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-rw-r--r--src/StringCompression.h82
1 files changed, 70 insertions, 12 deletions
diff --git a/src/StringCompression.h b/src/StringCompression.h
index 10c00a804..c091c27a0 100644
--- a/src/StringCompression.h
+++ b/src/StringCompression.h
@@ -1,27 +1,85 @@
// StringCompression.h
-// Interfaces to the wrapping functions for compression and decompression using AString as their data
+// Interfaces to the wrapping functions for compression and decompression
-#include "zlib/zlib.h" // Needed for the Z_XXX return values
+#pragma once
-/** Compresses a_Data into a_Compressed using ZLIB; returns Z_XXX error constants same as zlib's compress2() */
-extern int CompressString(const char * a_Data, size_t a_Length, AString & a_Compressed, int a_Factor);
+class cByteBuffer;
-/** Uncompresses a_Data into a_Uncompressed; returns Z_XXX error constants same as zlib's decompress() */
-extern int UncompressString(const char * a_Data, size_t a_Length, AString & a_Uncompressed, size_t a_UncompressedSize);
+struct libdeflate_compressor;
+struct libdeflate_decompressor;
-/** Compresses a_Data into a_Compressed using GZIP; returns Z_OK for success or Z_XXX error constants same as zlib */
-extern int CompressStringGZIP(const char * a_Data, size_t a_Length, AString & a_Compressed);
-/** Uncompresses a_Data into a_Uncompressed using GZIP; returns Z_OK for success or Z_XXX error constants same as zlib */
-extern int UncompressStringGZIP(const char * a_Data, size_t a_Length, AString & a_Uncompressed);
-/** Uncompresses a_Data into a_Uncompressed using Inflate; returns Z_OK for success or Z_XXX error constants same as zlib */
-extern int InflateString(const char * a_Data, size_t a_Length, AString & a_Uncompressed);
+namespace Compression
+{
+ /** Contains the result of a compression or extraction operation. */
+ struct Result
+ {
+ using Static = std::array<std::byte, 128 KiB>;
+ using Dynamic = std::unique_ptr<std::byte[]>;
+
+ static constexpr size_t StaticCapacity = sizeof(Compression::Result::Static) / sizeof(Compression::Result::Static::value_type);
+
+ /** Returns a view (of type char) of the internal store. */
+ std::string_view GetStringView() const;
+
+ /** Returns a view (of type std::byte) of the internal store. */
+ ContiguousByteBufferView GetView() const;
+
+ /** A store allocated on either the stack or heap. */
+ std::variant<Static, Dynamic> Storage;
+
+ /** The length of valid data in the store. */
+ size_t Size;
+ };
+
+ /** Contains routines for data compression. */
+ class Compressor
+ {
+ public:
+
+ /** Creates a new compressor instance with a compression factor [0-12]. */
+ Compressor(int CompressionFactor = 6);
+ ~Compressor();
+
+ Result CompressGZip(ContiguousByteBufferView Input);
+ Result CompressZLib(ContiguousByteBufferView Input);
+ Result CompressZLib(const void * Input, size_t Size);
+
+ private:
+
+ template <auto Algorithm>
+ Result Compress(const void * Input, size_t Size);
+
+ libdeflate_compressor * m_Handle;
+ };
+
+ /** Contains routines for data extraction. */
+ class Extractor
+ {
+ public:
+
+ /** Creates a new extractor instance. */
+ Extractor();
+ ~Extractor();
+
+ Result ExtractGZip(ContiguousByteBufferView Input);
+ Result ExtractZLib(ContiguousByteBufferView Input);
+ Result ExtractZLib(ContiguousByteBufferView Input, size_t UncompressedSize);
+
+ private:
+
+ template <auto Algorithm> Result Extract(ContiguousByteBufferView Input);
+ template <auto Algorithm> Result Extract(ContiguousByteBufferView Input, size_t UncompressedSize);
+
+ libdeflate_decompressor * m_Handle;
+ };
+}