- Renamed /lib subfolders to lowercase

lib/filesystem/CCompressedStream.h

@@ -0,0 +1,120 @@
+
+/*
+ * CLodStream.h, part of VCMI engine
+ *
+ * Authors: listed in file AUTHORS in main folder
+ *
+ * License: GNU General Public License v2.0 or later
+ * Full text of license available in license.txt file, in main folder
+ *
+ */
+
+#pragma once
+
+#include "CInputStream.h"
+
+struct z_stream_s;
+
+/**
+ * A class which provides method definitions for reading a gzip-compressed file
+ * This class implements lazy loading - data will be decompressed (and cached by this class) only by request
+ */
+class DLL_LINKAGE CCompressedStream : public CInputStream
+{
+public:
+	/**
+	 * C-tor.
+	 *
+	 * @param stream - stream with compresed data
+	 * @param gzip - this is gzipp'ed file e.g. campaign or maps, false for files in lod
+	 * @param decompressedSize - optional parameter to hint size of decompressed data
+	 */
+	CCompressedStream(std::unique_ptr<CInputStream> stream, bool gzip, size_t decompressedSize=0);
+
+	~CCompressedStream();
+
+	/**
+	 * Reads n bytes from the stream into the data buffer.
+	 *
+	 * @param data A pointer to the destination data array.
+	 * @param size The number of bytes to read.
+	 * @return the number of bytes read actually.
+	 *
+	 * @throws std::runtime_error if the file decompression was not successful
+	 */
+	si64 read(ui8 * data, si64 size);
+
+	/**
+	 * Seeks the internal read pointer to the specified position.
+	 * This will cause decompressing data till this position is found
+	 *
+	 * @param position The read position from the beginning.
+	 * @return the position actually moved to, -1 on error.
+	 */
+	si64 seek(si64 position);
+
+	/**
+	 * Gets the current read position in the stream.
+	 *
+	 * @return the read position.
+	 */
+	si64 tell();
+
+	/**
+	 * Skips delta numbers of bytes.
+	 *
+	 * @param delta The count of bytes to skip.
+	 * @return the count of bytes skipped actually.
+	 */
+	si64 skip(si64 delta);
+
+	/**
+	 * Gets the length in bytes of the stream.
+	 * Causes complete data decompression
+	 *
+	 * @return the length in bytes of the stream.
+	 */
+	si64 getSize();
+
+	/**
+	 * Prepare stream for decompression of next block (e.g. nect part of h3c)
+	 * Applicable only for streams that contain multiple concatenated compressed data
+	 *
+	 * @return false if next block was not found, true othervice
+	 */
+	bool getNextBlock();
+
+private:
+	/**
+	 * Decompresses data to ensure that buffer has newSize bytes or end of stream was reached
+	 */
+	void decompressTill(si64 newSize);
+
+	/** The file stream with compressed data. */
+	std::unique_ptr<CInputStream> gzipStream;
+
+	/** buffer with already decompressed data. Please note that size() != decompressed size */
+	std::vector<ui8> buffer;
+
+	/** size of already decompressed data */
+	si64 decompressedSize;
+
+	/** buffer with not yet decompressed data*/
+	std::vector<ui8> compressedBuffer;
+
+	/** struct with current zlib inflate state */
+	z_stream_s * inflateState;
+
+	/** Current read position */
+	si64 position;
+
+	enum EState
+	{
+		ERROR,
+		INITIALIZED,
+		IN_PROGRESS,
+		STREAM_END,
+		FINISHED
+	};
+
+};