initial commit

c_src/lz4.c

@@ -0,0 +1,149 @@
+/*
+Copyright 2011, Joe Williams <joe@joetify.com>
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated documentation
+files (the "Software"), to deal in the Software without
+restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include <erl_nif.h>
+#include <erl_driver.h>
+#include <errno.h>
+#include <stdlib.h>
+
+#include "lz4/lz4.h"
+#include "lz4/lz4hc.h"
+
+static ERL_NIF_TERM atom_ok;
+static ERL_NIF_TERM atom_error;
+
+static inline void store_le32(char *c, u_int32_t x)
+{
+  c[0] = x & 0xff;
+  c[1] = (x >> 8) & 0xff;
+  c[2] = (x >> 16) & 0xff;
+  c[3] = (x >> 24) & 0xff;
+}
+
+static inline u_int32_t load_le32(const char *c)
+{
+    const u_int8_t *d = (const u_int8_t *)c;
+    return d[0] | (d[1] << 8) | (d[2] << 16) | (d[3] << 24);
+}
+
+static const int hdr_size = sizeof(u_int32_t);
+
+static int
+load(ErlNifEnv* env, void** priv, ERL_NIF_TERM load_info)
+{
+  atom_ok = enif_make_atom(env, "ok");
+  atom_error = enif_make_atom(env, "error");
+
+  return 0;
+}
+
+static int
+reload(ErlNifEnv* env, void** priv, ERL_NIF_TERM load_info)
+{
+  return 0;
+}
+
+static int
+upgrade(ErlNifEnv* env, void** priv, void** old_priv, ERL_NIF_TERM load_info)
+{
+  return 0;
+}
+
+static void
+unload(ErlNifEnv* env, void* priv)
+{
+  return;
+}
+
+/**********************************************************************
+ * Name: compress
+ *
+ * Desc: compress binary
+ */
+
+static ERL_NIF_TERM
+compress(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) {
+  ERL_NIF_TERM result;
+  ErlNifBinary source;
+  char *result_buf = NULL;
+  int dest_size;
+
+  if (!enif_inspect_binary(env, argv[0], &source)) return enif_make_badarg(env);
+
+  dest_size = hdr_size + LZ4_compressBound(source.size);
+
+  result_buf = enif_make_new_binary(env, dest_size, &result);
+
+  store_le32(result_buf, source.size);
+
+  LZ4_compress(source.data, result_buf + hdr_size, source.size);
+
+  return enif_make_tuple2(env, atom_ok, result);
+}
+
+/**********************************************************************
+ * Name: compress_hc
+ *
+ * Desc: compress (high) binary
+ */
+
+static ERL_NIF_TERM
+compress_hc(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) {
+
+  return atom_ok;
+}
+
+/**********************************************************************
+ * Name: uncompress
+ *
+ * Desc: uncompress binary
+ */
+
+static ERL_NIF_TERM
+uncompress(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) {
+  ERL_NIF_TERM result;
+  ErlNifBinary source;
+  char *result_buf = NULL;
+  u_int32_t dest_size;
+
+  if (!enif_inspect_binary(env, argv[0], &source)) return enif_make_badarg(env);
+
+  dest_size = load_le32(source.data);
+
+  result_buf = enif_make_new_binary(env, dest_size, &result);
+
+  LZ4_uncompress(source.data + hdr_size, result_buf, dest_size);
+
+  return enif_make_tuple2(env, atom_ok, result);
+}
+
+static ErlNifFunc nif_funcs[] = {
+  {"compress", 1, compress},
+  {"compress_hc", 1, compress_hc},
+  {"uncompress", 1, uncompress}
+};
+
+ERL_NIF_INIT(lz4, nif_funcs, &load, &reload, &upgrade, &unload);
+