review: fix findings

* replace assert with test for LZ4F_uncompressedUpdate
* update documentation to incldue correct docstring
* remove unecessary entry point
* remove compress_linked_block_mode from fuzzing test

Signed-off-by: Alexander Mohr <alexander.m.mohr@mercedes-benz.com>

contrib/meson/meson/examples/meson.build

@@ -26,7 +26,7 @@ foreach e, src : examples
   executable(
     e,
     lz4_source_root / 'examples' / src,
-    dependencies: [liblz4_dep, liblz4_internal_dep],
+    dependencies: [liblz4_internal_dep],
     install: false
   )
 endforeach

doc/lz4frame_manual.html

@@ -355,6 +355,7 @@ <h1>1.9.4 Manual</h1>
   After an error, the state is left in a UB state, and must be re-initialized or freed.
   If previously a compressed block was written, buffered data is flushed
   before appending uncompressed data is continued.
+  This is only supported when LZ4F_blockIndependent is used
  `cOptPtr` is optional : NULL can be provided, in which case all options are set to default.
  @return : number of bytes written into `dstBuffer` (it can be zero, meaning input data was just buffered).
            or an error code if it fails (which can be tested using LZ4F_isError())

lib/lz4frame.c

@@ -1026,7 +1026,7 @@ size_t LZ4F_uncompressedUpdate(LZ4F_cctx* cctxPtr,
                                void* dstBuffer, size_t dstCapacity,
                          const void* srcBuffer, size_t srcSize,
                          const LZ4F_compressOptions_t* compressOptionsPtr) {
-    assert(cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockIndependent);
+    RETURN_ERROR_IF(cctxPtr->prefs.frameInfo.blockMode != LZ4F_blockIndependent, blockMode_invalid);
     return LZ4F_compressUpdateImpl(cctxPtr,
                                    dstBuffer, dstCapacity,
                                    srcBuffer, srcSize,

lib/lz4hc.h

@@ -405,18 +405,6 @@ LZ4LIB_STATIC_API void LZ4_attach_HC_dictionary(
           LZ4_streamHC_t *working_stream,
     const LZ4_streamHC_t *dictionary_stream);
 
-/*! LZ4_getDictHCSize():
- * Get the size of the dictionary. This can be used for adding data without
- * compression to the LZ4 archive. If linked blocked mode is used the memory
- * of the dictionary is kept free.
- * This way uncompressed data does not influence the effectiveness of the
- * dictionary.
- * @param LZ4_dict Pointer to the dictionary to get the size of.
- * @param dictSize The maximum dictionary size. (Normally 64 KB).
- * @return The size of the dictionary.
- */
-LZ4LIB_STATIC_API int LZ4_getDictHCSize(const LZ4_streamHC_t* LZ4_streamHCPtr, int dictSize);
-
 #if defined (__cplusplus)
 }
 #endif

ossfuzz/round_trip_frame_uncompressed_fuzzer.c

@@ -124,13 +124,6 @@ static void compress_round_trip(const uint8_t* data, size_t size,
   LZ4F_freeCompressionContext(ctx);
 }
 
-static void compress_linked_block_mode(const uint8_t* data, size_t size) {
-  FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(data, size);
-  LZ4F_preferences_t prefs = FUZZ_dataProducer_preferences(producer);
-  prefs.frameInfo.blockMode = LZ4F_blockLinked;
-  compress_round_trip(data, size, producer, prefs);
-}
-
 static void compress_independent_block_mode(const uint8_t* data, size_t size) {
   FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(data, size);
   LZ4F_preferences_t prefs = FUZZ_dataProducer_preferences(producer);
@@ -140,7 +133,6 @@ static void compress_independent_block_mode(const uint8_t* data, size_t size) {
 
 
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  compress_linked_block_mode(data, size);
   compress_independent_block_mode(data, size);
   return 0;
 }