more IcePatch work

7 files changed, 393 insertions, 207 deletions

diff --git a/cpp/src/IcePatch/Client.cpp b/cpp/src/IcePatch/Client.cpp
index 2752706d817..21fc1f9880e 100644
--- a/cpp/src/IcePatch/Client.cpp
+++ b/cpp/src/IcePatch/Client.cpp
@@ -508,7 +508,7 @@ IcePatch::Client::patch(const DirectoryDescPtr& dirDesc, const string& indent) c
 	    {
 		removeRecursive(*p + ".md5");
 	    }
-	    catch(const FileAccessException&);
+	    catch(const FileAccessException&)
 	    {
 		// Ignore, the MD5 file might not exist.
 	    }
diff --git a/cpp/src/IcePatch/ClientUtil.cpp b/cpp/src/IcePatch/ClientUtil.cpp
new file mode 100644
index 00000000000..d715d471893
--- /dev/null
+++ b/cpp/src/IcePatch/ClientUtil.cpp
@@ -0,0 +1,214 @@
+// **********************************************************************
+//
+// Copyright (c) 2002
+// Mutable Realms, Inc.
+// Huntsville, AL, USA
+//
+// All Rights Reserved
+//
+// **********************************************************************
+
+#include <IcePatch/Util.h>
+#include <IcePatch/ClientUtil.h>
+#include <fstream>
+#include <bzlib.h>
+
+using namespace std;
+using namespace Ice;
+using namespace IcePatch;
+
+string
+IcePatch::pathToName(const string& path)
+{
+    string::size_type pos = path.rfind('/');
+    if(pos == string::npos)
+    {
+	return path;
+    }
+    else
+    {
+	return path.substr(pos + 1);
+    }
+}
+
+void
+IcePatch::getRegular(const RegularPrx& regular, ProgressCB& progressCB)
+{
+    string path = identityToPath(regular->ice_getIdentity());
+    string pathBZ2 = path + ".bz2";
+    Int totalBZ2 = regular->getBZ2Size();
+    Int posBZ2 = 0;
+
+    //
+    // Check for partial BZ2 file.
+    //
+    FileInfo infoBZ2 = getFileInfo(pathBZ2, false);
+    if(infoBZ2.type == FileTypeRegular)
+    {
+	ByteSeq remoteBZ2MD5 = regular->getBZ2MD5(infoBZ2.size);
+	ByteSeq localBZ2MD5 = calcPartialMD5(pathBZ2, infoBZ2.size);
+
+	if(remoteBZ2MD5 == localBZ2MD5)
+	{
+	    posBZ2 = infoBZ2.size;
+	}
+    }
+
+    //
+    // Get the BZ2 file.
+    //
+    progressCB.startDownload(totalBZ2, posBZ2);
+
+    ofstream fileBZ2(pathBZ2.c_str(), ios::binary | (posBZ2 ? ios::app : 0));
+    if(!fileBZ2)
+    {
+	FileAccessException ex;
+	ex.reason = "cannot open `" + pathBZ2 + "' for writing: " + strerror(errno);
+	throw ex;
+    }
+
+    while(posBZ2 < totalBZ2)
+    {
+	static const Int numBZ2 = 64 * 1024;
+
+	ByteSeq bytesBZ2 = regular->getBZ2(posBZ2, numBZ2);
+	if(bytesBZ2.empty())
+	{
+	    break;
+	}
+	
+	posBZ2 += bytesBZ2.size();
+	
+	fileBZ2.write(&bytesBZ2[0], bytesBZ2.size());
+	if(!fileBZ2)
+	{
+	    FileAccessException ex;
+	    ex.reason = "cannot write `" + pathBZ2 + "': " + strerror(errno);
+	    throw ex;
+	}
+	
+	if(static_cast<Int>(bytesBZ2.size()) < numBZ2)
+	{
+	    break;
+	}
+	
+	progressCB.updateDownload(totalBZ2, posBZ2);
+    }
+
+    progressCB.finishedDownload(totalBZ2);
+
+    fileBZ2.close();
+    
+    //
+    // Read the BZ2 file in blocks and write the original file.
+    //
+    ofstream file(path.c_str(), ios::binary);
+    if(!file)
+    {
+	FileAccessException ex;
+	ex.reason = "cannot open `" + path + "' for writing: " + strerror(errno);
+	throw ex;
+    }
+    
+    FILE* stdioFileBZ2 = fopen(pathBZ2.c_str(), "rb");
+    if(!stdioFileBZ2)
+    {
+	FileAccessException ex;
+	ex.reason = "cannot open `" + pathBZ2 + "' for reading: " + strerror(errno);
+	throw ex;
+    }
+    
+    int bzError;
+    BZFILE* bzFile = BZ2_bzReadOpen(&bzError, stdioFileBZ2, 0, 0, 0, 0);
+    if(bzError != BZ_OK)
+    {
+	FileAccessException ex;
+	ex.reason = "BZ2_bzReadOpen failed";
+	if(bzError == BZ_IO_ERROR)
+	{
+	    ex.reason += string(": ") + strerror(errno);
+	}
+	fclose(stdioFileBZ2);
+	throw ex;
+    }
+    
+    static const Int numBZ2 = 64 * 1024;
+    Byte bytesBZ2[numBZ2];
+    
+    progressCB.startUncompress(totalBZ2, 0);
+    
+    while(bzError != BZ_STREAM_END)
+    {
+	int sz = BZ2_bzRead(&bzError, bzFile, bytesBZ2, numBZ2);
+	if(bzError != BZ_OK && bzError != BZ_STREAM_END)
+	{
+	    FileAccessException ex;
+	    ex.reason = "BZ2_bzRead failed";
+	    if(bzError == BZ_IO_ERROR)
+	    {
+		ex.reason += string(": ") + strerror(errno);
+	    }
+	    BZ2_bzReadClose(&bzError, bzFile);
+	    fclose(stdioFileBZ2);
+	    throw ex;
+	}
+	
+	if(sz > 0)
+	{
+	    long pos = ftell(stdioFileBZ2);
+	    if(pos == -1)
+	    {
+		FileAccessException ex;
+		ex.reason = "cannot get read position for `" + pathBZ2 + "': " + strerror(errno);
+		BZ2_bzReadClose(&bzError, bzFile);
+		fclose(stdioFileBZ2);
+		throw ex;
+	    }
+
+	    progressCB.updateUncompress(totalBZ2, pos);
+	    
+	    file.write(bytesBZ2, sz);
+	    if(!file)
+	    {
+		FileAccessException ex;
+		ex.reason = "cannot write `" + path + "': " + strerror(errno);
+		BZ2_bzReadClose(&bzError, bzFile);
+		fclose(stdioFileBZ2);
+		throw ex;
+	    }
+	}
+    }
+    
+    progressCB.finishedUncompress(totalBZ2);
+    
+    BZ2_bzReadClose(&bzError, bzFile);
+    if(bzError != BZ_OK)
+    {
+	FileAccessException ex;
+	ex.reason = "BZ2_bzReadClose failed";
+	if(bzError == BZ_IO_ERROR)
+	{
+	    ex.reason += string(": ") + strerror(errno);
+	}
+	fclose(stdioFileBZ2);
+	throw ex;
+    }
+
+    fclose(stdioFileBZ2);
+    file.close();
+    
+    //
+    // Remove the BZ2 file, it is not needed anymore.
+    //
+    if(::remove(pathBZ2.c_str()) == -1)
+    {
+	FileAccessException ex;
+	ex.reason = "cannot remove file `" + pathBZ2 + "': " + strerror(errno);
+	throw ex;
+    }
+
+    //
+    // Create a MD5 file for the original file.
+    //
+    createMD5(path);
+}
diff --git a/cpp/src/IcePatch/IcePatchI.cpp b/cpp/src/IcePatch/IcePatchI.cpp
index 502757b3232..55d8f66b387 100644
--- a/cpp/src/IcePatch/IcePatchI.cpp
+++ b/cpp/src/IcePatch/IcePatchI.cpp
@@ -15,15 +15,42 @@ using namespace std;
 using namespace Ice;
 using namespace IcePatch;
 
-IceUtil::RWRecMutex IcePatch::FileI::_globalMutex;
+static IceUtil::RWRecMutex globalMutex;
+
+IcePatch::InfoI::InfoI(const ObjectAdapterPtr& adapter) :
+    _adapter(adapter),
+    _busyTimeout(IceUtil::Time::seconds(adapter->getCommunicator()->getProperties()->
+					getPropertyAsIntWithDefault("IcePatch.BusyTimeout", 10)))
+{
+}
+
+Long
+IcePatch::InfoI::getStamp(const Current& current) const
+{
+    //
+    // ".icepatch" is our reserved name for the IcePatch info object,
+    // as well as for the directory that contains IcePatch info.
+    //
+    assert(current.id.name == ".icepatch");
+
+    try
+    {
+	IceUtil::RWRecMutex::TryRLock sync(globalMutex, _busyTimeout);
+	return readStamp();
+    }
+    catch(const IceUtil::LockedException&)
+    {
+	throw BusyException();
+    }
+}
 
 IcePatch::FileI::FileI(const ObjectAdapterPtr& adapter) :
     _adapter(adapter),
-    _logger(adapter->getCommunicator()->getLogger())
+    _logger(adapter->getCommunicator()->getLogger()),
+    _traceLevel(adapter->getCommunicator()->getProperties()->getPropertyAsInt("IcePatch.Trace.Files")),
+    _busyTimeout(IceUtil::Time::seconds(adapter->getCommunicator()->getProperties()->
+					getPropertyAsIntWithDefault("IcePatch.BusyTimeout", 10)))
 {
-    PropertiesPtr properties = adapter->getCommunicator()->getProperties();
-    _traceLevel = properties->getPropertyAsInt("IcePatch.Trace.Files");
-    _busyTimeout = IceUtil::Time::seconds(properties->getPropertyAsIntWithDefault("IcePatch.BusyTimeout", 10));
 }
 
 IcePatch::DirectoryI::DirectoryI(const ObjectAdapterPtr& adapter) :
@@ -32,7 +59,7 @@ IcePatch::DirectoryI::DirectoryI(const ObjectAdapterPtr& adapter) :
 }
 
 FileDescPtr
-IcePatch::DirectoryI::describe(const Current& current)
+IcePatch::DirectoryI::describe(const Current& current) const
 {
     // No mutex lock necessary.
     DirectoryDescPtr desc = new DirectoryDesc;
@@ -41,17 +68,18 @@ IcePatch::DirectoryI::describe(const Current& current)
 }
 
 FileDescSeq
-IcePatch::DirectoryI::getContents(const Current& current)
+IcePatch::DirectoryI::getContents(const Current& current) const
 {
     StringSeq filteredPaths;
 
     try
     {
-	IceUtil::RWRecMutex::TryRLock sync(_globalMutex, _busyTimeout);
+	IceUtil::RWRecMutex::TryRLock sync(globalMutex, _busyTimeout);
 
 	bool syncUpgraded = false;
 	string path = identityToPath(current.id);
 	StringSeq paths = readDirectory(path);
+	paths.erase(remove(paths.begin(), paths.end(), ".icepatch"), paths.end());
 	filteredPaths.reserve(paths.size() / 3);
 	for(StringSeq::const_iterator p = paths.begin(); p != paths.end(); ++p)
 	{
@@ -67,6 +95,7 @@ IcePatch::DirectoryI::getContents(const Current& current)
 			syncUpgraded = true;
 		    }
 		    StringSeq paths2 = readDirectory(path);
+		    paths.erase(remove(paths2.begin(), paths2.end(), ".icepatch"), paths2.end());
 		    pair<StringSeq::const_iterator, StringSeq::const_iterator> r2 =
 			equal_range(paths2.begin(), paths2.end(), removeSuffix(*p));
 		    if(r2.first == r2.second)
@@ -122,11 +151,11 @@ IcePatch::RegularI::RegularI(const ObjectAdapterPtr& adapter) :
 }
 
 FileDescPtr
-IcePatch::RegularI::describe(const Current& current)
+IcePatch::RegularI::describe(const Current& current) const
 {
     try
     {
-	IceUtil::RWRecMutex::TryRLock sync(_globalMutex, _busyTimeout);
+	IceUtil::RWRecMutex::TryRLock sync(globalMutex, _busyTimeout);
 	
 	string path = identityToPath(current.id);
 	FileInfo info = getFileInfo(path, true);
@@ -141,6 +170,7 @@ IcePatch::RegularI::describe(const Current& current)
 	    if(infoMD5.type != FileTypeRegular || infoMD5.time <= info.time)
 	    {
 		createMD5(path);
+		writeStamp(readStamp() + 1);
 		
 		if(_traceLevel > 0)
 		{
@@ -162,11 +192,11 @@ IcePatch::RegularI::describe(const Current& current)
 }
 
 Int
-IcePatch::RegularI::getBZ2Size(const Current& current)
+IcePatch::RegularI::getBZ2Size(const Current& current) const
 {
     try
     {
-	IceUtil::RWRecMutex::TryRLock sync(_globalMutex, _busyTimeout);
+	IceUtil::RWRecMutex::TryRLock sync(globalMutex, _busyTimeout);
 	
 	string path = identityToPath(current.id);
 	FileInfo info = getFileInfo(path, true);
@@ -206,11 +236,11 @@ IcePatch::RegularI::getBZ2Size(const Current& current)
 }
 
 ByteSeq
-IcePatch::RegularI::getBZ2(Int pos, Int num, const Current& current)
+IcePatch::RegularI::getBZ2(Int pos, Int num, const Current& current) const
 {
     try
     {
-	IceUtil::RWRecMutex::TryRLock sync(_globalMutex, _busyTimeout);
+	IceUtil::RWRecMutex::TryRLock sync(globalMutex, _busyTimeout);
 	
 	string path = identityToPath(current.id);
 	FileInfo info = getFileInfo(path, true);
@@ -243,11 +273,11 @@ IcePatch::RegularI::getBZ2(Int pos, Int num, const Current& current)
 }
 
 ByteSeq
-IcePatch::RegularI::getBZ2MD5(Int size, const Current& current)
+IcePatch::RegularI::getBZ2MD5(Int size, const Current& current) const
 {
     try
     {
-	IceUtil::RWRecMutex::TryRLock sync(_globalMutex, _busyTimeout);
+	IceUtil::RWRecMutex::TryRLock sync(globalMutex, _busyTimeout);
 	
 	string path = identityToPath(current.id);
 	FileInfo info = getFileInfo(path, true);
diff --git a/cpp/src/IcePatch/IcePatchI.h b/cpp/src/IcePatch/IcePatchI.h
index 934cbf1058e..69a6316e014 100644
--- a/cpp/src/IcePatch/IcePatchI.h
+++ b/cpp/src/IcePatch/IcePatchI.h
@@ -18,6 +18,20 @@
 namespace IcePatch
 {
 
+class InfoI : public Info
+{
+public:
+
+    InfoI(const Ice::ObjectAdapterPtr&);
+
+    Ice::Long getStamp(const Ice::Current&) const;
+
+private:
+
+    const Ice::ObjectAdapterPtr _adapter;
+    const IceUtil::Time _busyTimeout;
+};
+
 class FileI : virtual public File
 {
 public:
@@ -26,11 +40,10 @@ public:
 
 protected:
 
-    Ice::ObjectAdapterPtr _adapter;
-    Ice::LoggerPtr _logger;
-    Ice::Int _traceLevel;
-    IceUtil::Time _busyTimeout;
-    static IceUtil::RWRecMutex _globalMutex;
+    const Ice::ObjectAdapterPtr _adapter;
+    const Ice::LoggerPtr _logger;
+    const Ice::Int _traceLevel;
+    const IceUtil::Time _busyTimeout;
 };
 
 class DirectoryI : virtual public Directory,
@@ -40,8 +53,8 @@ public:
     
     DirectoryI(const Ice::ObjectAdapterPtr&);
 
-    virtual FileDescPtr describe(const Ice::Current&);
-    virtual FileDescSeq getContents(const Ice::Current&);
+    virtual FileDescPtr describe(const Ice::Current&) const;
+    virtual FileDescSeq getContents(const Ice::Current&) const;
 };
 
 class RegularI : virtual public Regular,
@@ -51,10 +64,10 @@ public:
     
     RegularI(const Ice::ObjectAdapterPtr&);
 
-    virtual FileDescPtr describe(const Ice::Current&);
-    virtual Ice::Int getBZ2Size(const Ice::Current&);
-    virtual Ice::ByteSeq getBZ2(Ice::Int, Ice::Int, const Ice::Current&);
-    virtual Ice::ByteSeq getBZ2MD5(Ice::Int, const Ice::Current&);
+    virtual FileDescPtr describe(const Ice::Current&) const;
+    virtual Ice::Int getBZ2Size(const Ice::Current&) const;
+    virtual Ice::ByteSeq getBZ2(Ice::Int, Ice::Int, const Ice::Current&) const;
+    virtual Ice::ByteSeq getBZ2MD5(Ice::Int, const Ice::Current&) const;
 };
 
 }
diff --git a/cpp/src/IcePatch/Makefile b/cpp/src/IcePatch/Makefile
index a01b561b99e..d45e84777a1 100644
--- a/cpp/src/IcePatch/Makefile
+++ b/cpp/src/IcePatch/Makefile
@@ -23,7 +23,8 @@ TARGETS		= $(NAME) $(VERSIONED_NAME) $(CLIENT) $(SERVER)
 
 OBJS		= IcePatch.o \
 		  FileDescFactory.o \
-		  Util.o
+		  Util.o \
+		  ClientUtil.o
 
 COBJS		= Client.o
 
diff --git a/cpp/src/IcePatch/Server.cpp b/cpp/src/IcePatch/Server.cpp
index 1e804670ddd..8f83ba69a04 100644
--- a/cpp/src/IcePatch/Server.cpp
+++ b/cpp/src/IcePatch/Server.cpp
@@ -11,6 +11,7 @@
 #include <IceUtil/IceUtil.h>
 #include <Ice/Application.h>
 #include <IcePatch/FileLocator.h>
+#include <IcePatch/IcePatchI.h>
 #include <IcePatch/Util.h>
 #ifdef _WIN32
 #   include <direct.h>
@@ -125,6 +126,12 @@ IcePatch::Server::run(int argc, char* argv[])
     ObjectAdapterPtr adapter = communicator()->createObjectAdapterFromProperty("IcePatch", endpointsProperty);
     ServantLocatorPtr fileLocator = new FileLocator(adapter);
     adapter->addServantLocator(fileLocator, "IcePatch");
+
+    //
+    // Create the "info" Ice Object.
+    //
+    InfoPtr info = new InfoI(adapter);
+    adapter->add(info, pathToIdentity(".icepatch")); // .icepatch is reserved, so lets use this for info identity.
     
     //
     // Start the updater if an update period is set.
diff --git a/cpp/src/IcePatch/Util.cpp b/cpp/src/IcePatch/Util.cpp
index dbbed190626..2906620819f 100644
--- a/cpp/src/IcePatch/Util.cpp
+++ b/cpp/src/IcePatch/Util.cpp
@@ -9,6 +9,7 @@
 // **********************************************************************
 
 #include <IcePatch/Util.h>
+#include <IceUtil/InputUtil.h>
 #include <fstream>
 #include <sys/stat.h>
 #include <openssl/md5.h>
@@ -344,18 +345,21 @@ IcePatch::createMD5(const string& path)
     
     ByteSeq bytes;
     bytes.resize(info.size);
-    file.read(&bytes[0], bytes.size());
-    if(!file)
-    {
-	FileAccessException ex;
-	ex.reason = "cannot read `" + path + "': " + strerror(errno);
-	throw ex;
-    }
-    if(file.gcount() < static_cast<int>(bytes.size()))
+    if(bytes.size() > 0)
     {
-	FileAccessException ex;
-	ex.reason = "could not read all bytes from `" + path + "'";
-	throw ex;
+	file.read(&bytes[0], bytes.size());
+	if(!file)
+	{
+	    FileAccessException ex;
+	    ex.reason = "cannot read `" + path + "': " + strerror(errno);
+	    throw ex;
+	}
+	if(file.gcount() < static_cast<int>(bytes.size()))
+	{
+	    FileAccessException ex;
+	    ex.reason = "could not read all bytes from `" + path + "'";
+	    throw ex;
+	}
     }
     
     file.close();
@@ -365,7 +369,14 @@ IcePatch::createMD5(const string& path)
     //
     ByteSeq bytesMD5;
     bytesMD5.resize(16);
-    MD5(reinterpret_cast<unsigned char*>(&bytes[0]), bytes.size(), reinterpret_cast<unsigned char*>(&bytesMD5[0]));
+    if(bytes.size() > 0)
+    {
+	MD5(reinterpret_cast<unsigned char*>(&bytes[0]), bytes.size(), reinterpret_cast<unsigned char*>(&bytesMD5[0]));
+    }
+    else
+    {
+	fill(bytesMD5.begin(), bytesMD5.end(), 0);
+    }
     
     //
     // Save the MD5 hash value to a temporary MD5 file.
@@ -436,18 +447,21 @@ IcePatch::calcPartialMD5(const string& path, Int size)
 
     ByteSeq bytes;
     bytes.resize(size);
-    file.read(&bytes[0], bytes.size());
-    if(!file)
+    if(bytes.size() > 0)
     {
-	FileAccessException ex;
-	ex.reason = "cannot read `" + path + "': " + strerror(errno);
-	throw ex;
-    }
-    if(file.gcount() < static_cast<int>(bytes.size()))
-    {
-	FileAccessException ex;
-	ex.reason = "could not read all bytes from `" + path + "'";
-	throw ex;
+	file.read(&bytes[0], bytes.size());
+	if(!file)
+	{
+	    FileAccessException ex;
+	    ex.reason = "cannot read `" + path + "': " + strerror(errno);
+	    throw ex;
+	}
+	if(file.gcount() < static_cast<int>(bytes.size()))
+	{
+	    FileAccessException ex;
+	    ex.reason = "could not read all bytes from `" + path + "'";
+	    throw ex;
+	}
     }
 
     file.close();
@@ -457,7 +471,14 @@ IcePatch::calcPartialMD5(const string& path, Int size)
     //
     ByteSeq bytesMD5;
     bytesMD5.resize(16);
-    MD5(reinterpret_cast<unsigned char*>(&bytes[0]), bytes.size(), reinterpret_cast<unsigned char*>(&bytesMD5[0]));
+    if(bytes.size() > 0)
+    {
+	MD5(reinterpret_cast<unsigned char*>(&bytes[0]), bytes.size(), reinterpret_cast<unsigned char*>(&bytesMD5[0]));
+    }
+    else
+    {
+	fill(bytesMD5.begin(), bytesMD5.end(), 0);
+    }
 
     return bytesMD5;
 }
@@ -632,184 +653,84 @@ IcePatch::createBZ2(const string& path)
     }
 }
 
-void
-IcePatch::getRegular(const RegularPrx& regular, ProgressCB& progressCB)
+Long
+IcePatch::readStamp()
 {
-    string path = identityToPath(regular->ice_getIdentity());
-    string pathBZ2 = path + ".bz2";
-    Int totalBZ2 = regular->getBZ2Size();
-    Int posBZ2 = 0;
-
-    //
-    // Check for partial BZ2 file.
-    //
-    FileInfo infoBZ2 = getFileInfo(pathBZ2, false);
-    if(infoBZ2.type == FileTypeRegular)
+    ifstream fileStamp(".icepatch/stamp");
+    if(!fileStamp) // Ignore any errors if the file cannot be read.
     {
-	ByteSeq remoteBZ2MD5 = regular->getBZ2MD5(infoBZ2.size);
-	ByteSeq localBZ2MD5 = calcPartialMD5(pathBZ2, infoBZ2.size);
-
-	if(remoteBZ2MD5 == localBZ2MD5)
-	{
-	    posBZ2 = infoBZ2.size;
-	}
+	return -1;
     }
 
-    //
-    // Get the BZ2 file.
-    //
-    progressCB.startDownload(totalBZ2, posBZ2);
-
-    ofstream fileBZ2(pathBZ2.c_str(), ios::binary | (posBZ2 ? ios::app : 0));
-    if(!fileBZ2)
-    {
-	FileAccessException ex;
-	ex.reason = "cannot open `" + pathBZ2 + "' for writing: " + strerror(errno);
-	throw ex;
-    }
+    string s;
+    fileStamp >> s;
+    fileStamp.close();
 
-    while(posBZ2 < totalBZ2)
+    Long stamp;
+    string::size_type dummy;
+    if(!IceUtil::stringToInt64(s, stamp, dummy)) // Ignore errors during conversion.
     {
-	static const Int numBZ2 = 64 * 1024;
-
-	ByteSeq bytesBZ2 = regular->getBZ2(posBZ2, numBZ2);
-	if(bytesBZ2.empty())
-	{
-	    break;
-	}
-	
-	posBZ2 += bytesBZ2.size();
-	
-	fileBZ2.write(&bytesBZ2[0], bytesBZ2.size());
-	if(!fileBZ2)
-	{
-	    FileAccessException ex;
-	    ex.reason = "cannot write `" + pathBZ2 + "': " + strerror(errno);
-	    throw ex;
-	}
-	
-	if(static_cast<Int>(bytesBZ2.size()) < numBZ2)
-	{
-	    break;
-	}
-	
-	progressCB.updateDownload(totalBZ2, posBZ2);
+	return -1;
     }
 
-    progressCB.finishedDownload(totalBZ2);
+    return stamp;
+}
 
-    fileBZ2.close();
-    
-    //
-    // Read the BZ2 file in blocks and write the original file.
-    //
-    ofstream file(path.c_str(), ios::binary);
-    if(!file)
-    {
-	FileAccessException ex;
-	ex.reason = "cannot open `" + path + "' for writing: " + strerror(errno);
-	throw ex;
-    }
-    
-    FILE* stdioFileBZ2 = fopen(pathBZ2.c_str(), "rb");
-    if(!stdioFileBZ2)
-    {
-	FileAccessException ex;
-	ex.reason = "cannot open `" + pathBZ2 + "' for reading: " + strerror(errno);
-	throw ex;
-    }
-    
-    int bzError;
-    BZFILE* bzFile = BZ2_bzReadOpen(&bzError, stdioFileBZ2, 0, 0, 0, 0);
-    if(bzError != BZ_OK)
+void
+IcePatch::writeStamp(Long stamp)
+{
+    ofstream fileStamp(".icepatch/stamp");
+    if(!fileStamp)
     {
+	//
+	// Prepare an exception, but don't throw yet.
+	//
 	FileAccessException ex;
-	ex.reason = "BZ2_bzReadOpen failed";
-	if(bzError == BZ_IO_ERROR)
-	{
-	    ex.reason += string(": ") + strerror(errno);
-	}
-	fclose(stdioFileBZ2);
-	throw ex;
-    }
-    
-    static const Int numBZ2 = 64 * 1024;
-    Byte bytesBZ2[numBZ2];
-    
-    progressCB.startUncompress(totalBZ2, 0);
-    
-    while(bzError != BZ_STREAM_END)
-    {
-	int sz = BZ2_bzRead(&bzError, bzFile, bytesBZ2, numBZ2);
-	if(bzError != BZ_OK && bzError != BZ_STREAM_END)
+	ex.reason = string("cannot open `.icepatch/stamp' for writing: ") + strerror(errno);
+	
+	//
+	// Check if the directory exists, and only throw the exception
+	// if it does exist. Otherwise create the directory, and try
+	// again.
+	//
+	FileInfo info = getFileInfo(".icepatch", false);
+	if(info.type == FileTypeDirectory)
 	{
-	    FileAccessException ex;
-	    ex.reason = "BZ2_bzRead failed";
-	    if(bzError == BZ_IO_ERROR)
-	    {
-		ex.reason += string(": ") + strerror(errno);
-	    }
-	    BZ2_bzReadClose(&bzError, bzFile);
-	    fclose(stdioFileBZ2);
+	    //
+	    // If the directory exists, throw the exception.
+	    //
 	    throw ex;
 	}
-	
-	if(sz > 0)
+	else
 	{
-	    long pos = ftell(stdioFileBZ2);
-	    if(pos == -1)
+	    //
+	    // If the directory does not exist, create it, and try
+	    // again.
+	    //
+	    if(info.type != FileTypeNotExist)
 	    {
-		FileAccessException ex;
-		ex.reason = "cannot get read position for `" + pathBZ2 + "': " + strerror(errno);
-		BZ2_bzReadClose(&bzError, bzFile);
-		fclose(stdioFileBZ2);
-		throw ex;
+		removeRecursive(".icepatch");
 	    }
-
-	    progressCB.updateUncompress(totalBZ2, pos);
 	    
-	    file.write(bytesBZ2, sz);
-	    if(!file)
+	    createDirectory(".icepatch");
+
+	    ofstream fileStamp(".icepatch/stamp");
+	    if(!fileStamp)
 	    {
 		FileAccessException ex;
-		ex.reason = "cannot write `" + path + "': " + strerror(errno);
-		BZ2_bzReadClose(&bzError, bzFile);
-		fclose(stdioFileBZ2);
+		ex.reason = string("cannot open `.icepatch/stamp' for writing: ") + strerror(errno);
 		throw ex;
 	    }
+	    else
+	    {
+		fileStamp << stamp << endl;
+		fileStamp.close();
+	    }
 	}
     }
-    
-    progressCB.finishedUncompress(totalBZ2);
-    
-    BZ2_bzReadClose(&bzError, bzFile);
-    if(bzError != BZ_OK)
-    {
-	FileAccessException ex;
-	ex.reason = "BZ2_bzReadClose failed";
-	if(bzError == BZ_IO_ERROR)
-	{
-	    ex.reason += string(": ") + strerror(errno);
-	}
-	fclose(stdioFileBZ2);
-	throw ex;
-    }
-
-    fclose(stdioFileBZ2);
-    file.close();
-    
-    //
-    // Remove the BZ2 file, it is not needed anymore.
-    //
-    if(::remove(pathBZ2.c_str()) == -1)
+    else
     {
-	FileAccessException ex;
-	ex.reason = "cannot remove file `" + pathBZ2 + "': " + strerror(errno);
-	throw ex;
+	fileStamp << stamp << endl;
+	fileStamp.close();
     }
-
-    //
-    // Create a MD5 file for the original file.
-    //
-    createMD5(path);
 }