Propagate more information about ValueStore errors to callers, notably an

chrome/browser/extensions/api/storage/settings_storage_quota_enforcer.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/api/storage/settings_storage_quota_enforcer.h"
 
 #include "base/bind.h"
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
+#include "base/strings/stringprintf.h"
+#include "chrome/browser/value_store/value_store_util.h"
 #include "chrome/common/extensions/api/extension_api.h"
-#include "extensions/common/error_utils.h"
+
+namespace util = value_store_util;
 
 namespace extensions {
 
 namespace {
 
-const char* kQuotaExceededError = "* quota exceeded.";
-
 // Resources there are a quota for.
 enum Resource {
   QUOTA_BYTES,
   QUOTA_BYTES_PER_ITEM,
   MAX_ITEMS
 };
 
 // Allocates a setting in a record of total and per-setting usage.
 void Allocate(
     const std::string& key,
@@ skipping 15 matching lines @@
 
 // Frees the allocation of a setting in a record of total and per-setting usage.
 void Free(
     size_t* used_total,
     std::map<std::string, size_t>* used_per_setting,
     const std::string& key) {
   *used_total -= (*used_per_setting)[key];
   used_per_setting->erase(key);
 }
 
-// Returns an error result and logs the quota exceeded to UMA.
-ValueStore::WriteResult QuotaExceededFor(Resource resource) {
-  std::string name;
+scoped_ptr<ValueStore::Error> QuotaExceededError(Resource resource,
+                                                 scoped_ptr<std::string> key) {
+  const char* name = NULL;
+  // TODO(kalman): These hisograms are both silly and untracked. Fix.
   switch (resource) {
     case QUOTA_BYTES:
       name = "QUOTA_BYTES";
       UMA_HISTOGRAM_COUNTS_100(
           "Extensions.SettingsQuotaExceeded.TotalBytes", 1);
       break;
     case QUOTA_BYTES_PER_ITEM:
       name = "QUOTA_BYTES_PER_ITEM";
       UMA_HISTOGRAM_COUNTS_100(
           "Extensions.SettingsQuotaExceeded.BytesPerSetting", 1);
       break;
     case MAX_ITEMS:
       name = "MAX_ITEMS";
       UMA_HISTOGRAM_COUNTS_100(
           "Extensions.SettingsQuotaExceeded.KeyCount", 1);
       break;
-    default:
-      NOTREACHED();
   }
-  return ValueStore::MakeWriteResult(
-      ErrorUtils::FormatErrorMessage(kQuotaExceededError, name));
+  CHECK(name);
+  return make_scoped_ptr(new ValueStore::Error(
+      ValueStore::QUOTA_EXCEEDED,
+      base::StringPrintf("%s quota exceeded", name),
+      key.Pass()));
 }
 
 }  // namespace
 
 SettingsStorageQuotaEnforcer::SettingsStorageQuotaEnforcer(
     const Limits& limits, ValueStore* delegate)
     : limits_(limits), delegate_(delegate), used_total_(0) {
   ReadResult maybe_settings = delegate_->Get();
   if (maybe_settings->HasError()) {
     LOG(WARNING) << "Failed to get initial settings for quota: " <<
-        maybe_settings->error();
+        maybe_settings->error().message;
     return;
   }
 
-  for (base::DictionaryValue::Iterator it(*maybe_settings->settings().get());
+  for (base::DictionaryValue::Iterator it(maybe_settings->settings());
        !it.IsAtEnd(); it.Advance()) {
     Allocate(it.key(), it.value(), &used_total_, &used_per_setting_);
   }
 }
 
 SettingsStorageQuotaEnforcer::~SettingsStorageQuotaEnforcer() {}
 
 size_t SettingsStorageQuotaEnforcer::GetBytesInUse(const std::string& key) {
   std::map<std::string, size_t>::iterator maybe_used =
       used_per_setting_.find(key);
@@ skipping 31 matching lines @@
 }
 
 ValueStore::WriteResult SettingsStorageQuotaEnforcer::Set(
     WriteOptions options, const std::string& key, const Value& value) {
   size_t new_used_total = used_total_;
   std::map<std::string, size_t> new_used_per_setting = used_per_setting_;
   Allocate(key, value, &new_used_total, &new_used_per_setting);
 
   if (!(options & IGNORE_QUOTA)) {
     if (new_used_total > limits_.quota_bytes) {
-      return QuotaExceededFor(QUOTA_BYTES);
+      return MakeWriteResult(
+          QuotaExceededError(QUOTA_BYTES, util::NewKey(key)));
     }
     if (new_used_per_setting[key] > limits_.quota_bytes_per_item) {
-      return QuotaExceededFor(QUOTA_BYTES_PER_ITEM);
+      return MakeWriteResult(
+          QuotaExceededError(QUOTA_BYTES_PER_ITEM, util::NewKey(key)));
     }
-    if (new_used_per_setting.size() > limits_.max_items) {
-      return QuotaExceededFor(MAX_ITEMS);
-    }
+    if (new_used_per_setting.size() > limits_.max_items)
+      return MakeWriteResult(QuotaExceededError(MAX_ITEMS, util::NewKey(key)));
   }
 
   WriteResult result = delegate_->Set(options, key, value);
   if (result->HasError()) {
     return result.Pass();
   }
 
   used_total_ = new_used_total;
   used_per_setting_.swap(new_used_per_setting);
   return result.Pass();
 }
 
 ValueStore::WriteResult SettingsStorageQuotaEnforcer::Set(
     WriteOptions options, const base::DictionaryValue& values) {
   size_t new_used_total = used_total_;
   std::map<std::string, size_t> new_used_per_setting = used_per_setting_;
   for (base::DictionaryValue::Iterator it(values); !it.IsAtEnd();
        it.Advance()) {
     Allocate(it.key(), it.value(), &new_used_total, &new_used_per_setting);
 
     if (!(options & IGNORE_QUOTA) &&
         new_used_per_setting[it.key()] > limits_.quota_bytes_per_item) {
-      return QuotaExceededFor(QUOTA_BYTES_PER_ITEM);
+      return MakeWriteResult(
+          QuotaExceededError(QUOTA_BYTES_PER_ITEM, util::NewKey(it.key())));
     }
   }
 
   if (!(options & IGNORE_QUOTA)) {
-    if (new_used_total > limits_.quota_bytes) {
-      return QuotaExceededFor(QUOTA_BYTES);
-    }
-    if (new_used_per_setting.size() > limits_.max_items) {
-      return QuotaExceededFor(MAX_ITEMS);
-    }
+    if (new_used_total > limits_.quota_bytes)
+      return MakeWriteResult(QuotaExceededError(QUOTA_BYTES, util::NoKey()));
+    if (new_used_per_setting.size() > limits_.max_items)
+      return MakeWriteResult(QuotaExceededError(MAX_ITEMS, util::NoKey()));
   }
 
   WriteResult result = delegate_->Set(options, values);
   if (result->HasError()) {
     return result.Pass();
   }
 
   used_total_ = new_used_total;
   used_per_setting_ = new_used_per_setting;
   return result.Pass();
@@ skipping 29 matching lines @@
     return result.Pass();
   }
 
   while (!used_per_setting_.empty()) {
     Free(&used_total_, &used_per_setting_, used_per_setting_.begin()->first);
   }
   return result.Pass();
 }
 
 }  // namespace extensions