1 files changed, 144 insertions, 0 deletions
diff --git a/modules/brotli/enc/backward_references.c b/modules/brotli/enc/backward_references.c
new file mode 100644
index 000000000..cd023d9b4
--- /dev/null
+++ b/modules/brotli/enc/backward_references.c
@@ -0,0 +1,144 @@
+/* Copyright 2013 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/* Function to find backward reference copies. */
+
+#include "./backward_references.h"
+
+#include "../common/constants.h"
+#include "../common/dictionary.h"
+#include "../common/platform.h"
+#include <brotli/types.h>
+#include "./command.h"
+#include "./dictionary_hash.h"
+#include "./memory.h"
+#include "./quality.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+static BROTLI_INLINE size_t ComputeDistanceCode(size_t distance,
+                                                size_t max_distance,
+                                                const int* dist_cache) {
+  if (distance <= max_distance) {
+    size_t distance_plus_3 = distance + 3;
+    size_t offset0 = distance_plus_3 - (size_t)dist_cache[0];
+    size_t offset1 = distance_plus_3 - (size_t)dist_cache[1];
+    if (distance == (size_t)dist_cache[0]) {
+      return 0;
+    } else if (distance == (size_t)dist_cache[1]) {
+      return 1;
+    } else if (offset0 < 7) {
+      return (0x9750468 >> (4 * offset0)) & 0xF;
+    } else if (offset1 < 7) {
+      return (0xFDB1ACE >> (4 * offset1)) & 0xF;
+    } else if (distance == (size_t)dist_cache[2]) {
+      return 2;
+    } else if (distance == (size_t)dist_cache[3]) {
+      return 3;
+    }
+  }
+  return distance + BROTLI_NUM_DISTANCE_SHORT_CODES - 1;
+}
+
+#define EXPAND_CAT(a, b) CAT(a, b)
+#define CAT(a, b) a ## b
+#define FN(X) EXPAND_CAT(X, HASHER())
+#define EXPORT_FN(X) EXPAND_CAT(X, EXPAND_CAT(PREFIX(), HASHER()))
+
+#define PREFIX() N
+
+#define HASHER() H2
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H3
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H4
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H5
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H6
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H40
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H41
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H42
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H54
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H35
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H55
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#define HASHER() H65
+/* NOLINTNEXTLINE(build/include) */
+#include "./backward_references_inc.h"
+#undef HASHER
+
+#undef PREFIX
+
+#undef EXPORT_FN
+#undef FN
+#undef CAT
+#undef EXPAND_CAT
+
+void BrotliCreateBackwardReferences(
+    size_t num_bytes, size_t position, const uint8_t* ringbuffer,
+    size_t ringbuffer_mask, const BrotliEncoderParams* params,
+    HasherHandle hasher, int* dist_cache, size_t* last_insert_len,
+    Command* commands, size_t* num_commands, size_t* num_literals) {
+  switch (params->hasher.type) {
+#define CASE_(N)                                                  \
+    case N:                                                       \
+      CreateBackwardReferencesNH ## N(                            \
+          num_bytes, position, ringbuffer,                        \
+          ringbuffer_mask, params, hasher, dist_cache,            \
+          last_insert_len, commands, num_commands, num_literals); \
+      return;
+    FOR_GENERIC_HASHERS(CASE_)
+#undef CASE_
+    default:
+      break;
+  }
+}
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif