BPackageWriter: Add Recompress()

Allows rewriting an existing package file with a different compression.

headers/os/package/hpkg/PackageReader.h

@@ -24,6 +24,7 @@ class BAbstractBufferedDataReader;
 class BErrorOutput;
 class BLowLevelPackageContentHandler;
 class BPackageContentHandler;
+class BPackageWriter;
 
 
 class BPackageReader {
@@ -43,6 +44,9 @@ public:
 			BAbstractBufferedDataReader* HeapReader() const;
 									// Only valid as long as the reader lives.
 
+private:
+			friend class BPackageWriter;
+
 private:
 			PackageReaderImpl*	fImpl;
 };

headers/os/package/hpkg/PackageWriter.h

@@ -16,6 +16,9 @@ namespace BPackageKit {
 namespace BHPKG {
 
 
+class BPackageReader;
+
+
 namespace BPrivate {
 	class PackageWriterImpl;
 }
@@ -72,6 +75,9 @@ public:
 			status_t			AddEntry(const char* fileName, int fd = -1);
 			status_t			Finish();
 
+			status_t			Recompress(BPackageReader* reader);
+									// to be called after Init(); no Finish()
+
 private:
 			PackageWriterImpl*	fImpl;
 };

headers/private/package/hpkg/PackageFileHeapAccessorBase.h

@@ -92,6 +92,10 @@ public:
 			void				SetFD(int fd)
 									{ fFD = fd; }
 
+			uint64				HeapOverhead(uint64 uncompressedSize) const;
+									// additional bytes needed when storing
+									// the given amount of data
+
 	// BAbstractBufferedDataReader
 	virtual	status_t			ReadDataToOutput(off_t offset,
 									size_t size, BDataIO* output);

headers/private/package/hpkg/PackageReaderImpl.h

@@ -22,6 +22,9 @@ class BPackageEntryAttribute;
 namespace BPrivate {
 
 
+class PackageWriterImpl;
+
+
 class PackageReaderImpl : public ReaderImplBase {
 	typedef	ReaderImplBase		inherited;
 public:
@@ -58,6 +61,8 @@ private:
 			struct EntryAttributeHandler;
 			struct RootAttributeHandler;
 
+			friend class PackageWriterImpl;
+
 private:
 			status_t			_ParseTOC(AttributeHandlerContext* context,
 									AttributeHandler* rootAttributeHandler);

headers/private/package/hpkg/PackageWriterImpl.h

@@ -35,6 +35,7 @@ class BPackageWriterParameters;
 namespace BPrivate {
 
 
+class PackageReaderImpl;
 struct hpkg_header;
 
 
@@ -53,6 +54,9 @@ public:
 			status_t			AddEntry(const char* fileName, int fd = -1);
 			status_t			Finish();
 
+			status_t			Recompress(PackageReaderImpl* reader);
+									// to be called after Init(); no Finish()
+
 private:
 			struct Attribute;
 			struct PackageContentHandler;
@@ -67,6 +71,8 @@ private:
 									const BPackageWriterParameters& parameters);
 			status_t			_Finish();
 
+			status_t			_Recompress(PackageReaderImpl* reader);
+
 			status_t			_RegisterEntry(const char* fileName, int fd);
 			Entry*				_RegisterEntry(Entry* parent,
 									const char* name, size_t nameLength, int fd,

headers/private/package/hpkg/WriterImplBase.h

@@ -151,6 +151,7 @@ protected:
 
 	inline	int					FD() const;
 	inline	uint32				Flags() const;
+	inline	const BPackageWriterParameters& Parameters() const;
 
 	inline	const PackageAttributeList&	PackageAttributes() const;
 	inline	PackageAttributeList&	PackageAttributes();
@@ -230,6 +231,13 @@ WriterImplBase::Flags() const
 }
 
 
+inline const BPackageWriterParameters&
+WriterImplBase::Parameters() const
+{
+	return fParameters;
+}
+
+
 inline const WriterImplBase::PackageAttributeList&
 WriterImplBase::PackageAttributes() const
 {