1583599051

Committed 11 Dec 2024 09:04AM UTC coverage: 76.259% (-0.2%) from 76.43%

Build # 1583599051

Build Type

push

gitlab-ci

Committed by

vpodzime

Commit Message

fix: Cancel the previous request before scheduling a new one in HTTP resumer

The `http::Client()` class is designed to always have only one
HTTP request in progress. Thus, before scheduling a new request
using the same `http::Client` instance, cancel the previous
request to make sure everything is properly reset for the new
one.

Ticket: MEN-7810
Changelog: Fix download resuming to reset the HTTP state and
avoid repeatedly hitting the same error in case of a bad state

Signed-off-by: Vratislav Podzimek <vratislav.podzimek@northern.tech>

Run Details

1 of 1 new or added line in 1 file covered. (100.0%)

55 existing lines in 11 files now uncovered.

7375 of 9671 relevant lines covered (76.26%)

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Source File
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86.32

/src/common/http/http_resumer.cpp

// Copyright 2023 Northern.tech AS
//
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
//
//        http://www.apache.org/licenses/LICENSE-2.0
//
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.

#include <common/http_resumer.hpp>

#include <regex>

#include <common/common.hpp>
#include <common/expected.hpp>

namespace mender {
namespace common {
namespace http {
namespace resumer {

namespace common = mender::common;
namespace expected = mender::common::expected;
namespace http = mender::common::http;

// Represents the parts of a Content-Range HTTP header
// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Range
struct RangeHeader {
        long long int range_start {0};
        long long int range_end {0};
        long long int size {0};
};
using ExpectedRangeHeader = expected::expected<RangeHeader, error::Error>;

// Parses the HTTP Content-Range header
// For an alternative implementation without regex dependency see:
// https://github.com/mendersoftware/mender/pull/1372/commits/ea711fc4dafa943266e9013fd6704da3d4518a27
ExpectedRangeHeader ParseRangeHeader(string header) {
        RangeHeader range_header {};

        std::regex content_range_regexp {R"(bytes\s+(\d+)\s?-\s?(\d+)\s?\/?\s?(\d+|\*)?)"};

        std::smatch range_matches;
        if (!regex_match(header, range_matches, content_range_regexp)) {
                return expected::unexpected(http::MakeError(
                        http::NoSuchHeaderError, "Invalid Content-Range returned from server: " + header));
        }

        auto exp_range_start = common::StringToLongLong(range_matches[1].str());
        auto exp_range_end = common::StringToLongLong(range_matches[2].str());
        if (!exp_range_start || !exp_range_end) {
                return expected::unexpected(http::MakeError(
                        http::NoSuchHeaderError, "Content-Range contains invalid number: " + header));
        }
        range_header.range_start = exp_range_start.value();
        range_header.range_end = exp_range_end.value();

        if (range_header.range_start > range_header.range_end) {
                return expected::unexpected(http::MakeError(
                        http::NoSuchHeaderError, "Invalid Content-Range returned from server: " + header));
        }

        if ((range_matches[3].matched) && (range_matches[3].str() != "*")) {
                auto exp_size = common::StringToLongLong(range_matches[3].str());
                if (!exp_size) {
                        return expected::unexpected(http::MakeError(
                                http::NoSuchHeaderError, "Content-Range contains invalid number: " + header));
                }
                range_header.size = exp_size.value();
        }

        return range_header;
}

class HeaderHandlerFunctor {
public:
        HeaderHandlerFunctor(weak_ptr<DownloadResumerClient> resumer) :
                resumer_client_ {resumer} {};

        void operator()(http::ExpectedIncomingResponsePtr exp_resp);

private:
        void HandleFirstResponse(
                const shared_ptr<DownloadResumerClient> &resumer_client,
                http::ExpectedIncomingResponsePtr exp_resp);
        void HandleNextResponse(
                const shared_ptr<DownloadResumerClient> &resumer_client,
                http::ExpectedIncomingResponsePtr exp_resp);

        weak_ptr<DownloadResumerClient> resumer_client_;
};

class BodyHandlerFunctor {
public:
        BodyHandlerFunctor(weak_ptr<DownloadResumerClient> resumer) :
                resumer_client_ {resumer} {};

        void operator()(http::ExpectedIncomingResponsePtr exp_resp);

private:
        weak_ptr<DownloadResumerClient> resumer_client_;
};

void HeaderHandlerFunctor::operator()(http::ExpectedIncomingResponsePtr exp_resp) {
        auto resumer_client = resumer_client_.lock();
        if (resumer_client) {
                // If an error has already occurred, schedule the next AsyncCall directly
                if (!exp_resp) {
                        resumer_client->logger_.Warning(exp_resp.error().String());
                        auto err = resumer_client->ScheduleNextResumeRequest();
                        if (err != error::NoError) {
                                resumer_client->logger_.Error(err.String());
                                resumer_client->CallUserHandler(expected::unexpected(err));
                        }
                        return;
                }

                if (resumer_client->resumer_state_->active_state == DownloadResumerActiveStatus::Resuming) {
                        HandleNextResponse(resumer_client, exp_resp);
                } else {
                        HandleFirstResponse(resumer_client, exp_resp);
                }
        }
}

void HeaderHandlerFunctor::HandleFirstResponse(
        const shared_ptr<DownloadResumerClient> &resumer_client,
        http::ExpectedIncomingResponsePtr exp_resp) {
        // The first response shall always call the user header callback. On resumable responses, we
        // create a our own incoming response and call the user header handler. On errors, we log a
        // warning and call the user handler with the original response

        auto resp = exp_resp.value();
        if (resp->GetStatusCode() != mender::common::http::StatusOK) {
                // Non-resumable response
                resumer_client->CallUserHandler(exp_resp);
                return;
        }

        auto exp_header = resp->GetHeader("Content-Length");
        if (!exp_header || exp_header.value() == "0") {
                resumer_client->logger_.Warning("Response does not contain Content-Length header");
                resumer_client->CallUserHandler(exp_resp);
                return;
        }

        auto exp_length = common::StringToLongLong(exp_header.value());
        if (!exp_length || exp_length.value() < 0) {
                resumer_client->logger_.Warning(
                        "Content-Length contains invalid number: " + exp_header.value());
                resumer_client->CallUserHandler(exp_resp);
                return;
        }

        // Resumable response
        resumer_client->resumer_state_->active_state = DownloadResumerActiveStatus::Resuming;
        resumer_client->resumer_state_->offset = 0;
        resumer_client->resumer_state_->content_length = exp_length.value();

        // Prepare a modified response and call user handler
        resumer_client->response_.reset(new http::IncomingResponse(*resumer_client, resp->cancelled_));
        resumer_client->response_->status_code_ = resp->GetStatusCode();
        resumer_client->response_->status_message_ = resp->GetStatusMessage();
        resumer_client->response_->headers_ = resp->GetHeaders();
        resumer_client->CallUserHandler(resumer_client->response_);
}

void HeaderHandlerFunctor::HandleNextResponse(
        const shared_ptr<DownloadResumerClient> &resumer_client,
        http::ExpectedIncomingResponsePtr exp_resp) {
        // If an error occurs during handling here, cancel the resuming and call the user handler.

        auto resp = exp_resp.value();
        auto resumer_reader = resumer_client->resumer_reader_.lock();
        if (!resumer_reader) {
                // Errors should already have been handled as part of the Cancel() inside the
                // destructor of the reader.
                return;
        }

        auto exp_content_range = resp->GetHeader("Content-Range").and_then(ParseRangeHeader);
        if (!exp_content_range) {
                resumer_client->logger_.Error(exp_content_range.error().String());
                resumer_client->CallUserHandler(expected::unexpected(exp_content_range.error()));
                return;
        }

        auto content_range = exp_content_range.value();
        if (content_range.size != 0
                && content_range.size != resumer_client->resumer_state_->content_length) {
                auto size_changed_err = http::MakeError(
                        http::DownloadResumerError,
                        "Size of artifact changed after download was resumed (expected "
                                + to_string(resumer_client->resumer_state_->content_length) + ", got "
                                + to_string(content_range.size) + ")");
                resumer_client->logger_.Error(size_changed_err.String());
                resumer_client->CallUserHandler(expected::unexpected(size_changed_err));
                return;
        }

        if ((content_range.range_end != resumer_client->resumer_state_->content_length - 1)
                || (content_range.range_start != resumer_client->resumer_state_->offset)) {
                auto bad_range_err = http::MakeError(
                        http::DownloadResumerError,
                        "HTTP server returned an different range than requested. Requested "
                                + to_string(resumer_client->resumer_state_->offset) + "-"
                                + to_string(resumer_client->resumer_state_->content_length - 1) + ", got "
                                + to_string(content_range.range_start) + "-" + to_string(content_range.range_end));
                resumer_client->logger_.Error(bad_range_err.String());
                resumer_client->CallUserHandler(expected::unexpected(bad_range_err));
                return;
        }

        // Get the reader for the new response
        auto exp_reader = resumer_client->client_.MakeBodyAsyncReader(resp);
        if (!exp_reader) {
                auto bad_range_err = exp_reader.error().WithContext("cannot get the reader after resume");
                resumer_client->logger_.Error(bad_range_err.String());
                resumer_client->CallUserHandler(expected::unexpected(bad_range_err));
                return;
        }
        // Update the inner reader of the user reader
        resumer_reader->inner_reader_ = exp_reader.value();

        // Resume reading reusing last user data (start, end, handler)
        auto err = resumer_reader->AsyncReadResume();
        if (err != error::NoError) {
                auto bad_read_err = err.WithContext("error reading after resume");
                resumer_client->logger_.Error(bad_read_err.String());
                resumer_client->CallUserHandler(expected::unexpected(bad_read_err));
                return;
        }
}

void BodyHandlerFunctor::operator()(http::ExpectedIncomingResponsePtr exp_resp) {
        auto resumer_client = resumer_client_.lock();
        if (!resumer_client) {
                return;
        }

        if (*resumer_client->cancelled_) {
                resumer_client->CallUserHandler(exp_resp);
                return;
        }

        if (resumer_client->resumer_state_->active_state == DownloadResumerActiveStatus::Inactive) {
                resumer_client->CallUserHandler(exp_resp);
                return;
        }

        // We resume the download if either:
        // * there is any error or
        // * successful read with status code Partial Content and there is still data missing
        const bool is_range_response =
                exp_resp && exp_resp.value()->GetStatusCode() == mender::common::http::StatusPartialContent;
        const bool is_data_missing =
                resumer_client->resumer_state_->offset < resumer_client->resumer_state_->content_length;
        if (!exp_resp || (is_range_response && is_data_missing)) {
                if (!exp_resp) {
                        auto resumer_reader = resumer_client->resumer_reader_.lock();
                        if (resumer_reader) {
                                resumer_reader->inner_reader_.reset();
                        }
                        if (exp_resp.error().code == make_error_condition(errc::operation_canceled)) {
                                // We don't want to resume cancelled requests, as these were
                                // cancelled for a reason.
                                resumer_client->CallUserHandler(exp_resp);
                                return;
                        }
                        resumer_client->logger_.Info(
                                "Will try to resume after error " + exp_resp.error().String());
                }

                auto err = resumer_client->ScheduleNextResumeRequest();
                if (err != error::NoError) {
                        resumer_client->logger_.Error(err.String());
                        resumer_client->CallUserHandler(expected::unexpected(err));
                        return;
                }
        } else {
                // Update headers with the last received server response. When resuming has taken place,
                // the user will get different headers on header and body handlers, representing (somehow)
                // what the resumer has been doing in its behalf.
                auto resp = exp_resp.value();
                resumer_client->response_->status_code_ = resp->GetStatusCode();
                resumer_client->response_->status_message_ = resp->GetStatusMessage();
                resumer_client->response_->headers_ = resp->GetHeaders();

                // Finished, call the user handler \o/
                resumer_client->logger_.Debug("Download resumed and completed successfully");
                resumer_client->CallUserHandler(resumer_client->response_);
        }
}

DownloadResumerAsyncReader::~DownloadResumerAsyncReader() {
        Cancel();
}

void DownloadResumerAsyncReader::Cancel() {
        auto resumer_client = resumer_client_.lock();
        if (!*cancelled_ && resumer_client) {
                resumer_client->Cancel();
        }
}

error::Error DownloadResumerAsyncReader::AsyncRead(
        vector<uint8_t>::iterator start, vector<uint8_t>::iterator end, io::AsyncIoHandler handler) {
        if (eof_) {
                handler(0);
                return error::NoError;
        }

        auto resumer_client = resumer_client_.lock();
        if (!resumer_client || *cancelled_) {
                return error::MakeError(
                        error::ProgrammingError,
                        "DownloadResumerAsyncReader::AsyncRead called after stream is destroyed");
        }
        // Save user parameters for further resumes of the body read
        resumer_client->last_read_ = {.start = start, .end = end, .handler = handler};
        return AsyncReadResume();
}

error::Error DownloadResumerAsyncReader::AsyncReadResume() {
        auto resumer_client = resumer_client_.lock();
        if (!resumer_client) {
                return error::MakeError(
                        error::ProgrammingError,
                        "DownloadResumerAsyncReader::AsyncReadResume called after client is destroyed");
        }
        return inner_reader_->AsyncRead(
                resumer_client->last_read_.start,
                resumer_client->last_read_.end,
                [this](io::ExpectedSize result) {
                        if (!result) {
                                logger_.Warning(
                                        "Reading error, a new request will be re-scheduled. "
                                        + result.error().String());
                        } else {
                                if (result.value() == 0) {
                                        eof_ = true;
                                }
                                resumer_state_->offset += result.value();
                                logger_.Debug("read " + to_string(result.value()) + " bytes");
                                auto resumer_client = resumer_client_.lock();
                                if (resumer_client) {
                                        resumer_client->last_read_.handler(result);
                                } else {
                                        logger_.Error(
                                                "AsyncRead finish handler called after resumer client has been destroyed.");
                                }
                        }
                });
}

DownloadResumerClient::DownloadResumerClient(
        const http::ClientConfig &config, events::EventLoop &event_loop) :
        resumer_state_ {make_shared<DownloadResumerClientState>()},
        client_(config, event_loop, "http_resumer:client"),
        logger_ {"http_resumer:client"},
        cancelled_ {make_shared<bool>(true)},
        retry_ {
                .backoff = http::ExponentialBackoff(chrono::minutes(1), 10),
                .wait_timer = events::Timer(event_loop)} {
}

DownloadResumerClient::~DownloadResumerClient() {
        if (!*cancelled_) {
                logger_.Warning("DownloadResumerClient destroyed while request is still active!");
        }
        client_.Cancel();
}

error::Error DownloadResumerClient::AsyncCall(
        http::OutgoingRequestPtr req,
        http::ResponseHandler user_header_handler,
        http::ResponseHandler user_body_handler) {
        HeaderHandlerFunctor resumer_header_handler {shared_from_this()};
        BodyHandlerFunctor resumer_body_handler {shared_from_this()};

        user_request_ = req;
        user_header_handler_ = user_header_handler;
        user_body_handler_ = user_body_handler;

        if (!*cancelled_) {
                return error::Error(
                        make_error_condition(errc::operation_in_progress), "HTTP resumer call already ongoing");
        }

        *cancelled_ = false;
        retry_.backoff.Reset();
        resumer_state_->active_state = DownloadResumerActiveStatus::Inactive;
        resumer_state_->user_handlers_state = DownloadResumerUserHandlersStatus::None;
        return client_.AsyncCall(req, resumer_header_handler, resumer_body_handler);
}

io::ExpectedAsyncReaderPtr DownloadResumerClient::MakeBodyAsyncReader(
        http::IncomingResponsePtr resp) {
        auto exp_reader = client_.MakeBodyAsyncReader(resp);
        if (!exp_reader) {
                return exp_reader;
        }
        auto resumer_reader = make_shared<DownloadResumerAsyncReader>(
                exp_reader.value(), resumer_state_, cancelled_, shared_from_this());
        resumer_reader_ = resumer_reader;
        return resumer_reader;
}

http::OutgoingRequestPtr DownloadResumerClient::RemainingRangeRequest() const {
        auto range_req = make_shared<http::OutgoingRequest>(*user_request_);
        if (resumer_state_->content_length > 0) {
                range_req->SetHeader(
                        "Range",
                        "bytes=" + to_string(resumer_state_->offset) + "-"
                                + to_string(resumer_state_->content_length - 1));
        }
        return range_req;
};

error::Error DownloadResumerClient::ScheduleNextResumeRequest() {
        // In any case, make sure the previous HTTP request is cancelled.
        client_.Cancel();

        auto exp_interval = retry_.backoff.NextInterval();
        if (!exp_interval) {
                return http::MakeError(
                        http::DownloadResumerError,
                        "Giving up on resuming the download: " + exp_interval.error().String());
        }

        auto interval = exp_interval.value();
        logger_.Info(
                "Resuming download after "
                + to_string(chrono::duration_cast<chrono::seconds>(interval).count()) + " seconds");

        HeaderHandlerFunctor resumer_next_header_handler {shared_from_this()};
        BodyHandlerFunctor resumer_next_body_handler {shared_from_this()};

        retry_.wait_timer.AsyncWait(
                interval, [this, resumer_next_header_handler, resumer_next_body_handler](error::Error err) {
                        if (err != error::NoError) {
                                auto err_user = http::MakeError(
                                        http::DownloadResumerError, "Unexpected error in wait timer: " + err.String());
                                logger_.Error(err_user.String());
                                CallUserHandler(expected::unexpected(err_user));
                                return;
                        }

                        auto next_call_err = client_.AsyncCall(
                                RemainingRangeRequest(), resumer_next_header_handler, resumer_next_body_handler);
                        if (next_call_err != error::NoError) {
                                // Schedule once more
                                auto err = ScheduleNextResumeRequest();
                                if (err != error::NoError) {
                                        logger_.Error(err.String());
                                        CallUserHandler(expected::unexpected(err));
                                }
                        }
                });

        return error::NoError;
}

void DownloadResumerClient::CallUserHandler(http::ExpectedIncomingResponsePtr exp_resp) {
        if (!exp_resp) {
                DoCancel();
        }
        if (resumer_state_->user_handlers_state == DownloadResumerUserHandlersStatus::None) {
                resumer_state_->user_handlers_state =
                        DownloadResumerUserHandlersStatus::HeaderHandlerCalled;
                user_header_handler_(exp_resp);
        } else if (
                resumer_state_->user_handlers_state
                == DownloadResumerUserHandlersStatus::HeaderHandlerCalled) {
                resumer_state_->user_handlers_state = DownloadResumerUserHandlersStatus::BodyHandlerCalled;
                DoCancel();
                user_body_handler_(exp_resp);
        } else {
                string msg;
                if (!exp_resp) {
                        msg = "error: " + exp_resp.error().String();
                } else {
                        auto &resp = exp_resp.value();
                        msg = "response: " + to_string(resp->GetStatusCode()) + " " + resp->GetStatusMessage();
                }
                logger_.Warning("Cannot call any user handler with " + msg);
        }
}

void DownloadResumerClient::Cancel() {
        DoCancel();
        client_.Cancel();
};

void DownloadResumerClient::DoCancel() {
        // Set cancel state and then make a new one. Those who are interested should have their own
        // pointer to the old one.
        *cancelled_ = true;
        cancelled_ = make_shared<bool>(true);
};

} // namespace resumer
} // namespace http
} // namespace common
} // namespace mender

1	// Copyright 2023 Northern.tech AS
2	//
3	// Licensed under the Apache License, Version 2.0 (the "License");
4	// you may not use this file except in compliance with the License.
5	// You may obtain a copy of the License at
6	//
7	// http://www.apache.org/licenses/LICENSE-2.0
8	//
9	// Unless required by applicable law or agreed to in writing, software
10	// distributed under the License is distributed on an "AS IS" BASIS,
11	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12	// See the License for the specific language governing permissions and
13	// limitations under the License.
14
15	#include <common/http_resumer.hpp>
16
17	#include <regex>
18
19	#include <common/common.hpp>
20	#include <common/expected.hpp>
21
22	namespace mender {
23	namespace common {
24	namespace http {
25	namespace resumer {
26
27	namespace common = mender::common;
28	namespace expected = mender::common::expected;
29	namespace http = mender::common::http;
30
31	// Represents the parts of a Content-Range HTTP header
32	// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Range
33	struct RangeHeader {
34	long long int range_start {0};
35	long long int range_end {0};
36	long long int size {0};
37	};
38	using ExpectedRangeHeader = expected::expected<RangeHeader, error::Error>;
39
40	// Parses the HTTP Content-Range header
41	// For an alternative implementation without regex dependency see:
42	// https://github.com/mendersoftware/mender/pull/1372/commits/ea711fc4dafa943266e9013fd6704da3d4518a27
43	ExpectedRangeHeader ParseRangeHeader(string header) {	41✔
44	RangeHeader range_header {};
45
46	std::regex content_range_regexp {R"(bytes\s+(\d+)\s?-\s?(\d+)\s?\/?\s?(\d+\|\*)?)"};	82✔
47
48	std::smatch range_matches;
49	if (!regex_match(header, range_matches, content_range_regexp)) {	41✔
50	return expected::unexpected(http::MakeError(	10✔
51	http::NoSuchHeaderError, "Invalid Content-Range returned from server: " + header));	30✔
52	}
53
54	auto exp_range_start = common::StringToLongLong(range_matches[1].str());	31✔
55	auto exp_range_end = common::StringToLongLong(range_matches[2].str());	62✔
56	if (!exp_range_start \|\| !exp_range_end) {	31✔
57	return expected::unexpected(http::MakeError(	×
58	http::NoSuchHeaderError, "Content-Range contains invalid number: " + header));	×
59	}
60	range_header.range_start = exp_range_start.value();	31✔
61	range_header.range_end = exp_range_end.value();	31✔
62
63	if (range_header.range_start > range_header.range_end) {	31✔
64	return expected::unexpected(http::MakeError(	1✔
65	http::NoSuchHeaderError, "Invalid Content-Range returned from server: " + header));	3✔
66	}
67
68	if ((range_matches[3].matched) && (range_matches[3].str() != "*")) {	55✔
69	auto exp_size = common::StringToLongLong(range_matches[3].str());	40✔
70	if (!exp_size) {	20✔
71	return expected::unexpected(http::MakeError(	×
72	http::NoSuchHeaderError, "Content-Range contains invalid number: " + header));	×
73	}
74	range_header.size = exp_size.value();	20✔
75	}
76
77	return range_header;
78	}
79
80	class HeaderHandlerFunctor {	581✔
81	public:
82	HeaderHandlerFunctor(weak_ptr<DownloadResumerClient> resumer) :
83	resumer_client_ {resumer} {};
84
85	void operator()(http::ExpectedIncomingResponsePtr exp_resp);
86
87	private:
88	void HandleFirstResponse(
89	const shared_ptr<DownloadResumerClient> &resumer_client,
90	http::ExpectedIncomingResponsePtr exp_resp);
91	void HandleNextResponse(
92	const shared_ptr<DownloadResumerClient> &resumer_client,
93	http::ExpectedIncomingResponsePtr exp_resp);
94
95	weak_ptr<DownloadResumerClient> resumer_client_;
96	};
97
98	class BodyHandlerFunctor {	599✔
99	public:
100	BodyHandlerFunctor(weak_ptr<DownloadResumerClient> resumer) :
101	resumer_client_ {resumer} {};
102
103	void operator()(http::ExpectedIncomingResponsePtr exp_resp);
104
105	private:
106	weak_ptr<DownloadResumerClient> resumer_client_;
107	};
108
109	void HeaderHandlerFunctor::operator()(http::ExpectedIncomingResponsePtr exp_resp) {	142✔
110	auto resumer_client = resumer_client_.lock();	142✔
111	if (resumer_client) {	142✔
112	// If an error has already occurred, schedule the next AsyncCall directly
113	if (!exp_resp) {	140✔
114	resumer_client->logger_.Warning(exp_resp.error().String());	24✔
115	auto err = resumer_client->ScheduleNextResumeRequest();	12✔
116	if (err != error::NoError) {	12✔
117	resumer_client->logger_.Error(err.String());	2✔
118	resumer_client->CallUserHandler(expected::unexpected(err));	2✔
119	}
120	return;
121	}
122
123	if (resumer_client->resumer_state_->active_state == DownloadResumerActiveStatus::Resuming) {	128✔
124	HandleNextResponse(resumer_client, exp_resp);	84✔
125	} else {
126	HandleFirstResponse(resumer_client, exp_resp);	172✔
127	}
128	}
129	}
130
131	void HeaderHandlerFunctor::HandleFirstResponse(	86✔
132	const shared_ptr<DownloadResumerClient> &resumer_client,
133	http::ExpectedIncomingResponsePtr exp_resp) {
134	// The first response shall always call the user header callback. On resumable responses, we
135	// create a our own incoming response and call the user header handler. On errors, we log a
136	// warning and call the user handler with the original response
137
138	auto resp = exp_resp.value();	86✔
139	if (resp->GetStatusCode() != mender::common::http::StatusOK) {	86✔
140	// Non-resumable response
141	resumer_client->CallUserHandler(exp_resp);	2✔
142	return;	2✔
143	}
144
145	auto exp_header = resp->GetHeader("Content-Length");	168✔
146	if (!exp_header \|\| exp_header.value() == "0") {	84✔
147	resumer_client->logger_.Warning("Response does not contain Content-Length header");	2✔
148	resumer_client->CallUserHandler(exp_resp);	1✔
149	return;	1✔
150	}
151
152	auto exp_length = common::StringToLongLong(exp_header.value());	83✔
153	if (!exp_length \|\| exp_length.value() < 0) {	83✔
154	resumer_client->logger_.Warning(	×
155	"Content-Length contains invalid number: " + exp_header.value());	×
156	resumer_client->CallUserHandler(exp_resp);	×
157	return;
158	}
159
160	// Resumable response
161	resumer_client->resumer_state_->active_state = DownloadResumerActiveStatus::Resuming;	83✔
162	resumer_client->resumer_state_->offset = 0;	83✔
163	resumer_client->resumer_state_->content_length = exp_length.value();	83✔
164
165	// Prepare a modified response and call user handler
166	resumer_client->response_.reset(new http::IncomingResponse(*resumer_client, resp->cancelled_));	166✔
167	resumer_client->response_->status_code_ = resp->GetStatusCode();	83✔
168	resumer_client->response_->status_message_ = resp->GetStatusMessage();	166✔
169	resumer_client->response_->headers_ = resp->GetHeaders();
170	resumer_client->CallUserHandler(resumer_client->response_);	166✔
171	}
172
173	void HeaderHandlerFunctor::HandleNextResponse(	42✔
174	const shared_ptr<DownloadResumerClient> &resumer_client,
175	http::ExpectedIncomingResponsePtr exp_resp) {
176	// If an error occurs during handling here, cancel the resuming and call the user handler.
177
178	auto resp = exp_resp.value();	42✔
179	auto resumer_reader = resumer_client->resumer_reader_.lock();	42✔
180	if (!resumer_reader) {	42✔
181	// Errors should already have been handled as part of the Cancel() inside the
182	// destructor of the reader.
183	return;
184	}
185
186	auto exp_content_range = resp->GetHeader("Content-Range").and_then(ParseRangeHeader);	84✔
187	if (!exp_content_range) {	42✔
188	resumer_client->logger_.Error(exp_content_range.error().String());	24✔
189	resumer_client->CallUserHandler(expected::unexpected(exp_content_range.error()));	24✔
190	return;	12✔
191	}
192
193	auto content_range = exp_content_range.value();	30✔
194	if (content_range.size != 0
195	&& content_range.size != resumer_client->resumer_state_->content_length) {	30✔
196	auto size_changed_err = http::MakeError(
197	http::DownloadResumerError,
198	"Size of artifact changed after download was resumed (expected "
199	+ to_string(resumer_client->resumer_state_->content_length) + ", got "	4✔
200	+ to_string(content_range.size) + ")");	8✔
201	resumer_client->logger_.Error(size_changed_err.String());	4✔
202	resumer_client->CallUserHandler(expected::unexpected(size_changed_err));	4✔
203	return;
204	}
205
206	if ((content_range.range_end != resumer_client->resumer_state_->content_length - 1)	28✔
207	\|\| (content_range.range_start != resumer_client->resumer_state_->offset)) {	28✔
208	auto bad_range_err = http::MakeError(
209	http::DownloadResumerError,
210	"HTTP server returned an different range than requested. Requested "
211	+ to_string(resumer_client->resumer_state_->offset) + "-"	4✔
212	+ to_string(resumer_client->resumer_state_->content_length - 1) + ", got "	8✔
213	+ to_string(content_range.range_start) + "-" + to_string(content_range.range_end));	8✔
214	resumer_client->logger_.Error(bad_range_err.String());	4✔
215	resumer_client->CallUserHandler(expected::unexpected(bad_range_err));	4✔
216	return;
217	}
218
219	// Get the reader for the new response
220	auto exp_reader = resumer_client->client_.MakeBodyAsyncReader(resp);	52✔
221	if (!exp_reader) {	26✔
222	auto bad_range_err = exp_reader.error().WithContext("cannot get the reader after resume");	×
223	resumer_client->logger_.Error(bad_range_err.String());	×
224	resumer_client->CallUserHandler(expected::unexpected(bad_range_err));	×
225	return;
226	}
227	// Update the inner reader of the user reader
228	resumer_reader->inner_reader_ = exp_reader.value();	26✔
229
230	// Resume reading reusing last user data (start, end, handler)
231	auto err = resumer_reader->AsyncReadResume();	26✔
232	if (err != error::NoError) {	26✔
233	auto bad_read_err = err.WithContext("error reading after resume");	×
234	resumer_client->logger_.Error(bad_read_err.String());	×
235	resumer_client->CallUserHandler(expected::unexpected(bad_read_err));	×
236	return;
237	}
238	}
239
240	void BodyHandlerFunctor::operator()(http::ExpectedIncomingResponsePtr exp_resp) {	128✔
241	auto resumer_client = resumer_client_.lock();	128✔
242	if (!resumer_client) {	128✔
243	return;
244	}
245
246	if (*resumer_client->cancelled_) {	128✔
247	resumer_client->CallUserHandler(exp_resp);	25✔
248	return;	25✔
249	}
250
251	if (resumer_client->resumer_state_->active_state == DownloadResumerActiveStatus::Inactive) {	103✔
252	resumer_client->CallUserHandler(exp_resp);	3✔
253	return;	3✔
254	}
255
256	// We resume the download if either:
257	// * there is any error or
258	// * successful read with status code Partial Content and there is still data missing
259	const bool is_range_response =
260	exp_resp && exp_resp.value()->GetStatusCode() == mender::common::http::StatusPartialContent;	100✔
261	const bool is_data_missing =
262	resumer_client->resumer_state_->offset < resumer_client->resumer_state_->content_length;	100✔
263	if (!exp_resp \|\| (is_range_response && is_data_missing)) {	100✔
264	if (!exp_resp) {	44✔
265	auto resumer_reader = resumer_client->resumer_reader_.lock();	44✔
266	if (resumer_reader) {	44✔
267	resumer_reader->inner_reader_.reset();	44✔
268	}
269	if (exp_resp.error().code == make_error_condition(errc::operation_canceled)) {	44✔
270	// We don't want to resume cancelled requests, as these were
271	// cancelled for a reason.
272	resumer_client->CallUserHandler(exp_resp);	×
273	return;
274	}
275	resumer_client->logger_.Info(	88✔
276	"Will try to resume after error " + exp_resp.error().String());	88✔
277	}
278
279	auto err = resumer_client->ScheduleNextResumeRequest();	44✔
280	if (err != error::NoError) {	44✔
281	resumer_client->logger_.Error(err.String());	×
282	resumer_client->CallUserHandler(expected::unexpected(err));	×
283	return;
284	}
285	} else {
286	// Update headers with the last received server response. When resuming has taken place,
287	// the user will get different headers on header and body handlers, representing (somehow)
288	// what the resumer has been doing in its behalf.
289	auto resp = exp_resp.value();	56✔
290	resumer_client->response_->status_code_ = resp->GetStatusCode();	56✔
291	resumer_client->response_->status_message_ = resp->GetStatusMessage();	112✔
292	resumer_client->response_->headers_ = resp->GetHeaders();
293
294	// Finished, call the user handler \o/
295	resumer_client->logger_.Debug("Download resumed and completed successfully");	112✔
296	resumer_client->CallUserHandler(resumer_client->response_);	112✔
297	}
298	}
299
300	DownloadResumerAsyncReader::~DownloadResumerAsyncReader() {	246✔
301	Cancel();	82✔
302	}	82✔
303
304	void DownloadResumerAsyncReader::Cancel() {	82✔
305	auto resumer_client = resumer_client_.lock();	82✔
306	if (!*cancelled_ && resumer_client) {	82✔
307	resumer_client->Cancel();	3✔
308	}
309	}	82✔
310
311	error::Error DownloadResumerAsyncReader::AsyncRead(	2,198✔
312	vector<uint8_t>::iterator start, vector<uint8_t>::iterator end, io::AsyncIoHandler handler) {
313	if (eof_) {	2,198✔
314	handler(0);	×
315	return error::NoError;	×
316	}
317
318	auto resumer_client = resumer_client_.lock();	2,198✔
319	if (!resumer_client \|\| *cancelled_) {	2,198✔
320	return error::MakeError(
321	error::ProgrammingError,
322	"DownloadResumerAsyncReader::AsyncRead called after stream is destroyed");	×
323	}
324	// Save user parameters for further resumes of the body read
325	resumer_client->last_read_ = {.start = start, .end = end, .handler = handler};	2,198✔
326	return AsyncReadResume();	2,198✔
327	}
328
329	error::Error DownloadResumerAsyncReader::AsyncReadResume() {	2,224✔
330	auto resumer_client = resumer_client_.lock();	2,224✔
331	if (!resumer_client) {	2,224✔
332	return error::MakeError(
333	error::ProgrammingError,
334	"DownloadResumerAsyncReader::AsyncReadResume called after client is destroyed");	×
335	}
336	return inner_reader_->AsyncRead(
337	resumer_client->last_read_.start,
338	resumer_client->last_read_.end,
339	[this](io::ExpectedSize result) {	2,223✔
340	if (!result) {	2,223✔
341	logger_.Warning(	88✔
342	"Reading error, a new request will be re-scheduled. "
343	+ result.error().String());	88✔
344	} else {
345	if (result.value() == 0) {	2,179✔
346	eof_ = true;	56✔
347	}
348	resumer_state_->offset += result.value();	2,179✔
349	logger_.Debug("read " + to_string(result.value()) + " bytes");	4,358✔
350	auto resumer_client = resumer_client_.lock();	2,179✔
351	if (resumer_client) {	2,179✔
352	resumer_client->last_read_.handler(result);	4,358✔
353	} else {
354	logger_.Error(	×
355	"AsyncRead finish handler called after resumer client has been destroyed.");	×
356	}
357	}
358	});	6,671✔
359	}
360
361	DownloadResumerClient::DownloadResumerClient(	126✔
362	const http::ClientConfig &config, events::EventLoop &event_loop) :
363	resumer_state_ {make_shared<DownloadResumerClientState>()},
364	client_(config, event_loop, "http_resumer:client"),
365	logger_ {"http_resumer:client"},
366	cancelled_ {make_shared<bool>(true)},	126✔
367	retry_ {
368	.backoff = http::ExponentialBackoff(chrono::minutes(1), 10),
369	.wait_timer = events::Timer(event_loop)} {	504✔
370	}	126✔
371
372	DownloadResumerClient::~DownloadResumerClient() {	252✔
373	if (!*cancelled_) {	126✔
374	logger_.Warning("DownloadResumerClient destroyed while request is still active!");	4✔
375	}
376	client_.Cancel();	126✔
377	}	126✔
378
379	error::Error DownloadResumerClient::AsyncCall(	88✔
380	http::OutgoingRequestPtr req,
381	http::ResponseHandler user_header_handler,
382	http::ResponseHandler user_body_handler) {
383	HeaderHandlerFunctor resumer_header_handler {shared_from_this()};	88✔
384	BodyHandlerFunctor resumer_body_handler {shared_from_this()};	88✔
385
386	user_request_ = req;
387	user_header_handler_ = user_header_handler;	88✔
388	user_body_handler_ = user_body_handler;	88✔
389
390	if (!*cancelled_) {	88✔
391	return error::Error(
392	make_error_condition(errc::operation_in_progress), "HTTP resumer call already ongoing");	×
393	}
394
395	*cancelled_ = false;	88✔
396	retry_.backoff.Reset();
397	resumer_state_->active_state = DownloadResumerActiveStatus::Inactive;	88✔
398	resumer_state_->user_handlers_state = DownloadResumerUserHandlersStatus::None;	88✔
399	return client_.AsyncCall(req, resumer_header_handler, resumer_body_handler);	352✔
400	}
401
402	io::ExpectedAsyncReaderPtr DownloadResumerClient::MakeBodyAsyncReader(	83✔
403	http::IncomingResponsePtr resp) {
404	auto exp_reader = client_.MakeBodyAsyncReader(resp);	166✔
405	if (!exp_reader) {	83✔
406	return exp_reader;
407	}
408	auto resumer_reader = make_shared<DownloadResumerAsyncReader>(
409	exp_reader.value(), resumer_state_, cancelled_, shared_from_this());	164✔
410	resumer_reader_ = resumer_reader;
411	return resumer_reader;	82✔
412	}
413
414	http::OutgoingRequestPtr DownloadResumerClient::RemainingRangeRequest() const {	54✔
415	auto range_req = make_shared<http::OutgoingRequest>(*user_request_);	54✔
416	if (resumer_state_->content_length > 0) {	54✔
417	range_req->SetHeader(	53✔
418	"Range",
419	"bytes=" + to_string(resumer_state_->offset) + "-"	106✔
420	+ to_string(resumer_state_->content_length - 1));	212✔
421	}
422	return range_req;	54✔
423	};
424
425	error::Error DownloadResumerClient::ScheduleNextResumeRequest() {	56✔
426	// In any case, make sure the previous HTTP request is cancelled.
427	client_.Cancel();	56✔
428
429	auto exp_interval = retry_.backoff.NextInterval();	56✔
430	if (!exp_interval) {	56✔
431	return http::MakeError(
432	http::DownloadResumerError,
433	"Giving up on resuming the download: " + exp_interval.error().String());	2✔
434	}
435
436	auto interval = exp_interval.value();	55✔
437	logger_.Info(	110✔
438	"Resuming download after "
439	+ to_string(chrono::duration_cast<chrono::seconds>(interval).count()) + " seconds");	110✔
440
441	HeaderHandlerFunctor resumer_next_header_handler {shared_from_this()};	55✔
442	BodyHandlerFunctor resumer_next_body_handler {shared_from_this()};	55✔
443
444	retry_.wait_timer.AsyncWait(	55✔
445	interval, [this, resumer_next_header_handler, resumer_next_body_handler](error::Error err) {	162✔
446	if (err != error::NoError) {	54✔
447	auto err_user = http::MakeError(
UNCOV 448	http::DownloadResumerError, "Unexpected error in wait timer: " + err.String());	×
UNCOV 449	logger_.Error(err_user.String());	×
UNCOV 450	CallUserHandler(expected::unexpected(err_user));	×
451	return;
452	}
453
454	auto next_call_err = client_.AsyncCall(
455	RemainingRangeRequest(), resumer_next_header_handler, resumer_next_body_handler);	162✔
456	if (next_call_err != error::NoError) {	54✔
457	// Schedule once more
UNCOV 458	auto err = ScheduleNextResumeRequest();	×
UNCOV 459	if (err != error::NoError) {	×
UNCOV 460	logger_.Error(err.String());	×
461	CallUserHandler(expected::unexpected(err));	×
462	}
463	}
464	});	165✔
465
466	return error::NoError;	55✔
467	}
468
469	void DownloadResumerClient::CallUserHandler(http::ExpectedIncomingResponsePtr exp_resp) {	187✔
470	if (!exp_resp) {	187✔
471	DoCancel();	42✔
472	}
473	if (resumer_state_->user_handlers_state == DownloadResumerUserHandlersStatus::None) {	187✔
474	resumer_state_->user_handlers_state =	86✔
475	DownloadResumerUserHandlersStatus::HeaderHandlerCalled;
476	user_header_handler_(exp_resp);	172✔
477	} else if (	101✔
478	resumer_state_->user_handlers_state
479	== DownloadResumerUserHandlersStatus::HeaderHandlerCalled) {
480	resumer_state_->user_handlers_state = DownloadResumerUserHandlersStatus::BodyHandlerCalled;	85✔
481	DoCancel();	85✔
482	user_body_handler_(exp_resp);	170✔
483	} else {
484	string msg;
485	if (!exp_resp) {	16✔
486	msg = "error: " + exp_resp.error().String();	32✔
487	} else {
UNCOV 488	auto &resp = exp_resp.value();	×
UNCOV 489	msg = "response: " + to_string(resp->GetStatusCode()) + " " + resp->GetStatusMessage();	×
490	}
491	logger_.Warning("Cannot call any user handler with " + msg);	32✔
492	}
493	}	187✔
494
495	void DownloadResumerClient::Cancel() {	11✔
496	DoCancel();	11✔
497	client_.Cancel();	11✔
498	};	11✔
499
500	void DownloadResumerClient::DoCancel() {	138✔
501	// Set cancel state and then make a new one. Those who are interested should have their own
502	// pointer to the old one.
503	*cancelled_ = true;	138✔
504	cancelled_ = make_shared<bool>(true);	138✔
505	};	138✔
506
507	} // namespace resumer
508	} // namespace http
509	} // namespace common
510	} // namespace mender

mendersoftware / mender / 1583599051

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