15161356083

Committed 21 May 2025 11:48AM UTC coverage: 58.614% (-10.4%) from 68.996%

Build # 15161356083

Build Type

Pull #9813

github

Committed by

web-flow

Commit Message

Merge a6343fe3a into c52a6ddeb

Pull Request Pull Request #9813: lnrpc: add HtlcIndex to ForwardingEvents

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80.93

/channeldb/forwarding_log.go

package channeldb

import (
        "bytes"
        "errors"
        "io"
        "sort"
        "time"

        "github.com/btcsuite/btcwallet/walletdb"
        "github.com/lightningnetwork/lnd/fn/v2"
        "github.com/lightningnetwork/lnd/kvdb"
        "github.com/lightningnetwork/lnd/lnwire"
)

var (
        // forwardingLogBucket is the bucket that we'll use to store the
        // forwarding log. The forwarding log contains a time series database
        // of the forwarding history of a lightning daemon. Each key within the
        // bucket is a timestamp (in nano seconds since the unix epoch), and
        // the value a slice of a forwarding event for that timestamp.
        forwardingLogBucket = []byte("circuit-fwd-log")
)

const (
        // forwardingEventSize is the size of a forwarding event. The breakdown
        // is as follows:
        //
        //  * 8 byte incoming chan ID || 8 byte outgoing chan ID || 8 byte value in
        //    || 8 byte value out || 8 byte incoming htlc id || 8 byte
        //    outgoing htlc id
        //
        // From the value in and value out, callers can easily compute the
        // total fee extract from a forwarding event.
        forwardingEventSize = 48

        // MaxResponseEvents is the max number of forwarding events that will
        // be returned by a single query response. This size was selected to
        // safely remain under gRPC's 4MiB message size response limit. As each
        // full forwarding event (including the timestamp) is 40 bytes, we can
        // safely return 50k entries in a single response.
        MaxResponseEvents = 50000
)

// ForwardingLog returns an instance of the ForwardingLog object backed by the
// target database instance.
func (d *DB) ForwardingLog() *ForwardingLog {
        return &ForwardingLog{
                db: d,
        }
}

// ForwardingLog is a time series database that logs the fulfillment of payment
// circuits by a lightning network daemon. The log contains a series of
// forwarding events which map a timestamp to a forwarding event. A forwarding
// event describes which channels were used to create+settle a circuit, and the
// amount involved. Subtracting the outgoing amount from the incoming amount
// reveals the fee charged for the forwarding service.
type ForwardingLog struct {
        db *DB
}

// ForwardingEvent is an event in the forwarding log's time series. Each
// forwarding event logs the creation and tear-down of a payment circuit. A
// circuit is created once an incoming HTLC has been fully forwarded, and
// destroyed once the payment has been settled.
type ForwardingEvent struct {
        // Timestamp is the settlement time of this payment circuit.
        Timestamp time.Time

        // IncomingChanID is the incoming channel ID of the payment circuit.
        IncomingChanID lnwire.ShortChannelID

        // OutgoingChanID is the outgoing channel ID of the payment circuit.
        OutgoingChanID lnwire.ShortChannelID

        // AmtIn is the amount of the incoming HTLC. Subtracting this from the
        // outgoing amount gives the total fees of this payment circuit.
        AmtIn lnwire.MilliSatoshi

        // AmtOut is the amount of the outgoing HTLC. Subtracting the incoming
        // amount from this gives the total fees for this payment circuit.
        AmtOut lnwire.MilliSatoshi

        // IncomingHtlcID is the ID of the incoming HTLC in the payment circuit.
        // If the HTLC ID is not set, the value will be nil.
        IncomingHtlcID fn.Option[uint64]

        // OutgoingHtlcID is the ID of the outgoing HTLC in the payment circuit.
        // If the HTLC ID is not set, the value will be nil.
        OutgoingHtlcID fn.Option[uint64]
}

// encodeForwardingEvent writes out the target forwarding event to the passed
// io.Writer, using the expected DB format. Note that the timestamp isn't
// serialized as this will be the key value within the bucket.
func encodeForwardingEvent(w io.Writer, f *ForwardingEvent) error {
        // First we write the required fields.
        err := WriteElements(
                w, f.IncomingChanID, f.OutgoingChanID, f.AmtIn, f.AmtOut,
        )
        if err != nil {
                return err
        }

        // Then we write the optional HTLC IDs if they are set.
        f.IncomingHtlcID.WhenSome(func(id uint64) {
                err = WriteElement(w, id)
        })
        if err != nil {
                return err
        }
        f.OutgoingHtlcID.WhenSome(func(id uint64) {
                err = WriteElement(w, id)
        })
        if err != nil {
                return err
        }

        return nil
}

// decodeForwardingEvent attempts to decode the raw bytes of a serialized
// forwarding event into the target ForwardingEvent. Note that the timestamp
// won't be decoded, as the caller is expected to set this due to the bucket
// structure of the forwarding log.
func decodeForwardingEvent(r io.Reader, f *ForwardingEvent) error {
        // Decode the original fields of the forwarding event.
        err := ReadElements(
                r, &f.IncomingChanID, &f.OutgoingChanID, &f.AmtIn, &f.AmtOut,
        )
        if err != nil {
                return err
        }

        // Decode the incoming and outgoing htlc IDs. For backward
        // compatibility with older records that don't have these fields, we
        // handle EOF by setting the ID to nil. Any other error is treated as
        // a read failure.
        var incomingHtlcID uint64
        if err := ReadElement(r, &incomingHtlcID); err != nil {
                if !errors.Is(err, io.EOF) {
                        return err
                }
                f.IncomingHtlcID = fn.None[uint64]()
        } else {
                f.IncomingHtlcID = fn.Some(incomingHtlcID)
        }

        var outgoingHtlcID uint64
        if err := ReadElement(r, &outgoingHtlcID); err != nil {
                if !errors.Is(err, io.EOF) {
                        return err
                }
                f.OutgoingHtlcID = fn.None[uint64]()
        } else {
                f.OutgoingHtlcID = fn.Some(outgoingHtlcID)
        }

        return nil
}

// AddForwardingEvents adds a series of forwarding events to the database.
// Before inserting, the set of events will be sorted according to their
// timestamp. This ensures that all writes to disk are sequential.
func (f *ForwardingLog) AddForwardingEvents(events []ForwardingEvent) error {
        // Before we create the database transaction, we'll ensure that the set
        // of forwarding events are properly sorted according to their
        // timestamp and that no duplicate timestamps exist to avoid collisions
        // in the key we are going to store the events under.
        makeUniqueTimestamps(events)

        var timestamp [8]byte

        return kvdb.Batch(f.db.Backend, func(tx kvdb.RwTx) error {
                // First, we'll fetch the bucket that stores our time series
                // log.
                logBucket, err := tx.CreateTopLevelBucket(
                        forwardingLogBucket,
                )
                if err != nil {
                        return err
                }

                // With the bucket obtained, we can now begin to write out the
                // series of events.
                for _, event := range events {
                        err := storeEvent(logBucket, event, timestamp[:])
                        if err != nil {
                                return err
                        }
                }

                return nil
        })
}

// storeEvent tries to store a forwarding event into the given bucket by trying
// to avoid collisions. If a key for the event timestamp already exists in the
// database, the timestamp is incremented in nanosecond intervals until a "free"
// slot is found.
func storeEvent(bucket walletdb.ReadWriteBucket, event ForwardingEvent,
        timestampScratchSpace []byte) error {

        // First, we'll serialize this timestamp into our
        // timestamp buffer.
        byteOrder.PutUint64(
                timestampScratchSpace, uint64(event.Timestamp.UnixNano()),
        )

        // Next we'll loop until we find a "free" slot in the bucket to store
        // the event under. This should almost never happen unless we're running
        // on a system that has a very bad system clock that doesn't properly
        // resolve to nanosecond scale. We try up to 100 times (which would come
        // to a maximum shift of 0.1 microsecond which is acceptable for most
        // use cases). If we don't find a free slot, we just give up and let
        // the collision happen. Something must be wrong with the data in that
        // case, even on a very fast machine forwarding payments _will_ take a
        // few microseconds at least so we should find a nanosecond slot
        // somewhere.
        const maxTries = 100
        tries := 0
        for tries < maxTries {
                val := bucket.Get(timestampScratchSpace)
                if val == nil {
                        break
                }

                // Collision, try the next nanosecond timestamp.
                nextNano := event.Timestamp.UnixNano() + 1
                event.Timestamp = time.Unix(0, nextNano)
                byteOrder.PutUint64(timestampScratchSpace, uint64(nextNano))
                tries++
        }

        // With the key encoded, we'll then encode the event
        // into our buffer, then write it out to disk.
        var eventBytes [forwardingEventSize]byte
        eventBuf := bytes.NewBuffer(eventBytes[0:0:forwardingEventSize])
        err := encodeForwardingEvent(eventBuf, &event)
        if err != nil {
                return err
        }
        return bucket.Put(timestampScratchSpace, eventBuf.Bytes())
}

// ForwardingEventQuery represents a query to the forwarding log payment
// circuit time series database. The query allows a caller to retrieve all
// records for a particular time slice, offset in that time slice, limiting the
// total number of responses returned.
type ForwardingEventQuery struct {
        // StartTime is the start time of the time slice.
        StartTime time.Time

        // EndTime is the end time of the time slice.
        EndTime time.Time

        // IndexOffset is the offset within the time slice to start at. This
        // can be used to start the response at a particular record.
        IndexOffset uint32

        // NumMaxEvents is the max number of events to return.
        NumMaxEvents uint32
}

// ForwardingLogTimeSlice is the response to a forwarding query. It includes
// the original query, the set  events that match the query, and an integer
// which represents the offset index of the last item in the set of returned
// events. This integer allows callers to resume their query using this offset
// in the event that the query's response exceeds the max number of returnable
// events.
type ForwardingLogTimeSlice struct {
        ForwardingEventQuery

        // ForwardingEvents is the set of events in our time series that answer
        // the query embedded above.
        ForwardingEvents []ForwardingEvent

        // LastIndexOffset is the index of the last element in the set of
        // returned ForwardingEvents above. Callers can use this to resume
        // their query in the event that the time slice has too many events to
        // fit into a single response.
        LastIndexOffset uint32
}

// Query allows a caller to query the forwarding event time series for a
// particular time slice. The caller can control the precise time as well as
// the number of events to be returned.
//
// TODO(roasbeef): rename?
func (f *ForwardingLog) Query(q ForwardingEventQuery) (ForwardingLogTimeSlice, error) {
        var resp ForwardingLogTimeSlice

        // If the user provided an index offset, then we'll not know how many
        // records we need to skip. We'll also keep track of the record offset
        // as that's part of the final return value.
        recordsToSkip := q.IndexOffset
        recordOffset := q.IndexOffset

        err := kvdb.View(f.db, func(tx kvdb.RTx) error {
                // If the bucket wasn't found, then there aren't any events to
                // be returned.
                logBucket := tx.ReadBucket(forwardingLogBucket)
                if logBucket == nil {
                        return ErrNoForwardingEvents
                }

                // We'll be using a cursor to seek into the database, so we'll
                // populate byte slices that represent the start of the key
                // space we're interested in, and the end.
                var startTime, endTime [8]byte
                byteOrder.PutUint64(startTime[:], uint64(q.StartTime.UnixNano()))
                byteOrder.PutUint64(endTime[:], uint64(q.EndTime.UnixNano()))

                // If we know that a set of log events exists, then we'll begin
                // our seek through the log in order to satisfy the query.
                // We'll continue until either we reach the end of the range,
                // or reach our max number of events.
                logCursor := logBucket.ReadCursor()
                timestamp, events := logCursor.Seek(startTime[:])
                for ; timestamp != nil && bytes.Compare(timestamp, endTime[:]) <= 0; timestamp, events = logCursor.Next() {
                        // If our current return payload exceeds the max number
                        // of events, then we'll exit now.
                        if uint32(len(resp.ForwardingEvents)) >= q.NumMaxEvents {
                                return nil
                        }

                        // If we're not yet past the user defined offset, then
                        // we'll continue to seek forward.
                        if recordsToSkip > 0 {
                                recordsToSkip--
                                continue
                        }

                        currentTime := time.Unix(
                                0, int64(byteOrder.Uint64(timestamp)),
                        )

                        // At this point, we've skipped enough records to start
                        // to collate our query. For each record, we'll
                        // increment the final record offset so the querier can
                        // utilize pagination to seek further.
                        readBuf := bytes.NewReader(events)
                        for readBuf.Len() != 0 {
                                var event ForwardingEvent
                                err := decodeForwardingEvent(readBuf, &event)
                                if err != nil {
                                        return err
                                }

                                event.Timestamp = currentTime
                                resp.ForwardingEvents = append(resp.ForwardingEvents, event)

                                recordOffset++
                        }
                }

                return nil
        }, func() {
                resp = ForwardingLogTimeSlice{
                        ForwardingEventQuery: q,
                }
        })
        if err != nil && err != ErrNoForwardingEvents {
                return ForwardingLogTimeSlice{}, err
        }

        resp.LastIndexOffset = recordOffset

        return resp, nil
}

// makeUniqueTimestamps takes a slice of forwarding events, sorts it by the
// event timestamps and then makes sure there are no duplicates in the
// timestamps. If duplicates are found, some of the timestamps are increased on
// the nanosecond scale until only unique values remain. This is a fix to
// address the problem that in some environments (looking at you, Windows) the
// system clock has such a bad resolution that two serial invocations of
// time.Now() might return the same timestamp, even if some time has elapsed
// between the calls.
func makeUniqueTimestamps(events []ForwardingEvent) {
        sort.Slice(events, func(i, j int) bool {
                return events[i].Timestamp.Before(events[j].Timestamp)
        })

        // Now that we know the events are sorted by timestamp, we can go
        // through the list and fix all duplicates until only unique values
        // remain.
        for outer := 0; outer < len(events)-1; outer++ {
                current := events[outer].Timestamp.UnixNano()
                next := events[outer+1].Timestamp.UnixNano()

                // We initially sorted the slice. So if the current is now
                // greater or equal to the next one, it's either because it's a
                // duplicate or because we increased the current in the last
                // iteration.
                if current >= next {
                        next = current + 1
                        events[outer+1].Timestamp = time.Unix(0, next)
                }
        }
}

1	package channeldb
2
3	import (
4	"bytes"
5	"errors"
6	"io"
7	"sort"
8	"time"
9
10	"github.com/btcsuite/btcwallet/walletdb"
11	"github.com/lightningnetwork/lnd/fn/v2"
12	"github.com/lightningnetwork/lnd/kvdb"
13	"github.com/lightningnetwork/lnd/lnwire"
14	)
15
16	var (
17	// forwardingLogBucket is the bucket that we'll use to store the
18	// forwarding log. The forwarding log contains a time series database
19	// of the forwarding history of a lightning daemon. Each key within the
20	// bucket is a timestamp (in nano seconds since the unix epoch), and
21	// the value a slice of a forwarding event for that timestamp.
22	forwardingLogBucket = []byte("circuit-fwd-log")
23	)
24
25	const (
26	// forwardingEventSize is the size of a forwarding event. The breakdown
27	// is as follows:
28	//
29	// * 8 byte incoming chan ID \|\| 8 byte outgoing chan ID \|\| 8 byte value in
30	// \|\| 8 byte value out \|\| 8 byte incoming htlc id \|\| 8 byte
31	// outgoing htlc id
32	//
33	// From the value in and value out, callers can easily compute the
34	// total fee extract from a forwarding event.
35	forwardingEventSize = 48
36
37	// MaxResponseEvents is the max number of forwarding events that will
38	// be returned by a single query response. This size was selected to
39	// safely remain under gRPC's 4MiB message size response limit. As each
40	// full forwarding event (including the timestamp) is 40 bytes, we can
41	// safely return 50k entries in a single response.
42	MaxResponseEvents = 50000
43	)
44
45	// ForwardingLog returns an instance of the ForwardingLog object backed by the
46	// target database instance.
47	func (d DB) ForwardingLog() ForwardingLog {	3✔
48	return &ForwardingLog{	3✔
49	db: d,	3✔
50	}	3✔
51	}	3✔
52
53	// ForwardingLog is a time series database that logs the fulfillment of payment
54	// circuits by a lightning network daemon. The log contains a series of
55	// forwarding events which map a timestamp to a forwarding event. A forwarding
56	// event describes which channels were used to create+settle a circuit, and the
57	// amount involved. Subtracting the outgoing amount from the incoming amount
58	// reveals the fee charged for the forwarding service.
59	type ForwardingLog struct {
60	db *DB
61	}
62
63	// ForwardingEvent is an event in the forwarding log's time series. Each
64	// forwarding event logs the creation and tear-down of a payment circuit. A
65	// circuit is created once an incoming HTLC has been fully forwarded, and
66	// destroyed once the payment has been settled.
67	type ForwardingEvent struct {
68	// Timestamp is the settlement time of this payment circuit.
69	Timestamp time.Time
70
71	// IncomingChanID is the incoming channel ID of the payment circuit.
72	IncomingChanID lnwire.ShortChannelID
73
74	// OutgoingChanID is the outgoing channel ID of the payment circuit.
75	OutgoingChanID lnwire.ShortChannelID
76
77	// AmtIn is the amount of the incoming HTLC. Subtracting this from the
78	// outgoing amount gives the total fees of this payment circuit.
79	AmtIn lnwire.MilliSatoshi
80
81	// AmtOut is the amount of the outgoing HTLC. Subtracting the incoming
82	// amount from this gives the total fees for this payment circuit.
83	AmtOut lnwire.MilliSatoshi
84
85	// IncomingHtlcID is the ID of the incoming HTLC in the payment circuit.
86	// If the HTLC ID is not set, the value will be nil.
87	IncomingHtlcID fn.Option[uint64]
88
89	// OutgoingHtlcID is the ID of the outgoing HTLC in the payment circuit.
90	// If the HTLC ID is not set, the value will be nil.
91	OutgoingHtlcID fn.Option[uint64]
92	}
93
94	// encodeForwardingEvent writes out the target forwarding event to the passed
95	// io.Writer, using the expected DB format. Note that the timestamp isn't
96	// serialized as this will be the key value within the bucket.
97	func encodeForwardingEvent(w io.Writer, f *ForwardingEvent) error {	3✔
98	// First we write the required fields.	3✔
99	err := WriteElements(	3✔
100	w, f.IncomingChanID, f.OutgoingChanID, f.AmtIn, f.AmtOut,	3✔
101	)	3✔
102	if err != nil {	3✔
NEW 103	return err	×
NEW 104	}	×
105
106	// Then we write the optional HTLC IDs if they are set.
107	f.IncomingHtlcID.WhenSome(func(id uint64) {	6✔
108	err = WriteElement(w, id)	3✔
109	})	3✔
110	if err != nil {	3✔
NEW 111	return err	×
NEW 112	}	×
113	f.OutgoingHtlcID.WhenSome(func(id uint64) {	6✔
114	err = WriteElement(w, id)	3✔
115	})	3✔
116	if err != nil {	3✔
NEW 117	return err	×
NEW 118	}	×
119
120	return nil	3✔
121	}
122
123	// decodeForwardingEvent attempts to decode the raw bytes of a serialized
124	// forwarding event into the target ForwardingEvent. Note that the timestamp
125	// won't be decoded, as the caller is expected to set this due to the bucket
126	// structure of the forwarding log.
127	func decodeForwardingEvent(r io.Reader, f *ForwardingEvent) error {	3✔
128	// Decode the original fields of the forwarding event.	3✔
129	err := ReadElements(	3✔
130	r, &f.IncomingChanID, &f.OutgoingChanID, &f.AmtIn, &f.AmtOut,	3✔
131	)	3✔
132	if err != nil {	3✔
NEW 133	return err	×
NEW 134	}	×
135
136	// Decode the incoming and outgoing htlc IDs. For backward
137	// compatibility with older records that don't have these fields, we
138	// handle EOF by setting the ID to nil. Any other error is treated as
139	// a read failure.
140	var incomingHtlcID uint64	3✔
141	if err := ReadElement(r, &incomingHtlcID); err != nil {	3✔
NEW 142	if !errors.Is(err, io.EOF) {	×
NEW 143	return err	×
NEW 144	}	×
NEW 145	f.IncomingHtlcID = fn.None[uint64]()	×
146	} else {	3✔
147	f.IncomingHtlcID = fn.Some(incomingHtlcID)	3✔
148	}	3✔
149
150	var outgoingHtlcID uint64	3✔
151	if err := ReadElement(r, &outgoingHtlcID); err != nil {	3✔
NEW 152	if !errors.Is(err, io.EOF) {	×
NEW 153	return err	×
NEW 154	}	×
NEW 155	f.OutgoingHtlcID = fn.None[uint64]()	×
156	} else {	3✔
157	f.OutgoingHtlcID = fn.Some(outgoingHtlcID)	3✔
158	}	3✔
159
160	return nil	3✔
161	}
162
163	// AddForwardingEvents adds a series of forwarding events to the database.
164	// Before inserting, the set of events will be sorted according to their
165	// timestamp. This ensures that all writes to disk are sequential.
166	func (f *ForwardingLog) AddForwardingEvents(events []ForwardingEvent) error {	3✔
167	// Before we create the database transaction, we'll ensure that the set	3✔
168	// of forwarding events are properly sorted according to their	3✔
169	// timestamp and that no duplicate timestamps exist to avoid collisions	3✔
170	// in the key we are going to store the events under.	3✔
171	makeUniqueTimestamps(events)	3✔
172		3✔
173	var timestamp [8]byte	3✔
174		3✔
175	return kvdb.Batch(f.db.Backend, func(tx kvdb.RwTx) error {	6✔
176	// First, we'll fetch the bucket that stores our time series	3✔
177	// log.	3✔
178	logBucket, err := tx.CreateTopLevelBucket(	3✔
179	forwardingLogBucket,	3✔
180	)	3✔
181	if err != nil {	3✔
182	return err	×
183	}	×
184
185	// With the bucket obtained, we can now begin to write out the
186	// series of events.
187	for _, event := range events {	6✔
188	err := storeEvent(logBucket, event, timestamp[:])	3✔
189	if err != nil {	3✔
190	return err	×
191	}	×
192	}
193
194	return nil	3✔
195	})
196	}
197
198	// storeEvent tries to store a forwarding event into the given bucket by trying
199	// to avoid collisions. If a key for the event timestamp already exists in the
200	// database, the timestamp is incremented in nanosecond intervals until a "free"
201	// slot is found.
202	func storeEvent(bucket walletdb.ReadWriteBucket, event ForwardingEvent,
203	timestampScratchSpace []byte) error {	3✔
204		3✔
205	// First, we'll serialize this timestamp into our	3✔
206	// timestamp buffer.	3✔
207	byteOrder.PutUint64(	3✔
208	timestampScratchSpace, uint64(event.Timestamp.UnixNano()),	3✔
209	)	3✔
210		3✔
211	// Next we'll loop until we find a "free" slot in the bucket to store	3✔
212	// the event under. This should almost never happen unless we're running	3✔
213	// on a system that has a very bad system clock that doesn't properly	3✔
214	// resolve to nanosecond scale. We try up to 100 times (which would come	3✔
215	// to a maximum shift of 0.1 microsecond which is acceptable for most	3✔
216	// use cases). If we don't find a free slot, we just give up and let	3✔
217	// the collision happen. Something must be wrong with the data in that	3✔
218	// case, even on a very fast machine forwarding payments _will_ take a	3✔
219	// few microseconds at least so we should find a nanosecond slot	3✔
220	// somewhere.	3✔
221	const maxTries = 100	3✔
222	tries := 0	3✔
223	for tries < maxTries {	6✔
224	val := bucket.Get(timestampScratchSpace)	3✔
225	if val == nil {	6✔
226	break	3✔
227	}
228
229	// Collision, try the next nanosecond timestamp.
UNCOV 230	nextNano := event.Timestamp.UnixNano() + 1	×
UNCOV 231	event.Timestamp = time.Unix(0, nextNano)	×
UNCOV 232	byteOrder.PutUint64(timestampScratchSpace, uint64(nextNano))	×
UNCOV 233	tries++	×
234	}
235
236	// With the key encoded, we'll then encode the event
237	// into our buffer, then write it out to disk.
238	var eventBytes [forwardingEventSize]byte	3✔
239	eventBuf := bytes.NewBuffer(eventBytes[0:0:forwardingEventSize])	3✔
240	err := encodeForwardingEvent(eventBuf, &event)	3✔
241	if err != nil {	3✔
242	return err	×
243	}	×
244	return bucket.Put(timestampScratchSpace, eventBuf.Bytes())	3✔
245	}
246
247	// ForwardingEventQuery represents a query to the forwarding log payment
248	// circuit time series database. The query allows a caller to retrieve all
249	// records for a particular time slice, offset in that time slice, limiting the
250	// total number of responses returned.
251	type ForwardingEventQuery struct {
252	// StartTime is the start time of the time slice.
253	StartTime time.Time
254
255	// EndTime is the end time of the time slice.
256	EndTime time.Time
257
258	// IndexOffset is the offset within the time slice to start at. This
259	// can be used to start the response at a particular record.
260	IndexOffset uint32
261
262	// NumMaxEvents is the max number of events to return.
263	NumMaxEvents uint32
264	}
265
266	// ForwardingLogTimeSlice is the response to a forwarding query. It includes
267	// the original query, the set events that match the query, and an integer
268	// which represents the offset index of the last item in the set of returned
269	// events. This integer allows callers to resume their query using this offset
270	// in the event that the query's response exceeds the max number of returnable
271	// events.
272	type ForwardingLogTimeSlice struct {
273	ForwardingEventQuery
274
275	// ForwardingEvents is the set of events in our time series that answer
276	// the query embedded above.
277	ForwardingEvents []ForwardingEvent
278
279	// LastIndexOffset is the index of the last element in the set of
280	// returned ForwardingEvents above. Callers can use this to resume
281	// their query in the event that the time slice has too many events to
282	// fit into a single response.
283	LastIndexOffset uint32
284	}
285
286	// Query allows a caller to query the forwarding event time series for a
287	// particular time slice. The caller can control the precise time as well as
288	// the number of events to be returned.
289	//
290	// TODO(roasbeef): rename?
291	func (f *ForwardingLog) Query(q ForwardingEventQuery) (ForwardingLogTimeSlice, error) {	3✔
292	var resp ForwardingLogTimeSlice	3✔
293		3✔
294	// If the user provided an index offset, then we'll not know how many	3✔
295	// records we need to skip. We'll also keep track of the record offset	3✔
296	// as that's part of the final return value.	3✔
297	recordsToSkip := q.IndexOffset	3✔
298	recordOffset := q.IndexOffset	3✔
299		3✔
300	err := kvdb.View(f.db, func(tx kvdb.RTx) error {	6✔
301	// If the bucket wasn't found, then there aren't any events to	3✔
302	// be returned.	3✔
303	logBucket := tx.ReadBucket(forwardingLogBucket)	3✔
304	if logBucket == nil {	3✔
305	return ErrNoForwardingEvents	×
306	}	×
307
308	// We'll be using a cursor to seek into the database, so we'll
309	// populate byte slices that represent the start of the key
310	// space we're interested in, and the end.
311	var startTime, endTime [8]byte	3✔
312	byteOrder.PutUint64(startTime[:], uint64(q.StartTime.UnixNano()))	3✔
313	byteOrder.PutUint64(endTime[:], uint64(q.EndTime.UnixNano()))	3✔
314		3✔
315	// If we know that a set of log events exists, then we'll begin	3✔
316	// our seek through the log in order to satisfy the query.	3✔
317	// We'll continue until either we reach the end of the range,	3✔
318	// or reach our max number of events.	3✔
319	logCursor := logBucket.ReadCursor()	3✔
320	timestamp, events := logCursor.Seek(startTime[:])	3✔
321	for ; timestamp != nil && bytes.Compare(timestamp, endTime[:]) <= 0; timestamp, events = logCursor.Next() {	6✔
322	// If our current return payload exceeds the max number	3✔
323	// of events, then we'll exit now.	3✔
324	if uint32(len(resp.ForwardingEvents)) >= q.NumMaxEvents {	3✔
UNCOV 325	return nil	×
UNCOV 326	}	×
327
328	// If we're not yet past the user defined offset, then
329	// we'll continue to seek forward.
330	if recordsToSkip > 0 {	6✔
331	recordsToSkip--	3✔
332	continue	3✔
333	}
334
335	currentTime := time.Unix(	3✔
336	0, int64(byteOrder.Uint64(timestamp)),	3✔
337	)	3✔
338		3✔
339	// At this point, we've skipped enough records to start	3✔
340	// to collate our query. For each record, we'll	3✔
341	// increment the final record offset so the querier can	3✔
342	// utilize pagination to seek further.	3✔
343	readBuf := bytes.NewReader(events)	3✔
344	for readBuf.Len() != 0 {	6✔
345	var event ForwardingEvent	3✔
346	err := decodeForwardingEvent(readBuf, &event)	3✔
347	if err != nil {	3✔
348	return err	×
349	}	×
350
351	event.Timestamp = currentTime	3✔
352	resp.ForwardingEvents = append(resp.ForwardingEvents, event)	3✔
353		3✔
354	recordOffset++	3✔
355	}
356	}
357
358	return nil	3✔
359	}, func() {	3✔
360	resp = ForwardingLogTimeSlice{	3✔
361	ForwardingEventQuery: q,	3✔
362	}	3✔
363	})	3✔
364	if err != nil && err != ErrNoForwardingEvents {	3✔
365	return ForwardingLogTimeSlice{}, err	×
366	}	×
367
368	resp.LastIndexOffset = recordOffset	3✔
369		3✔
370	return resp, nil	3✔
371	}
372
373	// makeUniqueTimestamps takes a slice of forwarding events, sorts it by the
374	// event timestamps and then makes sure there are no duplicates in the
375	// timestamps. If duplicates are found, some of the timestamps are increased on
376	// the nanosecond scale until only unique values remain. This is a fix to
377	// address the problem that in some environments (looking at you, Windows) the
378	// system clock has such a bad resolution that two serial invocations of
379	// time.Now() might return the same timestamp, even if some time has elapsed
380	// between the calls.
381	func makeUniqueTimestamps(events []ForwardingEvent) {	3✔
382	sort.Slice(events, func(i, j int) bool {	6✔
383	return events[i].Timestamp.Before(events[j].Timestamp)	3✔
384	})	3✔
385
386	// Now that we know the events are sorted by timestamp, we can go
387	// through the list and fix all duplicates until only unique values
388	// remain.
389	for outer := 0; outer < len(events)-1; outer++ {	6✔
390	current := events[outer].Timestamp.UnixNano()	3✔
391	next := events[outer+1].Timestamp.UnixNano()	3✔
392		3✔
393	// We initially sorted the slice. So if the current is now	3✔
394	// greater or equal to the next one, it's either because it's a	3✔
395	// duplicate or because we increased the current in the last	3✔
396	// iteration.	3✔
397	if current >= next {	3✔
UNCOV 398	next = current + 1	×
UNCOV 399	events[outer+1].Timestamp = time.Unix(0, next)	×
UNCOV 400	}	×
401	}
402	}

lightningnetwork / lnd / 15161356083

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