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      1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "chrome/service/cloud_print/printer_job_queue_handler.h"
      6 
      7 #include <math.h>
      8 
      9 #include <algorithm>
     10 
     11 #include "base/values.h"
     12 
     13 namespace cloud_print {
     14 
     15 class TimeProviderImpl : public PrinterJobQueueHandler::TimeProvider {
     16  public:
     17     virtual base::Time GetNow() OVERRIDE;
     18 };
     19 
     20 base::Time TimeProviderImpl::GetNow() {
     21   return base::Time::Now();
     22 }
     23 
     24 JobDetails::JobDetails() {}
     25 
     26 JobDetails::~JobDetails() {}
     27 
     28 void JobDetails::Clear() {
     29   job_id_.clear();
     30   job_title_.clear();
     31   print_ticket_.clear();
     32   print_data_mime_type_.clear();
     33   print_data_file_path_ = base::FilePath();
     34   print_data_url_.clear();
     35   print_ticket_url_.clear();
     36   tags_.clear();
     37   time_remaining_ = base::TimeDelta();
     38 }
     39 
     40 // static
     41 bool JobDetails::ordering(const JobDetails& first, const JobDetails& second) {
     42   return first.time_remaining_ < second.time_remaining_;
     43 }
     44 
     45 PrinterJobQueueHandler::PrinterJobQueueHandler(TimeProvider* time_provider)
     46     : time_provider_(time_provider) {}
     47 
     48 PrinterJobQueueHandler::PrinterJobQueueHandler()
     49     : time_provider_(new TimeProviderImpl()) {}
     50 
     51 PrinterJobQueueHandler::~PrinterJobQueueHandler() {}
     52 
     53 void PrinterJobQueueHandler::ConstructJobDetailsFromJson(
     54     const DictionaryValue* job_data,
     55     JobDetails* job_details) {
     56   job_details->Clear();
     57 
     58   job_data->GetString(kIdValue, &job_details->job_id_);
     59   job_data->GetString(kTitleValue, &job_details->job_title_);
     60 
     61   job_data->GetString(kTicketUrlValue, &job_details->print_ticket_url_);
     62   job_data->GetString(kFileUrlValue, &job_details->print_data_url_);
     63 
     64   // Get tags for print job.
     65   const ListValue* tags = NULL;
     66   if (job_data->GetList(kTagsValue, &tags)) {
     67     for (size_t i = 0; i < tags->GetSize(); i++) {
     68       std::string value;
     69       if (tags->GetString(i, &value))
     70         job_details->tags_.push_back(value);
     71     }
     72   }
     73 }
     74 
     75 base::TimeDelta PrinterJobQueueHandler::ComputeBackoffTime(
     76     const std::string& job_id) {
     77   FailedJobMap::const_iterator job_location = failed_job_map_.find(job_id);
     78   if (job_location == failed_job_map_.end()) {
     79     return base::TimeDelta();
     80   }
     81 
     82   base::TimeDelta backoff_time =
     83       base::TimeDelta::FromSeconds(kJobFirstWaitTimeSecs);
     84   backoff_time *=
     85       // casting argument to double and result to uint64 to avoid compilation
     86       // issues
     87       static_cast<int64>(pow(
     88           static_cast<long double>(kJobWaitTimeExponentialMultiplier),
     89           job_location->second.retries_) + 0.5);
     90   base::Time scheduled_retry =
     91       job_location->second.last_retry_ + backoff_time;
     92   base::Time now = time_provider_->GetNow();
     93   base::TimeDelta time_remaining;
     94 
     95   if (scheduled_retry < now) {
     96     return base::TimeDelta();
     97   }
     98   return scheduled_retry - now;
     99 }
    100 
    101 void PrinterJobQueueHandler::GetJobsFromQueue(const DictionaryValue* json_data,
    102                                               std::vector<JobDetails>* jobs) {
    103   std::vector<JobDetails> jobs_with_timeouts;
    104 
    105   jobs->clear();
    106 
    107   const ListValue* job_list = NULL;
    108   if (!json_data->GetList(kJobListValue, &job_list)) {
    109     return;
    110   }
    111 
    112   size_t list_size = job_list->GetSize();
    113   for (size_t cur_job = 0; cur_job < list_size; cur_job++) {
    114     const DictionaryValue* job_data = NULL;
    115     if (job_list->GetDictionary(cur_job, &job_data)) {
    116       JobDetails job_details_current;
    117       ConstructJobDetailsFromJson(job_data, &job_details_current);
    118 
    119       job_details_current.time_remaining_ =
    120           ComputeBackoffTime(job_details_current.job_id_);
    121 
    122       if (job_details_current.time_remaining_ == base::TimeDelta()) {
    123         jobs->push_back(job_details_current);
    124       } else {
    125         jobs_with_timeouts.push_back(job_details_current);
    126       }
    127     }
    128   }
    129 
    130   sort(jobs_with_timeouts.begin(), jobs_with_timeouts.end(),
    131        &JobDetails::ordering);
    132   jobs->insert(jobs->end(), jobs_with_timeouts.begin(),
    133                jobs_with_timeouts.end());
    134 }
    135 
    136 void PrinterJobQueueHandler::JobDone(const std::string& job_id) {
    137   failed_job_map_.erase(job_id);
    138 }
    139 
    140 bool PrinterJobQueueHandler::JobFetchFailed(const std::string& job_id) {
    141   FailedJobMetadata metadata;
    142   metadata.retries_ = 0;
    143   metadata.last_retry_ = time_provider_->GetNow();
    144 
    145   std::pair<FailedJobMap::iterator, bool> job_found =
    146       failed_job_map_.insert(FailedJobPair(job_id, metadata));
    147 
    148   // If the job has already failed once, increment the number of retries.
    149   // If it has failed too many times, remove it from the map and tell the caller
    150   // to report a failure.
    151   if (!job_found.second) {
    152     if (job_found.first->second.retries_ >= kNumRetriesBeforeAbandonJob) {
    153       failed_job_map_.erase(job_found.first);
    154       return false;
    155     }
    156 
    157     job_found.first->second.retries_ += 1;
    158     job_found.first->second.last_retry_ = time_provider_->GetNow();
    159   }
    160 
    161   return true;
    162 }
    163 
    164 }  // namespace cloud_print
    165 
    166