0d326bec3b3379c831b6a4cdc00438ac67f5 Mon Sep 17 00:00:00 2001
From: Stefan Boberg <stefan@boberg.org>
Date: Wed, 27 Oct 2021 21:01:50 +0200
Subject: Lockfile implementation (#24)

Implemented lockfile synchronization

To be used instead of or in conjunction with existing events to coordinate launching and discovery of server instances
---
 zenstore/basicfile.cpp | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

(limited to 'zenstore/basicfile.cpp')

diff --git a/zenstore/basicfile.cpp b/zenstore/basicfile.cpp
index bbb9e1036..9ed70a5ec 100644
--- a/zenstore/basicfile.cpp
+++ b/zenstore/basicfile.cpp
@@ -2,6 +2,7 @@
 
 #include "zenstore/basicfile.h"
 
+#include <zencore/compactbinary.h>
 #include <zencore/except.h>
 #include <zencore/filesystem.h>
 #include <zencore/fmtutils.h>
@@ -266,6 +267,53 @@ TemporaryFile::MoveTemporaryIntoPlace(std::filesystem::path FinalFileName, std::
 	std::filesystem::rename(m_TempPath, FinalFileName, Ec);
 }
 
+//////////////////////////////////////////////////////////////////////////
+
+LockFile::LockFile()
+{
+}
+
+LockFile::~LockFile()
+{
+}
+
+void
+LockFile::Create(std::filesystem::path FileName, CbObject Payload, std::error_code& Ec)
+{
+	Ec.clear();
+
+	const DWORD dwCreationDisposition = CREATE_ALWAYS;
+	DWORD		dwDesiredAccess		  = GENERIC_READ | GENERIC_WRITE | DELETE;
+	const DWORD dwShareMode			  = FILE_SHARE_READ;
+	const DWORD dwFlagsAndAttributes  = FILE_ATTRIBUTE_NORMAL | FILE_FLAG_DELETE_ON_CLOSE;
+	HANDLE		hTemplateFile		  = nullptr;
+
+	HANDLE FileHandle = CreateFile(FileName.c_str(),
+								   dwDesiredAccess,
+								   dwShareMode,
+								   /* lpSecurityAttributes */ nullptr,
+								   dwCreationDisposition,
+								   dwFlagsAndAttributes,
+								   hTemplateFile);
+
+	if (FileHandle == INVALID_HANDLE_VALUE)
+	{
+		Ec = zen::MakeErrorCodeFromLastError();
+
+		return;
+	}
+
+	m_FileHandle = FileHandle;
+
+	BasicFile::Write(Payload.GetBuffer(), 0, Ec);
+}
+
+void
+LockFile::Update(CbObject Payload, std::error_code& Ec)
+{
+	BasicFile::Write(Payload.GetBuffer(), 0, Ec);
+}
+
 /*
 		___________              __
 		\__    ___/___   _______/  |_  ______
-- 
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