Add brotli content-encoding filter.

net/filter/brotli_filter.cc

Index: net/filter/brotli_filter.cc
diff --git a/net/filter/brotli_filter.cc b/net/filter/brotli_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..74b3c767aac1c145ad6d486d3c8f336df3bc17ea
--- /dev/null
+++ b/net/filter/brotli_filter.cc
@@ -0,0 +1,96 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/filter/brotli_filter.h"
+
+#include "base/logging.h"
+#include "third_party/brotli/dec/decode.h"
+
+namespace net {
+
+BrotliFilter::BrotliFilter(FilterType type)
+    : Filter(type), decoding_status_(DECODING_UNINITIALIZED) {}
+
+BrotliFilter::~BrotliFilter() {
+  if (decoding_status_ != DECODING_UNINITIALIZED)
+    BrotliStateCleanup(brotli_state_.get());
+}
+
+bool BrotliFilter::InitDecoding() {
+  if (decoding_status_ != DECODING_UNINITIALIZED)
+    return false;
+
+  brotli_state_.reset(new BrotliState);
+  if (!brotli_state_.get())
+    return false;
+
+  BrotliStateInit(brotli_state_.get());
+
+  decoding_status_ = DECODING_IN_PROGRESS;
+  return true;
+}
+
+Filter::FilterStatus BrotliFilter::ReadFilteredData(char* dest_buffer,
+                                                    int* dest_len) {
+  if (!dest_buffer || !dest_len || *dest_len <= 0)
+    return Filter::FILTER_ERROR;
+
+  if (decoding_status_ == DECODING_DONE) {
+    *dest_len = 0;
+    return Filter::FILTER_DONE;
+  }
+
+  if (decoding_status_ != DECODING_IN_PROGRESS)
+    return Filter::FILTER_ERROR;
+
+  size_t available_in = stream_data_len_;
+  const uint8_t* next_in = bit_cast<uint8_t*>(next_stream_data_);
+  size_t available_out = *dest_len;
+  uint8_t* next_out = bit_cast<uint8_t*>(dest_buffer);
+  size_t total_out;
+  BrotliResult result =
+      BrotliDecompressStream(&available_in, &next_in, &available_out, &next_out,
+                             &total_out, brotli_state_.get());
+  int bytes_written = *dest_len - available_out;
+
+  Filter::FilterStatus status;
+  switch (result) {
+    case BROTLI_RESULT_ERROR: {
+      status = Filter::FILTER_ERROR;
+      break;
+    }
+    // Fall through.
+    case BROTLI_RESULT_NEEDS_MORE_OUTPUT:
+    case BROTLI_RESULT_SUCCESS: {
+      status = Filter::FILTER_OK;
+      *dest_len = bytes_written;
+      stream_data_len_ = available_in;
+      next_stream_data_ = bit_cast<char*>(next_in);
+      if (result == BROTLI_RESULT_SUCCESS)
+        status = Filter::FILTER_DONE;
+      break;
+    }
+    case BROTLI_RESULT_NEEDS_MORE_INPUT: {
+      status = Filter::FILTER_NEED_MORE_DATA;
+      *dest_len = bytes_written;
+      stream_data_len_ = 0;
+      next_stream_data_ = NULL;
+      break;
+    }
+    default: {
+      status = Filter::FILTER_ERROR;
+      break;
+    }
+  }
+
+  if (status == Filter::FILTER_DONE) {
+    decoding_status_ = DECODING_DONE;
+  } else if (status == Filter::FILTER_ERROR) {
+    decoding_status_ = DECODING_ERROR;
+  }
+
+  return status;
+}
+
+}  // namespace net