SimpleCache: merge the first and second stream in one file

net/disk_cache/simple/simple_synchronous_entry.h

 // 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.
 
 #ifndef NET_DISK_CACHE_SIMPLE_SIMPLE_SYNCHRONOUS_ENTRY_H_
 #define NET_DISK_CACHE_SIMPLE_SIMPLE_SYNCHRONOUS_ENTRY_H_
 
 #include <algorithm>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/files/file_path.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/platform_file.h"
 #include "base/time/time.h"
 #include "net/base/cache_type.h"
 #include "net/disk_cache/simple/simple_entry_format.h"
 
 namespace net {
+class GrowableIOBuffer;
 class IOBuffer;
 }
 
 namespace disk_cache {
 
 class SimpleSynchronousEntry;
 
-struct SimpleEntryStat {
-  SimpleEntryStat();
-  SimpleEntryStat(base::Time last_used_p,
-                  base::Time last_modified_p,
-                  const int32 data_size_p[]);
+class SimpleEntryStat {

[pasko, 2013/09/18 16:53:56]

Now please add a one-sentence comment describing what the class does.

[clamy, 2013/09/18 17:20:46]

Done.

+ public:
+  SimpleEntryStat(base::Time last_used,
+                  base::Time last_modified,
+                  const int32 data_size[]);
 
-  base::Time last_used;
-  base::Time last_modified;
-  int32 data_size[kSimpleEntryFileCount];
+  int GetOffsetInFile(const std::string& key,
+                      int offset,
+                      int stream_index) const;
+  int GetEOFOffsetInFile(const std::string& key, int stream_index) const;
+  int GetLastEOFOffsetInFile(const std::string& key, int file_index) const;
+  int GetFileSize(const std::string& key, int file_index) const;
+
+  base::Time last_used() const { return last_used_; }
+  base::Time last_modified() const { return last_modified_; }
+  void set_last_used(base::Time last_used) { last_used_ = last_used; }
+  void set_last_modified(base::Time last_modified) {
+    last_modified_ = last_modified;
+  }
+
+  int32 data_size(int i) const { return data_size_[i]; }

[pasko, 2013/09/18 16:53:56]

I would prefer s/i/stream/ or s/i/stream_index/

[clamy, 2013/09/18 17:20:46]

Done.

+  void set_data_size(int i, int data_size) { data_size_[i] = data_size; }
+
+ private:
+  base::Time last_used_;
+  base::Time last_modified_;
+  int32 data_size_[kSimpleEntryStreamCount];
 };
 
 struct SimpleEntryCreationResults {
   explicit SimpleEntryCreationResults(SimpleEntryStat entry_stat);
   ~SimpleEntryCreationResults();
 
   SimpleSynchronousEntry* sync_entry;
+  scoped_refptr<net::GrowableIOBuffer> stream_0_data;
   SimpleEntryStat entry_stat;
+  uint32 stream_0_crc32;
   int result;
 };
 
 // Worker thread interface to the very simple cache. This interface is not
 // thread safe, and callers must ensure that it is only ever accessed from
 // a single thread between synchronization points.
 class SimpleSynchronousEntry {
  public:
   struct CRCRecord {
     CRCRecord();
@@ skipping 40 matching lines @@
   // Like |DoomEntry()| above. Deletes all entries corresponding to the
   // |key_hashes|. Succeeds only when all entries are deleted. Returns a net
   // error code.
   static int DoomEntrySet(scoped_ptr<std::vector<uint64> > key_hashes,
                           const base::FilePath& path);
 
   // N.B. ReadData(), WriteData(), CheckEOFRecord() and Close() may block on IO.
   void ReadData(const EntryOperationData& in_entry_op,
                 net::IOBuffer* out_buf,
                 uint32* out_crc32,
-                base::Time* out_last_used,
+                SimpleEntryStat* out_entry_stat,
                 int* out_result) const;
   void WriteData(const EntryOperationData& in_entry_op,
                  net::IOBuffer* in_buf,
                  SimpleEntryStat* out_entry_stat,
                  int* out_result) const;
   void CheckEOFRecord(int index,
-                      int data_size,
+                      const SimpleEntryStat& entry_stat,
                       uint32 expected_crc32,
                       int* out_result) const;
 
   // Close all streams, and add write EOF records to streams indicated by the
   // CRCRecord entries in |crc32s_to_write|.
   void Close(const SimpleEntryStat& entry_stat,
-             scoped_ptr<std::vector<CRCRecord> > crc32s_to_write);
+             scoped_ptr<std::vector<CRCRecord> > crc32s_to_write,
+             net::GrowableIOBuffer* stream_0_data);
 
   const base::FilePath& path() const { return path_; }
   std::string key() const { return key_; }
 
  private:
   SimpleSynchronousEntry(
       net::CacheType cache_type,
       const base::FilePath& path,
       const std::string& key,
       uint64 entry_hash);
 
   // Like Entry, the SimpleSynchronousEntry self releases when Close() is
   // called.
   ~SimpleSynchronousEntry();
 
   bool OpenOrCreateFiles(bool create,
                          bool had_index,
                          SimpleEntryStat* out_entry_stat);
   void CloseFiles();
 
   // Returns a net error, i.e. net::OK on success.  |had_index| is passed
   // from the main entry for metrics purposes, and is true if the index was
   // initialized when the open operation began.
-  int InitializeForOpen(bool had_index, SimpleEntryStat* out_entry_stat);
+  int InitializeForOpen(bool had_index,
+                        SimpleEntryStat* out_entry_stat,
+                        scoped_refptr<net::GrowableIOBuffer>* stream_0_data,
+                        uint32* out_stream_0_crc32);
 
   // Returns a net error, including net::OK on success and net::FILE_EXISTS
   // when the entry already exists.  |had_index| is passed from the main entry
   // for metrics purposes, and is true if the index was initialized when the
   // create operation began.
   int InitializeForCreate(bool had_index, SimpleEntryStat* out_entry_stat);
 
+  // Allocates and fills a buffer with stream 0 data in |stream_0_data|, then
+  // checks its crc32.
+  int ReadAndValidateStream0(
+      int total_data_size,
+      SimpleEntryStat* out_entry_stat,
+      scoped_refptr<net::GrowableIOBuffer>* stream_0_data,
+      uint32* out_stream_0_crc32) const;
+
+  int GetEOFRecordData(int index,
+                       const SimpleEntryStat& entry_stat,
+                       bool* out_has_crc32,
+                       uint32* out_crc32,
+                       int* out_data_size) const;
   void Doom() const;
 
   static bool DeleteFilesForEntryHash(const base::FilePath& path,
                                       uint64 entry_hash);
 
   const net::CacheType cache_type_;
   const base::FilePath path_;
   const uint64 entry_hash_;
   std::string key_;
 
   bool have_open_files_;
   bool initialized_;
 
   base::PlatformFile files_[kSimpleEntryFileCount];
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_SIMPLE_SIMPLE_SYNCHRONOUS_ENTRY_H_