net/disk_cache/entry_unittest.cc

// Copyright (c) 2006-2009 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 "base/basictypes.h"
#include "base/platform_thread.h"
#include "base/timer.h"
#include "base/string_util.h"
#include "net/base/io_buffer.h"
#include "net/base/net_errors.h"
#include "net/disk_cache/disk_cache_test_base.h"
#include "net/disk_cache/disk_cache_test_util.h"
#include "net/disk_cache/entry_impl.h"
#include "net/disk_cache/mem_entry_impl.h"
#include "testing/gtest/include/gtest/gtest.h"

using base::Time;

extern volatile int g_cache_tests_received;
extern volatile bool g_cache_tests_error;

// Tests that can run with different types of caches.
class DiskCacheEntryTest : public DiskCacheTestWithCache {
 protected:
  void InternalSyncIO();
  void InternalAsyncIO();
  void ExternalSyncIO();
  void ExternalAsyncIO();
  void StreamAccess();
  void GetKey();
  void GrowData();
  void TruncateData();
  void ZeroLengthIO();
  void ReuseEntry(int size);
  void InvalidData();
  void DoomEntry();
  void DoomedEntry();
  void BasicSparseIO(bool async);
  void HugeSparseIO(bool async);
  void GetAvailableRange();
  void DoomSparseEntry();
  void PartialSparseEntry();
};

void DiskCacheEntryTest::InternalSyncIO() {
  disk_cache::Entry *entry1 = NULL;
  ASSERT_TRUE(cache_->CreateEntry("the first key", &entry1));
  ASSERT_TRUE(NULL != entry1);

  const int kSize1 = 10;
  scoped_refptr<net::IOBuffer> buffer1 = new net::IOBuffer(kSize1);
  CacheTestFillBuffer(buffer1->data(), kSize1, false);
  EXPECT_EQ(0, entry1->ReadData(0, 0, buffer1, kSize1, NULL));
  base::strlcpy(buffer1->data(), "the data", kSize1);
  EXPECT_EQ(10, entry1->WriteData(0, 0, buffer1, kSize1, NULL, false));
  memset(buffer1->data(), 0, kSize1);
  EXPECT_EQ(10, entry1->ReadData(0, 0, buffer1, kSize1, NULL));
  EXPECT_STREQ("the data", buffer1->data());

  const int kSize2 = 5000;
  const int kSize3 = 10000;
  scoped_refptr<net::IOBuffer> buffer2 = new net::IOBuffer(kSize2);
  scoped_refptr<net::IOBuffer> buffer3 = new net::IOBuffer(kSize3);
  memset(buffer3->data(), 0, kSize3);
  CacheTestFillBuffer(buffer2->data(), kSize2, false);
  base::strlcpy(buffer2->data(), "The really big data goes here", kSize2);
  EXPECT_EQ(5000, entry1->WriteData(1, 1500, buffer2, kSize2, NULL, false));
  memset(buffer2->data(), 0, kSize2);
  EXPECT_EQ(4989, entry1->ReadData(1, 1511, buffer2, kSize2, NULL));
  EXPECT_STREQ("big data goes here", buffer2->data());
  EXPECT_EQ(5000, entry1->ReadData(1, 0, buffer2, kSize2, NULL));
  EXPECT_EQ(0, memcmp(buffer2->data(), buffer3->data(), 1500));
  EXPECT_EQ(1500, entry1->ReadData(1, 5000, buffer2, kSize2, NULL));

  EXPECT_EQ(0, entry1->ReadData(1, 6500, buffer2, kSize2, NULL));
  EXPECT_EQ(6500, entry1->ReadData(1, 0, buffer3, kSize3, NULL));
  EXPECT_EQ(8192, entry1->WriteData(1, 0, buffer3, 8192, NULL, false));
  EXPECT_EQ(8192, entry1->ReadData(1, 0, buffer3, kSize3, NULL));
  EXPECT_EQ(8192, entry1->GetDataSize(1));

  entry1->Doom();
  entry1->Close();
  EXPECT_EQ(0, cache_->GetEntryCount());
}

TEST_F(DiskCacheEntryTest, InternalSyncIO) {
  InitCache();
  InternalSyncIO();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyInternalSyncIO) {
  SetMemoryOnlyMode();
  InitCache();
  InternalSyncIO();
}

void DiskCacheEntryTest::InternalAsyncIO() {
  disk_cache::Entry *entry1 = NULL;
  ASSERT_TRUE(cache_->CreateEntry("the first key", &entry1));
  ASSERT_TRUE(NULL != entry1);

  // Avoid using internal buffers for the test. We have to write something to
  // the entry and close it so that we flush the internal buffer to disk. After
  // that, IO operations will be really hitting the disk. We don't care about
  // the content, so just extending the entry is enough (all extensions zero-
  // fill any holes).
  EXPECT_EQ(0, entry1->WriteData(0, 15 * 1024, NULL, 0, NULL, false));
  EXPECT_EQ(0, entry1->WriteData(1, 15 * 1024, NULL, 0, NULL, false));
  entry1->Close();
  ASSERT_TRUE(cache_->OpenEntry("the first key", &entry1));

  // Let's verify that each IO goes to the right callback object.
  CallbackTest callback1(false);
  CallbackTest callback2(false);
  CallbackTest callback3(false);
  CallbackTest callback4(false);
  CallbackTest callback5(false);
  CallbackTest callback6(false);
  CallbackTest callback7(false);
  CallbackTest callback8(false);
  CallbackTest callback9(false);
  CallbackTest callback10(false);
  CallbackTest callback11(false);
  CallbackTest callback12(false);
  CallbackTest callback13(false);

  g_cache_tests_error = false;
  g_cache_tests_received = 0;

  MessageLoopHelper helper;

  const int kSize1 = 10;
  const int kSize2 = 5000;
  const int kSize3 = 10000;
  scoped_refptr<net::IOBuffer> buffer1 = new net::IOBuffer(kSize1);
  scoped_refptr<net::IOBuffer> buffer2 = new net::IOBuffer(kSize2);
  scoped_refptr<net::IOBuffer> buffer3 = new net::IOBuffer(kSize3);
  CacheTestFillBuffer(buffer1->data(), kSize1, false);
  CacheTestFillBuffer(buffer2->data(), kSize2, false);
  CacheTestFillBuffer(buffer3->data(), kSize3, false);

  EXPECT_EQ(0, entry1->ReadData(0, 15 * 1024, buffer1, kSize1, &callback1));
  base::strlcpy(buffer1->data(), "the data", kSize1);
  int expected = 0;
  int ret = entry1->WriteData(0, 0, buffer1, kSize1, &callback2, false);
  EXPECT_TRUE(10 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));
  memset(buffer2->data(), 0, kSize2);
  ret = entry1->ReadData(0, 0, buffer2, kSize1, &callback3);
  EXPECT_TRUE(10 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));
  EXPECT_STREQ("the data", buffer2->data());

  base::strlcpy(buffer2->data(), "The really big data goes here", kSize2);
  ret = entry1->WriteData(1, 1500, buffer2, kSize2, &callback4, true);
  EXPECT_TRUE(5000 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));
  memset(buffer3->data(), 0, kSize3);
  ret = entry1->ReadData(1, 1511, buffer3, kSize2, &callback5);
  EXPECT_TRUE(4989 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));
  EXPECT_STREQ("big data goes here", buffer3->data());
  ret = entry1->ReadData(1, 0, buffer2, kSize2, &callback6);
  EXPECT_TRUE(5000 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  memset(buffer3->data(), 0, kSize3);

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));
  EXPECT_EQ(0, memcmp(buffer2->data(), buffer3->data(), 1500));
  ret = entry1->ReadData(1, 5000, buffer2, kSize2, &callback7);
  EXPECT_TRUE(1500 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  ret = entry1->ReadData(1, 0, buffer3, kSize3, &callback9);
  EXPECT_TRUE(6500 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  ret = entry1->WriteData(1, 0, buffer3, 8192, &callback10, true);
  EXPECT_TRUE(8192 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));
  ret = entry1->ReadData(1, 0, buffer3, kSize3, &callback11);
  EXPECT_TRUE(8192 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_EQ(8192, entry1->GetDataSize(1));

  ret = entry1->ReadData(0, 0, buffer1, kSize1, &callback12);
  EXPECT_TRUE(10 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  ret = entry1->ReadData(1, 0, buffer2, kSize2, &callback13);
  EXPECT_TRUE(5000 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));

  EXPECT_FALSE(g_cache_tests_error);
  EXPECT_EQ(expected, g_cache_tests_received);

  entry1->Doom();
  entry1->Close();
  EXPECT_EQ(0, cache_->GetEntryCount());
}

TEST_F(DiskCacheEntryTest, InternalAsyncIO) {
  InitCache();
  InternalAsyncIO();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyInternalAsyncIO) {
  SetMemoryOnlyMode();
  InitCache();
  InternalAsyncIO();
}

void DiskCacheEntryTest::ExternalSyncIO() {
  disk_cache::Entry *entry1;
  ASSERT_TRUE(cache_->CreateEntry("the first key", &entry1));

  const int kSize1 = 17000;
  const int kSize2 = 25000;
  scoped_refptr<net::IOBuffer> buffer1 = new net::IOBuffer(kSize1);
  scoped_refptr<net::IOBuffer> buffer2 = new net::IOBuffer(kSize2);
  CacheTestFillBuffer(buffer1->data(), kSize1, false);
  CacheTestFillBuffer(buffer2->data(), kSize2, false);
  base::strlcpy(buffer1->data(), "the data", kSize1);
  EXPECT_EQ(17000, entry1->WriteData(0, 0, buffer1, kSize1, NULL, false));
  memset(buffer1->data(), 0, kSize1);
  EXPECT_EQ(17000, entry1->ReadData(0, 0, buffer1, kSize1, NULL));
  EXPECT_STREQ("the data", buffer1->data());

  base::strlcpy(buffer2->data(), "The really big data goes here", kSize2);
  EXPECT_EQ(25000, entry1->WriteData(1, 10000, buffer2, kSize2, NULL, false));
  memset(buffer2->data(), 0, kSize2);
  EXPECT_EQ(24989, entry1->ReadData(1, 10011, buffer2, kSize2, NULL));
  EXPECT_STREQ("big data goes here", buffer2->data());
  EXPECT_EQ(25000, entry1->ReadData(1, 0, buffer2, kSize2, NULL));
  EXPECT_EQ(0, memcmp(buffer2->data(), buffer2->data(), 10000));
  EXPECT_EQ(5000, entry1->ReadData(1, 30000, buffer2, kSize2, NULL));

  EXPECT_EQ(0, entry1->ReadData(1, 35000, buffer2, kSize2, NULL));
  EXPECT_EQ(17000, entry1->ReadData(1, 0, buffer1, kSize1, NULL));
  EXPECT_EQ(17000, entry1->WriteData(1, 20000, buffer1, kSize1, NULL, false));
  EXPECT_EQ(37000, entry1->GetDataSize(1));

  entry1->Doom();
  entry1->Close();
  EXPECT_EQ(0, cache_->GetEntryCount());
}

TEST_F(DiskCacheEntryTest, ExternalSyncIO) {
  InitCache();
  ExternalSyncIO();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyExternalSyncIO) {
  SetMemoryOnlyMode();
  InitCache();
  ExternalSyncIO();
}

void DiskCacheEntryTest::ExternalAsyncIO() {
  disk_cache::Entry *entry1;
  ASSERT_TRUE(cache_->CreateEntry("the first key", &entry1));

  // Let's verify that each IO goes to the right callback object.
  CallbackTest callback1(false);
  CallbackTest callback2(false);
  CallbackTest callback3(false);
  CallbackTest callback4(false);
  CallbackTest callback5(false);
  CallbackTest callback6(false);
  CallbackTest callback7(false);
  CallbackTest callback8(false);
  CallbackTest callback9(false);

  g_cache_tests_error = false;
  g_cache_tests_received = 0;
  int expected = 0;

  MessageLoopHelper helper;

  const int kSize1 = 17000;
  const int kSize2 = 25000;
  const int kSize3 = 25000;
  scoped_refptr<net::IOBuffer> buffer1 = new net::IOBuffer(kSize1);
  scoped_refptr<net::IOBuffer> buffer2 = new net::IOBuffer(kSize2);
  scoped_refptr<net::IOBuffer> buffer3 = new net::IOBuffer(kSize3);
  CacheTestFillBuffer(buffer1->data(), kSize1, false);
  CacheTestFillBuffer(buffer2->data(), kSize2, false);
  CacheTestFillBuffer(buffer3->data(), kSize3, false);
  base::strlcpy(buffer1->data(), "the data", kSize1);
  int ret = entry1->WriteData(0, 0, buffer1, kSize1, &callback1, false);
  EXPECT_TRUE(17000 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));

  memset(buffer2->data(), 0, kSize1);
  ret = entry1->ReadData(0, 0, buffer2, kSize1, &callback2);
  EXPECT_TRUE(17000 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));
  EXPECT_STREQ("the data", buffer1->data());

  base::strlcpy(buffer2->data(), "The really big data goes here", kSize2);
  ret = entry1->WriteData(1, 10000, buffer2, kSize2, &callback3, false);
  EXPECT_TRUE(25000 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));

  memset(buffer3->data(), 0, kSize3);
  ret = entry1->ReadData(1, 10011, buffer3, kSize3, &callback4);
  EXPECT_TRUE(24989 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));
  EXPECT_STREQ("big data goes here", buffer3->data());
  ret = entry1->ReadData(1, 0, buffer2, kSize2, &callback5);
  EXPECT_TRUE(25000 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));
  EXPECT_EQ(0, memcmp(buffer2->data(), buffer2->data(), 10000));
  ret = entry1->ReadData(1, 30000, buffer2, kSize2, &callback6);
  EXPECT_TRUE(5000 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;

  EXPECT_EQ(0, entry1->ReadData(1, 35000, buffer2, kSize2, &callback7));
  ret = entry1->ReadData(1, 0, buffer1, kSize1, &callback8);
  EXPECT_TRUE(17000 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;
  ret = entry1->WriteData(1, 20000, buffer1, kSize1, &callback9, false);
  EXPECT_TRUE(17000 == ret || net::ERR_IO_PENDING == ret);
  if (net::ERR_IO_PENDING == ret)
    expected++;
  EXPECT_EQ(37000, entry1->GetDataSize(1));

  EXPECT_TRUE(helper.WaitUntilCacheIoFinished(expected));

  EXPECT_FALSE(g_cache_tests_error);
  EXPECT_EQ(expected, g_cache_tests_received);

  entry1->Doom();
  entry1->Close();
  EXPECT_EQ(0, cache_->GetEntryCount());
}

TEST_F(DiskCacheEntryTest, ExternalAsyncIO) {
  InitCache();
  ExternalAsyncIO();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyExternalAsyncIO) {
  SetMemoryOnlyMode();
  InitCache();
  ExternalAsyncIO();
}

void DiskCacheEntryTest::StreamAccess() {
  disk_cache::Entry *entry = NULL;
  ASSERT_TRUE(cache_->CreateEntry("the first key", &entry));
  ASSERT_TRUE(NULL != entry);

  const int kBufferSize = 1024;
  scoped_refptr<net::IOBuffer> buffer1 = new net::IOBuffer(kBufferSize);
  scoped_refptr<net::IOBuffer> buffer2 = new net::IOBuffer(kBufferSize);

  const int kNumStreams = 3;
  for (int i = 0; i < kNumStreams; i++) {
    CacheTestFillBuffer(buffer1->data(), kBufferSize, false);
    EXPECT_EQ(kBufferSize, entry->WriteData(i, 0, buffer1, kBufferSize, NULL,
                                            false));
    memset(buffer2->data(), 0, kBufferSize);
    EXPECT_EQ(kBufferSize, entry->ReadData(i, 0, buffer2, kBufferSize, NULL));
    EXPECT_EQ(0, memcmp(buffer1->data(), buffer2->data(), kBufferSize));
  }

  EXPECT_EQ(net::ERR_INVALID_ARGUMENT,
            entry->ReadData(kNumStreams, 0, buffer1, kBufferSize, NULL));
  entry->Close();
}

TEST_F(DiskCacheEntryTest, StreamAccess) {
  InitCache();
  StreamAccess();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyStreamAccess) {
  SetMemoryOnlyMode();
  InitCache();
  StreamAccess();
}

void DiskCacheEntryTest::GetKey() {
  std::string key1("the first key");
  disk_cache::Entry *entry1;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));
  EXPECT_EQ(key1, entry1->GetKey()) << "short key";
  entry1->Close();

  int seed = static_cast<int>(Time::Now().ToInternalValue());
  srand(seed);
  char key_buffer[20000];

  CacheTestFillBuffer(key_buffer, 3000, true);
  key_buffer[1000] = '\0';

  key1 = key_buffer;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));
  EXPECT_TRUE(key1 == entry1->GetKey()) << "1000 bytes key";
  entry1->Close();

  key_buffer[1000] = 'p';
  key_buffer[3000] = '\0';
  key1 = key_buffer;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));
  EXPECT_TRUE(key1 == entry1->GetKey()) << "medium size key";
  entry1->Close();

  CacheTestFillBuffer(key_buffer, sizeof(key_buffer), true);
  key_buffer[19999] = '\0';

  key1 = key_buffer;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));
  EXPECT_TRUE(key1 == entry1->GetKey()) << "long key";
  entry1->Close();
}

TEST_F(DiskCacheEntryTest, GetKey) {
  InitCache();
  GetKey();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyGetKey) {
  SetMemoryOnlyMode();
  InitCache();
  GetKey();
}

void DiskCacheEntryTest::GrowData() {
  std::string key1("the first key");
  disk_cache::Entry *entry1, *entry2;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));

  const int kSize = 20000;
  scoped_refptr<net::IOBuffer> buffer1 = new net::IOBuffer(kSize);
  scoped_refptr<net::IOBuffer> buffer2 = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buffer1->data(), kSize, false);
  memset(buffer2->data(), 0, kSize);

  base::strlcpy(buffer1->data(), "the data", kSize);
  EXPECT_EQ(10, entry1->WriteData(0, 0, buffer1, 10, NULL, false));
  EXPECT_EQ(10, entry1->ReadData(0, 0, buffer2, 10, NULL));
  EXPECT_STREQ("the data", buffer2->data());
  EXPECT_EQ(10, entry1->GetDataSize(0));

  EXPECT_EQ(2000, entry1->WriteData(0, 0, buffer1, 2000, NULL, false));
  EXPECT_EQ(2000, entry1->GetDataSize(0));
  EXPECT_EQ(2000, entry1->ReadData(0, 0, buffer2, 2000, NULL));
  EXPECT_TRUE(!memcmp(buffer1->data(), buffer2->data(), 2000));

  EXPECT_EQ(20000, entry1->WriteData(0, 0, buffer1, kSize, NULL, false));
  EXPECT_EQ(20000, entry1->GetDataSize(0));
  EXPECT_EQ(20000, entry1->ReadData(0, 0, buffer2, kSize, NULL));
  EXPECT_TRUE(!memcmp(buffer1->data(), buffer2->data(), kSize));
  entry1->Close();

  memset(buffer2->data(), 0, kSize);
  ASSERT_TRUE(cache_->CreateEntry("Second key", &entry2));
  EXPECT_EQ(10, entry2->WriteData(0, 0, buffer1, 10, NULL, false));
  EXPECT_EQ(10, entry2->GetDataSize(0));
  entry2->Close();

  // Go from an internal address to a bigger block size.
  ASSERT_TRUE(cache_->OpenEntry("Second key", &entry2));
  EXPECT_EQ(2000, entry2->WriteData(0, 0, buffer1, 2000, NULL, false));
  EXPECT_EQ(2000, entry2->GetDataSize(0));
  EXPECT_EQ(2000, entry2->ReadData(0, 0, buffer2, 2000, NULL));
  EXPECT_TRUE(!memcmp(buffer1->data(), buffer2->data(), 2000));
  entry2->Close();
  memset(buffer2->data(), 0, kSize);

  // Go from an internal address to an external one.
  ASSERT_TRUE(cache_->OpenEntry("Second key", &entry2));
  EXPECT_EQ(20000, entry2->WriteData(0, 0, buffer1, kSize, NULL, false));
  EXPECT_EQ(20000, entry2->GetDataSize(0));
  EXPECT_EQ(20000, entry2->ReadData(0, 0, buffer2, kSize, NULL));
  EXPECT_TRUE(!memcmp(buffer1->data(), buffer2->data(), kSize));
  entry2->Close();
}

TEST_F(DiskCacheEntryTest, GrowData) {
  InitCache();
  GrowData();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyGrowData) {
  SetMemoryOnlyMode();
  InitCache();
  GrowData();
}

void DiskCacheEntryTest::TruncateData() {
  std::string key1("the first key");
  disk_cache::Entry *entry1;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));

  const int kSize1 = 20000;
  const int kSize2 = 20000;
  scoped_refptr<net::IOBuffer> buffer1 = new net::IOBuffer(kSize1);
  scoped_refptr<net::IOBuffer> buffer2 = new net::IOBuffer(kSize2);

  CacheTestFillBuffer(buffer1->data(), kSize1, false);
  memset(buffer2->data(), 0, kSize2);

  // Simple truncation:
  EXPECT_EQ(200, entry1->WriteData(0, 0, buffer1, 200, NULL, false));
  EXPECT_EQ(200, entry1->GetDataSize(0));
  EXPECT_EQ(100, entry1->WriteData(0, 0, buffer1, 100, NULL, false));
  EXPECT_EQ(200, entry1->GetDataSize(0));
  EXPECT_EQ(100, entry1->WriteData(0, 0, buffer1, 100, NULL, true));
  EXPECT_EQ(100, entry1->GetDataSize(0));
  EXPECT_EQ(0, entry1->WriteData(0, 50, buffer1, 0, NULL, true));
  EXPECT_EQ(50, entry1->GetDataSize(0));
  EXPECT_EQ(0, entry1->WriteData(0, 0, buffer1, 0, NULL, true));
  EXPECT_EQ(0, entry1->GetDataSize(0));
  entry1->Close();
  ASSERT_TRUE(cache_->OpenEntry(key1, &entry1));

  // Go to an external file.
  EXPECT_EQ(20000, entry1->WriteData(0, 0, buffer1, 20000, NULL, true));
  EXPECT_EQ(20000, entry1->GetDataSize(0));
  EXPECT_EQ(20000, entry1->ReadData(0, 0, buffer2, 20000, NULL));
  EXPECT_TRUE(!memcmp(buffer1->data(), buffer2->data(), 20000));
  memset(buffer2->data(), 0, kSize2);

  // External file truncation
  EXPECT_EQ(18000, entry1->WriteData(0, 0, buffer1, 18000, NULL, false));
  EXPECT_EQ(20000, entry1->GetDataSize(0));
  EXPECT_EQ(18000, entry1->WriteData(0, 0, buffer1, 18000, NULL, true));
  EXPECT_EQ(18000, entry1->GetDataSize(0));
  EXPECT_EQ(0, entry1->WriteData(0, 17500, buffer1, 0, NULL, true));
  EXPECT_EQ(17500, entry1->GetDataSize(0));

  // And back to an internal block.
  EXPECT_EQ(600, entry1->WriteData(0, 1000, buffer1, 600, NULL, true));
  EXPECT_EQ(1600, entry1->GetDataSize(0));
  EXPECT_EQ(600, entry1->ReadData(0, 1000, buffer2, 600, NULL));
  EXPECT_TRUE(!memcmp(buffer1->data(), buffer2->data(), 600));
  EXPECT_EQ(1000, entry1->ReadData(0, 0, buffer2, 1000, NULL));
  EXPECT_TRUE(!memcmp(buffer1->data(), buffer2->data(), 1000)) <<
      "Preserves previous data";

  // Go from external file to zero length.
  EXPECT_EQ(20000, entry1->WriteData(0, 0, buffer1, 20000, NULL, true));
  EXPECT_EQ(20000, entry1->GetDataSize(0));
  EXPECT_EQ(0, entry1->WriteData(0, 0, buffer1, 0, NULL, true));
  EXPECT_EQ(0, entry1->GetDataSize(0));

  entry1->Close();
}

TEST_F(DiskCacheEntryTest, TruncateData) {
  InitCache();
  TruncateData();

  // We generate asynchronous IO that is not really tracked until completion
  // so we just wait here before running the next test.
  MessageLoopHelper helper;
  helper.WaitUntilCacheIoFinished(1);
}

TEST_F(DiskCacheEntryTest, MemoryOnlyTruncateData) {
  SetMemoryOnlyMode();
  InitCache();
  TruncateData();
}

void DiskCacheEntryTest::ZeroLengthIO() {
  std::string key1("the first key");
  disk_cache::Entry *entry1;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));

  EXPECT_EQ(0, entry1->ReadData(0, 0, NULL, 0, NULL));
  EXPECT_EQ(0, entry1->WriteData(0, 0, NULL, 0, NULL, false));

  // This write should extend the entry.
  EXPECT_EQ(0, entry1->WriteData(0, 1000, NULL, 0, NULL, false));
  EXPECT_EQ(0, entry1->ReadData(0, 500, NULL, 0, NULL));
  EXPECT_EQ(0, entry1->ReadData(0, 2000, NULL, 0, NULL));
  EXPECT_EQ(1000, entry1->GetDataSize(0));
  entry1->Close();
}

TEST_F(DiskCacheEntryTest, ZeroLengthIO) {
  InitCache();
  ZeroLengthIO();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyZeroLengthIO) {
  SetMemoryOnlyMode();
  InitCache();
  ZeroLengthIO();
}

// Write more than the total cache capacity but to a single entry. |size| is the
// amount of bytes to write each time.
void DiskCacheEntryTest::ReuseEntry(int size) {
  std::string key1("the first key");
  disk_cache::Entry *entry;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry));

  entry->Close();
  std::string key2("the second key");
  ASSERT_TRUE(cache_->CreateEntry(key2, &entry));

  scoped_refptr<net::IOBuffer> buffer = new net::IOBuffer(size);
  CacheTestFillBuffer(buffer->data(), size, false);

  for (int i = 0; i < 15; i++) {
    EXPECT_EQ(0, entry->WriteData(0, 0, buffer, 0, NULL, true));
    EXPECT_EQ(size, entry->WriteData(0, 0, buffer, size, NULL, false));
    entry->Close();
    ASSERT_TRUE(cache_->OpenEntry(key2, &entry));
  }

  entry->Close();
  ASSERT_TRUE(cache_->OpenEntry(key1, &entry)) << "have not evicted this entry";
  entry->Close();
}

TEST_F(DiskCacheEntryTest, ReuseExternalEntry) {
  SetDirectMode();
  SetMaxSize(200 * 1024);
  InitCache();
  ReuseEntry(20 * 1024);
}

TEST_F(DiskCacheEntryTest, MemoryOnlyReuseExternalEntry) {
  SetDirectMode();
  SetMemoryOnlyMode();
  SetMaxSize(200 * 1024);
  InitCache();
  ReuseEntry(20 * 1024);
}

TEST_F(DiskCacheEntryTest, ReuseInternalEntry) {
  SetDirectMode();
  SetMaxSize(100 * 1024);
  InitCache();
  ReuseEntry(10 * 1024);
}

TEST_F(DiskCacheEntryTest, MemoryOnlyReuseInternalEntry) {
  SetDirectMode();
  SetMemoryOnlyMode();
  SetMaxSize(100 * 1024);
  InitCache();
  ReuseEntry(10 * 1024);
}

// Reading somewhere that was not written should return zeros.
void DiskCacheEntryTest::InvalidData() {
  std::string key1("the first key");
  disk_cache::Entry *entry1;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));

  const int kSize1 = 20000;
  const int kSize2 = 20000;
  const int kSize3 = 20000;
  scoped_refptr<net::IOBuffer> buffer1 = new net::IOBuffer(kSize1);
  scoped_refptr<net::IOBuffer> buffer2 = new net::IOBuffer(kSize2);
  scoped_refptr<net::IOBuffer> buffer3 = new net::IOBuffer(kSize3);

  CacheTestFillBuffer(buffer1->data(), kSize1, false);
  memset(buffer2->data(), 0, kSize2);

  // Simple data grow:
  EXPECT_EQ(200, entry1->WriteData(0, 400, buffer1, 200, NULL, false));
  EXPECT_EQ(600, entry1->GetDataSize(0));
  EXPECT_EQ(100, entry1->ReadData(0, 300, buffer3, 100, NULL));
  EXPECT_TRUE(!memcmp(buffer3->data(), buffer2->data(), 100));
  entry1->Close();
  ASSERT_TRUE(cache_->OpenEntry(key1, &entry1));

  // The entry is now on disk. Load it and extend it.
  EXPECT_EQ(200, entry1->WriteData(0, 800, buffer1, 200, NULL, false));
  EXPECT_EQ(1000, entry1->GetDataSize(0));
  EXPECT_EQ(100, entry1->ReadData(0, 700, buffer3, 100, NULL));
  EXPECT_TRUE(!memcmp(buffer3->data(), buffer2->data(), 100));
  entry1->Close();
  ASSERT_TRUE(cache_->OpenEntry(key1, &entry1));

  // This time using truncate.
  EXPECT_EQ(200, entry1->WriteData(0, 1800, buffer1, 200, NULL, true));
  EXPECT_EQ(2000, entry1->GetDataSize(0));
  EXPECT_EQ(100, entry1->ReadData(0, 1500, buffer3, 100, NULL));
  EXPECT_TRUE(!memcmp(buffer3->data(), buffer2->data(), 100));

  // Go to an external file.
  EXPECT_EQ(200, entry1->WriteData(0, 19800, buffer1, 200, NULL, false));
  EXPECT_EQ(20000, entry1->GetDataSize(0));
  EXPECT_EQ(4000, entry1->ReadData(0, 14000, buffer3, 4000, NULL));
  EXPECT_TRUE(!memcmp(buffer3->data(), buffer2->data(), 4000));

  // And back to an internal block.
  EXPECT_EQ(600, entry1->WriteData(0, 1000, buffer1, 600, NULL, true));
  EXPECT_EQ(1600, entry1->GetDataSize(0));
  EXPECT_EQ(600, entry1->ReadData(0, 1000, buffer3, 600, NULL));
  EXPECT_TRUE(!memcmp(buffer3->data(), buffer1->data(), 600));

  // Extend it again.
  EXPECT_EQ(600, entry1->WriteData(0, 2000, buffer1, 600, NULL, false));
  EXPECT_EQ(2600, entry1->GetDataSize(0));
  EXPECT_EQ(200, entry1->ReadData(0, 1800, buffer3, 200, NULL));
  EXPECT_TRUE(!memcmp(buffer3->data(), buffer2->data(), 200));

  // And again (with truncation flag).
  EXPECT_EQ(600, entry1->WriteData(0, 3000, buffer1, 600, NULL, true));
  EXPECT_EQ(3600, entry1->GetDataSize(0));
  EXPECT_EQ(200, entry1->ReadData(0, 2800, buffer3, 200, NULL));
  EXPECT_TRUE(!memcmp(buffer3->data(), buffer2->data(), 200));

  entry1->Close();
}

TEST_F(DiskCacheEntryTest, InvalidData) {
  InitCache();
  InvalidData();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyInvalidData) {
  SetMemoryOnlyMode();
  InitCache();
  InvalidData();
}

void DiskCacheEntryTest::DoomEntry() {
  std::string key1("the first key");
  disk_cache::Entry *entry1;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));
  entry1->Doom();
  entry1->Close();

  const int kSize = 20000;
  scoped_refptr<net::IOBuffer> buffer = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buffer->data(), kSize, true);
  buffer->data()[19999] = '\0';

  key1 = buffer->data();
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));
  EXPECT_EQ(20000, entry1->WriteData(0, 0, buffer, kSize, NULL, false));
  EXPECT_EQ(20000, entry1->WriteData(1, 0, buffer, kSize, NULL, false));
  entry1->Doom();
  entry1->Close();

  EXPECT_EQ(0, cache_->GetEntryCount());
}

TEST_F(DiskCacheEntryTest, DoomEntry) {
  InitCache();
  DoomEntry();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyDoomEntry) {
  SetMemoryOnlyMode();
  InitCache();
  DoomEntry();
}

// Verify that basic operations work as expected with doomed entries.
void DiskCacheEntryTest::DoomedEntry() {
  std::string key("the first key");
  disk_cache::Entry *entry;
  ASSERT_TRUE(cache_->CreateEntry(key, &entry));
  entry->Doom();

  EXPECT_EQ(0, cache_->GetEntryCount());
  Time initial = Time::Now();
  PlatformThread::Sleep(20);

  const int kSize1 = 2000;
  const int kSize2 = 2000;
  scoped_refptr<net::IOBuffer> buffer1 = new net::IOBuffer(kSize1);
  scoped_refptr<net::IOBuffer> buffer2 = new net::IOBuffer(kSize2);
  CacheTestFillBuffer(buffer1->data(), kSize1, false);
  memset(buffer2->data(), 0, kSize2);

  EXPECT_EQ(2000, entry->WriteData(0, 0, buffer1, 2000, NULL, false));
  EXPECT_EQ(2000, entry->ReadData(0, 0, buffer2, 2000, NULL));
  EXPECT_EQ(0, memcmp(buffer1->data(), buffer2->data(), kSize1));
  EXPECT_EQ(key, entry->GetKey());
  EXPECT_TRUE(initial < entry->GetLastModified());
  EXPECT_TRUE(initial < entry->GetLastUsed());

  entry->Close();
}

TEST_F(DiskCacheEntryTest, DoomedEntry) {
  InitCache();
  DoomEntry();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyDoomedEntry) {
  SetMemoryOnlyMode();
  InitCache();
  DoomEntry();
}

// Test that child entries in a memory cache backend are not visible from
// enumerations.
TEST_F(DiskCacheEntryTest, MemoryOnlyEnumerationWithSparseEntries) {
  SetMemoryOnlyMode();
  InitCache();

  const int kSize = 4096;
  scoped_refptr<net::IOBuffer> buf = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buf->data(), kSize, false);

  std::string key("the first key");
  disk_cache::Entry* parent_entry;
  ASSERT_TRUE(cache_->CreateEntry(key, &parent_entry));

  // Writes to the parent entry.
  EXPECT_EQ(kSize, parent_entry->WriteSparseData(0, buf, kSize, NULL));

  // This write creates a child entry and writes to it.
  EXPECT_EQ(kSize, parent_entry->WriteSparseData(8192, buf, kSize, NULL));

  parent_entry->Close();

  // Perform the enumerations.
  void* iter = NULL;
  disk_cache::Entry* entry = NULL;
  int count = 0;
  while (cache_->OpenNextEntry(&iter, &entry)) {
    ASSERT_TRUE(entry != NULL);
    ++count;
    disk_cache::MemEntryImpl* mem_entry =
        reinterpret_cast<disk_cache::MemEntryImpl*>(entry);
    EXPECT_EQ(disk_cache::MemEntryImpl::kParentEntry, mem_entry->type());
    mem_entry->Close();
  }
  EXPECT_EQ(1, count);
}

// Writes |buf_1| to offset and reads it back as |buf_2|.
void VerifySparseIO(disk_cache::Entry* entry, int64 offset,
                    net::IOBuffer* buf_1, int size, bool async,
                    net::IOBuffer* buf_2) {
  SimpleCallbackTest callback;
  SimpleCallbackTest* cb = async ? &callback : NULL;

  memset(buf_2->data(), 0, size);
  int ret = entry->ReadSparseData(offset, buf_2, size, cb);
  ret = callback.GetResult(ret);
  EXPECT_EQ(0, ret);

  ret = entry->WriteSparseData(offset, buf_1, size, cb);
  ret = callback.GetResult(ret);
  EXPECT_EQ(size, ret);

  ret = entry->ReadSparseData(offset, buf_2, size, cb);
  ret = callback.GetResult(ret);
  EXPECT_EQ(size, ret);

  EXPECT_EQ(0, memcmp(buf_1->data(), buf_2->data(), size));
}

// Reads |size| bytes from |entry| at |offset| and verifies that they are the
// same as the content of the provided |buffer|.
void VerifyContentSparseIO(disk_cache::Entry* entry, int64 offset, char* buffer,
                           int size, bool async) {
  SimpleCallbackTest callback;
  SimpleCallbackTest* cb = async ? &callback : NULL;

  scoped_refptr<net::IOBuffer> buf_1 = new net::IOBuffer(size);
  memset(buf_1->data(), 0, size);
  int ret = entry->ReadSparseData(offset, buf_1, size, cb);
  ret = callback.GetResult(ret);
  EXPECT_EQ(size, ret);

  EXPECT_EQ(0, memcmp(buf_1->data(), buffer, size));
}

void DiskCacheEntryTest::BasicSparseIO(bool async) {
  std::string key("the first key");
  disk_cache::Entry* entry;
  ASSERT_TRUE(cache_->CreateEntry(key, &entry));

  const int kSize = 2048;
  scoped_refptr<net::IOBuffer> buf_1 = new net::IOBuffer(kSize);
  scoped_refptr<net::IOBuffer> buf_2 = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buf_1->data(), kSize, false);

  // Write at offset 0.
  VerifySparseIO(entry, 0, buf_1, kSize, async, buf_2);

  // Write at offset 0x400000 (4 MB).
  VerifySparseIO(entry, 0x400000, buf_1, kSize, async, buf_2);

  // Write at offset 0x800000000 (32 GB).
  VerifySparseIO(entry, 0x800000000LL, buf_1, kSize, async, buf_2);

  entry->Close();

  // Check everything again.
  ASSERT_TRUE(cache_->OpenEntry(key, &entry));
  VerifyContentSparseIO(entry, 0, buf_1->data(), kSize, async);
  VerifyContentSparseIO(entry, 0x400000, buf_1->data(), kSize, async);
  VerifyContentSparseIO(entry, 0x800000000LL, buf_1->data(), kSize, async);
  entry->Close();
}

TEST_F(DiskCacheEntryTest, BasicSparseSyncIO) {
  InitCache();
  BasicSparseIO(false);
}

TEST_F(DiskCacheEntryTest, MemoryOnlyBasicSparseSyncIO) {
  SetMemoryOnlyMode();
  InitCache();
  BasicSparseIO(false);
}

TEST_F(DiskCacheEntryTest, BasicSparseAsyncIO) {
  InitCache();
  BasicSparseIO(true);
}

TEST_F(DiskCacheEntryTest, MemoryOnlyBasicSparseAsyncIO) {
  SetMemoryOnlyMode();
  InitCache();
  BasicSparseIO(true);
}

void DiskCacheEntryTest::HugeSparseIO(bool async) {
  std::string key("the first key");
  disk_cache::Entry* entry;
  ASSERT_TRUE(cache_->CreateEntry(key, &entry));

  // Write 1.2 MB so that we cover multiple entries.
  const int kSize = 1200 * 1024;
  scoped_refptr<net::IOBuffer> buf_1 = new net::IOBuffer(kSize);
  scoped_refptr<net::IOBuffer> buf_2 = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buf_1->data(), kSize, false);

  // Write at offset 0x20F0000 (33 MB - 64 KB).
  VerifySparseIO(entry, 0x20F0000, buf_1, kSize, async, buf_2);
  entry->Close();

  // Check it again.
  ASSERT_TRUE(cache_->OpenEntry(key, &entry));
  VerifyContentSparseIO(entry, 0x20F0000, buf_1->data(), kSize, async);
  entry->Close();
}

TEST_F(DiskCacheEntryTest, HugeSparseSyncIO) {
  InitCache();
  HugeSparseIO(false);
}

TEST_F(DiskCacheEntryTest, MemoryOnlyHugeSparseSyncIO) {
  SetMemoryOnlyMode();
  InitCache();
  HugeSparseIO(false);
}

TEST_F(DiskCacheEntryTest, HugeSparseAsyncIO) {
  InitCache();
  HugeSparseIO(true);
}

TEST_F(DiskCacheEntryTest, MemoryOnlyHugeSparseAsyncIO) {
  SetMemoryOnlyMode();
  InitCache();
  HugeSparseIO(true);
}

void DiskCacheEntryTest::GetAvailableRange() {
  std::string key("the first key");
  disk_cache::Entry* entry;
  ASSERT_TRUE(cache_->CreateEntry(key, &entry));

  const int kSize = 16 * 1024;
  scoped_refptr<net::IOBuffer> buf = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buf->data(), kSize, false);

  // Write at offset 0x20F0000 (33 MB - 64 KB), and 0x20F4400 (33 MB - 47 KB).
  EXPECT_EQ(kSize, entry->WriteSparseData(0x20F0000, buf, kSize, NULL));
  EXPECT_EQ(kSize, entry->WriteSparseData(0x20F4400, buf, kSize, NULL));

  // We stop at the first empty block.
  int64 start;
  EXPECT_EQ(kSize, entry->GetAvailableRange(0x20F0000, kSize * 2, &start));
  EXPECT_EQ(0x20F0000, start);

  start = 0;
  EXPECT_EQ(0, entry->GetAvailableRange(0, kSize, &start));
  EXPECT_EQ(0, entry->GetAvailableRange(0x20F0000 - kSize, kSize, &start));
  EXPECT_EQ(kSize, entry->GetAvailableRange(0, 0x2100000, &start));
  EXPECT_EQ(0x20F0000, start);

  // We should be able to Read based on the results of GetAvailableRange.
  start = -1;
  EXPECT_EQ(0, entry->GetAvailableRange(0x2100000, kSize, &start));
  EXPECT_EQ(0, entry->ReadSparseData(start, buf, kSize, NULL));

  start = 0;
  EXPECT_EQ(0x2000, entry->GetAvailableRange(0x20F2000, kSize, &start));
  EXPECT_EQ(0x20F2000, start);
  EXPECT_EQ(0x2000, entry->ReadSparseData(start, buf, kSize, NULL));

  // Make sure that we respect the |len| argument.
  start = 0;
  EXPECT_EQ(1, entry->GetAvailableRange(0x20F0001 - kSize, kSize, &start));
  EXPECT_EQ(0x20F0000, start);

  entry->Close();
}

TEST_F(DiskCacheEntryTest, GetAvailableRange) {
  InitCache();
  GetAvailableRange();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyGetAvailableRange) {
  SetMemoryOnlyMode();
  InitCache();
  GetAvailableRange();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyMisalignedSparseIO) {
  SetMemoryOnlyMode();
  InitCache();

  const int kSize = 8192;
  scoped_refptr<net::IOBuffer> buf_1 = new net::IOBuffer(kSize);
  scoped_refptr<net::IOBuffer> buf_2 = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buf_1->data(), kSize, false);

  std::string key("the first key");
  disk_cache::Entry* entry;
  ASSERT_TRUE(cache_->CreateEntry(key, &entry));

  // This loop writes back to back starting from offset 0 and 9000.
  for (int i = 0; i < kSize; i += 1024) {
    scoped_refptr<net::WrappedIOBuffer> buf_3 =
      new net::WrappedIOBuffer(buf_1->data() + i);
    VerifySparseIO(entry, i, buf_3, 1024, false, buf_2);
    VerifySparseIO(entry, 9000 + i, buf_3, 1024, false, buf_2);
  }

  // Make sure we have data written.
  VerifyContentSparseIO(entry, 0, buf_1->data(), kSize, false);
  VerifyContentSparseIO(entry, 9000, buf_1->data(), kSize, false);

  // This tests a large write that spans 3 entries from a misaligned offset.
  VerifySparseIO(entry, 20481, buf_1, 8192, false, buf_2);

  entry->Close();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyMisalignedGetAvailableRange) {
  SetMemoryOnlyMode();
  InitCache();

  const int kSize = 8192;
  scoped_refptr<net::IOBuffer> buf = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buf->data(), kSize, false);

  disk_cache::Entry* entry;
  std::string key("the first key");
  ASSERT_TRUE(cache_->CreateEntry(key, &entry));

  // Writes in the middle of an entry.
  EXPECT_EQ(1024, entry->WriteSparseData(0, buf, 1024, NULL));
  EXPECT_EQ(1024, entry->WriteSparseData(5120, buf, 1024, NULL));
  EXPECT_EQ(1024, entry->WriteSparseData(10000, buf, 1024, NULL));

  // Writes in the middle of an entry and spans 2 child entries.
  EXPECT_EQ(8192, entry->WriteSparseData(50000, buf, 8192, NULL));

  int64 start;
  // Test that we stop at a discontinuous child at the second block.
  EXPECT_EQ(1024, entry->GetAvailableRange(0, 10000, &start));
  EXPECT_EQ(0, start);

  // Test that number of bytes is reported correctly when we start from the
  // middle of a filled region.
  EXPECT_EQ(512, entry->GetAvailableRange(512, 10000, &start));
  EXPECT_EQ(512, start);

  // Test that we found bytes in the child of next block.
  EXPECT_EQ(1024, entry->GetAvailableRange(1024, 10000, &start));
  EXPECT_EQ(5120, start);

  // Test that the desired length is respected. It starts within a filled
  // region.
  EXPECT_EQ(512, entry->GetAvailableRange(5500, 512, &start));
  EXPECT_EQ(5500, start);

  // Test that the desired length is respected. It starts before a filled
  // region.
  EXPECT_EQ(500, entry->GetAvailableRange(5000, 620, &start));
  EXPECT_EQ(5120, start);

  // Test that multiple blocks are scanned.
  EXPECT_EQ(8192, entry->GetAvailableRange(40000, 20000, &start));
  EXPECT_EQ(50000, start);

  entry->Close();
}

void DiskCacheEntryTest::DoomSparseEntry() {
  std::string key1("the first key");
  std::string key2("the second key");
  disk_cache::Entry *entry1, *entry2;
  ASSERT_TRUE(cache_->CreateEntry(key1, &entry1));
  ASSERT_TRUE(cache_->CreateEntry(key2, &entry2));

  const int kSize = 4 * 1024;
  scoped_refptr<net::IOBuffer> buf = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buf->data(), kSize, false);

  int64 offset = 1024;
  // Write to a bunch of ranges.
  for (int i = 0; i < 12; i++) {
    EXPECT_EQ(kSize, entry1->WriteSparseData(offset, buf, kSize, NULL));
    // Keep the second map under the default size.
    if (i < 9)
      EXPECT_EQ(kSize, entry2->WriteSparseData(offset, buf, kSize, NULL));
    offset *= 4;
  }

  if (memory_only_)
    EXPECT_EQ(2, cache_->GetEntryCount());
  else
    EXPECT_EQ(15, cache_->GetEntryCount());

  // Doom the first entry while it's still open.
  entry1->Doom();
  entry1->Close();
  entry2->Close();

  // Doom the second entry after it's fully saved.
  EXPECT_TRUE(cache_->DoomEntry(key2));

  // Make sure we do all needed work. This may fail for entry2 if between Close
  // and DoomEntry the system decides to remove all traces of the file from the
  // system cache so we don't see that there is pending IO.
  MessageLoop::current()->RunAllPending();

  if (memory_only_) {
    EXPECT_EQ(0, cache_->GetEntryCount());
  } else {
    if (5 == cache_->GetEntryCount()) {
      // Most likely we are waiting for the result of reading the sparse info
      // (it's always async on Posix so it is easy to miss). Unfortunately we
      // don't have any signal to watch for so we can only wait.
      PlatformThread::Sleep(500);
      MessageLoop::current()->RunAllPending();
    }
    EXPECT_EQ(0, cache_->GetEntryCount());
  }
}

TEST_F(DiskCacheEntryTest, DoomSparseEntry) {
  InitCache();
  DoomSparseEntry();
}

TEST_F(DiskCacheEntryTest, MemoryOnlyDoomSparseEntry) {
  SetMemoryOnlyMode();
  InitCache();
  DoomSparseEntry();
}

void DiskCacheEntryTest::PartialSparseEntry() {
  std::string key("the first key");
  disk_cache::Entry* entry;
  ASSERT_TRUE(cache_->CreateEntry(key, &entry));

  // We should be able to deal with IO that is not aligned to the block size
  // of a sparse entry, at least to write a big range without leaving holes.
  const int kSize = 4 * 1024;
  const int kSmallSize = 128;
  scoped_refptr<net::IOBuffer> buf1 = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buf1->data(), kSize, false);

  // The first write is just to extend the entry. The third write occupies
  // a 1KB block partially, it may not be written internally depending on the
  // implementation.
  EXPECT_EQ(kSize, entry->WriteSparseData(20000, buf1, kSize, NULL));
  EXPECT_EQ(kSize, entry->WriteSparseData(500, buf1, kSize, NULL));
  EXPECT_EQ(kSmallSize,
            entry->WriteSparseData(1080321, buf1, kSmallSize, NULL));
  entry->Close();
  ASSERT_TRUE(cache_->OpenEntry(key, &entry));

  scoped_refptr<net::IOBuffer> buf2 = new net::IOBuffer(kSize);
  memset(buf2->data(), 0, kSize);
  EXPECT_EQ(0, entry->ReadSparseData(8000, buf2, kSize, NULL));

  EXPECT_EQ(500, entry->ReadSparseData(kSize, buf2, kSize, NULL));
  EXPECT_EQ(0, memcmp(buf2->data(), buf1->data() + kSize - 500, 500));
  EXPECT_EQ(0, entry->ReadSparseData(0, buf2, kSize, NULL));

  // This read should not change anything.
  EXPECT_EQ(96, entry->ReadSparseData(24000, buf2, kSize, NULL));
  EXPECT_EQ(500, entry->ReadSparseData(kSize, buf2, kSize, NULL));
  EXPECT_EQ(0, entry->ReadSparseData(499, buf2, kSize, NULL));

  int64 start;
  if (memory_only_) {
    EXPECT_EQ(100, entry->GetAvailableRange(0, 600, &start));
    EXPECT_EQ(500, start);
  } else {
    EXPECT_EQ(1024, entry->GetAvailableRange(0, 2048, &start));
    EXPECT_EQ(1024, start);
  }
  EXPECT_EQ(500, entry->GetAvailableRange(kSize, kSize, &start));
  EXPECT_EQ(kSize, start);
  EXPECT_EQ(3616, entry->GetAvailableRange(20 * 1024, 10000, &start));
  EXPECT_EQ(20 * 1024, start);

  // 1. Query before a filled 1KB block.
  // 2. Query within a filled 1KB block.
  // 3. Query beyond a filled 1KB block.
  if (memory_only_) {
    EXPECT_EQ(3496, entry->GetAvailableRange(19400, kSize, &start));
    EXPECT_EQ(20000, start);
  } else {
    EXPECT_EQ(3016, entry->GetAvailableRange(19400, kSize, &start));
    EXPECT_EQ(20480, start);
  }
  EXPECT_EQ(1523, entry->GetAvailableRange(3073, kSize, &start));
  EXPECT_EQ(3073, start);
  EXPECT_EQ(0, entry->GetAvailableRange(4600, kSize, &start));
  EXPECT_EQ(4600, start);

  // Now make another write and verify that there is no hole in between.
  EXPECT_EQ(kSize, entry->WriteSparseData(500 + kSize, buf1, kSize, NULL));
  EXPECT_EQ(7 * 1024 + 500, entry->GetAvailableRange(1024, 10000, &start));
  EXPECT_EQ(1024, start);
  EXPECT_EQ(kSize, entry->ReadSparseData(kSize, buf2, kSize, NULL));
  EXPECT_EQ(0, memcmp(buf2->data(), buf1->data() + kSize - 500, 500));
  EXPECT_EQ(0, memcmp(buf2->data() + 500, buf1->data(), kSize - 500));

  entry->Close();
}

TEST_F(DiskCacheEntryTest, PartialSparseEntry) {
  InitCache();
  PartialSparseEntry();
}

TEST_F(DiskCacheEntryTest, MemoryPartialSparseEntry) {
  SetMemoryOnlyMode();
  InitCache();
  PartialSparseEntry();
}

TEST_F(DiskCacheEntryTest, CleanupSparseEntry) {
  InitCache();
  std::string key("the first key");
  disk_cache::Entry* entry;
  ASSERT_TRUE(cache_->CreateEntry(key, &entry));

  // Corrupt sparse children should be removed automatically.
  const int kSize = 4 * 1024;
  scoped_refptr<net::IOBuffer> buf1 = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buf1->data(), kSize, false);

  const int k1Meg = 1024 * 1024;
  EXPECT_EQ(kSize, entry->WriteSparseData(8192, buf1, kSize, NULL));
  EXPECT_EQ(kSize, entry->WriteSparseData(k1Meg + 8192, buf1, kSize, NULL));
  EXPECT_EQ(kSize, entry->WriteSparseData(2 * k1Meg + 8192, buf1, kSize, NULL));
  entry->Close();
  EXPECT_EQ(4, cache_->GetEntryCount());

  void* iter = NULL;
  int count = 0;
  std::string child_key[2];
  while (cache_->OpenNextEntry(&iter, &entry)) {
    ASSERT_TRUE(entry != NULL);
    // Writing to an entry will alter the LRU list and invalidate the iterator.
    if (entry->GetKey() != key && count < 2)
      child_key[count++] = entry->GetKey();
    entry->Close();
  }
  for (int i = 0; i < 2; i++) {
    ASSERT_TRUE(cache_->OpenEntry(child_key[i], &entry));
    // Overwrite the header's magic and signature.
    EXPECT_EQ(12, entry->WriteData(2, 0, buf1, 12, NULL, false));
    entry->Close();
  }

  EXPECT_EQ(4, cache_->GetEntryCount());
  ASSERT_TRUE(cache_->OpenEntry(key, &entry));

  // Two children should be gone. One while reading and one while writing.
  EXPECT_EQ(0, entry->ReadSparseData(2 * k1Meg + 8192, buf1, kSize, NULL));
  EXPECT_EQ(kSize, entry->WriteSparseData(k1Meg + 16384, buf1, kSize, NULL));
  EXPECT_EQ(0, entry->ReadSparseData(k1Meg + 8192, buf1, kSize, NULL));

  // We never touched this one.
  EXPECT_EQ(kSize, entry->ReadSparseData(8192, buf1, kSize, NULL));
  entry->Close();

  // We re-created one of the corrupt children.
  EXPECT_EQ(3, cache_->GetEntryCount());
}

TEST_F(DiskCacheEntryTest, CancelSparseIO) {
  InitCache();
  std::string key("the first key");
  disk_cache::Entry* entry;
  ASSERT_TRUE(cache_->CreateEntry(key, &entry));

  const int kSize = 40 * 1024;
  scoped_refptr<net::IOBuffer> buf = new net::IOBuffer(kSize);
  CacheTestFillBuffer(buf->data(), kSize, false);

  SimpleCallbackTest cb1, cb2, cb3, cb4;
  int64 offset = 0;
  int tries = 0;
  const int maxtries = 100;   // Avoid hang on infinitely fast disks
  for (int ret = 0; ret != net::ERR_IO_PENDING; offset += kSize * 4) {
    ret = entry->WriteSparseData(offset, buf, kSize, &cb1);
    if (++tries > maxtries) {
       LOG(ERROR) << "Data writes never come back PENDING; skipping test";
       entry->Close();
       return;
    }
  }

  // Cannot use the entry at this point.
  offset = 0;
  EXPECT_EQ(net::ERR_CACHE_OPERATION_NOT_SUPPORTED,
            entry->GetAvailableRange(offset, kSize, &offset));
  EXPECT_EQ(net::OK, entry->ReadyForSparseIO(&cb2));

  // We cancel the pending operation, and register multiple notifications.
  entry->CancelSparseIO();
  EXPECT_EQ(net::ERR_IO_PENDING, entry->ReadyForSparseIO(&cb2));
  EXPECT_EQ(net::ERR_IO_PENDING, entry->ReadyForSparseIO(&cb3));
  entry->CancelSparseIO();  // Should be a no op at this point.
  EXPECT_EQ(net::ERR_IO_PENDING, entry->ReadyForSparseIO(&cb4));

  offset = 0;
  EXPECT_EQ(net::ERR_CACHE_OPERATION_NOT_SUPPORTED,
            entry->GetAvailableRange(offset, kSize, &offset));
  EXPECT_EQ(net::ERR_CACHE_OPERATION_NOT_SUPPORTED,
            entry->ReadSparseData(offset, buf, kSize, NULL));
  EXPECT_EQ(net::ERR_CACHE_OPERATION_NOT_SUPPORTED,
            entry->WriteSparseData(offset, buf, kSize, NULL));

  // Now see if we receive all notifications.
  EXPECT_EQ(kSize, cb1.GetResult(net::ERR_IO_PENDING));
  EXPECT_EQ(net::OK, cb2.GetResult(net::ERR_IO_PENDING));
  EXPECT_EQ(net::OK, cb3.GetResult(net::ERR_IO_PENDING));
  EXPECT_EQ(net::OK, cb4.GetResult(net::ERR_IO_PENDING));

  EXPECT_EQ(kSize, entry->GetAvailableRange(offset, kSize, &offset));
  EXPECT_EQ(net::OK, entry->ReadyForSparseIO(&cb2));
  entry->Close();
}