Initial refactor to get profiles to propagate storage partition details.

chrome/browser/storage_partition_details.h

+// 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.
+
+#ifndef CHROME_BROWSER_STORAGE_PARTITION_DETAILS_H_
+#define CHROME_BROWSER_STORAGE_PARTITION_DETAILS_H_
+
+#include "base/file_path.h"
+#include "base/hash.h"
+#include "base/hash_tables.h"
+
+// This structure combines the on-disk path and a boolean whether the partition
+// should be persisted on disk. It's purpose is to serve as a unique key to
+// look up RequestContext objects in the profile.
+struct StoragePartitionDetails {

[awong, 2012/10/18 22:36:15]

nit: Can we call this StoragePartitionDescriptor or something that indicates it
is an identiifer more than "Details"?

[nasko, 2012/10/19 17:29:14]

Done.

+  const FilePath path;
+  const bool in_memory;
+
+  StoragePartitionDetails(const FilePath& partition_path,

[awong, 2012/10/18 22:36:15]

The constructor should come first in declaration ordering.

[nasko, 2012/10/19 17:29:14]

Done.

+                          const bool in_memory_only)
+    : path(partition_path),
+      in_memory(in_memory_only) {}
+
+};
+
+// Functor for operator <.
+struct StoragePartitionDetailsLess {
+  bool operator()(const StoragePartitionDetails& left,

[awong, 2012/10/18 22:36:15]

lhs and rhs seem to be more common than "left" and "right"

[nasko, 2012/10/19 17:29:14]

Done.

+                  const StoragePartitionDetails& right) const {
+    if (left.path < right.path)
+      return true;
+    if (left.in_memory != right.in_memory)

[awong, 2012/10/18 22:36:15]

This isn't a valid Strict Weak Ordering which stl algorithms require.

SPD a("foo", false);
SPD b("foo", true);

here a < b and b < a.

[nasko, 2012/10/19 17:29:14]

Done.

+      return true;
+
+    return false;
+  }
+};
+
+// Functor for operator ==.
+struct StoragePartitionDetailsEq {
+  bool operator()(const StoragePartitionDetails& left,
+                  const StoragePartitionDetails& right) const {

[awong, 2012/10/18 22:36:15]

Simplify to

return left.path == right.path && left.in_memory == right.in_memory.

[nasko, 2012/10/19 17:29:14]

Done.

+    if (left.path != right.path)
+      return false;
+    if (left.in_memory != right.in_memory)
+      return false;
+
+    return true;
+  }
+};
+
+// Provide a hash function so that hash_sets and maps can contain
+// StoragePartitionDetails structs.
+namespace BASE_HASH_NAMESPACE {
+
+#if defined(COMPILER_MSVC)
+
+inline size_t hash_value(const StoragePartitionDetails& input) {
+  size_t value = hash_value(input.path.value());
+  return input.in_memory ? value : value + 1;
+}
+
+#elif defined(COMPILER_GCC)
+
+template <>
+struct hash<StoragePartitionDetails> {
+  size_t operator()(const StoragePartitionDetails& input) const {
+    size_t value = hash<FilePath::StringType>()(input.path.value());
+    return input.in_memory ? value : value + 1;

[awong, 2012/10/18 22:36:15]

My hash algorithm OCDness really wants to say this probably biases the range of
output in a way we don't expect. I betcha because our range of inputs are biased
to in_memory versus not, we might get more collisions on even numbers rather
than odd ones..but it also probably doesn't matter and I'm not sure how I'd fix
it. :-/

[nasko, 2012/10/19 17:29:14]

Done.

+  }
+};
+
+#endif
+}  // namespace BASE_HASH_NAMESPACE
+
+// A macro to typedef a hash_map, keyed by StoragePartitionDetails to lookup
+// other types. The goal is to save each place we use such map from including
+// all of this compiler specific syntax.
+#if defined(COMPILER_MSVC)
+  #define DefineStoragePartitionDetailsMap(_X_) \
+    typedef BASE_HASH_NAMESPACE::hash_map< \
+      StoragePartitionDetails, \
+      _X_, \
+      BASE_HASH_NAMESPACE::hash_compare<StoragePartitionDetails, \
+                                        StoragePartitionDetailsLess> >
+#elif defined(COMPILER_GCC)
+  #define DefineStoragePartitionDetailsMap(_X_) \
+    typedef BASE_HASH_NAMESPACE::hash_map< \
+      StoragePartitionDetails, \
+      _X_, \
+      BASE_HASH_NAMESPACE::hash<StoragePartitionDetails>, \
+      StoragePartitionDetailsEq>
+#endif
+
+#endif  // CHROME_BROWSER_STORAGE_PARTITION_DETAILS_H_