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Re: Create new files as sparse on NT systems. (2nd try)
- From: Vaclav Haisman <V dot Haisman at sh dot cvut dot cz>
- To: cygwin-patches at cygwin dot com
- Date: Mon, 17 Feb 2003 18:36:37 +0100 (CET)
- Subject: Re: Create new files as sparse on NT systems. (2nd try)
> This looks pretty good but the cygwin convention is to use wincap
> settings for this kind of thing rather than using is_winnt. So, please
> add a wincap capability to accomplish this.
>
> cgf
Modified as suggested.
Vaclav Haisman
2003-02-17 Vaclav Haisman <V.Haisman@sh.cvut.cz>
* wincap.h (wincaps::supports_sparse_files): New flag.
(wincapc::supports_sparse_files): New method.
* wincap.cc (wincap_unknown): Define value for the new flag.
(wincap_95): Ditto.
(wincap_95osr2): Ditto.
(wincap_98): Ditto.
(wincap_98se): Ditto.
(wincap_me): Ditto.
(wincap_nt3): Ditto.
(wincap_nt4): Ditto.
(wincap_nt4sp4): Ditto.
(wincap_2000): Ditto.
(wincap_xp): Ditto.
* fhandler.cc: Include winioctl.h for DeviceIoControl.
(fhandler::open): Try to set newly created and truncated files as
sparse.
2003-02-17 Vaclav Haisman <V.Haisman@sh.cvut.cz>
* include/winioctl.h (FSCTL_SET_SPARSE): Define.
Index: cygwin/fhandler.cc
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/fhandler.cc,v
retrieving revision 1.143
diff -u -p -r1.143 fhandler.cc
--- cygwin/fhandler.cc 20 Dec 2002 01:48:22 -0000 1.143
+++ cygwin/fhandler.cc 17 Feb 2003 17:23:43 -0000
@@ -27,6 +27,7 @@ details. */
#include "pinfo.h"
#include <assert.h>
#include <limits.h>
+#include <winioctl.h>
static NO_COPY const int CHUNK_SIZE = 1024; /* Used for crlf conversions */
@@ -486,6 +487,18 @@ fhandler_base::open (path_conv *pc, int
&& !allow_ntsec && allow_ntea)
set_file_attribute (has_acls (), get_win32_name (), mode);
+ /* Try to set newly created files as sparse files on NT system. */
+ if (wincap.supports_sparse_files () && get_device () == FH_DISK
+ && (access & GENERIC_WRITE) == GENERIC_WRITE
+ && (flags & (O_CREAT | O_TRUNC)))
+ {
+ DWORD dw;
+ BOOL r = DeviceIoControl (x, FSCTL_SET_SPARSE, NULL, 0, NULL, 0, &dw,
+ NULL);
+ syscall_printf ("%d = DeviceIoControl(0x%x, FSCTL_SET_SPARSE, NULL, 0, "
+ "NULL, 0, &dw, NULL)", r, x);
+ }
+
set_io_handle (x);
set_flags (flags, pc ? pc->binmode () : 0);
Index: cygwin/wincap.cc
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/wincap.cc,v
retrieving revision 1.18
diff -u -p -r1.18 wincap.cc
--- cygwin/wincap.cc 15 Oct 2002 17:04:20 -0000 1.18
+++ cygwin/wincap.cc 17 Feb 2003 17:23:44 -0000
@@ -47,7 +47,8 @@ static NO_COPY wincaps wincap_unknown =
has_64bit_file_access:false,
has_process_io_counters:false,
supports_reading_modem_output_lines:false,
- needs_memory_protection:false
+ needs_memory_protection:false,
+ supports_sparse_files:false
};
static NO_COPY wincaps wincap_95 = {
@@ -86,7 +87,8 @@ static NO_COPY wincaps wincap_95 = {
has_64bit_file_access:false,
has_process_io_counters:false,
supports_reading_modem_output_lines:false,
- needs_memory_protection:false
+ needs_memory_protection:false,
+ supports_sparse_files:false
};
static NO_COPY wincaps wincap_95osr2 = {
@@ -125,7 +127,8 @@ static NO_COPY wincaps wincap_95osr2 = {
has_64bit_file_access:false,
has_process_io_counters:false,
supports_reading_modem_output_lines:false,
- needs_memory_protection:false
+ needs_memory_protection:false,
+ supports_sparse_files:false
};
static NO_COPY wincaps wincap_98 = {
@@ -164,7 +167,8 @@ static NO_COPY wincaps wincap_98 = {
has_64bit_file_access:false,
has_process_io_counters:false,
supports_reading_modem_output_lines:false,
- needs_memory_protection:false
+ needs_memory_protection:false,
+ supports_sparse_files:false
};
static NO_COPY wincaps wincap_98se = {
@@ -203,7 +207,8 @@ static NO_COPY wincaps wincap_98se = {
has_64bit_file_access:false,
has_process_io_counters:false,
supports_reading_modem_output_lines:false,
- needs_memory_protection:false
+ needs_memory_protection:false,
+ supports_sparse_files:false
};
static NO_COPY wincaps wincap_me = {
@@ -242,7 +247,8 @@ static NO_COPY wincaps wincap_me = {
has_64bit_file_access:false,
has_process_io_counters:false,
supports_reading_modem_output_lines:false,
- needs_memory_protection:false
+ needs_memory_protection:false,
+ supports_sparse_files:false
};
static NO_COPY wincaps wincap_nt3 = {
@@ -281,7 +287,8 @@ static NO_COPY wincaps wincap_nt3 = {
has_64bit_file_access:true,
has_process_io_counters:false,
supports_reading_modem_output_lines:true,
- needs_memory_protection:true
+ needs_memory_protection:true,
+ supports_sparse_files:false
};
static NO_COPY wincaps wincap_nt4 = {
@@ -320,7 +327,8 @@ static NO_COPY wincaps wincap_nt4 = {
has_64bit_file_access:true,
has_process_io_counters:false,
supports_reading_modem_output_lines:true,
- needs_memory_protection:true
+ needs_memory_protection:true,
+ supports_sparse_files:false
};
static NO_COPY wincaps wincap_nt4sp4 = {
@@ -359,7 +367,8 @@ static NO_COPY wincaps wincap_nt4sp4 = {
has_64bit_file_access:true,
has_process_io_counters:false,
supports_reading_modem_output_lines:true,
- needs_memory_protection:true
+ needs_memory_protection:true,
+ supports_sparse_files:false
};
static NO_COPY wincaps wincap_2000 = {
@@ -398,7 +407,8 @@ static NO_COPY wincaps wincap_2000 = {
has_64bit_file_access:true,
has_process_io_counters:true,
supports_reading_modem_output_lines:true,
- needs_memory_protection:true
+ needs_memory_protection:true,
+ supports_sparse_files:true
};
static NO_COPY wincaps wincap_xp = {
@@ -437,7 +447,8 @@ static NO_COPY wincaps wincap_xp = {
has_64bit_file_access:true,
has_process_io_counters:true,
supports_reading_modem_output_lines:true,
- needs_memory_protection:true
+ needs_memory_protection:true,
+ supports_sparse_files:true
};
wincapc wincap;
Index: cygwin/wincap.h
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/wincap.h,v
retrieving revision 1.14
diff -u -p -r1.14 wincap.h
--- cygwin/wincap.h 15 Oct 2002 17:04:20 -0000 1.14
+++ cygwin/wincap.h 17 Feb 2003 17:23:44 -0000
@@ -49,6 +49,7 @@ struct wincaps
unsigned has_process_io_counters : 1;
unsigned supports_reading_modem_output_lines : 1;
unsigned needs_memory_protection : 1;
+ unsigned supports_sparse_files : 1;
};
class wincapc
@@ -102,6 +103,7 @@ public:
bool IMPLEMENT (has_process_io_counters)
bool IMPLEMENT (supports_reading_modem_output_lines)
bool IMPLEMENT (needs_memory_protection)
+ bool IMPLEMENT (supports_sparse_files)
#undef IMPLEMENT
};
Index: w32api/include/winioctl.h
===================================================================
RCS file: /cvs/src/src/winsup/w32api/include/winioctl.h,v
retrieving revision 1.8
diff -u -p -r1.8 winioctl.h
--- w32api/include/winioctl.h 7 Nov 2002 14:14:01 -0000 1.8
+++ w32api/include/winioctl.h 17 Feb 2003 17:23:59 -0000
@@ -69,6 +69,7 @@ extern "C" {
#define FSCTL_GET_REPARSE_POINT CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 42, METHOD_BUFFERED, FILE_ANY_ACCESS)
#define FSCTL_SET_REPARSE_POINT CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 41, METHOD_BUFFERED, FILE_WRITE_DATA)
#define FSCTL_DELETE_REPARSE_POINT CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 43, METHOD_BUFFERED, FILE_WRITE_DATA)
+#define FSCTL_SET_SPARSE CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 49, METHOD_BUFFERED, FILE_SPECIAL_ACCESS)
#define DEVICE_TYPE DWORD
#define FILE_DEVICE_BEEP 1
#define FILE_DEVICE_CD_ROM 2