#1469: lib: add brotli library (v1.0.9)

lib/brotli/LICENSE

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+Copyright (c) 2009, 2010, 2013-2016 by the Brotli Authors.
+
+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.

lib/brotli/README

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+BROTLI DATA COMPRESSION LIBRARY
+
+Brotli is a generic-purpose lossless compression algorithm that compresses data
+using a combination of a modern variant of the LZ77 algorithm, Huffman coding
+and 2nd order context modeling, with a compression ratio comparable to the best
+currently available general-purpose compression methods. It is similar in speed
+with deflate but offers more dense compression.
+
+The specification of the Brotli Compressed Data Format is defined in RFC 7932
+https://tools.ietf.org/html/rfc7932
+
+Brotli is open-sourced under the MIT License, see the LICENSE file.
+
+Brotli mailing list:
+https://groups.google.com/forum/#!forum/brotli

lib/brotli/README.md

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+<p align="center"><img src="https://brotli.org/brotli.svg" alt="Brotli" width="64"></p>
+
+# SECURITY NOTE
+
+Please consider updating brotli to version 1.0.9 (latest).
+
+Version 1.0.9 contains a fix to "integer overflow" problem. This happens when "one-shot" decoding API is used (or input chunk for streaming API is not limited), input size (chunk size) is larger than 2GiB, and input contains uncompressed blocks. After the overflow happens, `memcpy` is invoked with a gigantic `num` value, that will likely cause the crash.
+
+### Introduction
+
+Brotli is a generic-purpose lossless compression algorithm that compresses data
+using a combination of a modern variant of the LZ77 algorithm, Huffman coding
+and 2nd order context modeling, with a compression ratio comparable to the best
+currently available general-purpose compression methods. It is similar in speed
+with deflate but offers more dense compression.
+
+The specification of the Brotli Compressed Data Format is defined in [RFC 7932](https://tools.ietf.org/html/rfc7932).
+
+Brotli is open-sourced under the MIT License, see the LICENSE file.
+
+Brotli mailing list:
+https://groups.google.com/forum/#!forum/brotli
+
+[![TravisCI Build Status](https://travis-ci.org/google/brotli.svg?branch=master)](https://travis-ci.org/google/brotli)
+[![AppVeyor Build Status](https://ci.appveyor.com/api/projects/status/github/google/brotli?branch=master&svg=true)](https://ci.appveyor.com/project/szabadka/brotli)
+[![Fuzzing Status](https://oss-fuzz-build-logs.storage.googleapis.com/badges/brotli.svg)](https://oss-fuzz-build-logs.storage.googleapis.com/index.html#brotli)
+
+### Build instructions
+
+#### Vcpkg
+
+You can download and install brotli using the [vcpkg](https://github.com/Microsoft/vcpkg/) dependency manager:
+
+    git clone https://github.com/Microsoft/vcpkg.git
+    cd vcpkg
+    ./bootstrap-vcpkg.sh
+    ./vcpkg integrate install
+    vcpkg install brotli
+
+The brotli port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please [create an issue or pull request](https://github.com/Microsoft/vcpkg) on the vcpkg repository.
+
+#### Autotools-style CMake
+
+[configure-cmake](https://github.com/nemequ/configure-cmake) is an
+autotools-style configure script for CMake-based projects (not supported on Windows).
+
+The basic commands to build, test and install brotli are:
+
+    $ mkdir out && cd out
+    $ ../configure-cmake
+    $ make
+    $ make test
+    $ make install
+
+By default, debug binaries are built. To generate "release" `Makefile` specify `--disable-debug` option to `configure-cmake`.
+
+#### Bazel
+
+See [Bazel](http://www.bazel.build/)
+
+#### CMake
+
+The basic commands to build and install brotli are:
+
+    $ mkdir out && cd out
+    $ cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=./installed ..
+    $ cmake --build . --config Release --target install
+
+You can use other [CMake](https://cmake.org/) configuration.
+
+#### Premake5
+
+See [Premake5](https://premake.github.io/)
+
+#### Python
+
+To install the latest release of the Python module, run the following:
+
+    $ pip install brotli
+
+To install the tip-of-the-tree version, run:
+
+    $ pip install --upgrade git+https://github.com/google/brotli
+
+See the [Python readme](python/README.md) for more details on installing
+from source, development, and testing.
+
+### Benchmarks
+* [Squash Compression Benchmark](https://quixdb.github.io/squash-benchmark/) / [Unstable Squash Compression Benchmark](https://quixdb.github.io/squash-benchmark/unstable/)
+* [Large Text Compression Benchmark](http://mattmahoney.net/dc/text.html)
+* [Lzturbo Benchmark](https://sites.google.com/site/powturbo/home/benchmark)
+
+### Related projects
+> **Disclaimer:** Brotli authors take no responsibility for the third party projects mentioned in this section.
+
+Independent [decoder](https://github.com/madler/brotli) implementation by Mark Adler, based entirely on format specification.
+
+JavaScript port of brotli [decoder](https://github.com/devongovett/brotli.js). Could be used directly via `npm install brotli`
+
+Hand ported [decoder / encoder](https://github.com/dominikhlbg/BrotliHaxe) in haxe by Dominik Homberger. Output source code: JavaScript, PHP, Python, Java and C#
+
+7Zip [plugin](https://github.com/mcmilk/7-Zip-Zstd)
+
+Dart [native bindings](https://github.com/thosakwe/brotli)

lib/brotli/c/common/constants.c

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+/* Copyright 2013 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+#include "./constants.h"
+
+const BrotliPrefixCodeRange
+    _kBrotliPrefixCodeRanges[BROTLI_NUM_BLOCK_LEN_SYMBOLS] = {
+        {1, 2},     {5, 2},     {9, 2},   {13, 2},    {17, 3},    {25, 3},
+        {33, 3},    {41, 3},    {49, 4},  {65, 4},    {81, 4},    {97, 4},
+        {113, 5},   {145, 5},   {177, 5}, {209, 5},   {241, 6},   {305, 6},
+        {369, 7},   {497, 8},   {753, 9}, {1265, 10}, {2289, 11}, {4337, 12},
+        {8433, 13}, {16625, 24}};

lib/brotli/c/common/constants.h

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+/* Copyright 2016 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/**
+ * @file
+ * Common constants used in decoder and encoder API.
+ */
+
+#ifndef BROTLI_COMMON_CONSTANTS_H_
+#define BROTLI_COMMON_CONSTANTS_H_
+
+#include "./platform.h"
+#include <brotli/port.h>
+#include <brotli/types.h>
+
+/* Specification: 7.3. Encoding of the context map */
+#define BROTLI_CONTEXT_MAP_MAX_RLE 16
+
+/* Specification: 2. Compressed representation overview */
+#define BROTLI_MAX_NUMBER_OF_BLOCK_TYPES 256
+
+/* Specification: 3.3. Alphabet sizes: insert-and-copy length */
+#define BROTLI_NUM_LITERAL_SYMBOLS 256
+#define BROTLI_NUM_COMMAND_SYMBOLS 704
+#define BROTLI_NUM_BLOCK_LEN_SYMBOLS 26
+#define BROTLI_MAX_CONTEXT_MAP_SYMBOLS (BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + \
+                                        BROTLI_CONTEXT_MAP_MAX_RLE)
+#define BROTLI_MAX_BLOCK_TYPE_SYMBOLS (BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + 2)
+
+/* Specification: 3.5. Complex prefix codes */
+#define BROTLI_REPEAT_PREVIOUS_CODE_LENGTH 16
+#define BROTLI_REPEAT_ZERO_CODE_LENGTH 17
+#define BROTLI_CODE_LENGTH_CODES (BROTLI_REPEAT_ZERO_CODE_LENGTH + 1)
+/* "code length of 8 is repeated" */
+#define BROTLI_INITIAL_REPEATED_CODE_LENGTH 8
+
+/* "Large Window Brotli" */
+
+/**
+ * The theoretical maximum number of distance bits specified for large window
+ * brotli, for 64-bit encoders and decoders. Even when in practice 32-bit
+ * encoders and decoders only support up to 30 max distance bits, the value is
+ * set to 62 because it affects the large window brotli file format.
+ * Specifically, it affects the encoding of simple huffman tree for distances,
+ * see Specification RFC 7932 chapter 3.4.
+ */
+#define BROTLI_LARGE_MAX_DISTANCE_BITS 62U
+#define BROTLI_LARGE_MIN_WBITS 10
+/**
+ * The maximum supported large brotli window bits by the encoder and decoder.
+ * Large window brotli allows up to 62 bits, however the current encoder and
+ * decoder, designed for 32-bit integers, only support up to 30 bits maximum.
+ */
+#define BROTLI_LARGE_MAX_WBITS 30
+
+/* Specification: 4. Encoding of distances */
+#define BROTLI_NUM_DISTANCE_SHORT_CODES 16
+/**
+ * Maximal number of "postfix" bits.
+ *
+ * Number of "postfix" bits is stored as 2 bits in meta-block header.
+ */
+#define BROTLI_MAX_NPOSTFIX 3
+#define BROTLI_MAX_NDIRECT 120
+#define BROTLI_MAX_DISTANCE_BITS 24U
+#define BROTLI_DISTANCE_ALPHABET_SIZE(NPOSTFIX, NDIRECT, MAXNBITS) ( \
+    BROTLI_NUM_DISTANCE_SHORT_CODES + (NDIRECT) +                    \
+    ((MAXNBITS) << ((NPOSTFIX) + 1)))
+/* BROTLI_NUM_DISTANCE_SYMBOLS == 1128 */
+#define BROTLI_NUM_DISTANCE_SYMBOLS \
+    BROTLI_DISTANCE_ALPHABET_SIZE(  \
+        BROTLI_MAX_NDIRECT, BROTLI_MAX_NPOSTFIX, BROTLI_LARGE_MAX_DISTANCE_BITS)
+
+/* ((1 << 26) - 4) is the maximal distance that can be expressed in RFC 7932
+   brotli stream using NPOSTFIX = 0 and NDIRECT = 0. With other NPOSTFIX and
+   NDIRECT values distances up to ((1 << 29) + 88) could be expressed. */
+#define BROTLI_MAX_DISTANCE 0x3FFFFFC
+
+/* ((1 << 31) - 4) is the safe distance limit. Using this number as a limit
+   allows safe distance calculation without overflows, given the distance
+   alphabet size is limited to corresponding size
+   (see kLargeWindowDistanceCodeLimits). */
+#define BROTLI_MAX_ALLOWED_DISTANCE 0x7FFFFFFC
+
+
+/* Specification: 4. Encoding of Literal Insertion Lengths and Copy Lengths */
+#define BROTLI_NUM_INS_COPY_CODES 24
+
+/* 7.1. Context modes and context ID lookup for literals */
+/* "context IDs for literals are in the range of 0..63" */
+#define BROTLI_LITERAL_CONTEXT_BITS 6
+
+/* 7.2. Context ID for distances */
+#define BROTLI_DISTANCE_CONTEXT_BITS 2
+
+/* 9.1. Format of the Stream Header */
+/* Number of slack bytes for window size. Don't confuse
+   with BROTLI_NUM_DISTANCE_SHORT_CODES. */
+#define BROTLI_WINDOW_GAP 16
+#define BROTLI_MAX_BACKWARD_LIMIT(W) (((size_t)1 << (W)) - BROTLI_WINDOW_GAP)
+
+typedef struct BrotliDistanceCodeLimit {
+  uint32_t max_alphabet_size;
+  uint32_t max_distance;
+} BrotliDistanceCodeLimit;
+
+/* This function calculates maximal size of distance alphabet, such that the
+   distances greater than the given values can not be represented.
+
+   This limits are designed to support fast and safe 32-bit decoders.
+   "32-bit" means that signed integer values up to ((1 << 31) - 1) could be
+   safely expressed.
+
+   Brotli distance alphabet symbols do not represent consecutive distance
+   ranges. Each distance alphabet symbol (excluding direct distances and short
+   codes), represent interleaved (for NPOSTFIX > 0) range of distances.
+   A "group" of consecutive (1 << NPOSTFIX) symbols represent non-interleaved
+   range. Two consecutive groups require the same amount of "extra bits".
+
+   It is important that distance alphabet represents complete "groups".
+   To avoid complex logic on encoder side about interleaved ranges
+   it was decided to restrict both sides to complete distance code "groups".
+ */
+BROTLI_UNUSED_FUNCTION BrotliDistanceCodeLimit BrotliCalculateDistanceCodeLimit(
+    uint32_t max_distance, uint32_t npostfix, uint32_t ndirect) {
+  BrotliDistanceCodeLimit result;
+  /* Marking this function as unused, because not all files
+     including "constants.h" use it -> compiler warns about that. */
+  BROTLI_UNUSED(&BrotliCalculateDistanceCodeLimit);
+  if (max_distance <= ndirect) {
+    /* This case never happens / exists only for the sake of completeness. */
+    result.max_alphabet_size = max_distance + BROTLI_NUM_DISTANCE_SHORT_CODES;
+    result.max_distance = max_distance;
+    return result;
+  } else {
+    /* The first prohibited value. */
+    uint32_t forbidden_distance = max_distance + 1;
+    /* Subtract "directly" encoded region. */
+    uint32_t offset = forbidden_distance - ndirect - 1;
+    uint32_t ndistbits = 0;
+    uint32_t tmp;
+    uint32_t half;
+    uint32_t group;
+    /* Postfix for the last dcode in the group. */
+    uint32_t postfix = (1u << npostfix) - 1;
+    uint32_t extra;
+    uint32_t start;
+    /* Remove postfix and "head-start". */
+    offset = (offset >> npostfix) + 4;
+    /* Calculate the number of distance bits. */
+    tmp = offset / 2;
+    /* Poor-man's log2floor, to avoid extra dependencies. */
+    while (tmp != 0) {ndistbits++; tmp = tmp >> 1;}
+    /* One bit is covered with subrange addressing ("half"). */
+    ndistbits--;
+    /* Find subrange. */
+    half = (offset >> ndistbits) & 1;
+    /* Calculate the "group" part of dcode. */
+    group = ((ndistbits - 1) << 1) | half;
+    /* Calculated "group" covers the prohibited distance value. */
+    if (group == 0) {
+      /* This case is added for correctness; does not occur for limit > 128. */
+      result.max_alphabet_size = ndirect + BROTLI_NUM_DISTANCE_SHORT_CODES;
+      result.max_distance = ndirect;
+      return result;
+    }
+    /* Decrement "group", so it is the last permitted "group". */
+    group--;
+    /* After group was decremented, ndistbits and half must be recalculated. */
+    ndistbits = (group >> 1) + 1;
+    /* The last available distance in the subrange has all extra bits set. */
+    extra = (1u << ndistbits) - 1;
+    /* Calculate region start. NB: ndistbits >= 1. */
+    start = (1u << (ndistbits + 1)) - 4;
+    /* Move to subregion. */
+    start += (group & 1) << ndistbits;
+    /* Calculate the alphabet size. */
+    result.max_alphabet_size = ((group << npostfix) | postfix) + ndirect +
+        BROTLI_NUM_DISTANCE_SHORT_CODES + 1;
+    /* Calculate the maximal distance representable by alphabet. */
+    result.max_distance = ((start + extra) << npostfix) + postfix + ndirect + 1;
+    return result;
+  }
+}
+
+/* Represents the range of values belonging to a prefix code:
+   [offset, offset + 2^nbits) */
+typedef struct {
+  uint16_t offset;
+  uint8_t nbits;
+} BrotliPrefixCodeRange;
+
+/* "Soft-private", it is exported, but not "advertised" as API. */
+BROTLI_COMMON_API extern const BrotliPrefixCodeRange
+    _kBrotliPrefixCodeRanges[BROTLI_NUM_BLOCK_LEN_SYMBOLS];
+
+#endif  /* BROTLI_COMMON_CONSTANTS_H_ */