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Changed Xeromyces to care about the .xml's size/mtime rather than its contents (to avoid needing to load the .xml), and also to store that information in the .xmb's filename rather than inside the file (to avoid getting confused when rewriting files that are inside archives)

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This was SVN commit r1480.
This commit is contained in:
Ykkrosh 2004-12-09 16:57:21 +00:00
parent c3fafdca99
commit 0598081a57
3 changed files with 66 additions and 49 deletions
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4
source/ps/XeroXMB.cpp
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@ -1,4 +1,4 @@
// $Id: XeroXMB.cpp,v 1.8 2004/11/11 07:09:32 markt Exp $
// $Id$
#include "precompiled.h"
@ -19,8 +19,6 @@ void XMBFile::Initialise(char* FileData)
int Header = *(int*)m_Pointer; m_Pointer += 4;
assert(Header == HeaderMagic && "Invalid XMB header!");
/*int Checksum = *(int*)m_Pointer;*/ m_Pointer += 4;
int i;
#ifdef XERO_USEMAP

107
source/ps/Xeromyces.cpp
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@ -140,7 +140,7 @@ public:
// Non-SAX2 stuff, used for storing the
// parsed data and constructing the XMB:
void CreateXMB(unsigned long crc);
void CreateXMB();
membuffer buffer;
private:
@ -192,39 +192,66 @@ void CXeromyces::Terminate()
PSRETURN CXeromyces::Load(const char* filename)
{
// Open the file, so that its checksum can be calculated
CVFSFile file;
if (file.Load(filename) != PSRETURN_OK)
// Make sure the .xml actually exists
if (! vfs_exists(filename))
{
LOG(ERROR, LOG_CATEGORY, "CXeromyces: XML open of %s failed", filename);
LOG(ERROR, LOG_CATEGORY, "CXeromyces: Failed to find XML file %s", filename);
return PSRETURN_Xeromyces_XMLOpenFailed;
}
// Start the checksum with a particular seed value, so the XMBs will
// be recreated whenever the file format has changed.
unsigned long SeedChecksum = crc32(0L, Z_NULL, 0);
// Depend on the version of the file format
const char* ChecksumID = "version C";
SeedChecksum = crc32(SeedChecksum, (Bytef*)ChecksumID, (int)strlen(ChecksumID));
// Also depend on the machine's endianness
u32 EndiannessIndicator = 0x12345678;
SeedChecksum = crc32(SeedChecksum, (Bytef*)&EndiannessIndicator, 4);
// And finally depend on the actual contents of the XML file
unsigned long XMLChecksum = crc32(SeedChecksum, (Bytef*)file.GetBuffer(), (int)file.GetBufferSize());
// Get some data about the .xml file
struct stat xmlStat;
if (vfs_stat(filename, &xmlStat) < 0)
{
LOG(ERROR, LOG_CATEGORY, "CXeromyces: Failed to stat XML file %s", filename);
return PSRETURN_Xeromyces_XMLOpenFailed;
}
// Check whether the XMB file needs to be regenerated:
/*
XMBs are stored with a unique name, where the name is generated from
characteristics of the XML file. If a file already exists with the
generated name, it is assumed that that file is a valid conversion of
the XML, and so it's loaded. Otherwise, the XMB is created with that
filename.
This means it's never necessary to overwrite existing XMB files; since
the XMBs are often in archives, it's not easy to rewrite those files,
and it's not possible to switch to using a loose file because the VFS
has already decided that file is inside an archive. So each XMB is given
a unique name, and old ones are somehow purged.
*/
// Generate the XMB's filename
CStr filenameXMB = filename;
filenameXMB[(int)filenameXMB.Length()-1] = 'b';
// Generate the filename for the xmb:
// <xml filename>_<mtime><size><format version>.xmb
// with mtime/size as 8-digit hex
// Load the entire file, with the assumption that usually it's
// going to be valid and will then be passed to XMBFile().
if (vfs_exists(filenameXMB) && ReadXMBFile(filenameXMB, true, XMLChecksum))
return PSRETURN_OK;
CStr xmbFilename = filename;
// Strip the .xml suffix
int pos;
if ((pos = xmbFilename.FindInsensitive(".xml")) != -1)
xmbFilename = xmbFilename.Left(pos);
const int bufLen = 22;
char buf[bufLen+1];
if (sprintf(buf, "_%08x%08xA.xmb", xmlStat.st_mtime, xmlStat.st_size) != bufLen)
{
debug_warn("Failed to create filename (?!)");
return PSRETURN_Xeromyces_XMLOpenFailed;
}
xmbFilename += buf;
// If the file exists, use it
if (vfs_exists(xmbFilename))
{
if (ReadXMBFile(xmbFilename))
return PSRETURN_OK;
else
return PSRETURN_Xeromyces_XMLOpenFailed;
}
// XMB isn't up to date with the XML, so rebuild it:
@ -236,9 +263,15 @@ PSRETURN CXeromyces::Load(const char* filename)
XercesLoaded = 1;
}
// Open the .xml file
CVFSInputSource source;
source.OpenBuffer(filename, file.GetBuffer(), file.GetBufferSize());
if (source.OpenFile(filename) < 0)
{
LOG(ERROR, LOG_CATEGORY, "CXeromyces: Failed to open XML file %s", filename);
return PSRETURN_Xeromyces_XMLOpenFailed;
}
// Set up the Xerces parser
SAX2XMLReader* Parser = XMLReaderFactory::createXMLReader();
// Enable validation
@ -273,10 +306,10 @@ PSRETURN CXeromyces::Load(const char* filename)
}
// Convert the data structures into the XMB format
handler.CreateXMB(XMLChecksum);
handler.CreateXMB();
// Save the file to disk, so it can be loaded quickly next time
vfs_store(filenameXMB, handler.buffer.buffer, handler.buffer.length, FILE_NO_AIO);
vfs_store(xmbFilename, handler.buffer.buffer, handler.buffer.length, FILE_NO_AIO);
// Store the buffer so it can be freed later
XMBBuffer = handler.buffer.steal_buffer();
@ -287,7 +320,7 @@ PSRETURN CXeromyces::Load(const char* filename)
return PSRETURN_OK;
}
bool CXeromyces::ReadXMBFile(const char* filename, bool CheckCRC, unsigned long CRC)
bool CXeromyces::ReadXMBFile(const char* filename)
{
CVFSFile* file = new CVFSFile;
if (file->Load(filename) != PSRETURN_OK)
@ -298,17 +331,6 @@ bool CXeromyces::ReadXMBFile(const char* filename, bool CheckCRC, unsigned long
assert(file->GetBufferSize() >= 42 && "Invalid XMB file"); // 42 bytes is the smallest possible XMB. (Well, maybe not quite, but it's a nice number.)
assert(*(int*)buffer == HeaderMagic && "Invalid XMB file header");
if (CheckCRC)
{
unsigned long fileCRC = *((unsigned long*)buffer + 1); // read the second four-byte number
if (CRC != fileCRC)
{
// Checksums don't match; have to regenerate from the XML
delete file;
return false;
}
}
// Store the Handle so it can be closed later
XMBFileHandle = file;
@ -381,14 +403,11 @@ void XeroHandler::characters(const XMLCh* const chars, const unsigned int UNUSED
}
void XeroHandler::CreateXMB(unsigned long crc)
void XeroHandler::CreateXMB()
{
// Header
buffer.write((void*)HeaderMagicStr, 4);
// Checksum
buffer.write(&crc, 4);
std::set<std::string>::iterator it;
int i;

4
source/ps/Xeromyces.h
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@ -1,4 +1,4 @@
/* $Id: Xeromyces.h,v 1.7 2004/07/31 11:38:13 janwas Exp $
/* $Id$
Xeromyces file-loading interface.
Automatically creates and caches relatively
@ -31,7 +31,7 @@ public:
static void Terminate();
private:
bool ReadXMBFile(const char* filename, bool CheckCRC, unsigned long CRC);
bool ReadXMBFile(const char* filename);
XMBFile* XMB;
CVFSFile* XMBFileHandle; // if it's being read from disk