From dc4d50b117716a3b7df9805be4da21c2b75802b1 Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Sat, 14 Feb 2009 03:56:07 +0000
Subject: [PATCH] don't make files sparse when allocation mode is set on the
 storage (windows only)

---
 include/libtorrent/file.hpp | 1 +
 src/file.cpp                | 2 +-
 src/storage.cpp             | 7 +++++--
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/include/libtorrent/file.hpp b/include/libtorrent/file.hpp
index 3f781f9dd..1b16d0c7e 100644
--- a/include/libtorrent/file.hpp
+++ b/include/libtorrent/file.hpp
@@ -95,6 +95,7 @@ namespace libtorrent
 			rw_mask = read_only | write_only | read_write,
 			no_buffer = 4,
 			mode_mask = rw_mask | no_buffer,
+			sparse = 8,
 
 			attribute_hidden = 0x1000,
 			attribute_executable = 0x2000,
diff --git a/src/file.cpp b/src/file.cpp
index a93c7db2d..ecefaa2da 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -193,7 +193,7 @@ namespace libtorrent
 		}
 
 		// try to make the file sparse if supported
-		if ((mode & rw_mask) == write_only || (mode & rw_mask)  == read_write)
+		if (mode & file::sparse)
 		{
 			DWORD temp;
 			::DeviceIoControl(m_file_handle, FSCTL_SET_SPARSE, 0, 0
diff --git a/src/storage.cpp b/src/storage.cpp
index ce38f10e1..49e28f05a 100644
--- a/src/storage.cpp
+++ b/src/storage.cpp
@@ -416,6 +416,7 @@ namespace libtorrent
 			: m_files(fs)
 			, m_pool(fp)
 			, m_page_size(4096)
+			, m_allocate_files(false)
 		{
 			TORRENT_ASSERT(m_files.begin() != m_files.end());
 			m_save_path = fs::complete(path);
@@ -483,6 +484,7 @@ namespace libtorrent
 		file_pool& m_pool;
 
 		int m_page_size;
+		bool m_allocate_files;
 	};
 
 	sha1_hash storage::hash_for_slot(int slot, partial_hash& ph, int piece_size)
@@ -516,6 +518,7 @@ namespace libtorrent
 
 	bool storage::initialize(bool allocate_files)
 	{
+		m_allocate_files = allocate_files;
 		error_code ec;
 		// first, create all missing directories
 		fs::path last_path;
@@ -570,6 +573,7 @@ namespace libtorrent
 					|| (settings().disk_io_read_mode == session_settings::disable_os_cache_for_aligned_files
 					&& ((file_iter->offset + file_iter->file_base) & (m_page_size-1)) == 0)))
 					mode |= file::no_buffer;
+				if (!m_allocate_files) mode |= file::sparse;
 				boost::shared_ptr<file> f = m_pool.open_file(this
 					, m_save_path / file_iter->path, mode, ec);
 				if (ec) set_error(m_save_path / file_iter->path, ec);
@@ -1164,9 +1168,8 @@ ret:
 			if (op.cache_setting == session_settings::disable_os_cache
 				|| (op.cache_setting == session_settings::disable_os_cache_for_aligned_files
 				&& ((file_iter->offset + file_iter->file_base) & (m_page_size-1)) == 0))
-			{
 				mode |= file::no_buffer;
-			}
+			if (!m_allocate_files) mode |= file::sparse;
 
 			file_handle = m_pool.open_file(this, path, mode, ec);
 			if (!file_handle || ec)