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// Copyright (c) 2006-2008 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/eviction.h"
#include "base/logging.h"
#include "base/message_loop.h"
#include "base/string_util.h"
#include "base/time.h"
#include "net/disk_cache/backend_impl.h"
#include "net/disk_cache/entry_impl.h"
#include "net/disk_cache/trace.h"
using base::Time;
namespace {
const int kCleanUpMargin = 1024 * 1024;
int LowWaterAdjust(int high_water) {
if (high_water < kCleanUpMargin)
return 0;
return high_water - kCleanUpMargin;
}
} // namespace
namespace disk_cache {
void Eviction::Init(BackendImpl* backend) {
// We grab a bunch of info from the backend to make the code a little cleaner
// when we're actually doing work.
backend_ = backend;
rankings_ = &backend->rankings_;
header_ = &backend_->data_->header;
max_size_ = LowWaterAdjust(backend_->max_size_);
}
void Eviction::TrimCache(bool empty) {
Trace("*** Trim Cache ***");
if (backend_->disabled_)
return;
Time start = Time::Now();
Rankings::ScopedRankingsBlock node(rankings_);
Rankings::ScopedRankingsBlock next(rankings_,
rankings_->GetPrev(node.get(), Rankings::NO_USE));
DCHECK(next.get());
int target_size = empty ? 0 : max_size_;
int deleted = 0;
while (header_->num_bytes > target_size && next.get()) {
node.reset(next.release());
next.reset(rankings_->GetPrev(node.get(), Rankings::NO_USE));
if (!node->Data()->pointer || empty) {
// This entry is not being used by anybody.
EntryImpl* entry;
bool dirty;
if (backend_->NewEntry(Addr(node->Data()->contents), &entry, &dirty)) {
Trace("NewEntry failed on Trim 0x%x", node->address().value());
continue;
}
if (node->Data()->pointer) {
entry = EntryImpl::Update(entry);
}
ReportTrimTimes(entry);
entry->Doom();
entry->Release();
if (!empty)
backend_->OnEvent(Stats::TRIM_ENTRY);
if (++deleted == 4 && !empty) {
#if defined(OS_WIN)
MessageLoop::current()->PostTask(FROM_HERE,
factory_.NewRunnableMethod(&Eviction::TrimCache, false));
break;
#endif
}
}
}
UMA_HISTOGRAM_TIMES(L"DiskCache.TotalTrimTime", Time::Now() - start);
Trace("*** Trim Cache end ***");
return;
}
void Eviction::UpdateRank(EntryImpl* entry, bool modified) {
rankings_->UpdateRank(entry->rankings(), modified, GetListForEntry(entry));
}
void Eviction::OnOpenEntry(EntryImpl* entry) {
}
void Eviction::OnCreateEntry(EntryImpl* entry) {
rankings_->Insert(entry->rankings(), true, GetListForEntry(entry));
}
void Eviction::OnDoomEntry(EntryImpl* entry) {
rankings_->Remove(entry->rankings(), GetListForEntry(entry));
}
void Eviction::OnDestroyEntry(EntryImpl* entry) {
}
void Eviction::ReportTrimTimes(EntryImpl* entry) {
static bool first_time = true;
if (first_time) {
first_time = false;
std::wstring name(StringPrintf(L"DiskCache.TrimAge_%d",
header_->experiment));
static Histogram counter(name.c_str(), 1, 10000, 50);
counter.SetFlags(kUmaTargetedHistogramFlag);
counter.Add((Time::Now() - entry->GetLastUsed()).InHours());
}
}
Rankings::List Eviction::GetListForEntry(EntryImpl* entry) {
return Rankings::NO_USE;
}
} // namespace disk_cache
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