Make initialization of the QuicInMemoryCache explicit to avoid spooky action at a distance which co…

net/tools/quic/quic_in_memory_cache.cc

 // Copyright (c) 2012 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/tools/quic/quic_in_memory_cache.h"
 
 #include "base/files/file_enumerator.h"
 #include "base/files/file_util.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "net/tools/balsa/balsa_frame.h"
 #include "net/tools/balsa/balsa_headers.h"
 #include "net/tools/balsa/noop_balsa_visitor.h"
 #include "net/tools/quic/spdy_utils.h"
 
 using base::FilePath;
 using base::StringPiece;
 using std::string;
 
 namespace net {
 namespace tools {
 
-// Specifies the directory used during QuicInMemoryCache
-// construction to seed the cache. Cache directory can be
-// generated using `wget -p --save-headers <url>
-string FLAGS_quic_in_memory_cache_dir = "";
-
 namespace {
 
 // BalsaVisitor implementation (glue) which caches response bodies.
 class CachingBalsaVisitor : public NoOpBalsaVisitor {
  public:
   CachingBalsaVisitor() : done_framing_(false) {}
   void ProcessBodyData(const char* input, size_t size) override {
     AppendToBody(input, size);
   }
   void MessageDone() override { done_framing_ = true; }
@@ skipping 57 matching lines @@
   AddResponseImpl(host, path, REGULAR_RESPONSE, response_headers,
                   response_body);
 }
 
 void QuicInMemoryCache::AddSpecialResponse(StringPiece host,
                                            StringPiece path,
                                            SpecialResponseType response_type) {
   AddResponseImpl(host, path, response_type, SpdyHeaderBlock(), "");
 }
 
-QuicInMemoryCache::QuicInMemoryCache() {
-  Initialize();
-}
+QuicInMemoryCache::QuicInMemoryCache() {}
 
 void QuicInMemoryCache::ResetForTests() {
   STLDeleteValues(&responses_);
-  Initialize();
 }
 
-void QuicInMemoryCache::Initialize() {
-  // If there's no defined cache dir, we have no initialization to do.
-  if (FLAGS_quic_in_memory_cache_dir.empty()) {
-    VLOG(1) << "No cache directory found. Skipping initialization.";
+void QuicInMemoryCache::InitializeFromDirectory(const string& cache_directory) {
+  if (cache_directory.empty()) {
+    LOG(DFATAL) << "cache_directory must not be empty.";
     return;
   }
   VLOG(1) << "Attempting to initialize QuicInMemoryCache from directory: "
-          << FLAGS_quic_in_memory_cache_dir;
-
-  FilePath directory(FLAGS_quic_in_memory_cache_dir);
+            << cache_directory;

[ramant (doing other things), 2015/03/24 21:49:36]

nit: indentation.

[Ryan Hamilton, 2015/03/24 22:03:09]

Done. (In final CL)

+  FilePath directory(cache_directory);
   base::FileEnumerator file_list(directory,
                                  true,
                                  base::FileEnumerator::FILES);
 
-  for (FilePath file = file_list.Next(); !file.empty();
-       file = file_list.Next()) {
+  for (FilePath file_iter = file_list.Next(); !file_iter.empty();
+       file_iter = file_list.Next()) {
+    BalsaHeaders request_headers, response_headers;
     // Need to skip files in .svn directories
-    if (file.value().find("/.svn/") != string::npos) {
+    if (file_iter.value().find("/.svn/") != string::npos) {
       continue;
     }
 
-    BalsaHeaders request_headers, response_headers;
+    // Tease apart filename into host and path.
+    StringPiece file(file_iter.value());
+    file.remove_prefix(cache_directory.length());
+    if (file[0] == '/') {
+      file.remove_prefix(1);
+    }
 
     string file_contents;
-    base::ReadFileToString(file, &file_contents);
+    base::ReadFileToString(file_iter, &file_contents);
 
     // Frame HTTP.
     CachingBalsaVisitor caching_visitor;
     BalsaFrame framer;
     framer.set_balsa_headers(&response_headers);
     framer.set_balsa_visitor(&caching_visitor);
     size_t processed = 0;
     while (processed < file_contents.length() &&
            !caching_visitor.done_framing()) {
       processed += framer.ProcessInput(file_contents.c_str() + processed,
                                        file_contents.length() - processed);
     }
 
     if (!caching_visitor.done_framing()) {
-      LOG(DFATAL) << "Did not frame entire message from file: " << file.value()
+      LOG(DFATAL) << "Did not frame entire message from file: " << file
                   << " (" << processed << " of " << file_contents.length()
                   << " bytes).";
     }
     if (processed < file_contents.length()) {
       // Didn't frame whole file. Assume remainder is body.
       // This sometimes happens as a result of incompatibilities between
       // BalsaFramer and wget's serialization of HTTP sans content-length.
       caching_visitor.AppendToBody(file_contents.c_str() + processed,
                                    file_contents.length() - processed);
       processed += file_contents.length();
     }
 
-    StringPiece base = file.value();
+    StringPiece base = file;
     if (response_headers.HasHeader("X-Original-Url")) {
       base = response_headers.GetHeader("X-Original-Url");
       response_headers.RemoveAllOfHeader("X-Original-Url");
       // Remove the protocol so that the string is of the form host + path,
       // which is parsed properly below.
       if (StringPieceUtils::StartsWithIgnoreCase(base, "https://")) {
         base.remove_prefix(8);
       } else if (StringPieceUtils::StartsWithIgnoreCase(base, "http://")) {
         base.remove_prefix(7);
       }
@@ skipping 33 matching lines @@
   new_response->set_body(response_body);
   responses_[key] = new_response;
 }
 
 string QuicInMemoryCache::GetKey(StringPiece host, StringPiece path) const {
   return host.as_string() + path.as_string();
 }
 
 }  // namespace tools
 }  // namespace net