Reland of "Remove void** from disk_cache interface" w/ blockfile iter fix.

net/disk_cache/simple/simple_backend_impl.cc

 // Copyright (c) 2013 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/simple/simple_backend_impl.h"
 
 #include <algorithm>
 #include <cstdlib>
 #include <functional>
 
@@ skipping 455 matching lines @@
       base::Bind(&SimpleBackendImpl::IndexReadyForDoom, AsWeakPtr(),
                  initial_time, end_time, callback));
 }
 
 int SimpleBackendImpl::DoomEntriesSince(
     const Time initial_time,
     const CompletionCallback& callback) {
   return DoomEntriesBetween(initial_time, Time(), callback);
 }
 
-int SimpleBackendImpl::OpenNextEntry(void** iter,
-                                     Entry** next_entry,
-                                     const CompletionCallback& callback) {
-  CompletionCallback get_next_entry =
-      base::Bind(&SimpleBackendImpl::GetNextEntryInIterator, AsWeakPtr(), iter,
-                 next_entry, callback);
-  return index_->ExecuteWhenReady(get_next_entry);
-}
+class SimpleBackendImpl::SimpleIterator FINAL : public Iterator {
+ public:
+  explicit SimpleIterator(base::WeakPtr<SimpleBackendImpl> backend)
+      : backend_(backend),
+        weak_factory_(this) {
+  }
 
-void SimpleBackendImpl::EndEnumeration(void** iter) {
-  active_enumerations_.Remove(IteratorToEnumerationId(iter));
-  *iter = NULL;
+  // From Backend::Iterator:
+  virtual int OpenNextEntry(Entry** next_entry,
+                            const CompletionCallback& callback) OVERRIDE {
+    CompletionCallback open_next_entry_impl =
+        base::Bind(&SimpleIterator::OpenNextEntryImpl,
+                   weak_factory_.GetWeakPtr(), next_entry, callback);
+    return backend_->index_->ExecuteWhenReady(open_next_entry_impl);
+  }
+
+  void OpenNextEntryImpl(Entry** next_entry,
+                         const CompletionCallback& callback,
+                         int index_initialization_error_code) {
+    if (!backend_) {
+      callback.Run(net::ERR_FAILED);
+      return;
+    }
+    if (index_initialization_error_code != net::OK) {
+      callback.Run(index_initialization_error_code);
+      return;
+    }
+    if (!hashes_to_enumerate_)
+      hashes_to_enumerate_ = backend_->index()->GetAllHashes().Pass();
+
+    while (!hashes_to_enumerate_->empty()) {
+      uint64 entry_hash = hashes_to_enumerate_->back();
+      hashes_to_enumerate_->pop_back();
+      if (backend_->index()->Has(entry_hash)) {
+        *next_entry = NULL;
+        CompletionCallback continue_iteration = base::Bind(
+            &SimpleIterator::CheckIterationReturnValue,
+            weak_factory_.GetWeakPtr(),
+            next_entry,
+            callback);
+        int error_code_open = backend_->OpenEntryFromHash(entry_hash,
+                                                          next_entry,
+                                                          continue_iteration);
+        if (error_code_open == net::ERR_IO_PENDING)
+          return;
+        if (error_code_open != net::ERR_FAILED) {
+          callback.Run(error_code_open);
+          return;
+        }
+      }
+    }
+    callback.Run(net::ERR_FAILED);
+  }
+
+  void CheckIterationReturnValue(Entry** entry,
+                                 const CompletionCallback& callback,
+                                 int error_code) {
+    if (error_code == net::ERR_FAILED) {
+      OpenNextEntry(entry, callback);
+      return;
+    }
+    callback.Run(error_code);
+  }
+
+ private:
+  base::WeakPtr<SimpleBackendImpl> backend_;
+  scoped_ptr<std::vector<uint64> > hashes_to_enumerate_;
+  base::WeakPtrFactory<SimpleIterator> weak_factory_;
+};
+
+scoped_ptr<Backend::Iterator> SimpleBackendImpl::CreateIterator() {
+  return scoped_ptr<Iterator>(new SimpleIterator(AsWeakPtr()));
 }
 
 void SimpleBackendImpl::GetStats(
     std::vector<std::pair<std::string, std::string> >* stats) {
   std::pair<std::string, std::string> item;
   item.first = "Cache type";
   item.second = "Simple Cache";
   stats->push_back(item);
 }
 
 void SimpleBackendImpl::OnExternalCacheHit(const std::string& key) {
   index_->UseIfExists(simple_util::GetEntryHashKey(key));
 }
 
-// static
-SimpleBackendImpl::ActiveEnumerationMap::KeyType
-    SimpleBackendImpl::IteratorToEnumerationId(void** iter) {
-  COMPILE_ASSERT(sizeof(ptrdiff_t) >= sizeof(*iter),
-                 integer_type_must_fit_ptr_type_for_cast_to_be_reversible);
-  const ptrdiff_t ptrdiff_enumeration_id = reinterpret_cast<ptrdiff_t>(*iter);
-  const ActiveEnumerationMap::KeyType enumeration_id = ptrdiff_enumeration_id;
-  DCHECK_EQ(enumeration_id, ptrdiff_enumeration_id);
-  return enumeration_id;
-}
-
-// static
-void* SimpleBackendImpl::EnumerationIdToIterator(
-    ActiveEnumerationMap::KeyType enumeration_id) {
-  const ptrdiff_t ptrdiff_enumeration_id = enumeration_id;
-  DCHECK_EQ(enumeration_id, ptrdiff_enumeration_id);
-  COMPILE_ASSERT(sizeof(ptrdiff_t) >= sizeof(void*),
-                 integer_type_must_fit_ptr_type_for_cast_to_be_reversible);
-  return reinterpret_cast<void*>(ptrdiff_enumeration_id);
-}
-
 void SimpleBackendImpl::InitializeIndex(const CompletionCallback& callback,
                                         const DiskStatResult& result) {
   if (result.net_error == net::OK) {
     index_->SetMaxSize(result.max_size);
     index_->Initialize(result.cache_dir_mtime);
   }
   callback.Run(result.net_error);
 }
 
 SimpleBackendImpl::DiskStatResult SimpleBackendImpl::InitCacheStructureOnDisk(
@@ skipping 93 matching lines @@
     return active_it->second->DoomEntry(callback);
 
   // There's no pending dooms, nor any open entry. We can make a trivial
   // call to DoomEntries() to delete this entry.
   std::vector<uint64> entry_hash_vector;
   entry_hash_vector.push_back(entry_hash);
   DoomEntries(&entry_hash_vector, callback);
   return net::ERR_IO_PENDING;
 }
 
-void SimpleBackendImpl::GetNextEntryInIterator(
-    void** iter,
-    Entry** next_entry,
-    const CompletionCallback& callback,
-    int error_code) {
-  if (error_code != net::OK) {
-    callback.Run(error_code);
-    return;
-  }
-  std::vector<uint64>* entry_list = NULL;
-  if (*iter == NULL) {
-    const ActiveEnumerationMap::KeyType new_enumeration_id =
-        active_enumerations_.Add(
-            entry_list = index()->GetAllHashes().release());
-    *iter = EnumerationIdToIterator(new_enumeration_id);
-  } else {
-    entry_list = active_enumerations_.Lookup(IteratorToEnumerationId(iter));
-  }
-  while (entry_list->size() > 0) {
-    uint64 entry_hash = entry_list->back();
-    entry_list->pop_back();
-    if (index()->Has(entry_hash)) {
-      *next_entry = NULL;
-      CompletionCallback continue_iteration = base::Bind(
-          &SimpleBackendImpl::CheckIterationReturnValue,
-          AsWeakPtr(),
-          iter,
-          next_entry,
-          callback);
-      int error_code_open = OpenEntryFromHash(entry_hash,
-                                              next_entry,
-                                              continue_iteration);
-      if (error_code_open == net::ERR_IO_PENDING)
-        return;
-      if (error_code_open != net::ERR_FAILED) {
-        callback.Run(error_code_open);
-        return;
-      }
-    }
-  }
-  callback.Run(net::ERR_FAILED);
-}
-
 void SimpleBackendImpl::OnEntryOpenedFromHash(
     uint64 hash,
     Entry** entry,
     const scoped_refptr<SimpleEntryImpl>& simple_entry,
     const CompletionCallback& callback,
     int error_code) {
   if (error_code != net::OK) {
     callback.Run(error_code);
     return;
   }
@@ skipping 33 matching lines @@
       simple_entry->Close();
       final_code = net::ERR_FAILED;
     } else {
       DCHECK_EQ(simple_entry->entry_hash(), simple_util::GetEntryHashKey(key));
     }
     SIMPLE_CACHE_UMA(BOOLEAN, "KeyMatchedOnOpen", cache_type_, key_matches);
   }
   callback.Run(final_code);
 }
 
-void SimpleBackendImpl::CheckIterationReturnValue(
-    void** iter,
-    Entry** entry,
-    const CompletionCallback& callback,
-    int error_code) {
-  if (error_code == net::ERR_FAILED) {
-    OpenNextEntry(iter, entry, callback);
-    return;
-  }
-  callback.Run(error_code);
-}
-
 void SimpleBackendImpl::DoomEntriesComplete(
     scoped_ptr<std::vector<uint64> > entry_hashes,
     const net::CompletionCallback& callback,
     int result) {
   std::for_each(
       entry_hashes->begin(), entry_hashes->end(),
       std::bind1st(std::mem_fun(&SimpleBackendImpl::OnDoomComplete),
                    this));
   callback.Run(result);
 }
 
 void SimpleBackendImpl::FlushWorkerPoolForTesting() {
   if (g_sequenced_worker_pool)
     g_sequenced_worker_pool->FlushForTesting();
 }
 
 }  // namespace disk_cache