Get rid of DownloadIdFactory and instead get the next id from DownloadManagerDelegate. I've also moved DownloadId to the public directory and into the content namespace.

BUG=98716
Review URL: https://chromiumcodereview.appspot.com/9169036

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@119310 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 101 insertions, 0 deletions

diff --git a/content/public/browser/download_id.h b/content/public/browser/download_id.h
new file mode 100644
index 0000000..96ecc63
--- /dev/null
+++ b/content/public/browser/download_id.h
@@ -0,0 +1,101 @@
+// Copyright (c) 2011 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 CONTENT_PUBLIC_BROWSER_DOWNLOAD_ID_H_
+#define CONTENT_PUBLIC_BROWSER_DOWNLOAD_ID_H_
+#pragma once
+
+#include <iosfwd>
+#include <string>
+
+#include "base/hash_tables.h"
+#include "base/stringprintf.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+// DownloadId combines per-profile Download ids with an indication of which
+// profile in order to be globally unique. DownloadIds are not persistent across
+// sessions, but their local() field is.
+class DownloadId {
+ public:
+  static DownloadId Invalid() { return DownloadId(NULL, -1); }
+
+  // Domain separates spaces of local ids.
+  typedef const void* Domain;
+
+  DownloadId(Domain domain, int32 local_id)
+    : domain_(domain),
+      local_id_(local_id) {
+  }
+
+  // Return the per-profile and persistent part of this DownloadId.
+  int32 local() const { return local_id_; }
+
+  // Returns true if this DownloadId has been allocated and could possibly refer
+  // to a DownloadItem that exists.
+  bool IsValid() const { return ((domain_ != NULL) && (local_id_ >= 0)); }
+
+  // The following methods (operator==, hash(), copy, and assign) provide
+  // support for STL containers such as hash_map.
+
+  bool operator==(const DownloadId& that) const {
+    return ((that.local_id_ == local_id_) &&
+            (that.domain_ == domain_));
+  }
+  bool operator<(const DownloadId& that) const {
+    // Even though Domain::operator< is not well defined and
+    // GCC does not require it for hash_map, MSVC requires operator< for
+    // hash_map. We don't ifdef it out here because we will probably make a
+    // set<DownloadId> at some point, when GCC will require it.
+    return ((domain_ < that.domain_) ||
+            ((domain_ == that.domain_) && (local_id_ < that.local_id_)));
+  }
+
+  size_t hash() const {
+    // The top half of domain_ is unlikely to be distinct, and the user is
+    // unlikely to have >64K downloads. If these assumptions are incorrect, then
+    // DownloadFileManager's hash_map might have a few collisions, but it will
+    // use operator== to safely disambiguate.
+    return reinterpret_cast<size_t>(domain_) +
+           (static_cast<size_t>(local_id_) << (4 * sizeof(size_t)));
+  }
+
+  std::string DebugString() const {
+    return base::StringPrintf("%p:%d", domain_, local_id_);
+  }
+
+ private:
+  Domain domain_;
+
+  int32 local_id_;
+
+  // Allow copy and assign.
+};
+
+}  // namespace content
+
+// Allow logging DownloadIds. Looks like "0x01234567:42".
+CONTENT_EXPORT std::ostream& operator<<(std::ostream& out,
+                                        const content::DownloadId& global_id);
+inline std::ostream& operator<<(std::ostream& out,
+                                const content::DownloadId& global_id) {
+  return out << global_id.DebugString();
+}
+
+// Allow using DownloadIds as keys in hash_maps.
+namespace BASE_HASH_NAMESPACE {
+#if defined(COMPILER_GCC)
+template<> struct hash<content::DownloadId> {
+  std::size_t operator()(const content::DownloadId& id) const {
+    return id.hash();
+  }
+};
+#elif defined(COMPILER_MSVC)
+inline size_t hash_value(const content::DownloadId& id) {
+  return id.hash();
+}
+#endif  // COMPILER
+}
+#endif  // CONTENT_PUBLIC_BROWSER_DOWNLOAD_ID_H_