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(MESS) support for writing to compressed hard drives using diff files. [smf]

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smf- 2012-09-08 11:59:58 +00:00
parent 679e9323be
commit 44cd4a476a
3 changed files with 88 additions and 45 deletions
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127
src/emu/imagedev/harddriv.c
View File

@ -2,10 +2,6 @@
Code to interface the image code with harddisk core.
We do not support diff files as it will involve some changes in
the image code. Additionally, the need for diff files comes
from MAME's need for "canonical" hard drive images.
Raphael Nabet 2003
Update: 23-Feb-2004 - Unlike floppy disks, for which we support
@ -16,6 +12,7 @@
*********************************************************************/
#include "emu.h"
#include "emuopts.h"
#include "harddisk.h"
#include "harddriv.h"
@ -140,14 +137,14 @@ bool harddisk_image_device::call_create(int create_format, option_resolution *cr
/* create the CHD file */
chd_codec_type compression[4] = { CHD_CODEC_NONE };
err = m_self_chd.create(*image_core_file(), (UINT64)totalsectors * (UINT64)sectorsize, hunksize, sectorsize, compression);
err = m_origchd.create(*image_core_file(), (UINT64)totalsectors * (UINT64)sectorsize, hunksize, sectorsize, compression);
if (err != CHDERR_NONE)
goto error;
/* if we created the image and hence, have metadata to set, set the metadata */
metadata.format(HARD_DISK_METADATA_FORMAT, cylinders, heads, sectors, sectorsize);
err = m_self_chd.write_metadata(HARD_DISK_METADATA_TAG, 0, metadata);
m_self_chd.close();
err = m_origchd.write_metadata(HARD_DISK_METADATA_TAG, 0, metadata);
m_origchd.close();
if (err != CHDERR_NONE)
goto error;
@ -172,60 +169,102 @@ void harddisk_image_device::call_unload()
m_hard_disk_handle = NULL;
}
if (m_chd != NULL)
m_origchd.close();
m_diffchd.close();
m_chd = NULL;
}
/*-------------------------------------------------
open_disk_diff - open a DISK diff file
-------------------------------------------------*/
static chd_error open_disk_diff(emu_options &options, const char *name, chd_file &source, chd_file &diff_chd)
{
astring fname(name, ".dif");
/* try to open the diff */
//printf("Opening differencing image file: %s\n", fname.cstr());
emu_file diff_file(options.diff_directory(), OPEN_FLAG_READ | OPEN_FLAG_WRITE);
file_error filerr = diff_file.open(fname);
if (filerr == FILERR_NONE)
{
if (m_self_chd.opened())
m_self_chd.close();
m_chd = NULL;
astring fullpath(diff_file.fullpath());
diff_file.close();
//printf("Opening differencing image file: %s\n", fullpath.cstr());
return diff_chd.open(fullpath, true, &source);
}
/* didn't work; try creating it instead */
//printf("Creating differencing image: %s\n", fname.cstr());
diff_file.set_openflags(OPEN_FLAG_READ | OPEN_FLAG_WRITE | OPEN_FLAG_CREATE | OPEN_FLAG_CREATE_PATHS);
filerr = diff_file.open(fname);
if (filerr == FILERR_NONE)
{
astring fullpath(diff_file.fullpath());
diff_file.close();
/* create the CHD */
//printf("Creating differencing image file: %s\n", fullpath.cstr());
chd_codec_type compression[4] = { CHD_CODEC_NONE };
chd_error err = diff_chd.create(fullpath, source.logical_bytes(), source.hunk_bytes(), compression, source);
if (err != CHDERR_NONE)
return err;
return diff_chd.clone_all_metadata(source);
}
return CHDERR_FILE_NOT_FOUND;
}
int harddisk_image_device::internal_load_hd()
{
chd_error err = (chd_error)0;
int is_writeable;
astring tempstring;
chd_error err = CHDERR_NONE;
m_chd = NULL;
/* open the CHD file */
if (software_entry() != NULL)
{
m_chd = get_disk_handle(device().machine(), device().subtag(tempstring,"harddriv"));
} else {
do
{
is_writeable = !is_readonly();
err = m_self_chd.open(*image_core_file(), is_writeable);
if (err == CHDERR_NONE)
m_chd = &m_self_chd;
/* special case; if we get CHDERR_FILE_NOT_WRITEABLE, make the
* image read only and repeat */
if (err == CHDERR_FILE_NOT_WRITEABLE)
make_readonly();
}
while(!m_chd && is_writeable && (err == CHDERR_FILE_NOT_WRITEABLE));
}
if (!m_chd)
goto done;
/* open the hard disk file */
m_hard_disk_handle = hard_disk_open(m_chd);
if (!m_hard_disk_handle)
goto done;
done:
if (err)
else
{
/* if we had an error, close out the CHD */
if (m_chd != NULL)
err = m_origchd.open(*image_core_file(), true);
if (err == CHDERR_NONE)
{
if (m_self_chd.opened())
m_self_chd.close();
m_chd = NULL;
m_chd = &m_origchd;
}
else if (err == CHDERR_FILE_NOT_WRITEABLE)
{
err = m_origchd.open(*image_core_file(), false);
if (err == CHDERR_NONE)
{
err = open_disk_diff(device().machine().options(), basename_noext(), m_origchd, m_diffchd);
if (err == CHDERR_NONE)
{
m_chd = &m_diffchd;
}
}
}
seterror(IMAGE_ERROR_UNSPECIFIED, chd_file::error_string(err));
}
return err ? IMAGE_INIT_FAIL : IMAGE_INIT_PASS;
if (m_chd != NULL)
{
/* open the hard disk file */
m_hard_disk_handle = hard_disk_open(m_chd);
if (m_hard_disk_handle != NULL)
return IMAGE_INIT_PASS;
}
/* if we had an error, close out the CHD */
m_origchd.close();
m_diffchd.close();
m_chd = NULL;
seterror(IMAGE_ERROR_UNSPECIFIED, chd_file::error_string(err));
return IMAGE_INIT_FAIL;
}
/*************************************

3
src/emu/imagedev/harddriv.h
View File

@ -67,7 +67,8 @@ protected:
int internal_load_hd();
chd_file *m_chd;
chd_file m_self_chd;
chd_file m_origchd; /* handle to the original CHD */
chd_file m_diffchd; /* handle to the diff CHD */
hard_disk_file *m_hard_disk_handle;
image_device_format m_format;

3
src/lib/util/chd.c
View File

@ -1589,6 +1589,9 @@ void chd_file::parse_v5_header(UINT8 *rawheader, sha1_t &parentsha1)
m_compression[2] = be_read(&rawheader[24], 4);
m_compression[3] = be_read(&rawheader[28], 4);
if (compressed() && m_allow_writes)
throw CHDERR_FILE_NOT_WRITEABLE;
// describe the format
m_mapoffset_offset = 40;
m_metaoffset_offset = 48;