Error diagnostics for Blacklist IO...

chrome/browser/privacy_blacklist/blacklist_store.h

 // Copyright (c) 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.
 
 #ifndef CHROME_BROWSER_PRIVACY_BLACKLIST_BLACKLIST_DB_H_
 #define CHROME_BROWSER_PRIVACY_BLACKLIST_BLACKLIST_DB_H_
 
 #include <cstdio>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 
 class FilePath;
 
-// TODO(idanan): Error handling needed. I/O errors can always happen!
-
 ////////////////////////////////////////////////////////////////////////////////
 //
 // Blacklist Binary Storage Output Class
 //
 // Stores aggregate Privacy Blacklists efficiently on disk. The public
 // functions below must be called in the order they are declared, as
 // the input class is expected to read them in that order. The provider
 // and entry output functions must be called the number of times set.
 //
 ////////////////////////////////////////////////////////////////////////////////
 class BlacklistStoreOutput {
  public:
   explicit BlacklistStoreOutput(FILE* file);
   ~BlacklistStoreOutput();
 
-  // Sets the number of providers stored.
-  void ReserveProviders(uint32);
+  // Returns true if the object initialized without error.
+  bool is_good() const { return is_good_; }
 
-  // Stores a provider.
-  void StoreProvider(const std::string& name, const std::string& url);
+  // Sets the number of providers stored. Returns true if successful.
+  bool ReserveProviders(uint32);
 
-  // Sets the number of entries stored.
-  void ReserveEntries(uint32);
+  // Stores a provider. Returns true if successful.
+  bool StoreProvider(const std::string& name, const std::string& url);
 
-  // Stores an entry.
-  void StoreEntry(const std::string& pattern,
+  // Sets the number of entries stored. Returns true if successful.
+  bool ReserveEntries(uint32);
+
+  // Stores an entry. Returns true if successful.
+  bool StoreEntry(const std::string& pattern,
                   uint32 attributes,
                   const std::vector<std::string>& types,
                   uint32 provider);
 
  private:
-  // Writes basic types to the stream.
-  void WriteUInt(uint32);
-  void WriteString(const std::string&);
+  // Writes basic types to the stream. Returns true if successful.
+  bool WriteUInt(uint32);
+  bool WriteString(const std::string&);
 
   FILE* file_;
+  bool is_good_;
   DISALLOW_COPY_AND_ASSIGN(BlacklistStoreOutput);
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 //
 // Blacklist Binary Storage Input Class
 //
 // Stores aggregate Privacy Blacklists efficiently on disk. The public
 // functions below must be called in the order they are declared, as
 // the output class is expected to write them in that order. The provider
 // entries read functions must be called the correct number of times.
 //
 ////////////////////////////////////////////////////////////////////////////////
 class BlacklistStoreInput {
  public:
   explicit BlacklistStoreInput(FILE* file);
   ~BlacklistStoreInput();
 
+  // Returns true if this object initialized without error.
+  bool is_good() const { return is_good_; }
+
   // Reads the number of providers.
   uint32 ReadNumProviders();
 
-  // Reads a provider.
-  void ReadProvider(std::string* name, std::string* url);
+  // Reads a provider. Returns true on success.
+  bool ReadProvider(std::string* name, std::string* url);
 
-  // Reads the number of entries.
+  // Reads the number of entries. Returns true on success.
   uint32 ReadNumEntries();
 
   // Reads an entry.
-  void ReadEntry(std::string* pattern,
+  bool ReadEntry(std::string* pattern,
                  uint32* attributes,
                  std::vector<std::string>* types,
                  uint32* provider);
 
  private:
   uint32 ReadUInt();
   std::string ReadString();
 
   FILE* file_;
+  bool is_good_;
   DISALLOW_COPY_AND_ASSIGN(BlacklistStoreInput);
 };
 
 #endif