Remove the provisional store and just store the staged log when writing to

components/metrics/persisted_logs.h

 // Copyright 2014 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 COMPONENTS_METRICS_PERSISTED_LOGS_H_
 #define COMPONENTS_METRICS_PERSISTED_LOGS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 19 matching lines @@
     LOG_STRING_CORRUPTION,  // Failed to recover log string using GetAsString().
     CHECKSUM_CORRUPTION,    // Failed to verify checksum.
     CHECKSUM_STRING_CORRUPTION,  // Failed to recover checksum string using
                                  // GetAsString().
     DECODE_FAIL,            // Failed to decode log.
     DEPRECATED_XML_PROTO_MISMATCH,  // The XML and protobuf logs have
                                     // inconsistent data.
     END_RECALL_STATUS       // Number of bins to use to create the histogram.
   };
 
-  enum StoreType {
-    NORMAL_STORE,       // A standard store operation.
-    PROVISIONAL_STORE,  // A store operation that can be easily reverted later.
-  };
-
   // Constructs a PersistedLogs that stores data in |local_state| under the
   // preference |pref_name| and also reads from legacy pref |old_pref_name|.
   // Calling code is responsible for ensuring that the lifetime of |local_state|
   // is longer than the lifetime of PersistedLogs.
   //
   // When saving logs to disk, stores either the first |min_log_count| logs, or
   // at least |min_log_bytes| bytes of logs, whichever is greater.
   //
   // If the optional |max_log_size| parameter is non-zero, all logs larger than
   // that limit will be skipped when writing to disk.
@@ skipping 14 matching lines @@
   // Adds a log to the list.
   void StoreLog(const std::string& log_data);
 
   // Stages the most recent log.  The staged_log will remain the same even if
   // additional logs are added.
   void StageLog();
 
   // Remove the staged log.
   void DiscardStagedLog();
 
-  // Saves the staged log, then clears staged_log().
-  // If |store_type| is PROVISIONAL_STORE, it can be dropped from storage with
-  // a later call to DiscardLastProvisionalStore (if it hasn't already been
-  // staged again).
-  // This is intended to be used when logs are being saved while an upload is in
-  // progress, in case the upload later succeeds.
-  // This can only be called if has_staged_log() is true.
-  void StoreStagedLogAsUnsent(StoreType store_type);
-
-  // Discards the last log stored with StoreStagedLogAsUnsent with |store_type|
-  // set to PROVISIONAL_STORE, as long as it hasn't already been re-staged. If
-  // the log is no longer present, this is a no-op.
-  void DiscardLastProvisionalStore();
-
   // True if a log has been staged.
-  bool has_staged_log() const {
-    return !staged_log_.compressed_log_data.empty();
-  }
+  bool has_staged_log() const { return staged_log_index_ != -1; };
 
   // Returns the element in the front of the list.
   const std::string& staged_log() const {
     DCHECK(has_staged_log());
-    return staged_log_.compressed_log_data;
+    return list_[staged_log_index_].compressed_log_data;
   }
 
   // Returns the element in the front of the list.
   const std::string& staged_log_hash() const {
     DCHECK(has_staged_log());
-    return staged_log_.hash;
+    return list_[staged_log_index_].hash;
   }
 
   // The number of elements currently stored.
   size_t size() const { return list_.size(); }
 
   // True if there are no stored logs.
   bool empty() const { return list_.empty(); }
 
  private:
   // Writes the list to the ListValue.
@@ skipping 24 matching lines @@
   const size_t min_log_count_;
   const size_t min_log_bytes_;
 
   // Logs greater than this size will not be written to disk.
   const size_t max_log_size_;
 
   struct LogHashPair {
     // Initializes the members based on uncompressed |log_data|.
     void Init(const std::string& log_data);
 
-    // Clears the struct members.
-    void Clear();
-
-    // Swap both log and hash from another LogHashPair.
-    void Swap(LogHashPair* input);
-
     // Compressed log data - a serialized protobuf that's been gzipped.
     std::string compressed_log_data;
 
     // The SHA1 hash of log, stored to catch errors from memory corruption.
     std::string hash;
   };
   // A list of all of the stored logs, stored with SHA1 hashes to check for
   // corruption while they are stored in memory.
   std::vector<LogHashPair> list_;
 
-  // The log staged for upload.
-  LogHashPair staged_log_;
-
-  // The index and type of the last provisional store. If nothing has been
-  // provisionally stored, or the last provisional store has already been
-  // re-staged, the index will be -1;
-  // This is necessary because during an upload there are two logs (staged
-  // and current) and a client might store them in either order, so it's
-  // not necessarily the case that the provisional store is the last store.
-  int last_provisional_store_index_;
+  // The index and type of the log staged for upload. If nothing has been
+  // staged, the index will be -1.
+  int staged_log_index_;
 
   DISALLOW_COPY_AND_ASSIGN(PersistedLogs);
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_PERSISTED_LOGS_H_