1 files changed, 170 insertions, 0 deletions
diff --git a/modules/brotli/enc/memory.c b/modules/brotli/enc/memory.c
new file mode 100644
index 000000000..f6ed7e3cb
--- /dev/null
+++ b/modules/brotli/enc/memory.c
@@ -0,0 +1,170 @@
+/* Copyright 2015 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/* Algorithms for distributing the literals and commands of a metablock between
+   block types and contexts. */
+
+#include "./memory.h"
+
+#include <stdlib.h>  /* exit, free, malloc */
+#include <string.h>  /* memcpy */
+
+#include "../common/platform.h"
+#include <brotli/types.h>
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+#define MAX_PERM_ALLOCATED 128
+#define MAX_NEW_ALLOCATED 64
+#define MAX_NEW_FREED 64
+
+#define PERM_ALLOCATED_OFFSET 0
+#define NEW_ALLOCATED_OFFSET MAX_PERM_ALLOCATED
+#define NEW_FREED_OFFSET (MAX_PERM_ALLOCATED + MAX_NEW_ALLOCATED)
+
+void BrotliInitMemoryManager(
+    MemoryManager* m, brotli_alloc_func alloc_func, brotli_free_func free_func,
+    void* opaque) {
+  if (!alloc_func) {
+    m->alloc_func = BrotliDefaultAllocFunc;
+    m->free_func = BrotliDefaultFreeFunc;
+    m->opaque = 0;
+  } else {
+    m->alloc_func = alloc_func;
+    m->free_func = free_func;
+    m->opaque = opaque;
+  }
+#if !defined(BROTLI_ENCODER_EXIT_ON_OOM)
+  m->is_oom = BROTLI_FALSE;
+  m->perm_allocated = 0;
+  m->new_allocated = 0;
+  m->new_freed = 0;
+#endif  /* BROTLI_ENCODER_EXIT_ON_OOM */
+}
+
+#if defined(BROTLI_ENCODER_EXIT_ON_OOM)
+
+void* BrotliAllocate(MemoryManager* m, size_t n) {
+  void* result = m->alloc_func(m->opaque, n);
+  if (!result) exit(EXIT_FAILURE);
+  return result;
+}
+
+void BrotliFree(MemoryManager* m, void* p) {
+  m->free_func(m->opaque, p);
+}
+
+void BrotliWipeOutMemoryManager(MemoryManager* m) {
+  BROTLI_UNUSED(m);
+}
+
+#else  /* BROTLI_ENCODER_EXIT_ON_OOM */
+
+static void SortPointers(void** items, const size_t n) {
+  /* Shell sort. */
+  static const size_t gaps[] = {23, 10, 4, 1};
+  int g = 0;
+  for (; g < 4; ++g) {
+    size_t gap = gaps[g];
+    size_t i;
+    for (i = gap; i < n; ++i) {
+      size_t j = i;
+      void* tmp = items[i];
+      for (; j >= gap && tmp < items[j - gap]; j -= gap) {
+        items[j] = items[j - gap];
+      }
+      items[j] = tmp;
+    }
+  }
+}
+
+static size_t Annihilate(void** a, size_t a_len, void** b, size_t b_len) {
+  size_t a_read_index = 0;
+  size_t b_read_index = 0;
+  size_t a_write_index = 0;
+  size_t b_write_index = 0;
+  size_t annihilated = 0;
+  while (a_read_index < a_len && b_read_index < b_len) {
+    if (a[a_read_index] == b[b_read_index]) {
+      a_read_index++;
+      b_read_index++;
+      annihilated++;
+    } else if (a[a_read_index] < b[b_read_index]) {
+      a[a_write_index++] = a[a_read_index++];
+    } else {
+      b[b_write_index++] = b[b_read_index++];
+    }
+  }
+  while (a_read_index < a_len) a[a_write_index++] = a[a_read_index++];
+  while (b_read_index < b_len) b[b_write_index++] = b[b_read_index++];
+  return annihilated;
+}
+
+static void CollectGarbagePointers(MemoryManager* m) {
+  size_t annihilated;
+  SortPointers(m->pointers + NEW_ALLOCATED_OFFSET, m->new_allocated);
+  SortPointers(m->pointers + NEW_FREED_OFFSET, m->new_freed);
+  annihilated = Annihilate(
+      m->pointers + NEW_ALLOCATED_OFFSET, m->new_allocated,
+      m->pointers + NEW_FREED_OFFSET, m->new_freed);
+  m->new_allocated -= annihilated;
+  m->new_freed -= annihilated;
+
+  if (m->new_freed != 0) {
+    annihilated = Annihilate(
+        m->pointers + PERM_ALLOCATED_OFFSET, m->perm_allocated,
+        m->pointers + NEW_FREED_OFFSET, m->new_freed);
+    m->perm_allocated -= annihilated;
+    m->new_freed -= annihilated;
+    BROTLI_DCHECK(m->new_freed == 0);
+  }
+
+  if (m->new_allocated != 0) {
+    BROTLI_DCHECK(m->perm_allocated + m->new_allocated <= MAX_PERM_ALLOCATED);
+    memcpy(m->pointers + PERM_ALLOCATED_OFFSET + m->perm_allocated,
+           m->pointers + NEW_ALLOCATED_OFFSET,
+           sizeof(void*) * m->new_allocated);
+    m->perm_allocated += m->new_allocated;
+    m->new_allocated = 0;
+    SortPointers(m->pointers + PERM_ALLOCATED_OFFSET, m->perm_allocated);
+  }
+}
+
+void* BrotliAllocate(MemoryManager* m, size_t n) {
+  void* result = m->alloc_func(m->opaque, n);
+  if (!result) {
+    m->is_oom = BROTLI_TRUE;
+    return NULL;
+  }
+  if (m->new_allocated == MAX_NEW_ALLOCATED) CollectGarbagePointers(m);
+  m->pointers[NEW_ALLOCATED_OFFSET + (m->new_allocated++)] = result;
+  return result;
+}
+
+void BrotliFree(MemoryManager* m, void* p) {
+  if (!p) return;
+  m->free_func(m->opaque, p);
+  if (m->new_freed == MAX_NEW_FREED) CollectGarbagePointers(m);
+  m->pointers[NEW_FREED_OFFSET + (m->new_freed++)] = p;
+}
+
+void BrotliWipeOutMemoryManager(MemoryManager* m) {
+  size_t i;
+  CollectGarbagePointers(m);
+  /* Now all unfreed pointers are in perm-allocated list. */
+  for (i = 0; i < m->perm_allocated; ++i) {
+    m->free_func(m->opaque, m->pointers[PERM_ALLOCATED_OFFSET + i]);
+  }
+  m->perm_allocated = 0;
+}
+
+#endif  /* BROTLI_ENCODER_EXIT_ON_OOM */
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif