4 files changed, 88 insertions, 143 deletions
diff --git a/src/OSSupport/File.cpp b/src/OSSupport/File.cpp
index 8c5eb92a4..618463bd6 100644
--- a/src/OSSupport/File.cpp
+++ b/src/OSSupport/File.cpp
@@ -157,19 +157,18 @@ int cFile::Read (void * a_Buffer, size_t a_NumBytes)
 
 
 
-AString cFile::Read(size_t a_NumBytes)
+ContiguousByteBuffer cFile::Read(size_t a_NumBytes)
 {
 	ASSERT(IsOpen());
 
 	if (!IsOpen())
 	{
-		return AString();
+		return {};
 	}
 
-	// HACK: This depends on the knowledge that AString::data() returns the internal buffer, rather than a copy of it.
-	AString res;
-	res.resize(a_NumBytes);
-	auto newSize = fread(const_cast<char *>(res.data()), 1, a_NumBytes, m_File);
+	ContiguousByteBuffer res;
+	res.resize(a_NumBytes);  // TODO: investigate if worth hacking around std::string internals to avoid initialisation
+	auto newSize = fread(res.data(), sizeof(std::byte), a_NumBytes, m_File);
 	res.resize(newSize);
 	return res;
 }
@@ -284,9 +283,8 @@ int cFile::ReadRestOfFile(AString & a_Contents)
 
 	auto DataSize = static_cast<size_t>(TotalSize - Position);
 
-	// HACK: This depends on the internal knowledge that AString's data() function returns the internal buffer directly
-	a_Contents.assign(DataSize, '\0');
-	return Read(static_cast<void *>(const_cast<char *>(a_Contents.data())), DataSize);
+	a_Contents.resize(DataSize);  // TODO: investigate if worth hacking around std::string internals to avoid initialisation
+	return Read(a_Contents.data(), DataSize);
 }
 
 
@@ -709,3 +707,54 @@ void cFile::Flush(void)
 {
 	fflush(m_File);
 }
+
+
+
+
+
+template <class StreamType>
+FileStream<StreamType>::FileStream(const std::string & Path)
+{
+	// Except on failbit, which is what open sets on failure:
+	FileStream::exceptions(FileStream::failbit | FileStream::badbit);
+
+	// Open the file:
+	FileStream::open(Path);
+
+	// Only subsequently except on serious errors, and not on conditions like EOF or malformed input:
+	FileStream::exceptions(FileStream::badbit);
+}
+
+
+
+
+
+template <class StreamType>
+FileStream<StreamType>::FileStream(const std::string & Path, const typename FileStream::openmode Mode)
+{
+	// Except on failbit, which is what open sets on failure:
+	FileStream::exceptions(FileStream::failbit | FileStream::badbit);
+
+	// Open the file:
+	FileStream::open(Path, Mode);
+
+	// Only subsequently except on serious errors, and not on conditions like EOF or malformed input:
+	FileStream::exceptions(FileStream::badbit);
+}
+
+
+
+
+
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wweak-template-vtables"  // http://bugs.llvm.org/show_bug.cgi?id=18733
+#endif
+
+// Instantiate the templated wrapper for input and output:
+template class FileStream<std::ifstream>;
+template class FileStream<std::ofstream>;
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
diff --git a/src/OSSupport/File.h b/src/OSSupport/File.h
index 59f3a5558..7a3333483 100644
--- a/src/OSSupport/File.h
+++ b/src/OSSupport/File.h
@@ -75,7 +75,7 @@ public:
 	int Read(void * a_Buffer, size_t a_NumBytes);
 
 	/** Reads up to a_NumBytes bytes, returns the bytes actually read, or empty string on failure; asserts if not open */
-	AString Read(size_t a_NumBytes);
+	std::basic_string<std::byte> Read(size_t a_NumBytes);
 
 	/** Writes up to a_NumBytes bytes from a_Buffer, returns the number of bytes actually written, or -1 on failure; asserts if not open */
 	int Write(const void * a_Buffer, size_t a_NumBytes);
@@ -192,17 +192,8 @@ class FileStream final : public StreamType
 {
 public:
 
-	FileStream(const std::string & Path)
-	{
-		// Except on failbit, which is what open sets on failure:
-		FileStream::exceptions(FileStream::failbit | FileStream::badbit);
-
-		// Open the file:
-		FileStream::open(Path);
-
-		// Only subsequently except on serious errors, and not on conditions like EOF or malformed input:
-		FileStream::exceptions(FileStream::badbit);
-	}
+	FileStream(const std::string & Path);
+	FileStream(const std::string & Path, const typename FileStream::openmode Mode);
 };
 
 
@@ -211,3 +202,15 @@ public:
 
 using InputFileStream = FileStream<std::ifstream>;
 using OutputFileStream = FileStream<std::ofstream>;
+
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wweak-template-vtables"  // http://bugs.llvm.org/show_bug.cgi?id=18733
+#endif
+
+extern template class FileStream<std::ifstream>;
+extern template class FileStream<std::ofstream>;
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
diff --git a/src/OSSupport/GZipFile.cpp b/src/OSSupport/GZipFile.cpp
index e83d42583..0bf26dfed 100644
--- a/src/OSSupport/GZipFile.cpp
+++ b/src/OSSupport/GZipFile.cpp
@@ -4,107 +4,27 @@
 // Implements the cGZipFile class representing a RAII wrapper over zlib's GZip file routines
 
 #include "Globals.h"
+#include "File.h"
 #include "GZipFile.h"
 
 
 
 
 
-cGZipFile::cGZipFile(void) :
-	m_File(nullptr), m_Mode(fmRead)
+Compression::Result GZipFile::ReadRestOfFile(const std::string & a_FileName)
 {
-}
-
-
-
-
-
-cGZipFile::~cGZipFile()
-{
-	Close();
-}
-
+	InputFileStream File(a_FileName, InputFileStream::binary);
+	const std::string Input{ std::istreambuf_iterator<char>(File), std::istreambuf_iterator<char>() };
+	const ContiguousByteBufferView Data{ reinterpret_cast<const std::byte *>(Input.data()), Input.size() };
 
-
-
-
-bool cGZipFile::Open(const AString & a_FileName, eMode a_Mode)
-{
-	if (m_File != nullptr)
-	{
-		ASSERT(!"A file is already open in this object");
-		return false;
-	}
-	m_File = gzopen(a_FileName.c_str(), (a_Mode == fmRead) ? "r" : "w");
-	m_Mode = a_Mode;
-	return (m_File != nullptr);
+	return Compression::Extractor().ExtractGZip(Data);
 }
 
 
 
 
 
-void cGZipFile::Close(void)
+void GZipFile::Write(const std::string & a_FileName, ContiguousByteBufferView a_Contents)
 {
-	if (m_File != nullptr)
-	{
-		gzclose(m_File);
-		m_File = nullptr;
-	}
+	OutputFileStream(a_FileName, OutputFileStream::binary) << Compression::Compressor().CompressGZip(a_Contents).GetStringView();
 }
-
-
-
-
-
-int cGZipFile::ReadRestOfFile(AString & a_Contents)
-{
-	if (m_File == nullptr)
-	{
-		ASSERT(!"No file has been opened");
-		return -1;
-	}
-
-	if (m_Mode != fmRead)
-	{
-		ASSERT(!"Bad file mode, cannot read");
-		return -1;
-	}
-
-	// Since the gzip format doesn't really support getting the uncompressed length, we need to read incrementally. Yuck!
-	int NumBytesRead = 0;
-	int TotalBytes = 0;
-	char Buffer[64 KiB];
-	while ((NumBytesRead = gzread(m_File, Buffer, sizeof(Buffer))) > 0)
-	{
-		TotalBytes += NumBytesRead;
-		a_Contents.append(Buffer, static_cast<size_t>(NumBytesRead));
-	}
-	// NumBytesRead is < 0 on error
-	return (NumBytesRead >= 0) ? TotalBytes : NumBytesRead;
-}
-
-
-
-
-
-bool cGZipFile::Write(const char * a_Contents, int a_Size)
-{
-	if (m_File == nullptr)
-	{
-		ASSERT(!"No file has been opened");
-		return false;
-	}
-
-	if (m_Mode != fmWrite)
-	{
-		ASSERT(!"Bad file mode, cannot write");
-		return false;
-	}
-
-	return (gzwrite(m_File, a_Contents, static_cast<unsigned int>(a_Size)) != 0);
-}
-
-
-
-
diff --git a/src/OSSupport/GZipFile.h b/src/OSSupport/GZipFile.h
index 00a2fd717..dd4999339 100644
--- a/src/OSSupport/GZipFile.h
+++ b/src/OSSupport/GZipFile.h
@@ -1,7 +1,7 @@
 
 // GZipFile.h
 
-// Declares the cGZipFile class representing a RAII wrapper over zlib's GZip file routines
+// Declares the GZipFile namespace representing a wrapper over a file stream that can read and write to GZip'd files
 
 
 
@@ -9,44 +9,17 @@
 
 #pragma once
 
-#include "zlib/zlib.h"
+#include "StringCompression.h"
 
 
 
 
 
-class cGZipFile
+namespace GZipFile
 {
-public:
-	enum eMode
-	{
-		fmRead,      // Read-only. If the file doesn't exist, object will not be valid
-		fmWrite,     // Write-only. If the file already exists, it will be overwritten
-	} ;
+	/** Reads the rest of the file and returns the decompressed contents. */
+	Compression::Result ReadRestOfFile(const std::string & a_FileName);
 
-	cGZipFile(void);
-	~cGZipFile();
-
-	/** Opens the file. Returns true if successful. Fails if a file has already been opened through this object. */
-	bool Open(const AString & a_FileName, eMode a_Mode);
-
-	/** Closes the file, flushing all buffers. This object may be then reused for a different file and / or mode */
-	void Close(void);
-
-	/** Reads the rest of the file and decompresses it into a_Contents. Returns the number of decompressed bytes, <0 for error */
-	int ReadRestOfFile(AString & a_Contents);
-
-	/** Writes a_Contents into file, compressing it along the way. Returns true if successful. Multiple writes are supported. */
-	bool Write(const AString & a_Contents) { return Write(a_Contents.data(), static_cast<int>(a_Contents.size())); }
-
-	bool Write(const char * a_Data, int a_Size);
-
-protected:
-	gzFile m_File;
-	eMode  m_Mode;
+	/** Writes a_Contents into file, compressing it along the way. */
+	void Write(const std::string & a_FileName, ContiguousByteBufferView a_Contents);
 } ;
-
-
-
-
-