Implement content_decoder_tool.cc to decode offline any resources.

net/tools/content_decoder_tool/content_decoder_tool.cc

Index: net/tools/content_decoder_tool/content_decoder_tool.cc
diff --git a/net/tools/content_decoder_tool/content_decoder_tool.cc b/net/tools/content_decoder_tool/content_decoder_tool.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e6e1f0aeaba06c58b09c87756fd5a167e3c1d004
--- /dev/null
+++ b/net/tools/content_decoder_tool/content_decoder_tool.cc
@@ -0,0 +1,92 @@
+// Copyright 2016 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 <iostream>
+
+#include "base/command_line.h"
+#include "net/base/io_buffer.h"
+#include "net/filter/filter.h"
+#include "net/filter/mock_filter_context.h"
+
+using net::Filter;
+
+namespace {
+
+// Print the command line help.
+void PrintHelp(const char* command_line_name) {
+  std::cout << command_line_name << " content_encoding [content_encoding]..."
+            << std::endl
+            << std::endl;
+  std::cout << "Decodes the stdin into the stdout using an content_encoding "
+            << "list given in arguments. This list is expected to be the "
+            << "Content-Encoding HTTP response header's value splitted by `,`."

[gavinp, 2016/03/22 14:56:58]

Nit: "split" not "splitted" and ' not `.

[gabadie, 2016/03/22 16:20:42]

Done.

+            << std::endl;
+}
+
+}  // namespace
+
+int main(int argc, char* argv[]) {
+  base::CommandLine::Init(argc, argv);
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
+
+  std::vector<std::string> content_encodings;
+#if defined(OS_WIN)
+  base::CommandLine::StringVector wide_args = command_line.GetArgs();
+  for (const auto& arg : wide_args) {

[gavinp, 2016/03/22 14:56:58]

Nit: braces not needed.

[gabadie, 2016/03/22 16:20:43]

Done.

+    content_encodings.push_back(base::WideToUTF8(arg));
+  }
+#else
+  content_encodings = command_line.GetArgs();
+#endif
+
+  if (content_encodings.size() == 0) {
+    PrintHelp(argv[0]);
+    return 1;
+  }
+
+  std::vector<Filter::FilterType> filter_types;
+  for (const auto& content_encoding : content_encodings) {
+    Filter::FilterType filter_type =
+        Filter::ConvertEncodingToType(content_encoding);
+    if (filter_type == Filter::FILTER_TYPE_UNSUPPORTED) {
+      std::cerr << "Unsupported decoder `" << content_encoding << "`."

[gavinp, 2016/03/22 14:56:58]

nit: I think using ` here is a bit odd. Would ' make more sense?

[gabadie, 2016/03/22 16:20:43]

Done.

+                << std::endl;
+      return 1;
+    }
+    filter_types.push_back(filter_type);
+  }
+
+  net::MockFilterContext filter_context;
+  scoped_ptr<Filter> filter(Filter::Factory(filter_types, filter_context));
+  if (!filter) {
+    std::cerr << "Couldn't create the decoder." << std::endl;
+    return 1;
+  }
+
+  net::IOBuffer* pre_filter_buf = filter->stream_buffer();
+  int pre_filter_buf_len = filter->stream_buffer_size();
+  while (std::cin) {
+    std::cin.read(pre_filter_buf->data(), pre_filter_buf_len);
+    int pre_filter_data_len = std::cin.gcount();
+    filter->FlushStreamBuffer(pre_filter_data_len);
+
+    while (true) {
+      int kPostFilterBufLen = 4096;
+      char post_filter_buf[kPostFilterBufLen];
+      int post_filter_data_len = kPostFilterBufLen;
+      Filter::FilterStatus filter_status =
+          filter->ReadData(post_filter_buf, &post_filter_data_len);
+      std::cout.write(post_filter_buf, post_filter_data_len);
+      if (filter_status == Filter::FILTER_ERROR) {
+        std::cerr << "Couldn't decode stdin." << std::endl;
+        return 1;
+      } else if (filter_status != Filter::FILTER_OK) {
+        break;
+      }
+    }
+  }
+
+  return 0;
+}