--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/brotli/c/enc/encoder_dict.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,640 @@
+/* Copyright 2017 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+#include "encoder_dict.h"
+
+#include <stdlib.h>  /* malloc, free */
+
+#include "../common/dictionary.h"
+#include "../common/platform.h"
+#include "../common/shared_dictionary_internal.h"
+#include "../common/transform.h"
+#include "compound_dictionary.h"
+#include "dictionary_hash.h"
+#include "memory.h"
+#include "quality.h"
+#include "hash.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+#define NUM_HASH_BITS 15u
+#define NUM_HASH_BUCKETS (1u << NUM_HASH_BITS)
+
+static void BrotliTrieInit(BrotliTrie* trie) {
+  trie->pool_capacity = 0;
+  trie->pool_size = 0;
+  trie->pool = 0;
+
+  /* Set up the root node */
+  trie->root.single = 0;
+  trie->root.len_ = 0;
+  trie->root.idx_ = 0;
+  trie->root.sub = 0;
+}
+
+static void BrotliTrieFree(MemoryManager* m, BrotliTrie* trie) {
+  BrotliFree(m, trie->pool);
+}
+
+/* Initializes to RFC 7932 static dictionary / transforms. */
+static void InitEncoderDictionary(BrotliEncoderDictionary* dict) {
+  dict->words = BrotliGetDictionary();
+  dict->num_transforms = (uint32_t)BrotliGetTransforms()->num_transforms;
+
+  dict->hash_table_words = kStaticDictionaryHashWords;
+  dict->hash_table_lengths = kStaticDictionaryHashLengths;
+  dict->buckets = kStaticDictionaryBuckets;
+  dict->dict_words = kStaticDictionaryWords;
+
+  dict->cutoffTransformsCount = kCutoffTransformsCount;
+  dict->cutoffTransforms = kCutoffTransforms;
+
+  dict->parent = 0;
+
+  dict->hash_table_data_words_ = 0;
+  dict->hash_table_data_lengths_ = 0;
+  dict->buckets_alloc_size_ = 0;
+  dict->buckets_data_ = 0;
+  dict->dict_words_alloc_size_ = 0;
+  dict->dict_words_data_ = 0;
+  dict->words_instance_ = 0;
+  dict->has_words_heavy = BROTLI_FALSE;
+  BrotliTrieInit(&dict->trie);
+}
+
+static void BrotliDestroyEncoderDictionary(MemoryManager* m,
+    BrotliEncoderDictionary* dict) {
+  BrotliFree(m, dict->hash_table_data_words_);
+  BrotliFree(m, dict->hash_table_data_lengths_);
+  BrotliFree(m, dict->buckets_data_);
+  BrotliFree(m, dict->dict_words_data_);
+  BrotliFree(m, dict->words_instance_);
+  BrotliTrieFree(m, &dict->trie);
+}
+
+#if defined(BROTLI_EXPERIMENTAL)
+/* Word length must be at least 4 bytes */
+static uint32_t Hash(const uint8_t* data, int bits) {
+  uint32_t h = BROTLI_UNALIGNED_LOAD32LE(data) * kHashMul32;
+  /* The higher bits contain more mixture from the multiplication,
+     so we take our results from there. */
+  return h >> (32 - bits);
+}
+
+/* Theoretical max possible word size after transform */
+#define kTransformedBufferSize \
+    (256 + 256 + SHARED_BROTLI_MAX_DICTIONARY_WORD_LENGTH)
+
+/* To be safe buffer must have at least kTransformedBufferSize */
+static void TransformedDictionaryWord(uint32_t word_idx, int len, int transform,
+    const BrotliTransforms* transforms,
+    const BrotliEncoderDictionary* dict,
+    uint8_t* buffer, size_t* size) {
+  const uint8_t* dict_word = &dict->words->data[
+      dict->words->offsets_by_length[len] + (uint32_t)len * word_idx];
+  *size = (size_t)BrotliTransformDictionaryWord(buffer, dict_word, len,
+      transforms, transform);
+}
+
+static DictWord MakeDictWord(uint8_t len, uint8_t transform, uint16_t idx) {
+  DictWord result;
+  result.len = len;
+  result.transform = transform;
+  result.idx = idx;
+  return result;
+}
+
+static uint32_t BrotliTrieAlloc(MemoryManager* m, size_t num, BrotliTrie* trie,
+                                BrotliTrieNode** keep) {
+  uint32_t result;
+  uint32_t keep_index = 0;
+  if (keep && *keep != &trie->root) {
+    /* Optional node to keep, since address may change after re-allocating */
+    keep_index = (uint32_t)(*keep - trie->pool);
+  }
+  if (trie->pool_size == 0) {
+    /* Have a placeholder node in the front. We do not want the result to be 0,
+       it must be at least 1, 0 represents "null pointer" */
+    trie->pool_size = 1;
+  }
+  BROTLI_ENSURE_CAPACITY(m, BrotliTrieNode, trie->pool, trie->pool_capacity,
+                         trie->pool_size + num);
+  if (BROTLI_IS_OOM(m)) return 0;
+  /* Init the new nodes to empty */
+  memset(trie->pool + trie->pool_size, 0, sizeof(*trie->pool) * num);
+  result = (uint32_t)trie->pool_size;
+  trie->pool_size += num;
+  if (keep && *keep != &trie->root) {
+    *keep = trie->pool + keep_index;
+  }
+  return result;
+}
+
+/**
+ * len and idx: payload for last node
+ * word, size: the string
+ * index: position in the string
+ */
+static BROTLI_BOOL BrotliTrieNodeAdd(MemoryManager* m, uint8_t len,
+    uint32_t idx, const uint8_t* word, size_t size, int index,
+    BrotliTrieNode* node, BrotliTrie* trie) {
+  BrotliTrieNode* child = 0;
+  uint8_t c;
+  if ((size_t)index == size) {
+    if (!node->len_ || idx < node->idx_) {
+      node->len_ = len;
+      node->idx_ = idx;
+    }
+    return BROTLI_TRUE;
+  }
+  c = word[index];
+  if (node->single && c != node->c) {
+    BrotliTrieNode old = trie->pool[node->sub];
+    uint32_t new_nodes = BrotliTrieAlloc(m, 32, trie, &node);
+    if (BROTLI_IS_OOM(m)) return BROTLI_FALSE;
+    node->single = 0;
+    node->sub = new_nodes;
+    trie->pool[node->sub + (node->c >> 4)].sub = new_nodes + 16;
+    trie->pool[trie->pool[node->sub + (node->c >> 4)].sub + (node->c & 15)] =
+        old;
+  }
+  if (!node->sub) {
+    uint32_t new_node = BrotliTrieAlloc(m, 1, trie, &node);
+    if (BROTLI_IS_OOM(m)) return BROTLI_FALSE;
+    node->single = 1;
+    node->c = c;
+    node->sub = new_node;
+  }
+  if (node->single) {
+    child = &trie->pool[node->sub];
+  } else {
+    if (!trie->pool[node->sub + (c >> 4)].sub) {
+      uint32_t new_nodes = BrotliTrieAlloc(m, 16, trie, &node);
+      if (BROTLI_IS_OOM(m)) return BROTLI_FALSE;
+      trie->pool[node->sub + (c >> 4)].sub = new_nodes;
+    }
+    child = &trie->pool[trie->pool[node->sub + (c >> 4)].sub + (c & 15)];
+  }
+  return BrotliTrieNodeAdd(m, len, idx, word, size, index + 1, child, trie);
+}
+
+static BROTLI_BOOL BrotliTrieAdd(MemoryManager* m, uint8_t len, uint32_t idx,
+                          const uint8_t* word, size_t size, BrotliTrie* trie) {
+  return BrotliTrieNodeAdd(m, len, idx, word, size, 0, &trie->root, trie);
+}
+
+const BrotliTrieNode* BrotliTrieSub(const BrotliTrie* trie,
+                                    const BrotliTrieNode* node, uint8_t c) {
+  BrotliTrieNode* temp_node;
+  if (node->single) {
+    if (node->c == c) return &trie->pool[node->sub];
+    return 0;
+  }
+  if (!node->sub) return 0;
+  temp_node = &trie->pool[node->sub + (c >> 4)];
+  if (!temp_node->sub) return 0;
+  return &trie->pool[temp_node->sub + (c & 15)];
+}
+
+static const BrotliTrieNode* BrotliTrieFind(const BrotliTrie* trie,
+                                            const uint8_t* word, size_t size) {
+  const BrotliTrieNode* node = &trie->root;
+  size_t i;
+  for (i = 0; i < size; i++) {
+    node = BrotliTrieSub(trie, node, word[i]);
+    if (!node) return 0;
+  }
+  return node;
+}
+
+static BROTLI_BOOL BuildDictionaryLut(MemoryManager* m,
+    const BrotliTransforms* transforms,
+    BrotliEncoderDictionary* dict) {
+  uint32_t i;
+  DictWord* dict_words;
+  uint16_t* buckets;
+  DictWord** words_by_hash;
+  size_t* words_by_hash_size;
+  size_t* words_by_hash_capacity;
+  BrotliTrie dedup;
+  uint8_t word[kTransformedBufferSize];
+  size_t word_size;
+  size_t total = 0;
+  uint8_t l;
+  uint16_t idx;
+
+  BrotliTrieInit(&dedup);
+
+  words_by_hash = (DictWord**)BrotliAllocate(m,
+      sizeof(*words_by_hash) * NUM_HASH_BUCKETS);
+  words_by_hash_size = (size_t*)BrotliAllocate(m,
+      sizeof(*words_by_hash_size) * NUM_HASH_BUCKETS);
+  words_by_hash_capacity = (size_t*)BrotliAllocate(m,
+      sizeof(*words_by_hash_capacity) * NUM_HASH_BUCKETS);
+  if (BROTLI_IS_OOM(m)) return BROTLI_FALSE;
+  memset(words_by_hash, 0, sizeof(*words_by_hash) * NUM_HASH_BUCKETS);
+  memset(words_by_hash_size, 0, sizeof(*words_by_hash_size) * NUM_HASH_BUCKETS);
+  memset(words_by_hash_capacity, 0,
+         sizeof(*words_by_hash_capacity) * NUM_HASH_BUCKETS);
+
+  if (transforms->num_transforms > 0) {
+    for (l = SHARED_BROTLI_MIN_DICTIONARY_WORD_LENGTH;
+        l <= SHARED_BROTLI_MAX_DICTIONARY_WORD_LENGTH; ++l) {
+      uint16_t n = dict->words->size_bits_by_length[l] ?
+          (uint16_t)(1 << dict->words->size_bits_by_length[l]) : 0u;
+      for (idx = 0; idx < n; ++idx) {
+        uint32_t key;
+        /* First transform (usually identity) */
+        TransformedDictionaryWord(idx, l, 0, transforms, dict, word,
+                                  &word_size);
+        /* Cannot hash words smaller than 4 bytes */
+        if (word_size < 4) {
+          /* Break instead of continue, all next words of this length will have
+             same length after transform */
+          break;
+        }
+        if (!BrotliTrieAdd(m, 0, idx, word, word_size, &dedup)) {
+          return BROTLI_FALSE;
+        }
+        key = Hash(word, NUM_HASH_BITS);
+        BROTLI_ENSURE_CAPACITY_APPEND(m, DictWord, words_by_hash[key],
+            words_by_hash_capacity[key], words_by_hash_size[key],
+            MakeDictWord(l, 0, idx));
+        ++total;
+      }
+    }
+  }
+
+  /* These LUT transforms only supported if no custom transforms. This is
+     ok, we will use the heavy trie instead. */
+  if (transforms == BrotliGetTransforms()) {
+    for (l = SHARED_BROTLI_MIN_DICTIONARY_WORD_LENGTH;
+        l <= SHARED_BROTLI_MAX_DICTIONARY_WORD_LENGTH; ++l) {
+      uint16_t n = dict->words->size_bits_by_length[l] ?
+          (uint16_t)(1 << dict->words->size_bits_by_length[l]) : 0u;
+      for (idx = 0; idx < n; ++idx) {
+        int k;
+        BROTLI_BOOL is_ascii = BROTLI_TRUE;
+        size_t offset = dict->words->offsets_by_length[l] + (size_t)l * idx;
+        const uint8_t* data = &dict->words->data[offset];
+        for (k = 0; k < l; ++k) {
+          if (data[k] >= 128) is_ascii = BROTLI_FALSE;
+        }
+        if (data[0] < 128) {
+          int transform = 9;  /* {empty, uppercase first, empty} */
+          uint32_t ix = idx + (uint32_t)transform * n;
+          const BrotliTrieNode* it;
+          TransformedDictionaryWord(idx, l, transform, transforms,
+                                   dict, word, &word_size);
+          it = BrotliTrieFind(&dedup, word, word_size);
+          if (!it || it->idx_ > ix) {
+            uint32_t key = Hash(word, NUM_HASH_BITS);
+            if (!BrotliTrieAdd(m, 0, ix, word, word_size, &dedup)) {
+              return BROTLI_FALSE;
+            }
+            BROTLI_ENSURE_CAPACITY_APPEND(m, DictWord, words_by_hash[key],
+                words_by_hash_capacity[key], words_by_hash_size[key],
+                MakeDictWord(l, BROTLI_TRANSFORM_UPPERCASE_FIRST, idx));
+            ++total;
+          }
+        }
+        if (is_ascii) {
+          int transform = 44;  /* {empty, uppercase all, empty} */
+          uint32_t ix = idx + (uint32_t)transform * n;
+          const BrotliTrieNode* it;
+          TransformedDictionaryWord(idx, l, transform, transforms,
+                                    dict, word, &word_size);
+          it = BrotliTrieFind(&dedup, word, word_size);
+          if (!it || it->idx_ > ix) {
+            uint32_t key = Hash(word, NUM_HASH_BITS);
+            if (!BrotliTrieAdd(m, 0, ix, word, word_size, &dedup)) {
+              return BROTLI_FALSE;
+            }
+            BROTLI_ENSURE_CAPACITY_APPEND(m, DictWord, words_by_hash[key],
+                words_by_hash_capacity[key], words_by_hash_size[key],
+                MakeDictWord(l, BROTLI_TRANSFORM_UPPERCASE_ALL, idx));
+            ++total;
+          }
+        }
+      }
+    }
+  }
+
+  dict_words = (DictWord*)BrotliAllocate(m,
+      sizeof(*dict->dict_words) * (total + 1));
+  buckets = (uint16_t*)BrotliAllocate(m,
+      sizeof(*dict->buckets) * NUM_HASH_BUCKETS);
+  if (BROTLI_IS_OOM(m)) return BROTLI_FALSE;
+  dict->dict_words_alloc_size_ = total + 1;
+  dict->dict_words = dict->dict_words_data_ = dict_words;
+  dict->buckets_alloc_size_ = NUM_HASH_BUCKETS;
+  dict->buckets = dict->buckets_data_ = buckets;
+
+  /* Unused; makes offsets start from 1. */
+  dict_words[0] = MakeDictWord(0, 0, 0);
+  total = 1;
+  for (i = 0; i < NUM_HASH_BUCKETS; ++i) {
+    size_t num_words = words_by_hash_size[i];
+    if (num_words > 0) {
+      buckets[i] = (uint16_t)(total);
+      memcpy(&dict_words[total], &words_by_hash[i][0],
+          sizeof(dict_words[0]) * num_words);
+      total += num_words;
+      dict_words[total - 1].len |= 0x80;
+    } else {
+      buckets[i] = 0;
+    }
+  }
+
+  for (i = 0; i < NUM_HASH_BUCKETS; ++i) {
+    BrotliFree(m, words_by_hash[i]);
+  }
+  BrotliFree(m, words_by_hash);
+  BrotliFree(m, words_by_hash_size);
+  BrotliFree(m, words_by_hash_capacity);
+  BrotliTrieFree(m, &dedup);
+
+  return BROTLI_TRUE;
+}
+
+static void BuildDictionaryHashTable(uint16_t* hash_table_words,
+    uint8_t* hash_table_lengths, const BrotliDictionary* dict) {
+  int j, len;
+  /* The order of the loops is such that in case of collision, words with
+     shorter length are preferred, and in case of same length, words with
+     smaller index. There is only a single word per bucket. */
+  /* TODO(lode): consider adding optional user-supplied frequency_map to use
+     for preferred words instead, this can make the encoder better for
+     quality 9 and below without affecting the decoder */
+  memset(hash_table_words, 0, sizeof(kStaticDictionaryHashWords));
+  memset(hash_table_lengths, 0, sizeof(kStaticDictionaryHashLengths));
+  for (len = SHARED_BROTLI_MAX_DICTIONARY_WORD_LENGTH;
+      len >= SHARED_BROTLI_MIN_DICTIONARY_WORD_LENGTH; --len) {
+    const size_t num_words = dict->size_bits_by_length[len] ?
+        (1u << dict->size_bits_by_length[len]) : 0;
+    for (j = (int)num_words - 1; j >= 0; --j) {
+      size_t offset = dict->offsets_by_length[len] +
+          (size_t)len * (size_t)j;
+      const uint8_t* word = &dict->data[offset];
+      const uint32_t key = Hash(word, 14);
+      int idx = (int)(key << 1) + (len < 8 ? 1 : 0);
+      BROTLI_DCHECK(idx < (int)NUM_HASH_BUCKETS);
+      hash_table_words[idx] = (uint16_t)j;
+      hash_table_lengths[idx] = (uint8_t)len;
+    }
+  }
+}
+
+static BROTLI_BOOL GenerateWordsHeavy(MemoryManager* m,
+    const BrotliTransforms* transforms,
+    BrotliEncoderDictionary* dict) {
+  int i, j, l;
+  for (j = (int)transforms->num_transforms - 1; j >= 0 ; --j) {
+    for (l = 0; l < 32; l++) {
+      int num = (int)((1u << dict->words->size_bits_by_length[l]) & ~1u);
+      for (i = 0; i < num; i++) {
+        uint8_t transformed[kTransformedBufferSize];
+        size_t size;
+        TransformedDictionaryWord(
+            (uint32_t)i, l, j, transforms, dict, transformed, &size);
+        if (size < 4) continue;
+        if (!BrotliTrieAdd(m, (uint8_t)l, (uint32_t)(i + num * j),
+            transformed, size, &dict->trie)) {
+          return BROTLI_FALSE;
+        }
+      }
+    }
+  }
+  return BROTLI_TRUE;
+}
+
+/* Computes cutoffTransformsCount (in count) and cutoffTransforms (in data) for
+   the custom transforms, where possible within the limits of the
+   cutoffTransforms encoding. The fast encoder uses this to do fast lookup for
+   transforms that remove the N last characters (OmitLast). */
+static void ComputeCutoffTransforms(
+    const BrotliTransforms* transforms,
+    uint32_t* count, uint64_t* data) {
+  int i;
+  /* The encoding in a 64-bit integer of transform N in the data is: (N << 2) +
+     ((cutoffTransforms >> (N * 6)) & 0x3F), so for example the identity
+     transform code must be 0-63, for N=1 the transform code must be 4-67, ...,
+     for N=9 it must be 36-99.
+     TODO(lode): consider a simple flexible uint8_t[10] instead of the uint64_t
+     for the cutoff transforms, so that shared dictionaries can have the
+     OmitLast transforms anywhere without loss. */
+  *count = 0;
+  *data = 0;
+  for (i = 0; i < BROTLI_TRANSFORMS_MAX_CUT_OFF + 1; i++) {
+    int idx = transforms->cutOffTransforms[i];
+    if (idx == -1) break;  /* Not found */
+    if (idx < (i << 2)) break;  /* Too small for the encoding */
+    if (idx >= (i << 2) + 64) break;  /* Too large for the encoding */
+    (*count)++;
+    *data |= (uint64_t)(((uint64_t)idx -
+        ((uint64_t)i << 2u)) << ((uint64_t)i * 6u));
+  }
+}
+
+static BROTLI_BOOL ComputeDictionary(MemoryManager* m, int quality,
+    const BrotliTransforms* transforms,
+    BrotliEncoderDictionary* current) {
+  int default_words = current->words == BrotliGetDictionary();
+  int default_transforms = transforms == BrotliGetTransforms();
+
+  if (default_words && default_transforms) {
+    /* hashes are already set to Brotli defaults */
+    return BROTLI_TRUE;
+  }
+
+  current->hash_table_data_words_ = (uint16_t*)BrotliAllocate(
+      m, sizeof(kStaticDictionaryHashWords));
+  current->hash_table_data_lengths_ = (uint8_t*)BrotliAllocate(
+      m, sizeof(kStaticDictionaryHashLengths));
+  if (BROTLI_IS_OOM(m)) return BROTLI_FALSE;
+  current->hash_table_words = current->hash_table_data_words_;
+  current->hash_table_lengths = current->hash_table_data_lengths_;
+
+  BuildDictionaryHashTable(current->hash_table_data_words_,
+      current->hash_table_data_lengths_, current->words);
+
+  ComputeCutoffTransforms(transforms,
+      &current->cutoffTransformsCount, &current->cutoffTransforms);
+
+  /* Only compute the data for slow encoder if the requested quality is high
+     enough to need it */
+  if (quality >= ZOPFLIFICATION_QUALITY) {
+    if (!BuildDictionaryLut(m, transforms, current)) return BROTLI_FALSE;
+
+    /* For the built-in Brotli transforms, there is a hard-coded function to
+       handle all transforms, but for custom transforms, we use the following
+       large hammer instead */
+    current->has_words_heavy = !default_transforms;
+    if (current->has_words_heavy) {
+      if (!GenerateWordsHeavy(m, transforms, current)) return BROTLI_FALSE;
+    }
+  }
+
+  return BROTLI_TRUE;
+}
+#endif  /* BROTLI_EXPERIMENTAL */
+
+void BrotliInitSharedEncoderDictionary(SharedEncoderDictionary* dict) {
+  dict->magic = kSharedDictionaryMagic;
+
+  dict->compound.num_chunks = 0;
+  dict->compound.total_size = 0;
+  dict->compound.chunk_offsets[0] = 0;
+  dict->compound.num_prepared_instances_ = 0;
+
+  dict->contextual.context_based = 0;
+  dict->contextual.num_dictionaries = 1;
+  dict->contextual.instances_ = 0;
+  dict->contextual.num_instances_ = 1;  /* The instance_ field */
+  dict->contextual.dict[0] = &dict->contextual.instance_;
+  InitEncoderDictionary(&dict->contextual.instance_);
+  dict->contextual.instance_.parent = &dict->contextual;
+
+  dict->max_quality = BROTLI_MAX_QUALITY;
+}
+
+#if defined(BROTLI_EXPERIMENTAL)
+/* TODO(eustas): make sure that tooling will warn user if not all the cutoff
+   transforms are available (for low-quality encoder). */
+static BROTLI_BOOL InitCustomSharedEncoderDictionary(
+    MemoryManager* m, const BrotliSharedDictionary* decoded_dict,
+    int quality, SharedEncoderDictionary* dict) {
+  ContextualEncoderDictionary* contextual;
+  CompoundDictionary* compound;
+  BrotliEncoderDictionary* instances;
+  int i;
+  BrotliInitSharedEncoderDictionary(dict);
+
+  contextual = &dict->contextual;
+  compound = &dict->compound;
+
+  for (i = 0; i < (int)decoded_dict->num_prefix; i++) {
+    PreparedDictionary* prepared = CreatePreparedDictionary(m,
+        decoded_dict->prefix[i], decoded_dict->prefix_size[i]);
+    AttachPreparedDictionary(compound, prepared);
+    /* remember for cleanup */
+    compound->prepared_instances_[
+        compound->num_prepared_instances_++] = prepared;
+  }
+
+  dict->max_quality = quality;
+  contextual->context_based = decoded_dict->context_based;
+  if (decoded_dict->context_based) {
+    memcpy(contextual->context_map, decoded_dict->context_map,
+        SHARED_BROTLI_NUM_DICTIONARY_CONTEXTS);
+  }
+
+  contextual->num_dictionaries = decoded_dict->num_dictionaries;
+  contextual->num_instances_ = decoded_dict->num_dictionaries;
+  if (contextual->num_instances_ == 1) {
+    instances = &contextual->instance_;
+  } else {
+    contextual->instances_ = (BrotliEncoderDictionary*)
+        BrotliAllocate(m, sizeof(*contextual->instances_) *
+        contextual->num_instances_);
+    if (BROTLI_IS_OOM(m)) return BROTLI_FALSE;
+    instances = contextual->instances_;
+  }
+  for (i = 0; i < (int)contextual->num_instances_; i++) {
+    BrotliEncoderDictionary* current = &instances[i];
+    InitEncoderDictionary(current);
+    current->parent = &dict->contextual;
+    if (decoded_dict->words[i] == BrotliGetDictionary()) {
+      current->words = BrotliGetDictionary();
+    } else {
+      current->words_instance_ = (BrotliDictionary*)BrotliAllocate(
+          m, sizeof(BrotliDictionary));
+      if (BROTLI_IS_OOM(m)) return BROTLI_FALSE;
+      *current->words_instance_ = *decoded_dict->words[i];
+      current->words = current->words_instance_;
+    }
+    current->num_transforms =
+        (uint32_t)decoded_dict->transforms[i]->num_transforms;
+    if (!ComputeDictionary(
+        m, quality, decoded_dict->transforms[i], current)) {
+      return BROTLI_FALSE;
+    }
+
+    contextual->dict[i] = current;
+  }
+
+  return BROTLI_TRUE;  /* success */
+}
+
+BROTLI_BOOL BrotliInitCustomSharedEncoderDictionary(
+    MemoryManager* m, const uint8_t* encoded_dict, size_t size,
+    int quality, SharedEncoderDictionary* dict) {
+  BROTLI_BOOL success = BROTLI_FALSE;
+  BrotliSharedDictionary* decoded_dict = BrotliSharedDictionaryCreateInstance(
+      m->alloc_func, m->free_func, m->opaque);
+  if (!decoded_dict) {  /* OOM */
+    return BROTLI_FALSE;
+  }
+  success = BrotliSharedDictionaryAttach(
+      decoded_dict, BROTLI_SHARED_DICTIONARY_SERIALIZED, size, encoded_dict);
+  if (success) {
+    success = InitCustomSharedEncoderDictionary(m,
+        decoded_dict, quality, dict);
+  }
+  BrotliSharedDictionaryDestroyInstance(decoded_dict);
+  return success;
+}
+#endif  /* BROTLI_EXPERIMENTAL */
+
+void BrotliCleanupSharedEncoderDictionary(MemoryManager* m,
+                                          SharedEncoderDictionary* dict) {
+  size_t i;
+  for (i = 0; i < dict->compound.num_prepared_instances_; i++) {
+    DestroyPreparedDictionary(m,
+        (PreparedDictionary*)dict->compound.prepared_instances_[i]);
+  }
+  if (dict->contextual.num_instances_ == 1) {
+    BrotliDestroyEncoderDictionary(m, &dict->contextual.instance_);
+  } else if (dict->contextual.num_instances_ > 1) {
+    for (i = 0; i < dict->contextual.num_instances_; i++) {
+      BrotliDestroyEncoderDictionary(m, &dict->contextual.instances_[i]);
+    }
+    BrotliFree(m, dict->contextual.instances_);
+  }
+}
+
+ManagedDictionary* BrotliCreateManagedDictionary(
+    brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque) {
+  ManagedDictionary* result = (ManagedDictionary*)BrotliBootstrapAlloc(
+      sizeof(ManagedDictionary), alloc_func, free_func, opaque);
+  if (result == NULL) return NULL;
+
+  result->magic = kManagedDictionaryMagic;
+  BrotliInitMemoryManager(
+      &result->memory_manager_, alloc_func, free_func, opaque);
+  result->dictionary = NULL;
+
+  return result;
+}
+
+void BrotliDestroyManagedDictionary(ManagedDictionary* dictionary) {
+  if (!dictionary) return;
+  BrotliBootstrapFree(dictionary, &dictionary->memory_manager_);
+}
+
+/* Escalate internal functions visibility; for testing purposes only. */
+#if defined(BROTLI_TEST)
+void InitEncoderDictionaryForTest(BrotliEncoderDictionary*);
+void InitEncoderDictionaryForTest(BrotliEncoderDictionary* d) {
+  InitEncoderDictionary(d);
+}
+#endif
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif