Moved ExtensionInfoMap and ExtensionsQuotaService to extensions/

chrome/browser/extensions/extensions_quota_service.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/extensions_quota_service.h"
-
-#include "base/message_loop/message_loop.h"
-#include "base/stl_util.h"
-#include "chrome/browser/extensions/extension_function.h"
-#include "extensions/common/error_utils.h"
-
-namespace {
-
-// If the browser stays open long enough, we reset state once a day.
-// Whatever this value is, it should be an order of magnitude longer than
-// the longest interval in any of the QuotaLimitHeuristics in use.
-const int kPurgeIntervalInDays = 1;
-
-const char kOverQuotaError[] = "This request exceeds the * quota.";
-
-}  // namespace
-
-ExtensionsQuotaService::ExtensionsQuotaService() {
-  if (base::MessageLoop::current() != NULL) {  // Null in unit tests.
-    purge_timer_.Start(FROM_HERE,
-                       base::TimeDelta::FromDays(kPurgeIntervalInDays),
-                       this, &ExtensionsQuotaService::Purge);
-  }
-}
-
-ExtensionsQuotaService::~ExtensionsQuotaService() {
-  DCHECK(CalledOnValidThread());
-  purge_timer_.Stop();
-  Purge();
-}
-
-std::string ExtensionsQuotaService::Assess(
-    const std::string& extension_id,
-    ExtensionFunction* function,
-    const base::ListValue* args,
-    const base::TimeTicks& event_time) {
-  DCHECK(CalledOnValidThread());
-
-  if (function->ShouldSkipQuotaLimiting())
-    return std::string();
-
-  // Lookup function list for extension.
-  FunctionHeuristicsMap& functions = function_heuristics_[extension_id];
-
-  // Lookup heuristics for function, create if necessary.
-  QuotaLimitHeuristics& heuristics = functions[function->name()];
-  if (heuristics.empty())
-    function->GetQuotaLimitHeuristics(&heuristics);
-
-  if (heuristics.empty())
-    return std::string();  // No heuristic implies no limit.
-
-  ViolationErrorMap::iterator violation_error =
-      violation_errors_.find(extension_id);
-  if (violation_error != violation_errors_.end())
-    return violation_error->second;  // Repeat offender.
-
-  QuotaLimitHeuristic* failed_heuristic = NULL;
-  for (QuotaLimitHeuristics::iterator heuristic = heuristics.begin();
-       heuristic != heuristics.end(); ++heuristic) {
-    // Apply heuristic to each item (bucket).
-    if (!(*heuristic)->ApplyToArgs(args, event_time)) {
-      failed_heuristic = *heuristic;
-      break;
-    }
-  }
-
-  if (!failed_heuristic)
-    return std::string();
-
-  std::string error = failed_heuristic->GetError();
-  DCHECK_GT(error.length(), 0u);
-
-  PurgeFunctionHeuristicsMap(&functions);
-  function_heuristics_.erase(extension_id);
-  violation_errors_[extension_id] = error;
-  return error;
-}
-
-void ExtensionsQuotaService::PurgeFunctionHeuristicsMap(
-    FunctionHeuristicsMap* map) {
-  FunctionHeuristicsMap::iterator heuristics = map->begin();
-  while (heuristics != map->end()) {
-    STLDeleteElements(&heuristics->second);
-    map->erase(heuristics++);
-  }
-}
-
-void ExtensionsQuotaService::Purge() {
-  DCHECK(CalledOnValidThread());
-  std::map<std::string, FunctionHeuristicsMap>::iterator it =
-      function_heuristics_.begin();
-  for (; it != function_heuristics_.end(); function_heuristics_.erase(it++))
-    PurgeFunctionHeuristicsMap(&it->second);
-}
-
-void QuotaLimitHeuristic::Bucket::Reset(const Config& config,
-    const base::TimeTicks& start) {
-  num_tokens_ = config.refill_token_count;
-  expiration_ = start + config.refill_interval;
-}
-
-void QuotaLimitHeuristic::SingletonBucketMapper::GetBucketsForArgs(
-    const base::ListValue* args,
-    BucketList* buckets) {
-  buckets->push_back(&bucket_);
-}
-
-QuotaLimitHeuristic::QuotaLimitHeuristic(const Config& config,
-                                         BucketMapper* map,
-                                         const std::string& name)
-    : config_(config), bucket_mapper_(map), name_(name) {
-}
-
-QuotaLimitHeuristic::~QuotaLimitHeuristic() {}
-
-bool QuotaLimitHeuristic::ApplyToArgs(const base::ListValue* args,
-    const base::TimeTicks& event_time) {
-  BucketList buckets;
-  bucket_mapper_->GetBucketsForArgs(args, &buckets);
-  for (BucketList::iterator i = buckets.begin(); i != buckets.end(); ++i) {
-    if ((*i)->expiration().is_null())  // A brand new bucket.
-      (*i)->Reset(config_, event_time);
-    if (!Apply(*i, event_time))
-      return false;  // It only takes one to spoil it for everyone.
-  }
-  return true;
-}
-
-std::string QuotaLimitHeuristic::GetError() const {
-  return extensions::ErrorUtils::FormatErrorMessage(kOverQuotaError, name_);
-}
-
-ExtensionsQuotaService::SustainedLimit::SustainedLimit(
-    const base::TimeDelta& sustain,
-    const Config& config,
-    BucketMapper* map,
-    const std::string& name)
-    : QuotaLimitHeuristic(config, map, name),
-      repeat_exhaustion_allowance_(sustain.InSeconds() /
-                                   config.refill_interval.InSeconds()),
-      num_available_repeat_exhaustions_(repeat_exhaustion_allowance_) {
-}
-
-bool ExtensionsQuotaService::TimedLimit::Apply(Bucket* bucket,
-    const base::TimeTicks& event_time) {
-  if (event_time > bucket->expiration())
-    bucket->Reset(config(), event_time);
-
-  return bucket->DeductToken();
-}
-
-bool ExtensionsQuotaService::SustainedLimit::Apply(Bucket* bucket,
-    const base::TimeTicks& event_time) {
-  if (event_time > bucket->expiration()) {
-    // We reset state for this item and start over again if this request breaks
-    // the bad cycle that was previously being tracked.  This occurs if the
-    // state in the bucket expired recently (it has been long enough since the
-    // event that we don't care about the last event), but the bucket still has
-    // tokens (so pressure was not sustained over that time), OR we are more
-    // than 1 full refill interval away from the last event (so even if we used
-    // up all the tokens in the last bucket, nothing happened in the entire
-    // next refill interval, so it doesn't matter).
-    if (bucket->has_tokens() || event_time > bucket->expiration() +
-        config().refill_interval) {
-      bucket->Reset(config(), event_time);
-      num_available_repeat_exhaustions_ = repeat_exhaustion_allowance_;
-    } else if (--num_available_repeat_exhaustions_ > 0) {
-      // The last interval was saturated with requests, and this is the first
-      // event in the next interval. If this happens
-      // repeat_exhaustion_allowance_ times, it's a violation. Reset the bucket
-      // state to start timing from the end of the last interval (and we'll
-      // deduct the token below) so we can detect this each time it happens.
-      bucket->Reset(config(), bucket->expiration());
-    } else {
-      // No allowances left; this request is a violation.
-      return false;
-    }
-  }
-
-  // We can go negative since we check has_tokens when we get to *next* bucket,
-  // and for the small interval all that matters is whether we used up all the
-  // tokens (which is true if num_tokens_ <= 0).
-  bucket->DeductToken();
-  return true;
-}