Update decoder.

* Reduce memory usage
 * Update API documentation
 * Remove deprecated API
 * Move non-API declatarions from decode.h
 * Remove streams
 * Add more debug logging
 * Fix shift in BrotliBitReaderUnload
 * Allocate ringbuffer at later stages
 * Sort / fix includes
 * Fix whitespaces
 * Eliminate dead code
 * Drive-by code simplifications

dec/Makefile

@@ -4,7 +4,7 @@ include ../shared.mk
 
 CFLAGS += -Wall
 
-OBJS = bit_reader.o decode.o dictionary.o huffman.o state.o streams.o
+OBJS = bit_reader.o decode.o dictionary.o huffman.o state.o
 
 all : $(OBJS)
 

dec/bit_reader.c

@@ -6,10 +6,10 @@
 
 /* Bit reading helpers */
 
-#include <stdlib.h>
-
 #include "./bit_reader.h"
+
 #include "./port.h"
+#include "./types.h"
 
 #if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {

dec/bit_reader.h

@@ -9,8 +9,8 @@
 #ifndef BROTLI_DEC_BIT_READER_H_
 #define BROTLI_DEC_BIT_READER_H_
 
-#include <stdio.h>
+#include <string.h>  /* memcpy */
-#include <string.h>
+
 #include "./port.h"
 #include "./types.h"
 
@@ -283,7 +283,11 @@ static BROTLI_INLINE void BrotliBitReaderUnload(BrotliBitReader* br) {
   uint32_t unused_bits = unused_bytes << 3;
   br->avail_in += unused_bytes;
   br->next_in -= unused_bytes;
-  br->val_ <<= unused_bits;
+  if (unused_bits == sizeof(br->val_) << 3) {
+    br->val_ = 0;
+  } else {
+    br->val_ <<= unused_bits;
+  }
   br->bit_pos_ += unused_bits;
 }
 
@@ -349,9 +353,7 @@ static BROTLI_INLINE int BrotliJumpToByteBoundary(BrotliBitReader* br) {
 static BROTLI_INLINE int BrotliPeekByte(BrotliBitReader* br, size_t offset) {
   uint32_t available_bits = BrotliGetAvailableBits(br);
   size_t bytes_left = available_bits >> 3;
-  if (available_bits & 7) {
+  BROTLI_DCHECK((available_bits & 7) == 0);
-    return -1;
-  }
   if (offset < bytes_left) {
     return (BrotliGetBitsUnmasked(br) >> (unsigned)(offset << 3)) & 0xFF;
   }

dec/decode.c

@@ -4,26 +4,42 @@
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
 
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include "./bit_reader.h"
-#include "./context.h"
 #include "./decode.h"
-#include "./dictionary.h"
-#include "./port.h"
-#include "./transform.h"
-#include "./huffman.h"
-#include "./prefix.h"
 
 #ifdef __ARM_NEON__
 #include <arm_neon.h>
 #endif
 
+#include <stdio.h>  /* printf (debug output) */
+#include <stdlib.h>  /* free, malloc */
+#include <string.h>  /* memcpy, memset */
+
+#include "./bit_reader.h"
+#include "./context.h"
+#include "./dictionary.h"
+#include "./huffman.h"
+#include "./port.h"
+#include "./prefix.h"
+#include "./transform.h"
+
 #if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {
 #endif
 
+/* BROTLI_FAILURE macro unwraps to BROTLI_RESULT_ERROR in non-debug build. */
+/* In debug build it dumps file name, line and pretty function name. */
+#if defined(_MSC_VER) || !defined(BROTLI_DEBUG)
+#define BROTLI_FAILURE() BROTLI_RESULT_ERROR
+#else
+#define BROTLI_FAILURE() \
+    BrotliFailure(__FILE__, __LINE__, __PRETTY_FUNCTION__)
+static inline BrotliResult BrotliFailure(const char *f, int l, const char *fn) {
+  fprintf(stderr, "ERROR at %s:%d (%s)\n", f, l, fn);
+  fflush(stderr);
+  return BROTLI_RESULT_ERROR;
+}
+#endif
+
 #ifdef BROTLI_DECODE_DEBUG
 #define BROTLI_LOG_UINT(name)                                    \
   printf("[%s] %s = %lu\n", __func__, #name, (unsigned long)(name))
@@ -239,7 +255,7 @@ static BrotliResult BROTLI_NOINLINE DecodeMetaBlockLength(BrotliState* s,
         /* No break, transit to the next state. */
 
       case BROTLI_STATE_METABLOCK_HEADER_UNCOMPRESSED:
-        if (!s->is_last_metablock && !s->is_metadata) {
+        if (!s->is_last_metablock) {
           if (!BrotliSafeReadBits(br, 1, &bits)) {
             return BROTLI_RESULT_NEEDS_MORE_INPUT;
           }
@@ -283,9 +299,9 @@ static BrotliResult BROTLI_NOINLINE DecodeMetaBlockLength(BrotliState* s,
           }
           s->meta_block_remaining_len |= (int)(bits << (i * 8));
         }
-        s->substate_metablock_header =
+        ++s->meta_block_remaining_len;
-            BROTLI_STATE_METABLOCK_HEADER_UNCOMPRESSED;
+        s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NONE;
-        break;
+        return BROTLI_RESULT_SUCCESS;
 
       default:
         return BROTLI_FAILURE();
@@ -473,6 +489,8 @@ static BROTLI_INLINE void ProcessSingleCodeLength(uint32_t code_len,
     *prev_code_len = code_len;
     *space -= 32768U >> code_len;
     code_length_histo[code_len]++;
+    BROTLI_LOG(("[ReadHuffmanCode] code_length[%d] = %d\n",
+                *symbol, code_len));
   }
   (*symbol)++;
 }
@@ -513,6 +531,8 @@ static BROTLI_INLINE void ProcessRepeatedCodeLength(uint32_t code_len,
     *space = 0xFFFFF;
     return;
   }
+  BROTLI_LOG(("[ReadHuffmanCode] code_length[%d..%d] = %d\n",
+              *symbol, *symbol + repeat_delta - 1, *repeat_code_len));
   if (*repeat_code_len != 0) {
     unsigned last = *symbol + repeat_delta;
     int next = next_symbol[*repeat_code_len];
@@ -1018,9 +1038,9 @@ rleCode:
       s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_NONE;
       return BROTLI_RESULT_SUCCESS;
     }
+    default:
+      return BROTLI_FAILURE();
   }
-
-  return BROTLI_FAILURE();
 }
 
 /* Decodes a command or literal and updates block type ringbuffer.
@@ -1028,9 +1048,10 @@ rleCode:
 static BROTLI_INLINE int DecodeBlockTypeAndLength(int safe,
     BrotliState* s, int tree_type) {
   uint32_t max_block_type = s->num_block_types[tree_type];
-  int tree_offset = tree_type * BROTLI_HUFFMAN_MAX_TABLE_SIZE;
+  const HuffmanCode* type_tree = &s->block_type_trees[
-  const HuffmanCode* type_tree = &s->block_type_trees[tree_offset];
+      tree_type * BROTLI_HUFFMAN_MAX_SIZE_258];
-  const HuffmanCode* len_tree = &s->block_len_trees[tree_offset];
+  const HuffmanCode* len_tree = &s->block_len_trees[
+      tree_type * BROTLI_HUFFMAN_MAX_SIZE_26];
   BrotliBitReader* br = &s->br;
   uint32_t* ringbuffer = &s->block_type_rb[tree_type * 2];
   uint32_t block_type;
@@ -1152,7 +1173,7 @@ static BrotliResult WriteRingBuffer(size_t* available_out, uint8_t** next_out,
   *available_out -= num_written;
   BROTLI_LOG_UINT(to_write);
   BROTLI_LOG_UINT(num_written);
-  s->partial_pos_out += (size_t)num_written;
+  s->partial_pos_out += num_written;
   *total_out = s->partial_pos_out;
   if (num_written < to_write) {
     return BROTLI_RESULT_NEEDS_MORE_OUTPUT;
@@ -1160,9 +1181,48 @@ static BrotliResult WriteRingBuffer(size_t* available_out, uint8_t** next_out,
   return BROTLI_RESULT_SUCCESS;
 }
 
+/* Allocates ringbuffer.
+
+  s->ringbuffer_size MUST be updated by BrotliCalculateRingBufferSize before
+  this function is called.
+
+   Last two bytes of ringbuffer are initialized to 0, so context calculation
+   could be done uniformly for the first two and all other positions.
+
+   Custom dictionary, if any, is copied to the end of ringbuffer.
+*/
+static int BROTLI_NOINLINE BrotliAllocateRingBuffer(BrotliState* s) {
+  /* We need the slack region for the following reasons:
+      - doing up to two 16-byte copies for fast backward copying
+      - inserting transformed dictionary word (5 prefix + 24 base + 8 suffix) */
+  static const int kRingBufferWriteAheadSlack = 42;
+  s->ringbuffer = (uint8_t*)BROTLI_ALLOC(s, (size_t)(s->ringbuffer_size +
+      kRingBufferWriteAheadSlack));
+  if (s->ringbuffer == 0) {
+    return 0;
+  }
+
+  s->ringbuffer_end = s->ringbuffer + s->ringbuffer_size;
+
+  s->ringbuffer[s->ringbuffer_size - 2] = 0;
+  s->ringbuffer[s->ringbuffer_size - 1] = 0;
+
+  if (s->custom_dict) {
+    memcpy(&s->ringbuffer[(-s->custom_dict_size) & s->ringbuffer_mask],
+                          s->custom_dict, (size_t)s->custom_dict_size);
+  }
+
+  return 1;
+}
+
 static BrotliResult BROTLI_NOINLINE CopyUncompressedBlockToOutput(
     size_t* available_out, uint8_t** next_out, size_t* total_out,
     BrotliState* s) {
+  /* TODO: avoid allocation for single uncompressed block. */
+  if (!s->ringbuffer && !BrotliAllocateRingBuffer(s)) {
+    return BROTLI_FAILURE();
+  }
+
   /* State machine */
   for (;;) {
     switch (s->substate_uncompressed) {
@@ -1185,7 +1245,6 @@ static BrotliResult BROTLI_NOINLINE CopyUncompressedBlockToOutput(
           return BROTLI_RESULT_NEEDS_MORE_INPUT;
         }
         s->substate_uncompressed = BROTLI_STATE_UNCOMPRESSED_WRITE;
-        /*s->partial_pos_rb += (size_t)s->ringbuffer_size;*/
         /* No break, continue to next state */
       }
       case BROTLI_STATE_UNCOMPRESSED_WRITE: {
@@ -1231,21 +1290,15 @@ int BrotliDecompressedSize(size_t encoded_size,
   return (next_block_header != -1) && ((next_block_header & 3) == 3);
 }
 
-/* Allocates the smallest feasible ring buffer.
+/* Calculates the smallest feasible ring buffer.
 
    If we know the data size is small, do not allocate more ringbuffer
    size than needed to reduce memory usage.
 
-   This method is called before the first non-empty non-metadata block is
+   When this method is called, metablock size and flags MUST be decoded.
-   processed. When this method is called, metablock size and flags MUST be
-   decoded.
 */
-static int BROTLI_NOINLINE BrotliAllocateRingBuffer(BrotliState* s,
+static void BROTLI_NOINLINE BrotliCalculateRingBufferSize(BrotliState* s,
     BrotliBitReader* br) {
-  /* We need the slack region for the following reasons:
-      - doing up to two 16-byte copies for fast backward copying
-      - inserting transformed dictionary word (5 prefix + 24 base + 8 suffix) */
-  static const int kRingBufferWriteAheadSlack = 42;
   int is_last = s->is_last_metablock;
   s->ringbuffer_size = 1 << s->window_bits;
 
@@ -1274,20 +1327,6 @@ static int BROTLI_NOINLINE BrotliAllocateRingBuffer(BrotliState* s,
   }
 
   s->ringbuffer_mask = s->ringbuffer_size - 1;
-  s->ringbuffer = (uint8_t*)BROTLI_ALLOC(s, (size_t)(s->ringbuffer_size +
-      kRingBufferWriteAheadSlack + kBrotliMaxDictionaryWordLength));
-  if (s->ringbuffer == 0) {
-    return 0;
-  }
-  s->ringbuffer_end = s->ringbuffer + s->ringbuffer_size;
-  s->ringbuffer[s->ringbuffer_size - 2] = 0;
-  s->ringbuffer[s->ringbuffer_size - 1] = 0;
-  if (s->custom_dict) {
-    memcpy(&s->ringbuffer[(-s->custom_dict_size) & s->ringbuffer_mask],
-                          s->custom_dict, (size_t)s->custom_dict_size);
-  }
-
-  return 1;
 }
 
 /* Reads 1..256 2-bit context modes. */
@@ -1461,13 +1500,6 @@ static BROTLI_INLINE int SafeReadCommand(BrotliState* s, BrotliBitReader* br,
   return ReadCommandInternal(1, s, br, insert_length);
 }
 
-static BROTLI_INLINE int WarmupBitReader(int safe, BrotliBitReader* const br) {
-  if (safe) {
-    return 1;
-  }
-  return BrotliWarmupBitReader(br);
-}
-
 static BROTLI_INLINE int CheckInputAmount(int safe,
     BrotliBitReader* const br, size_t num) {
   if (safe) {
@@ -1494,10 +1526,13 @@ static BROTLI_INLINE BrotliResult ProcessCommandsInternal(int safe,
   BrotliResult result = BROTLI_RESULT_SUCCESS;
   BrotliBitReader* br = &s->br;
 
-  if (!CheckInputAmount(safe, br, 28) || !WarmupBitReader(safe, br)) {
+  if (!CheckInputAmount(safe, br, 28)) {
     result = BROTLI_RESULT_NEEDS_MORE_INPUT;
     goto saveStateAndReturn;
   }
+  if (!safe) {
+    BROTLI_UNUSED(BrotliWarmupBitReader(br));
+  }
 
   /* Jump into state machine. */
   if (s->state == BROTLI_STATE_COMMAND_BEGIN) {
@@ -1527,9 +1562,8 @@ CommandBegin:
   }
   /* Read the insert/copy length in the command */
   BROTLI_SAFE(ReadCommand(s, br, &i));
-  BROTLI_LOG_UINT(i);
+  BROTLI_LOG(("[ProcessCommandsInternal] pos = %d insert = %d copy = %d\n",
-  BROTLI_LOG_UINT(s->copy_length);
+              pos, i, s->copy_length));
-  BROTLI_LOG_UINT(s->distance_code);
   if (i == 0) {
     goto CommandPostDecodeLiterals;
   }
@@ -1615,6 +1649,7 @@ CommandInner:
       }
     } while (--i != 0);
   }
+  BROTLI_LOG_UINT(s->meta_block_remaining_len);
   if (s->meta_block_remaining_len <= 0) {
     s->state = BROTLI_STATE_METABLOCK_DONE;
     goto saveStateAndReturn;
@@ -1635,7 +1670,8 @@ CommandPostDecodeLiterals:
   }
   BROTLI_SAFE(ReadDistance(s, br));
 postReadDistance:
-  BROTLI_LOG_UINT(s->distance_code);
+  BROTLI_LOG(("[ProcessCommandsInternal] pos = %d distance = %d\n",
+              pos, s->distance_code));
   if (s->max_distance != s->max_backward_distance) {
     if (pos < s->max_backward_distance_minus_custom_dict_size) {
       s->max_distance = pos + s->custom_dict_size;
@@ -1649,7 +1685,7 @@ postReadDistance:
   if (s->distance_code > s->max_distance) {
     if (i >= kBrotliMinDictionaryWordLength &&
         i <= kBrotliMaxDictionaryWordLength) {
-      int offset = kBrotliDictionaryOffsetsByLength[i];
+      int offset = (int)kBrotliDictionaryOffsetsByLength[i];
       int word_id = s->distance_code - s->max_distance - 1;
       uint32_t shift = kBrotliDictionarySizeBitsByLength[i];
       int mask = (int)BitMask(shift);
@@ -1734,6 +1770,7 @@ postReadDistance:
       }
     }
   }
+  BROTLI_LOG_UINT(s->meta_block_remaining_len);
   if (s->meta_block_remaining_len <= 0) {
     /* Next metablock, if any */
     s->state = BROTLI_STATE_METABLOCK_DONE;
@@ -1813,113 +1850,6 @@ BrotliResult BrotliDecompressBuffer(size_t encoded_size,
   return result;
 }
 
-BrotliResult BrotliDecompress(BrotliInput input, BrotliOutput output) {
-  BrotliState s;
-  BrotliResult result;
-  BrotliStateInit(&s);
-  result = BrotliDecompressStreaming(input, output, 1, &s);
-  if (result == BROTLI_RESULT_NEEDS_MORE_INPUT) {
-    /* Not ok: it didn't finish even though this is a non-streaming function. */
-    result = BROTLI_FAILURE();
-  }
-  BrotliStateCleanup(&s);
-  return result;
-}
-
-BrotliResult BrotliDecompressBufferStreaming(size_t* available_in,
-                                             const uint8_t** next_in,
-                                             int finish,
-                                             size_t* available_out,
-                                             uint8_t** next_out,
-                                             size_t* total_out,
-                                             BrotliState* s) {
-  BrotliResult result = BrotliDecompressStream(available_in, next_in,
-      available_out, next_out, total_out, s);
-  if (finish && result == BROTLI_RESULT_NEEDS_MORE_INPUT) {
-    result = BROTLI_FAILURE();
-  }
-  return result;
-}
-
-BrotliResult BrotliDecompressStreaming(BrotliInput input, BrotliOutput output,
-                                       int finish, BrotliState* s) {
-  const size_t kBufferSize = 65536;
-  BrotliResult result;
-  uint8_t* input_buffer;
-  uint8_t* output_buffer;
-  size_t avail_in;
-  const uint8_t* next_in;
-  size_t total_out;
-
-  if (s->legacy_input_buffer == 0) {
-    s->legacy_input_buffer = (uint8_t*)BROTLI_ALLOC(s, kBufferSize);
-  }
-  if (s->legacy_output_buffer == 0) {
-    s->legacy_output_buffer = (uint8_t*)BROTLI_ALLOC(s, kBufferSize);
-  }
-  if (s->legacy_input_buffer == 0 || s->legacy_output_buffer == 0) {
-    return BROTLI_FAILURE();
-  }
-  input_buffer = s->legacy_input_buffer;
-  output_buffer = s->legacy_output_buffer;
-
-  /* Push remaining output. */
-  if (s->legacy_output_len > s->legacy_output_pos) {
-    size_t to_write = s->legacy_output_len - s->legacy_output_pos;
-    int num_written = BrotliWrite(
-        output, output_buffer + s->legacy_output_pos, to_write);
-    if (num_written < 0) {
-      return BROTLI_FAILURE();
-    }
-    s->legacy_output_pos += (size_t)num_written;
-    if ((size_t)num_written < to_write) {
-      return BROTLI_RESULT_NEEDS_MORE_OUTPUT;
-    }
-  }
-  s->legacy_output_pos = 0;
-
-  avail_in = s->legacy_input_len - s->legacy_input_pos;
-  next_in = input_buffer + s->legacy_input_pos;
-
-  while (1) {
-    size_t to_write;
-    int num_written;
-    size_t avail_out = kBufferSize;
-    uint8_t* next_out = output_buffer;
-    result = BrotliDecompressStream(&avail_in, &next_in,
-        &avail_out, &next_out, &total_out, s);
-    s->legacy_input_pos = (size_t)(next_out - input_buffer);
-    to_write = (size_t)(next_out - output_buffer);
-    num_written = BrotliWrite(output, output_buffer, to_write);
-    if (num_written < 0) {
-      return BROTLI_FAILURE();
-    }
-    if ((size_t)num_written < to_write) {
-      s->legacy_output_len = to_write;
-      s->legacy_output_pos = (size_t)num_written;
-      return BROTLI_RESULT_NEEDS_MORE_OUTPUT;
-    }
-    if (result == BROTLI_RESULT_NEEDS_MORE_INPUT) {
-      int num_read = BrotliRead(input, input_buffer, kBufferSize);
-      if (num_read < 0 || (num_read == 0 && finish)) {
-        return BROTLI_FAILURE();
-      }
-      if (num_read == 0) {
-        s->legacy_input_len = 0;
-        s->legacy_input_pos = 0;
-        return BROTLI_RESULT_NEEDS_MORE_INPUT;
-      }
-      avail_in = (size_t)num_read;
-      next_in = input_buffer;
-      s->legacy_input_len = avail_in;
-      s->legacy_input_pos = 0;
-    } else if (result != BROTLI_RESULT_NEEDS_MORE_OUTPUT) {
-      /* Success or failure. */
-      return result;
-    }
-  }
-}
-
 /* Invariant: input stream is never overconsumed:
     * invalid input implies that the whole stream is invalid -> any amount of
       input could be read and discarded
@@ -2030,13 +1960,14 @@ BrotliResult BrotliDecompressStream(size_t* available_in,
 
         /* Allocate memory for both block_type_trees and block_len_trees. */
         s->block_type_trees = (HuffmanCode*)BROTLI_ALLOC(s,
-            6 * BROTLI_HUFFMAN_MAX_TABLE_SIZE * sizeof(HuffmanCode));
+            sizeof(HuffmanCode) * 3 *
+                (BROTLI_HUFFMAN_MAX_SIZE_258 + BROTLI_HUFFMAN_MAX_SIZE_26));
         if (s->block_type_trees == 0) {
           result = BROTLI_FAILURE();
           break;
         }
         s->block_len_trees = s->block_type_trees +
-            3 * BROTLI_HUFFMAN_MAX_TABLE_SIZE;
+            3 * BROTLI_HUFFMAN_MAX_SIZE_258;
 
         s->state = BROTLI_STATE_METABLOCK_BEGIN;
         /* No break, continue to next state */
@@ -2069,10 +2000,7 @@ BrotliResult BrotliDecompressStream(size_t* available_in,
           break;
         }
         if (!s->ringbuffer) {
-          if (!BrotliAllocateRingBuffer(s, br)) {
+          BrotliCalculateRingBufferSize(s, br);
-            result = BROTLI_FAILURE();
-            break;
-          }
         }
         if (s->is_uncompressed) {
           s->state = BROTLI_STATE_UNCOMPRESSED;
@@ -2124,7 +2052,7 @@ BrotliResult BrotliDecompressStream(size_t* available_in,
         s->state = BROTLI_STATE_HUFFMAN_CODE_1;
         /* No break, continue to next state */
       case BROTLI_STATE_HUFFMAN_CODE_1: {
-        int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_TABLE_SIZE;
+        int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_SIZE_258;
         result = ReadHuffmanCode(s->num_block_types[s->loop_counter] + 2,
             &s->block_type_trees[tree_offset], NULL, s);
         if (result != BROTLI_RESULT_SUCCESS) break;
@@ -2132,7 +2060,7 @@ BrotliResult BrotliDecompressStream(size_t* available_in,
         /* No break, continue to next state */
       }
       case BROTLI_STATE_HUFFMAN_CODE_2: {
-        int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_TABLE_SIZE;
+        int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_SIZE_26;
         result = ReadHuffmanCode(kNumBlockLengthCodes,
             &s->block_len_trees[tree_offset], NULL, s);
         if (result != BROTLI_RESULT_SUCCESS) break;
@@ -2140,7 +2068,7 @@ BrotliResult BrotliDecompressStream(size_t* available_in,
         /* No break, continue to next state */
       }
       case BROTLI_STATE_HUFFMAN_CODE_3: {
-        int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_TABLE_SIZE;
+        int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_SIZE_26;
         if (!SafeReadBlockLength(s, &s->block_length[s->loop_counter],
             &s->block_len_trees[tree_offset], br)) {
           result = BROTLI_RESULT_NEEDS_MORE_INPUT;
@@ -2212,7 +2140,7 @@ BrotliResult BrotliDecompressStream(size_t* available_in,
                                      s->num_literal_htrees);
           BrotliHuffmanTreeGroupInit(s, &s->insert_copy_hgroup,
                                      kNumInsertAndCopyCodes,
-              s->num_block_types[1]);
+                                     s->num_block_types[1]);
           BrotliHuffmanTreeGroupInit(s, &s->distance_hgroup, num_distance_codes,
                                      s->num_dist_htrees);
           if (s->literal_hgroup.codes == 0 ||
@@ -2252,6 +2180,10 @@ BrotliResult BrotliDecompressStream(size_t* available_in,
               &kContextLookup[kContextLookupOffsets[context_mode + 1]];
           s->htree_command = s->insert_copy_hgroup.htrees[0];
           s->literal_htree = s->literal_hgroup.htrees[s->literal_htree_index];
+          if (!s->ringbuffer && !BrotliAllocateRingBuffer(s)) {
+            result = BROTLI_FAILURE();
+            break;
+          }
           s->state = BROTLI_STATE_COMMAND_BEGIN;
         }
         break;
@@ -2276,7 +2208,7 @@ BrotliResult BrotliDecompressStream(size_t* available_in,
         s->max_distance = s->max_backward_distance;
         if (s->state == BROTLI_STATE_COMMAND_POST_WRITE_1) {
           memcpy(s->ringbuffer, s->ringbuffer_end, (size_t)s->pos);
-          if (s->meta_block_remaining_len <= 0) {
+          if (s->meta_block_remaining_len == 0) {
             /* Next metablock, if any */
             s->state = BROTLI_STATE_METABLOCK_DONE;
           } else {
@@ -2287,7 +2219,7 @@ BrotliResult BrotliDecompressStream(size_t* available_in,
           s->state = BROTLI_STATE_COMMAND_POST_WRAP_COPY;
         } else {  /* BROTLI_STATE_COMMAND_INNER_WRITE */
           if (s->loop_counter == 0) {
-            if (s->meta_block_remaining_len <= 0) {
+            if (s->meta_block_remaining_len == 0) {
               s->state = BROTLI_STATE_METABLOCK_DONE;
             } else {
               s->state = BROTLI_STATE_COMMAND_POST_DECODE_LITERALS;

dec/decode.h

@@ -10,7 +10,6 @@
 #define BROTLI_DEC_DECODE_H_
 
 #include "./state.h"
-#include "./streams.h"
 #include "./types.h"
 
 #if defined(__cplusplus) || defined(c_plusplus)
@@ -18,126 +17,57 @@ extern "C" {
 #endif
 
 typedef enum {
-  /* Decoding error, e.g. corrupt input or no memory */
+  /* Decoding error, e.g. corrupt input or memory allocation problem */
   BROTLI_RESULT_ERROR = 0,
-  /* Successfully completely done */
+  /* Decoding successfully completed */
   BROTLI_RESULT_SUCCESS = 1,
-  /* Partially done, but must be called again with more input */
+  /* Partially done; should be called again with more input */
   BROTLI_RESULT_NEEDS_MORE_INPUT = 2,
-  /* Partially done, but must be called again with more output */
+  /* Partially done; should be called again with more output */
   BROTLI_RESULT_NEEDS_MORE_OUTPUT = 3
 } BrotliResult;
 
-/* BROTLI_FAILURE macro unwraps to BROTLI_RESULT_ERROR in non-debug build. */
+/* Creates the instance of BrotliState and initializes it. |alloc_func| and
-/* In debug build it dumps file name, line and pretty function name. */
+   |free_func| MUST be both zero or both non-zero. In the case they are both
-#if defined(_MSC_VER) || !defined(BROTLI_DEBUG)
+   zero, default memory allocators are used. |opaque| is passed to |alloc_func|
-#define BROTLI_FAILURE() BROTLI_RESULT_ERROR
+   and |free_func| when they are called. */
-#else
-#define BROTLI_FAILURE() \
-    BrotliFailure(__FILE__, __LINE__, __PRETTY_FUNCTION__)
-static inline BrotliResult BrotliFailure(const char *f, int l, const char *fn) {
-  fprintf(stderr, "ERROR at %s:%d (%s)\n", f, l, fn);
-  fflush(stderr);
-  return BROTLI_RESULT_ERROR;
-}
-#endif
-
-/* Creates the instance of BrotliState and initializes it. alloc_func and
-   free_func MUST be both zero or both non-zero. In the case they are both zero,
-   default memory allocators are used. opaque parameter is passed to alloc_func
-   and free_func when they are called. */
 BrotliState* BrotliCreateState(
     brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque);
 
 /* Deinitializes and frees BrotliState instance. */
 void BrotliDestroyState(BrotliState* state);
 
-/* Sets *decoded_size to the decompressed size of the given encoded stream. */
+/* Sets |*decoded_size| to the decompressed size of the given encoded stream.
-/* This function only works if the encoded buffer has a single meta block, */
+   This function only works if the encoded buffer has a single meta block,
-/* or if it has two meta-blocks, where the first is uncompressed and the */
+   or if it has two meta-blocks, where the first is uncompressed and the
-/* second is empty. */
+   second is empty.
-/* Returns 1 on success, 0 on failure. */
+   Returns 1 on success, 0 on failure. */
 int BrotliDecompressedSize(size_t encoded_size,
                            const uint8_t* encoded_buffer,
                            size_t* decoded_size);
 
-/* Decompresses the data in encoded_buffer into decoded_buffer, and sets */
+/* Decompresses the data in |encoded_buffer| into |decoded_buffer|, and sets
-/* *decoded_size to the decompressed length. */
+   |*decoded_size| to the decompressed length. */
 BrotliResult BrotliDecompressBuffer(size_t encoded_size,
                                     const uint8_t* encoded_buffer,
                                     size_t* decoded_size,
                                     uint8_t* decoded_buffer);
 
-/* Same as above, but uses the specified input and output callbacks instead */
+/* Decompresses the data. Supports partial input and output.
-/* of reading from and writing to pre-allocated memory buffers. */
-/* DEPRECATED */
-BrotliResult BrotliDecompress(BrotliInput input, BrotliOutput output);
 
-/* Same as above, but supports the caller to call the decoder repeatedly with
+   Must be called with an allocated input buffer in |*next_in| and an allocated
-   partial data to support streaming. The state must be initialized with
+   output buffer in |*next_out|. The values |*available_in| and |*available_out|
-   BrotliStateInit and reused with every call for the same stream.
+   must specify the allocated size in |*next_in| and |*next_out| respectively.
-   Return values:
-   0: failure.
-   1: success, and done.
-   2: success so far, end not reached so should call again with more input.
-   The finish parameter is used as follows, for a series of calls with the
-   same state:
-   0: Every call except the last one must be called with finish set to 0. The
-      last call may have finish set to either 0 or 1. Only if finish is 0, can
-      the function return 2. It may also return 0 or 1, in that case no more
-      calls (even with finish 1) may be made.
-   1: Only the last call may have finish set to 1. It's ok to give empty input
-      if all input was already given to previous calls. It is also ok to have
-      only one single call in total, with finish 1, and with all input
-      available immediately. That matches the non-streaming case. If finish is
-      1, the function can only return 0 or 1, never 2. After a finish, no more
-      calls may be done.
-   After everything is done, the state must be cleaned with BrotliStateCleanup
-   to free allocated resources.
-   The given BrotliOutput must always accept all output and make enough space,
-   it returning a smaller value than the amount of bytes to write always results
-   in an error.
-*/
-/* DEPRECATED */
-BrotliResult BrotliDecompressStreaming(BrotliInput input, BrotliOutput output,
-                                       int finish, BrotliState* s);
 
-/* Same as above, but with memory buffers.
+   After each call, |*available_in| will be decremented by the amount of input
-   Must be called with an allocated input buffer in *next_in and an allocated
+   bytes consumed, and the |*next_in| pointer will be incremented by that
-   output buffer in *next_out. The values *available_in and *available_out
+   amount. Similarly, |*available_out| will be decremented by the amount of
-   must specify the allocated size in *next_in and *next_out respectively.
+   output bytes written, and the |*next_out| pointer will be incremented by that
-   The value *total_out must be 0 initially, and will be summed with the
+   amount. |total_out| will be set to the number of bytes decompressed since
-   amount of output bytes written after each call, so that at the end it
+   last state initialization.
-   gives the complete decoded size.
-   After each call, *available_in will be decremented by the amount of input
-   bytes consumed, and the *next_in pointer will be incremented by that amount.
-   Similarly, *available_out will be decremented by the amount of output
-   bytes written, and the *next_out pointer will be incremented by that
-   amount.
-
-   The input may be partial. With each next function call, *next_in and
-   *available_in must be updated to point to a next part of the compressed
-   input. The current implementation will always consume all input unless
-   an error occurs, so normally *available_in will always be 0 after
-   calling this function and the next adjacent part of input is desired.
-
-   In the current implementation, the function requires that there is enough
-   output buffer size to write all currently processed input, so
-   *available_out must be large enough. Since the function updates *next_out
-   each time, as long as the output buffer is large enough you can keep
-   reusing this variable. It is also possible to update *next_out and
-   *available_out yourself before a next call, e.g. to point to a new larger
-   buffer.
-*/
-/* DEPRECATED */
-BrotliResult BrotliDecompressBufferStreaming(size_t* available_in,
-                                             const uint8_t** next_in,
-                                             int finish,
-                                             size_t* available_out,
-                                             uint8_t** next_out,
-                                             size_t* total_out,
-                                             BrotliState* s);
 
+   Input is never overconsumed, so |next_in| and |available_in| could be passed
+   to the next consumer after decoding is complete. */
 BrotliResult BrotliDecompressStream(size_t* available_in,
                                     const uint8_t** next_in,
                                     size_t* available_out,
@@ -150,10 +80,10 @@ BrotliResult BrotliDecompressStream(size_t* available_in,
    Not to be confused with the built-in transformable dictionary of Brotli.
    The dictionary must exist in memory until decoding is done and is owned by
    the caller. To use:
-   -initialize state with BrotliStateInit
+    1) initialize state with BrotliStateInit
-   -use BrotliSetCustomDictionary
+    2) use BrotliSetCustomDictionary
-   -use BrotliDecompressBufferStreaming
+    3) use BrotliDecompressStream
-   -clean up with BrotliStateCleanup
+    4) clean up with BrotliStateCleanup
 */
 void BrotliSetCustomDictionary(
     size_t size, const uint8_t* dict, BrotliState* s);

dec/dictionary.h

@@ -17,7 +17,7 @@ extern "C" {
 
 extern const uint8_t kBrotliDictionary[122784];
 
-static const int kBrotliDictionaryOffsetsByLength[] = {
+static const uint32_t kBrotliDictionaryOffsetsByLength[] = {
      0,     0,     0,     0,     0,  4096,  9216, 21504, 35840, 44032,
  53248, 63488, 74752, 87040, 93696, 100864, 104704, 106752, 108928, 113536,
  115968, 118528, 119872, 121280, 122016,

dec/huffman.c

@@ -6,11 +6,12 @@
 
 /* Utilities for building Huffman decoding tables. */
 
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
 #include "./huffman.h"
+
+#include <string.h>  /* memcpy, memset */
+
 #include "./port.h"
+#include "./types.h"
 
 #if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {
@@ -237,7 +238,7 @@ uint32_t BrotliBuildHuffmanTable(HuffmanCode* root_table,
   for (len = root_bits + 1, step = 2; len <= max_length; ++len) {
     symbol = len - (BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1);
     for (; count[len] != 0; --count[len]) {
-      if (sub_key == (uint32_t)(BROTLI_REVERSE_BITS_LOWEST << 1)) {
+      if (sub_key == (BROTLI_REVERSE_BITS_LOWEST << 1U)) {
         table += table_size;
         table_bits = NextTableBitSize(count, len, root_bits);
         table_size = 1 << table_bits;

dec/huffman.h

@@ -20,9 +20,14 @@ extern "C" {
 /* For current format this constant equals to kNumInsertAndCopyCodes */
 #define BROTLI_HUFFMAN_MAX_CODE_LENGTHS_SIZE 704
 
-/* Maximum possible Huffman table size for an alphabet size of 704, max code
+/* Maximum possible Huffman table size for an alphabet size of (index * 32),
- * length 15 and root table bits 8. */
+ * max code length 15 and root table bits 8. */
-#define BROTLI_HUFFMAN_MAX_TABLE_SIZE 1080
+static const uint16_t kMaxHuffmanTableSize[] = {
+  256, 402, 436, 468, 500, 534, 566, 598, 630, 662, 694, 726, 758, 790, 822,
+  854, 886, 920, 952, 984, 1016, 1048, 1080};
+#define BROTLI_HUFFMAN_MAX_SIZE_26 396
+#define BROTLI_HUFFMAN_MAX_SIZE_258 632
+#define BROTLI_HUFFMAN_MAX_SIZE_272 646
 
 #define BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH 5
 

dec/prefix.h

@@ -11,6 +11,8 @@
 #ifndef BROTLI_DEC_PREFIX_H_
 #define BROTLI_DEC_PREFIX_H_
 
+#include "./types.h"
+
 /* Represents the range of values belonging to a prefix code: */
 /* [offset, offset + 2^nbits) */
 struct PrefixCodeRange {

dec/state.c

@@ -4,11 +4,12 @@
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
 
-#include "./huffman.h"
 #include "./state.h"
 
-#include <stdlib.h>
+#include <stdlib.h>  /* free, malloc */
-#include <string.h>
+
+#include "./huffman.h"
+#include "./types.h"
 
 #if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {
@@ -94,13 +95,6 @@ void BrotliStateInitWithCustomAllocators(BrotliState* s,
   s->symbol_lists = &s->symbols_lists_array[BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1];
 
   s->mtf_upper_bound = 255;
-
-  s->legacy_input_buffer = 0;
-  s->legacy_output_buffer = 0;
-  s->legacy_input_len = 0;
-  s->legacy_output_len = 0;
-  s->legacy_input_pos = 0;
-  s->legacy_output_pos = 0;
 }
 
 void BrotliStateMetablockBegin(BrotliState* s) {
@@ -150,8 +144,6 @@ void BrotliStateCleanup(BrotliState* s) {
 
   BROTLI_FREE(s, s->ringbuffer);
   BROTLI_FREE(s, s->block_type_trees);
-  BROTLI_FREE(s, s->legacy_input_buffer);
-  BROTLI_FREE(s, s->legacy_output_buffer);
 }
 
 int BrotliStateIsStreamStart(const BrotliState* s) {
@@ -166,9 +158,9 @@ int BrotliStateIsStreamEnd(const BrotliState* s) {
 void BrotliHuffmanTreeGroupInit(BrotliState* s, HuffmanTreeGroup* group,
     uint32_t alphabet_size, uint32_t ntrees) {
   /* Pack two allocations into one */
-  const size_t code_size =
+  const size_t max_table_size = kMaxHuffmanTableSize[(alphabet_size + 31) >> 5];
-      sizeof(HuffmanCode) * (size_t)(ntrees * BROTLI_HUFFMAN_MAX_TABLE_SIZE);
+  const size_t code_size = sizeof(HuffmanCode) * ntrees * max_table_size;
-  const size_t htree_size = sizeof(HuffmanCode*) * (size_t)ntrees;
+  const size_t htree_size = sizeof(HuffmanCode*) * ntrees;
   char *p = (char*)BROTLI_ALLOC(s, code_size + htree_size);
   group->alphabet_size = (uint16_t)alphabet_size;
   group->num_htrees = (uint16_t)ntrees;

dec/state.h

@@ -9,7 +9,6 @@
 #ifndef BROTLI_DEC_STATE_H_
 #define BROTLI_DEC_STATE_H_
 
-#include <stdio.h>
 #include "./bit_reader.h"
 #include "./huffman.h"
 #include "./types.h"
@@ -95,6 +94,10 @@ typedef enum {
 
 struct BrotliStateStruct {
   BrotliRunningState state;
+
+  /* This counter is reused for several disjoint loops. */
+  int loop_counter;
+
   BrotliBitReader br;
 
   brotli_alloc_func alloc_func;
@@ -108,8 +111,6 @@ struct BrotliStateStruct {
   } buffer;
   uint32_t buffer_length;
 
-  /* This counter is reused for several disjoint loops. */
-  int loop_counter;
   int pos;
   int max_backward_distance;
   int max_backward_distance_minus_custom_dict_size;
@@ -188,7 +189,7 @@ struct BrotliStateStruct {
   uint32_t context_index;
   uint32_t max_run_length_prefix;
   uint32_t code;
-  HuffmanCode context_map_table[BROTLI_HUFFMAN_MAX_TABLE_SIZE];
+  HuffmanCode context_map_table[BROTLI_HUFFMAN_MAX_SIZE_272];
 
   /* For InverseMoveToFrontTransform */
   uint32_t mtf_upper_bound;
@@ -217,13 +218,6 @@ struct BrotliStateStruct {
   uint32_t num_literal_htrees;
   uint8_t* context_map;
   uint8_t* context_modes;
-
-  uint8_t* legacy_input_buffer;
-  uint8_t* legacy_output_buffer;
-  size_t legacy_input_len;
-  size_t legacy_output_len;
-  size_t legacy_input_pos;
-  size_t legacy_output_pos;
 };
 
 typedef struct BrotliStateStruct BrotliState;

dec/transform.h

@@ -9,8 +9,6 @@
 #ifndef BROTLI_DEC_TRANSFORM_H_
 #define BROTLI_DEC_TRANSFORM_H_
 
-#include <stdio.h>
-#include <ctype.h>
 #include "./port.h"
 #include "./types.h"
 
@@ -269,22 +267,19 @@ static BROTLI_NOINLINE int TransformDictionaryWord(
   }
   {
     const int t = kTransforms[transform].transform;
-    int skip = t < kOmitFirst1 ? 0 : t - (kOmitFirst1 - 1);
     int i = 0;
-    uint8_t* uppercase;
+    int skip = t - (kOmitFirst1 - 1);
-    if (skip > len) {
+    if (skip > 0) {
-      skip = len;
+      word += skip;
-    }
+      len -= skip;
-    word += skip;
+    } else if (t <= kOmitLast9) {
-    len -= skip;
-    if (t <= kOmitLast9) {
       len -= t;
     }
     while (i < len) { dst[idx++] = word[i++]; }
-    uppercase = &dst[idx - len];
     if (t == kUppercaseFirst) {
-      ToUpperCase(uppercase);
+      ToUpperCase(&dst[idx - len]);
     } else if (t == kUppercaseAll) {
+      uint8_t* uppercase = &dst[idx - len];
       while (len > 0) {
         int step = ToUpperCase(uppercase);
         uppercase += step;