Add enable long matching distance (#54)

Author: raz-adroll

c_src/zstd_nif.c

@@ -112,6 +112,7 @@ static ERL_NIF_TERM zstd_nif_new_decompression_stream(ErlNifEnv* env, int argc,
 static ERL_NIF_TERM zstd_nif_init_compression_stream(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) {
   int level = ZSTD_CLEVEL_DEFAULT;
   int window_log = 0;
+  int enable_long_distance_matching = 0;
   size_t ret;
   ZSTD_CStream **pzcs;
 
@@ -124,14 +125,20 @@ static ERL_NIF_TERM zstd_nif_init_compression_stream(ErlNifEnv* env, int argc, c
       return enif_make_badarg(env);
 
   /* extract the window log if any */
-  if ((argc == 3) && !(enif_get_int(env, argv[2], &window_log)))
+  if ((argc >= 3) && !(enif_get_int(env, argv[2], &window_log)))
+      return enif_make_badarg(env);
+
+  /* extract the enable long distance matching if any */
+  if ((argc == 4) && !(enif_get_int(env, argv[3], &enable_long_distance_matching)))
       return enif_make_badarg(env);
 
   /* initialize the stream */
   if (ZSTD_isError(ret = ZSTD_initCStream(*pzcs, level)))
       return enif_make_tuple2(env, zstd_atom_error, enif_make_string(env, ZSTD_getErrorName(ret), ERL_NIF_LATIN1));
   if (ZSTD_isError(ret = ZSTD_CCtx_setParameter(*pzcs, ZSTD_c_windowLog, window_log)))
       return enif_make_tuple2(env, zstd_atom_error, enif_make_string(env, ZSTD_getErrorName(ret), ERL_NIF_LATIN1));
+  if (ZSTD_isError(ret = ZSTD_CCtx_setParameter(*pzcs, ZSTD_c_enableLongDistanceMatching, enable_long_distance_matching)))
+      return enif_make_tuple2(env, zstd_atom_error, enif_make_string(env, ZSTD_getErrorName(ret), ERL_NIF_LATIN1));
   if (ZSTD_isError(ret = ZSTD_CCtx_setParameter(*pzcs, ZSTD_c_checksumFlag, 1)))
       return enif_make_tuple2(env, zstd_atom_error, enif_make_string(env, ZSTD_getErrorName(ret), ERL_NIF_LATIN1));
 
@@ -423,6 +430,7 @@ static ErlNifFunc nif_funcs[] = {
   { "compression_stream_init"     , 1, zstd_nif_init_compression_stream    , ERL_DIRTY_JOB_CPU_BOUND },
   { "compression_stream_init"     , 2, zstd_nif_init_compression_stream    , ERL_DIRTY_JOB_CPU_BOUND },
   { "compression_stream_init"     , 3, zstd_nif_init_compression_stream    , ERL_DIRTY_JOB_CPU_BOUND },
+  { "compression_stream_init"     , 4, zstd_nif_init_compression_stream    , ERL_DIRTY_JOB_CPU_BOUND },
   { "decompression_stream_init"   , 1, zstd_nif_init_decompression_stream  , ERL_DIRTY_JOB_CPU_BOUND },
 
   { "compression_stream_reset"    , 2, zstd_nif_reset_compression_stream                             },

src/zstd.erl

@@ -3,8 +3,8 @@
 -export([compress/1, compress/2]).
 -export([decompress/1]).
 -export([new_compression_stream/0, compression_stream_init/1, compression_stream_init/2,
-         compression_stream_init/3, compression_stream_reset/1, compression_stream_reset/2,
-         stream_compress/2, stream_flush/1, new_decompression_stream/0,
+         compression_stream_init/3, compression_stream_init/4, compression_stream_reset/1,
+         compression_stream_reset/2, stream_compress/2, stream_flush/1, new_decompression_stream/0,
          decompression_stream_init/1, decompression_stream_reset/1, stream_decompress/2]).
 
 -on_load init/0.
@@ -46,6 +46,11 @@ compression_stream_init(_Ref, _Level) ->
 compression_stream_init(_Ref, _Level, _WindowLog) ->
     erlang:nif_error(?LINE).
 
+-spec compression_stream_init(reference(), 0..22, integer(), integer()) ->
+                                 ok | {error, invalid | string()}.
+compression_stream_init(_Ref, _Level, _WindowLog, _EnableLongDistanceMatching) ->
+    erlang:nif_error(?LINE).
+
 -spec decompression_stream_init(reference()) -> ok | {error, invalid | string()}.
 decompression_stream_init(_Ref) ->
     erlang:nif_error(?LINE).

test/zstd_tests.erl

@@ -1,5 +1,9 @@
 -module(zstd_tests).
 
+-define(COMPRESSION_LEVEL, 5).
+-define(WINDOW_LOG, 23).
+-define(ENABLE_LONG_DISTANCE_MATCHING, 1).
+
 -include_lib("eunit/include/eunit.hrl").
 
 zstd_test() ->
@@ -11,7 +15,11 @@ zstd_test() ->
 zstd_stream_test() ->
     Bin = << <<"A">> || _ <- lists:seq(1, 1024 * 1024) >>,
     CStream = zstd:new_compression_stream(),
-    ok = zstd:compression_stream_init(CStream, 5, 23),
+    ok =
+        zstd:compression_stream_init(CStream,
+                                     ?COMPRESSION_LEVEL,
+                                     ?WINDOW_LOG,
+                                     ?ENABLE_LONG_DISTANCE_MATCHING),
     {ok, CompressionBin} = zstd:stream_compress(CStream, Bin),
     {ok, FlushBin} = zstd:stream_flush(CStream),