Create lzf.h

Author: CandyMi

lzf.h

@@ -0,0 +1,66 @@
+#ifndef LZF_H
+#define LZF_H
+
+/* API version (major * 256 + minor)
+ * major API version gets bumped on incompatible changes.
+ * minor API version gets bumped on compatible changes.
+ * 1.5 => 1.6: add LZF_MAX_COMPRESSED_SIZE
+ */
+#define LZF_VERSION 0x0106
+
+/*
+ * Compress in_len bytes stored at the memory block starting at
+ * in_data and write the result to out_data, up to a maximum length
+ * of out_len bytes.
+ *
+ * If the output buffer is not large enough or any error occurs return 0,
+ * otherwise return the number of bytes used, which might be considerably
+ * more than in_len (but less than 1 + 104% of the original size), so it
+ * makes sense to always use out_len == in_len - 1), to ensure _some_
+ * compression, and store the data uncompressed otherwise (with a flag, of
+ * course.
+ *
+ * lzf_compress might use different algorithms on different systems and
+ * even different runs, thus might result in different compressed strings
+ * depending on the phase of the moon or similar factors. However, all
+ * these strings are architecture-independent and will result in the
+ * original data when decompressed using lzf_decompress.
+ *
+ * The buffers must not be overlapping.
+ *
+ * If the option LZF_STATE_ARG is enabled, an extra argument must be
+ * supplied which is not reflected in this header file. Refer to lzfP.h
+ * and lzf_c.c.
+ *
+ */
+unsigned int lzf_compress (const void *const in_data, unsigned int in_len, void *out_data, unsigned int out_len);
+
+/*
+ * The maximum out_len that needs to be allocated to make sure
+ * any input data can be compressed without overflowing the output
+ * buffer, i.e. maximum out_len = LZF_MAX_COMPRESSED_SIZE (in_len).
+ * This is useful if you don't want to bother with the case of
+ * incompressible data and just want to provide a buffer that is
+ * guaranteeed to be big enough.
+ * This macro can be used at preprocessing time.
+ */
+#define LZF_MAX_COMPRESSED_SIZE(n) ((((n) * 33) >> 5 ) + 1)
+
+/*
+ * Decompress data compressed with some version of the lzf_compress
+ * function and stored at location in_data and length in_len. The result
+ * will be stored at out_data up to a maximum of out_len characters.
+ *
+ * If the output buffer is not large enough to hold the decompressed
+ * data, a 0 is returned and errno is set to E2BIG. Otherwise the number
+ * of decompressed bytes (i.e. the original length of the data) is
+ * returned.
+ *
+ * If an error in the compressed data is detected, a zero is returned and
+ * errno is set to EINVAL.
+ *
+ * This function is very fast, about as fast as a copying loop.
+ */
+unsigned int lzf_decompress (const void *const in_data, unsigned int in_len, void *out_data, unsigned int out_len);
+
+#endif