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| 1 // Copyright (c) 2010 The Chromium OS 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 #ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MULTI_RANGE_HTTP_FETCHER_H__ |
| 6 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_MULTI_RANGE_HTTP_FETCHER_H__ |
| 7 |
| 8 #include <deque> |
| 9 #include <utility> |
| 10 #include <vector> |
| 11 |
| 12 #include <base/scoped_ptr.h> |
| 13 |
| 14 #include "update_engine/http_fetcher.h" |
| 15 |
| 16 // This class is a simple wrapper around an HttpFetcher. The client |
| 17 // specifies a vector of byte ranges. MultiRangeHTTPFetcher will fetch bytes |
| 18 // from those offsets, using the same bash fetcher for all ranges. Thus, the |
| 19 // fetcher must support beginning a transfter after one has stopped. Pass -1 |
| 20 // as a length to specify unlimited length. It really only would make sense |
| 21 // for the last range specified to have unlimited length, tho it is legal for |
| 22 // other entries to have unlimited length. |
| 23 |
| 24 // There are three states a MultiRangeHTTPFetcher object will be in: |
| 25 // - Stopped (start state) |
| 26 // - Downloading |
| 27 // - Pending transfer ended |
| 28 // Various functions below that might change state indicate possible |
| 29 // state changes. |
| 30 |
| 31 namespace chromeos_update_engine { |
| 32 |
| 33 class MultiRangeHTTPFetcher : public HttpFetcher, public HttpFetcherDelegate { |
| 34 public: |
| 35 // Takes ownership of the passed in fetcher. |
| 36 explicit MultiRangeHTTPFetcher(HttpFetcher* base_fetcher) |
| 37 : HttpFetcher(base_fetcher->proxy_resolver()), |
| 38 base_fetcher_(base_fetcher), |
| 39 base_fetcher_active_(false), |
| 40 pending_transfer_ended_(false), |
| 41 terminating_(false), |
| 42 current_index_(0), |
| 43 bytes_received_this_range_(0) {} |
| 44 ~MultiRangeHTTPFetcher() {} |
| 45 |
| 46 void ClearRanges() { ranges_.clear(); } |
| 47 |
| 48 void AddRange(off_t offset, off_t size) { |
| 49 ranges_.push_back(std::make_pair(offset, size)); |
| 50 } |
| 51 |
| 52 virtual void SetOffset(off_t offset) {} // for now, doesn't support this |
| 53 |
| 54 // Begins the transfer to the specified URL. |
| 55 // State change: Stopped -> Downloading |
| 56 // (corner case: Stopped -> Stopped for an empty request) |
| 57 virtual void BeginTransfer(const std::string& url); |
| 58 |
| 59 // State change: Downloading -> Pending transfer ended |
| 60 virtual void TerminateTransfer(); |
| 61 |
| 62 virtual void Pause() { base_fetcher_->Pause(); } |
| 63 |
| 64 virtual void Unpause() { base_fetcher_->Unpause(); } |
| 65 |
| 66 // These functions are overloaded in LibcurlHttp fetcher for testing purposes. |
| 67 virtual void set_idle_seconds(int seconds) { |
| 68 base_fetcher_->set_idle_seconds(seconds); |
| 69 } |
| 70 virtual void set_retry_seconds(int seconds) { |
| 71 base_fetcher_->set_retry_seconds(seconds); |
| 72 } |
| 73 virtual void SetConnectionAsExpensive(bool is_expensive) { |
| 74 base_fetcher_->SetConnectionAsExpensive(is_expensive); |
| 75 } |
| 76 virtual void SetBuildType(bool is_official) { |
| 77 base_fetcher_->SetBuildType(is_official); |
| 78 } |
| 79 virtual void SetProxies(const std::deque<std::string>& proxies) { |
| 80 base_fetcher_->SetProxies(proxies); |
| 81 } |
| 82 |
| 83 private: |
| 84 // pair<offset, length>: |
| 85 typedef std::vector<std::pair<off_t, off_t> > RangesVect; |
| 86 |
| 87 // State change: Stopped or Downloading -> Downloading |
| 88 void StartTransfer(); |
| 89 |
| 90 // State change: Downloading -> Downloading or Pending transfer ended |
| 91 virtual void ReceivedBytes(HttpFetcher* fetcher, |
| 92 const char* bytes, |
| 93 int length); |
| 94 |
| 95 // State change: Pending transfer ended -> Stopped |
| 96 void TransferEnded(HttpFetcher* fetcher, bool successful); |
| 97 // These two call TransferEnded(): |
| 98 virtual void TransferComplete(HttpFetcher* fetcher, bool successful); |
| 99 virtual void TransferTerminated(HttpFetcher* fetcher); |
| 100 |
| 101 void Reset(); |
| 102 |
| 103 scoped_ptr<HttpFetcher> base_fetcher_; |
| 104 |
| 105 // If true, do not send any more data or TransferComplete to the delegate. |
| 106 bool base_fetcher_active_; |
| 107 |
| 108 // If true, the next fetcher needs to be started when TransferTerminated is |
| 109 // received from the current fetcher. |
| 110 bool pending_transfer_ended_; |
| 111 |
| 112 // True if we are waiting for base fetcher to terminate b/c we are |
| 113 // ourselves terminating. |
| 114 bool terminating_; |
| 115 |
| 116 RangesVect ranges_; |
| 117 |
| 118 RangesVect::size_type current_index_; // index into ranges_ |
| 119 off_t bytes_received_this_range_; |
| 120 |
| 121 DISALLOW_COPY_AND_ASSIGN(MultiRangeHTTPFetcher); |
| 122 }; |
| 123 |
| 124 } // namespace chromeos_update_engine |
| 125 |
| 126 #endif // CHROMEOS_PLATFORM_UPDATE_ENGINE_MULTI_RANGE_HTTP_FETCHER_H__ |
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