Add basic tracing functionality

lib/zstd.h

@@ -1001,13 +1001,13 @@ ZSTDLIB_API size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, s
 /*! ZSTD_DCtx_refDDict() :
  *  Reference a prepared dictionary, to be used to decompress next frames.
  *  The dictionary remains active for decompression of future frames using same DCtx.
- * 
+ *
  *  If called with ZSTD_d_refMultipleDDicts enabled, repeated calls of this function
  *  will store the DDict references in a table, and the DDict used for decompression
  *  will be determined at decompression time, as per the dict ID in the frame.
  *  The memory for the table is allocated on the first call to refDDict, and can be
  *  freed with ZSTD_freeDCtx().
- * 
+ *
  * @result : 0, or an error code (which can be tested with ZSTD_isError()).
  *  Note 1 : Currently, only one dictionary can be managed.
  *           Referencing a new dictionary effectively "discards" any previous one.
@@ -1892,7 +1892,7 @@ ZSTDLIB_API size_t ZSTD_CCtxParams_setParameter(ZSTD_CCtx_params* params, ZSTD_c
  * Get the requested value of one compression parameter, selected by enum ZSTD_cParameter.
  * @result : 0, or an error code (which can be tested with ZSTD_isError()).
  */
-ZSTDLIB_API size_t ZSTD_CCtxParams_getParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, int* value);
+ZSTDLIB_API size_t ZSTD_CCtxParams_getParameter(const ZSTD_CCtx_params* params, ZSTD_cParameter param, int* value);
 
 /*! ZSTD_CCtx_setParametersUsingCCtxParams() :
  *  Apply a set of ZSTD_CCtx_params to the compression context.
@@ -2027,15 +2027,15 @@ ZSTDLIB_API size_t ZSTD_DCtx_getParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param
  * using a given ZSTD_DCtx, rather than overwriting the previous DDict reference, will instead
  * store all references. At decompression time, the appropriate dictID is selected
  * from the set of DDicts based on the dictID in the frame.
- * 
+ *
  * Usage is simply calling ZSTD_refDDict() on multiple dict buffers.
- * 
+ *
  * Param has values of byte ZSTD_refMultipleDDicts_e
- * 
+ *
  * WARNING: Enabling this parameter and calling ZSTD_DCtx_refDDict(), will trigger memory
  * allocation for the hash table. ZSTD_freeDCtx() also frees this memory.
  * Memory is allocated as per ZSTD_DCtx::customMem.
- * 
+ *
  * Although this function allocates memory for the table, the user is still responsible for
  * memory management of the underlying ZSTD_DDict* themselves.
  */