Reland of "Remove void** from disk_cache interface."

net/disk_cache/memory/mem_backend_impl.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/disk_cache/memory/mem_backend_impl.h"
 
 #include "base/logging.h"
 #include "base/sys_info.h"
 #include "net/base/net_errors.h"
 #include "net/disk_cache/cache_util.h"
@@ skipping 11 matching lines @@
     return 0;
 
   return high_water - kCleanUpMargin;
 }
 
 }  // namespace
 
 namespace disk_cache {
 
 MemBackendImpl::MemBackendImpl(net::NetLog* net_log)
-    : max_size_(0), current_size_(0), net_log_(net_log) {}
+    : max_size_(0), current_size_(0), net_log_(net_log), weak_factory_(this) {
+}
 
 MemBackendImpl::~MemBackendImpl() {
   EntryMap::iterator it = entries_.begin();
   while (it != entries_.end()) {
     it->second->Doom();
     it = entries_.begin();
   }
   DCHECK(!current_size_);
 }
 
@@ skipping 130 matching lines @@
 }
 
 int MemBackendImpl::DoomEntriesSince(const base::Time initial_time,
                                      const CompletionCallback& callback) {
   if (DoomEntriesSince(initial_time))
     return net::OK;
 
   return net::ERR_FAILED;
 }
 
-int MemBackendImpl::OpenNextEntry(void** iter, Entry** next_entry,
-                                  const CompletionCallback& callback) {
-  if (OpenNextEntry(iter, next_entry))
-    return net::OK;
+class MemBackendImpl::MemIterator : public Backend::Iterator {
+ public:
+  explicit MemIterator(base::WeakPtr<MemBackendImpl> backend)
+      : backend_(backend), current_(NULL) {
+  }
 
-  return net::ERR_FAILED;
-}
+  virtual int OpenNextEntry(Entry** next_entry,
+                            const CompletionCallback& callback) OVERRIDE {
+    if (!backend_)
+      return net::ERR_FAILED;
 
-void MemBackendImpl::EndEnumeration(void** iter) {
-  *iter = NULL;
+    MemEntryImpl* node = backend_->rankings_.GetNext(current_);
+    // We should never return a child entry so iterate until we hit a parent
+    // entry.
+    while (node && node->type() != MemEntryImpl::kParentEntry)
+      node = backend_->rankings_.GetNext(node);
+    *next_entry = node;
+    current_ = node;
+
+    if (node) {
+      node->Open();
+      return net::OK;
+    }
+    return net::ERR_FAILED;
+  }
+
+ private:
+  base::WeakPtr<MemBackendImpl> backend_;
+  MemEntryImpl* current_;
+};
+
+scoped_ptr<Backend::Iterator> MemBackendImpl::CreateIterator() {
+  return scoped_ptr<Backend::Iterator>(
+      new MemIterator(weak_factory_.GetWeakPtr()));
 }
 
 void MemBackendImpl::OnExternalCacheHit(const std::string& key) {
   EntryMap::iterator it = entries_.find(key);
   if (it != entries_.end()) {
     UpdateRank(it->second);
   }
 }
 
 bool MemBackendImpl::OpenEntry(const std::string& key, Entry** entry) {
@@ skipping 77 matching lines @@
     // Get the entry in the front.
     Entry* entry = rankings_.GetNext(NULL);
 
     // Break the loop when there are no more entries or the entry is too old.
     if (!entry || entry->GetLastUsed() < initial_time)
       return true;
     entry->Doom();
   }
 }
 
-bool MemBackendImpl::OpenNextEntry(void** iter, Entry** next_entry) {
-  MemEntryImpl* current = reinterpret_cast<MemEntryImpl*>(*iter);
-  MemEntryImpl* node = rankings_.GetNext(current);
-  // We should never return a child entry so iterate until we hit a parent
-  // entry.
-  while (node && node->type() != MemEntryImpl::kParentEntry) {
-    node = rankings_.GetNext(node);
-  }
-  *next_entry = node;
-  *iter = node;
-
-  if (node)
-    node->Open();
-
-  return NULL != node;
-}
-
 void MemBackendImpl::TrimCache(bool empty) {
   MemEntryImpl* next = rankings_.GetPrev(NULL);
   if (!next)
     return;
 
   int target_size = empty ? 0 : LowWaterAdjust(max_size_);
   while (current_size_ > target_size && next) {
     MemEntryImpl* node = next;
     next = rankings_.GetPrev(next);
     if (!node->InUse() || empty) {
@@ skipping 11 matching lines @@
   if (current_size_ > max_size_)
     TrimCache(false);
 }
 
 void MemBackendImpl::SubstractStorageSize(int32 bytes) {
   current_size_ -= bytes;
   DCHECK_GE(current_size_, 0);
 }
 
 }  // namespace disk_cache