func TestRebuildRoleChannels(t *testing.T) {
computer := mockComputer{channels: ch.AtSequence(ch.SetOf("derived1", "derived2"), 1)}
auth := NewAuthenticator(gTestBucket, &computer)
role, _ := auth.NewRole("testRole", ch.SetOf("explicit1"))
err := auth.InvalidateChannels(role)
assert.Equals(t, err, nil)
role2, err := auth.GetRole("testRole")
assert.Equals(t, err, nil)
assert.DeepEquals(t, role2.Channels(), ch.AtSequence(ch.SetOf("explicit1", "derived1", "derived2", "!"), 1))
}
func TestRebuildUserChannels(t *testing.T) {
computer := mockComputer{channels: ch.AtSequence(ch.SetOf("derived1", "derived2"), 1)}
auth := NewAuthenticator(gTestBucket, &computer)
user, _ := auth.NewUser("testUser", "password", ch.SetOf("explicit1"))
user.setChannels(nil)
err := auth.Save(user)
assert.Equals(t, err, nil)
user2, err := auth.GetUser("testUser")
assert.Equals(t, err, nil)
assert.DeepEquals(t, user2.Channels(), ch.AtSequence(ch.SetOf("explicit1", "derived1", "derived2", "!"), 1))
}
func TestRebuildUserRoles(t *testing.T) {
computer := mockComputer{roles: ch.AtSequence(base.SetOf("role1", "role2"), 3)}
auth := NewAuthenticator(gTestBucket, &computer)
user, _ := auth.NewUser("testUser", "letmein", nil)
user.SetExplicitRoles(ch.TimedSet{"role3": ch.NewVbSimpleSequence(1), "role1": ch.NewVbSimpleSequence(1)})
err := auth.InvalidateRoles(user)
assert.Equals(t, err, nil)
user2, err := auth.GetUser("testUser")
assert.Equals(t, err, nil)
expected := ch.AtSequence(base.SetOf("role1", "role3"), 1)
expected.AddChannel("role2", 3)
assert.DeepEquals(t, user2.RoleNames(), expected)
}
// Updates a document's channel/role UserAccessMap with new access settings from an AccessMap.
// Returns an array of the user/role names whose access has changed as a result.
func (accessMap *UserAccessMap) updateAccess(doc *document, newAccess channels.AccessMap) (changedUsers []string) {
// Update users already appearing in doc.Access:
for name, access := range *accessMap {
if access.UpdateAtSequence(newAccess[name], doc.Sequence) {
if len(access) == 0 {
delete(*accessMap, name)
}
changedUsers = append(changedUsers, name)
}
}
// Add new users who are in newAccess but not accessMap:
for name, access := range newAccess {
if _, existed := (*accessMap)[name]; !existed {
if *accessMap == nil {
*accessMap = UserAccessMap{}
}
(*accessMap)[name] = channels.AtSequence(access, doc.Sequence)
changedUsers = append(changedUsers, name)
}
}
if changedUsers != nil {
what := "channel"
if accessMap == &doc.RoleAccess {
what = "role"
}
base.LogTo("Access", "Doc %q grants %s access: %v", doc.ID, what, *accessMap)
}
return changedUsers
}
func (auth *Authenticator) defaultGuestUser() User {
user := &userImpl{
roleImpl: roleImpl{
ExplicitChannels_: ch.AtSequence(ch.SetOf(), 1),
},
userImplBody: userImplBody{
Disabled_: true,
},
auth: auth,
}
user.Channels_ = user.ExplicitChannels_.Copy()
return user
}
func (user *userImpl) UnmarshalJSON(data []byte) error {
if err := json.Unmarshal(data, &user.userImplBody); err != nil {
return err
} else if err := json.Unmarshal(data, &user.roleImpl); err != nil {
return err
}
// Migrate "admin_roles" field:
if user.OldExplicitRoles_ != nil {
user.ExplicitRoles_ = ch.AtSequence(base.SetFromArray(user.OldExplicitRoles_), 1)
user.OldExplicitRoles_ = nil
}
return nil
}
func TestAccessFunction(t *testing.T) {
/*
var logKeys = map[string]bool {
"CRUD": true,
"Access": true,
}
base.UpdateLogKeys(logKeys, true)
*/
db := setupTestDB(t)
defer tearDownTestDB(t, db)
authenticator := auth.NewAuthenticator(db.Bucket, db)
var err error
db.ChannelMapper = channels.NewChannelMapper(`function(doc){access(doc.users,doc.userChannels);}`)
user, _ := authenticator.NewUser("naomi", "letmein", channels.SetOf("Netflix"))
user.SetExplicitRoles(channels.TimedSet{"animefan": channels.NewVbSimpleSequence(1), "tumblr": channels.NewVbSimpleSequence(1)})
assertNoError(t, authenticator.Save(user), "Save")
body := Body{"users": []string{"naomi"}, "userChannels": []string{"Hulu"}}
_, err = db.Put("doc1", body)
assertNoError(t, err, "")
body = Body{"users": []string{"role:animefan"}, "userChannels": []string{"CrunchyRoll"}}
_, err = db.Put("doc2", body)
assertNoError(t, err, "")
// Create the role _after_ creating the documents, to make sure the previously-indexed access
// privileges are applied.
role, _ := authenticator.NewRole("animefan", nil)
authenticator.Save(role)
user, err = authenticator.GetUser("naomi")
assertNoError(t, err, "GetUser")
expected := channels.AtSequence(channels.SetOf("Hulu", "Netflix", "!"), 1)
assert.DeepEquals(t, user.Channels(), expected)
expected.AddChannel("CrunchyRoll", 2)
assert.DeepEquals(t, user.InheritedChannels(), expected)
}
func WriteDirectWithChannelGrant(db *Database, channelArray []string, sequence uint64, username string, channelGrantArray []string) {
docId := fmt.Sprintf("doc-%v", sequence)
rev := "1-a"
chanMap := make(map[string]*channels.ChannelRemoval, 10)
for _, channel := range channelArray {
chanMap[channel] = nil
}
accessMap := make(map[string]channels.TimedSet)
channelTimedSet := channels.AtSequence(base.SetFromArray(channelGrantArray), sequence)
accessMap[username] = channelTimedSet
syncData := &syncData{
CurrentRev: rev,
Sequence: sequence,
Channels: chanMap,
Access: accessMap,
}
db.Bucket.Add(docId, 0, Body{"_sync": syncData, "key": docId})
}
func TestRoleInheritance(t *testing.T) {
// Create some roles:
auth := NewAuthenticator(gTestBucket, nil)
role, _ := auth.NewRole("square", ch.SetOf("dull", "duller", "dullest"))
assert.Equals(t, auth.Save(role), nil)
role, _ = auth.NewRole("frood", ch.SetOf("hoopy", "hoopier", "hoopiest"))
assert.Equals(t, auth.Save(role), nil)
user, _ := auth.NewUser("arthur", "password", ch.SetOf("britain"))
user.(*userImpl).setRolesSince(ch.TimedSet{"square": ch.NewVbSimpleSequence(0x3), "nonexistent": ch.NewVbSimpleSequence(0x42), "frood": ch.NewVbSimpleSequence(0x4)})
assert.DeepEquals(t, user.RoleNames(), ch.TimedSet{"square": ch.NewVbSimpleSequence(0x3), "nonexistent": ch.NewVbSimpleSequence(0x42), "frood": ch.NewVbSimpleSequence(0x4)})
auth.Save(user)
user2, err := auth.GetUser("arthur")
assert.Equals(t, err, nil)
log.Printf("Channels = %s", user2.Channels())
assert.DeepEquals(t, user2.Channels(), ch.AtSequence(ch.SetOf("!", "britain"), 1))
assert.DeepEquals(t, user2.InheritedChannels(),
ch.TimedSet{"!": ch.NewVbSimpleSequence(0x1), "britain": ch.NewVbSimpleSequence(0x1), "dull": ch.NewVbSimpleSequence(0x3), "duller": ch.NewVbSimpleSequence(0x3), "dullest": ch.NewVbSimpleSequence(0x3), "hoopy": ch.NewVbSimpleSequence(0x4), "hoopier": ch.NewVbSimpleSequence(0x4), "hoopiest": ch.NewVbSimpleSequence(0x4)})
assert.True(t, user2.CanSeeChannel("britain"))
assert.True(t, user2.CanSeeChannel("duller"))
assert.True(t, user2.CanSeeChannel("hoopy"))
assert.Equals(t, user2.AuthorizeAllChannels(ch.SetOf("britain", "dull", "hoopiest")), nil)
}
// Returns the (ordered) union of all of the changes made to multiple channels.
func (db *Database) VectorMultiChangesFeed(chans base.Set, options ChangesOptions) (<-chan *ChangeEntry, error) {
to := ""
var userVbNo uint16
if db.user != nil && db.user.Name() != "" {
to = fmt.Sprintf(" (to %s)", db.user.Name())
userVbNo = uint16(db.Bucket.VBHash(db.user.DocID()))
}
base.LogTo("Changes+", "Vector MultiChangesFeed(%s, %+v) ... %s", chans, options, to)
output := make(chan *ChangeEntry, 50)
go func() {
var cumulativeClock *base.SyncSequenceClock
var lastHashedValue string
hashedEntryCount := 0
defer func() {
base.LogTo("Changes+", "MultiChangesFeed done %s", to)
close(output)
}()
var changeWaiter *changeWaiter
var userChangeCount uint64
var addedChannels base.Set // Tracks channels added to the user during changes processing.
if options.Wait {
// Note (Adam): I don't think there's a reason to set this to false here. We're outside the
// main iteration loop (so the if check above should only happen once), and I don't believe
// options.Wait is referenced elsewhere once MultiChangesFeed is called. Leaving it as-is
// makes it possible for channels to identify whether a getChanges call has options.Wait set to true,
// which is useful to identify active change listeners. However, it's possible there's a subtlety of
// longpoll or continuous processing I'm missing here - leaving this note instead of just deleting for now.
//options.Wait = false
changeWaiter = db.startChangeWaiter(chans)
userChangeCount = changeWaiter.CurrentUserCount()
}
cumulativeClock = base.NewSyncSequenceClock()
cumulativeClock.SetTo(getChangesClock(options.Since))
// This loop is used to re-run the fetch after every database change, in Wait mode
outer:
for {
// Get the last polled stable sequence. We don't return anything later than stable sequence in each iteration
stableClock, err := db.changeCache.GetStableClock(true)
if err != nil {
base.Warn("MultiChangesFeed got error reading stable sequence: %v", err)
return
}
// Restrict to available channels, expand wild-card, and find since when these channels
// have been available to the user:
var channelsSince channels.TimedSet
if db.user != nil {
channelsSince = db.user.FilterToAvailableChannels(chans)
} else {
channelsSince = channels.AtSequence(chans, 0)
}
// Updates the changeWaiter to the current set of available channels.
if changeWaiter != nil {
changeWaiter.UpdateChannels(channelsSince)
}
base.LogTo("Changes+", "MultiChangesFeed: channels expand to %#v ... %s", channelsSince, to)
// Build the channel feeds.
feeds, err := db.initializeChannelFeeds(channelsSince, options, addedChannels, userVbNo)
if err != nil {
return
}
// This loop reads the available entries from all the feeds in parallel, merges them,
// and writes them to the output channel:
current := make([]*ChangeEntry, len(feeds))
var sentSomething bool
nextEntry := getNextSequenceFromFeeds(current, feeds)
for {
minEntry := nextEntry
if minEntry == nil {
break // Exit the loop when there are no more entries
}
// Calculate next entry here, to help identify whether minEntry is the last entry we're sending,
// to guarantee hashing
nextEntry = getNextSequenceFromFeeds(current, feeds)
// Don't send any entries later than the stable sequence
if stableClock.GetSequence(minEntry.Seq.vbNo) < minEntry.Seq.Seq {
continue
}
// Add the doc body or the conflicting rev IDs, if those options are set:
if options.IncludeDocs || options.Conflicts {
db.addDocToChangeEntry(minEntry, options)
}
// Clock handling
if minEntry.Seq.TriggeredBy == 0 {
// Update the cumulative clock, and stick it on the entry.
cumulativeClock.SetMaxSequence(minEntry.Seq.vbNo, minEntry.Seq.Seq)
// Force new hash generation for non-continuous changes feeds if this is the last entry to be sent - either
// because there are no more entries in the channel feeds, or we're going to hit the limit.
forceHash := false
if options.Continuous == false && (nextEntry == nil || options.Limit == 1) {
forceHash = true
}
lastHashedValue = db.calculateHashWhenNeeded(
options,
minEntry,
cumulativeClock,
&hashedEntryCount,
lastHashedValue,
forceHash,
)
} else {
// For backfill (triggered by), we don't want to update the cumulative clock. All entries triggered by the
// same sequence reference the same triggered by clock, so it should only need to get hashed once.
// If this is the first entry for this triggered by, initialize the triggered by clock's
// hash value.
if minEntry.Seq.TriggeredByClock.GetHashedValue() == "" {
cumulativeClock.SetMaxSequence(minEntry.Seq.TriggeredByVbNo, minEntry.Seq.TriggeredBy)
clockHash, err := db.SequenceHasher.GetHash(cumulativeClock)
if err != nil {
base.Warn("Error calculating hash for triggered by clock:%v", base.PrintClock(cumulativeClock))
} else {
minEntry.Seq.TriggeredByClock.SetHashedValue(clockHash)
}
}
}
// Send the entry, and repeat the loop:
select {
case <-options.Terminator:
return
case output <- minEntry:
}
sentSomething = true
// Stop when we hit the limit (if any):
if options.Limit > 0 {
options.Limit--
if options.Limit == 0 {
break outer
}
}
}
if !options.Continuous && (sentSomething || changeWaiter == nil) {
break
}
// Update options.Since for use in the next outer loop iteration.
options.Since.Clock = cumulativeClock
// If nothing found, and in wait mode: wait for the db to change, then run again.
// First notify the reader that we're waiting by sending a nil.
base.LogTo("Changes+", "MultiChangesFeed waiting... %s", to)
output <- nil
waitForChanges:
for {
waitResponse := changeWaiter.Wait()
if waitResponse == WaiterClosed {
break outer
} else if waitResponse == WaiterHasChanges {
select {
case <-options.Terminator:
return
default:
break waitForChanges
}
} else if waitResponse == WaiterCheckTerminated {
// Check whether I was terminated while waiting for a change. If not, resume wait.
select {
case <-options.Terminator:
return
default:
}
}
}
// Before checking again, update the User object in case its channel access has
// changed while waiting:
userChangeCount, addedChannels, err = db.checkForUserUpdates(userChangeCount, changeWaiter)
if err != nil {
change := makeErrorEntry("User not found during reload - terminating changes feed")
base.LogTo("Changes+", "User not found during reload - terminating changes feed with entry %+v", change)
output <- &change
return
}
}
}()
return output, nil
}
func TestUserAccess(t *testing.T) {
// User with no access:
auth := NewAuthenticator(gTestBucket, nil)
user, _ := auth.NewUser("foo", "password", nil)
assert.DeepEquals(t, user.ExpandWildCardChannel(ch.SetOf("*")), ch.SetOf("!"))
assert.False(t, user.CanSeeChannel("x"))
assert.True(t, canSeeAllChannels(user, ch.SetOf()))
assert.False(t, canSeeAllChannels(user, ch.SetOf("x")))
assert.False(t, canSeeAllChannels(user, ch.SetOf("x", "y")))
assert.False(t, canSeeAllChannels(user, ch.SetOf("*")))
assert.False(t, user.AuthorizeAllChannels(ch.SetOf("*")) == nil)
assert.False(t, user.AuthorizeAnyChannel(ch.SetOf("x", "y")) == nil)
assert.False(t, user.AuthorizeAnyChannel(ch.SetOf()) == nil)
// User with access to one channel:
user.setChannels(ch.AtSequence(ch.SetOf("x"), 1))
assert.DeepEquals(t, user.ExpandWildCardChannel(ch.SetOf("*")), ch.SetOf("x"))
assert.True(t, canSeeAllChannels(user, ch.SetOf()))
assert.True(t, canSeeAllChannels(user, ch.SetOf("x")))
assert.False(t, canSeeAllChannels(user, ch.SetOf("x", "y")))
assert.False(t, user.AuthorizeAllChannels(ch.SetOf("x", "y")) == nil)
assert.False(t, user.AuthorizeAllChannels(ch.SetOf("*")) == nil)
assert.True(t, user.AuthorizeAnyChannel(ch.SetOf("x", "y")) == nil)
assert.False(t, user.AuthorizeAnyChannel(ch.SetOf("y")) == nil)
assert.False(t, user.AuthorizeAnyChannel(ch.SetOf()) == nil)
// User with access to one channel and one derived channel:
user.setChannels(ch.AtSequence(ch.SetOf("x", "z"), 1))
assert.DeepEquals(t, user.ExpandWildCardChannel(ch.SetOf("*")), ch.SetOf("x", "z"))
assert.DeepEquals(t, user.ExpandWildCardChannel(ch.SetOf("x")), ch.SetOf("x"))
assert.True(t, canSeeAllChannels(user, ch.SetOf()))
assert.True(t, canSeeAllChannels(user, ch.SetOf("x")))
assert.False(t, canSeeAllChannels(user, ch.SetOf("x", "y")))
assert.False(t, user.AuthorizeAllChannels(ch.SetOf("x", "y")) == nil)
assert.False(t, user.AuthorizeAllChannels(ch.SetOf("*")) == nil)
// User with access to two channels:
user.setChannels(ch.AtSequence(ch.SetOf("x", "z"), 1))
assert.DeepEquals(t, user.ExpandWildCardChannel(ch.SetOf("*")), ch.SetOf("x", "z"))
assert.DeepEquals(t, user.ExpandWildCardChannel(ch.SetOf("x")), ch.SetOf("x"))
assert.True(t, canSeeAllChannels(user, ch.SetOf()))
assert.True(t, canSeeAllChannels(user, ch.SetOf("x")))
assert.False(t, canSeeAllChannels(user, ch.SetOf("x", "y")))
assert.False(t, user.AuthorizeAllChannels(ch.SetOf("x", "y")) == nil)
assert.False(t, user.AuthorizeAllChannels(ch.SetOf("*")) == nil)
user.setChannels(ch.AtSequence(ch.SetOf("x", "y"), 1))
assert.DeepEquals(t, user.ExpandWildCardChannel(ch.SetOf("*")), ch.SetOf("x", "y"))
assert.True(t, canSeeAllChannels(user, ch.SetOf()))
assert.True(t, canSeeAllChannels(user, ch.SetOf("x")))
assert.True(t, canSeeAllChannels(user, ch.SetOf("x", "y")))
assert.False(t, canSeeAllChannels(user, ch.SetOf("x", "y", "z")))
assert.True(t, user.AuthorizeAllChannels(ch.SetOf("x", "y")) == nil)
assert.False(t, user.AuthorizeAllChannels(ch.SetOf("*")) == nil)
// User with wildcard access:
user.setChannels(ch.AtSequence(ch.SetOf("*", "q"), 1))
assert.DeepEquals(t, user.ExpandWildCardChannel(ch.SetOf("*")), ch.SetOf("*", "q"))
assert.True(t, user.CanSeeChannel("*"))
assert.True(t, canSeeAllChannels(user, ch.SetOf()))
assert.True(t, canSeeAllChannels(user, ch.SetOf("x")))
assert.True(t, canSeeAllChannels(user, ch.SetOf("x", "y")))
assert.True(t, user.AuthorizeAllChannels(ch.SetOf("x", "y")) == nil)
assert.True(t, user.AuthorizeAllChannels(ch.SetOf("*")) == nil)
assert.True(t, user.AuthorizeAnyChannel(ch.SetOf("x")) == nil)
assert.True(t, user.AuthorizeAnyChannel(ch.SetOf("*")) == nil)
assert.True(t, user.AuthorizeAnyChannel(ch.SetOf()) == nil)
}
func (role *roleImpl) initRole(name string, channels base.Set) error {
channels = ch.ExpandingStar(channels)
role.Name_ = name
role.ExplicitChannels_ = ch.AtSequence(channels, 1)
return role.validate()
}
// Returns the (ordered) union of all of the changes made to multiple channels.
func (db *Database) SimpleMultiChangesFeed(chans base.Set, options ChangesOptions) (<-chan *ChangeEntry, error) {
to := ""
if db.user != nil && db.user.Name() != "" {
to = fmt.Sprintf(" (to %s)", db.user.Name())
}
base.LogTo("Changes", "MultiChangesFeed(%s, %+v) ... %s", chans, options, to)
output := make(chan *ChangeEntry, 50)
go func() {
defer func() {
base.LogTo("Changes", "MultiChangesFeed done %s", to)
close(output)
}()
var changeWaiter *changeWaiter
var userChangeCount uint64
var lowSequence uint64
var lateSequenceFeeds map[string]*lateSequenceFeed
var addedChannels base.Set // Tracks channels added to the user during changes processing.
// lowSequence is used to send composite keys to clients, so that they can obtain any currently
// skipped sequences in a future iteration or request.
oldestSkipped := db.changeCache.getOldestSkippedSequence()
if oldestSkipped > 0 {
lowSequence = oldestSkipped - 1
} else {
lowSequence = 0
}
if options.Wait {
options.Wait = false
changeWaiter = db.startChangeWaiter(chans)
userChangeCount = changeWaiter.CurrentUserCount()
}
// If a request has a low sequence that matches the current lowSequence,
// ignore the low sequence. This avoids infinite looping of the records between
// low::high. It also means any additional skipped sequences between low::high won't
// be sent until low arrives or is abandoned.
if options.Since.LowSeq != 0 && options.Since.LowSeq == lowSequence {
options.Since.LowSeq = 0
}
// For a continuous feed, initialise the lateSequenceFeeds that track late-arriving sequences
// to the channel caches.
if options.Continuous {
lateSequenceFeeds = make(map[string]*lateSequenceFeed)
}
// This loop is used to re-run the fetch after every database change, in Wait mode
outer:
for {
// Restrict to available channels, expand wild-card, and find since when these channels
// have been available to the user:
var channelsSince channels.TimedSet
if db.user != nil {
channelsSince = db.user.FilterToAvailableChannels(chans)
} else {
channelsSince = channels.AtSequence(chans, 0)
}
// Updates the changeWaiter to the current set of available channels
if changeWaiter != nil {
changeWaiter.UpdateChannels(channelsSince)
}
base.LogTo("Changes+", "MultiChangesFeed: channels expand to %#v ... %s", channelsSince, to)
// lowSequence is used to send composite keys to clients, so that they can obtain any currently
// skipped sequences in a future iteration or request.
oldestSkipped = db.changeCache.getOldestSkippedSequence()
if oldestSkipped > 0 {
lowSequence = oldestSkipped - 1
} else {
lowSequence = 0
}
// Populate the parallel arrays of channels and names:
feeds := make([]<-chan *ChangeEntry, 0, len(channelsSince))
names := make([]string, 0, len(channelsSince))
// Get read lock for late-arriving sequences, to avoid sending the same late arrival in
// two different changes iterations. e.g. without the RLock, a late-arriving sequence
// could be written to channel X during one iteration, and channel Y during another. Users
// with access to both channels would see two versions on the feed.
for name, vbSeqAddedAt := range channelsSince {
chanOpts := options
seqAddedAt := vbSeqAddedAt.Sequence
// Check whether requires backfill based on addedChannels in this _changes feed
isNewChannel := false
if addedChannels != nil {
_, isNewChannel = addedChannels[name]
}
// Check whether requires backfill based on current sequence, seqAddedAt
// Triggered by handling:
// 1. options.Since.TriggeredBy == seqAddedAt : We're in the middle of backfill for this channel, based
// on the access grant in sequence options.Since.TriggeredBy. Normally the entire backfill would be done in one
// changes feed iteration, but this can be split over multiple iterations when 'limit' is used.
// 2. options.Since.TriggeredBy == 0 : Not currently doing a backfill
// 3. options.Since.TriggeredBy != 0 and <= seqAddedAt: We're in the middle of a backfill for another channel, but the backfill for
// this channel is still pending. Initiate the backfill for this channel - will be ordered below in the usual way (iterating over all channels)
// Backfill required when seqAddedAt is before current sequence
backfillRequired := seqAddedAt > 1 && options.Since.Before(SequenceID{Seq: seqAddedAt})
// Ensure backfill isn't already in progress for this seqAddedAt
backfillPending := options.Since.TriggeredBy == 0 || options.Since.TriggeredBy < seqAddedAt
if isNewChannel || (backfillRequired && backfillPending) {
// Newly added channel so initiate backfill:
chanOpts.Since = SequenceID{Seq: 0, TriggeredBy: seqAddedAt}
}
feed, err := db.changesFeed(name, chanOpts)
if err != nil {
base.Warn("MultiChangesFeed got error reading changes feed %q: %v", name, err)
return
}
feeds = append(feeds, feed)
names = append(names, name)
// Late sequence handling - for out-of-order sequences prior to options.Since that
// have arrived in the channel cache since this changes request started. Only need for
// continuous feeds - one-off changes requests only need the standard channel cache.
if options.Continuous {
lateSequenceFeedHandler := lateSequenceFeeds[name]
if lateSequenceFeedHandler != nil {
latefeed, err := db.getLateFeed(lateSequenceFeedHandler)
if err != nil {
base.Warn("MultiChangesFeed got error reading late sequence feed %q: %v", name, err)
} else {
// Mark feed as actively used in this iteration. Used to remove lateSequenceFeeds
// when the user loses channel access
lateSequenceFeedHandler.active = true
feeds = append(feeds, latefeed)
names = append(names, fmt.Sprintf("late_%s", name))
}
} else {
// Initialize lateSequenceFeeds[name] for next iteration
lateSequenceFeeds[name] = db.newLateSequenceFeed(name)
}
}
}
// If the user object has changed, create a special pseudo-feed for it:
if db.user != nil {
feeds, names = db.appendUserFeed(feeds, names, options)
}
current := make([]*ChangeEntry, len(feeds))
// This loop reads the available entries from all the feeds in parallel, merges them,
// and writes them to the output channel:
var sentSomething bool
for {
// Read more entries to fill up the current[] array:
for i, cur := range current {
if cur == nil && feeds[i] != nil {
var ok bool
current[i], ok = <-feeds[i]
if !ok {
feeds[i] = nil
}
}
}
// Find the current entry with the minimum sequence:
minSeq := MaxSequenceID
var minEntry *ChangeEntry
for _, cur := range current {
if cur != nil && cur.Seq.Before(minSeq) {
minSeq = cur.Seq
minEntry = cur
}
}
if minEntry == nil {
break // Exit the loop when there are no more entries
}
// Clear the current entries for the sequence just sent:
if minEntry.Removed != nil {
minEntry.allRemoved = true
}
for i, cur := range current {
if cur != nil && cur.Seq == minSeq {
current[i] = nil
// Track whether this is a removal from all user's channels
if cur.Removed == nil && minEntry.allRemoved == true {
minEntry.allRemoved = false
}
// Also concatenate the matching entries' Removed arrays:
if cur != minEntry && cur.Removed != nil {
if minEntry.Removed == nil {
minEntry.Removed = cur.Removed
} else {
minEntry.Removed = minEntry.Removed.Union(cur.Removed)
}
}
}
}
if options.ActiveOnly {
if minEntry.Deleted || minEntry.allRemoved {
continue
}
}
// Update options.Since for use in the next outer loop iteration. Only update
// when minSeq is greater than the previous options.Since value - we don't want to
// roll back the Since value when we get an late sequence is processed.
if options.Since.Before(minSeq) {
options.Since = minSeq
}
// Add the doc body or the conflicting rev IDs, if those options are set:
if options.IncludeDocs || options.Conflicts {
db.addDocToChangeEntry(minEntry, options)
}
// Update the low sequence on the entry we're going to send
minEntry.Seq.LowSeq = lowSequence
// Send the entry, and repeat the loop:
base.LogTo("Changes+", "MultiChangesFeed sending %+v %s", minEntry, to)
select {
case <-options.Terminator:
return
case output <- minEntry:
}
sentSomething = true
// Stop when we hit the limit (if any):
if options.Limit > 0 {
options.Limit--
if options.Limit == 0 {
break outer
}
}
}
if !options.Continuous && (sentSomething || changeWaiter == nil) {
break
}
// If nothing found, and in wait mode: wait for the db to change, then run again.
// First notify the reader that we're waiting by sending a nil.
base.LogTo("Changes+", "MultiChangesFeed waiting... %s", to)
output <- nil
waitForChanges:
for {
waitResponse := changeWaiter.Wait()
if waitResponse == WaiterClosed {
break outer
} else if waitResponse == WaiterHasChanges {
select {
case <-options.Terminator:
return
default:
break waitForChanges
}
} else if waitResponse == WaiterCheckTerminated {
// Check whether I was terminated while waiting for a change. If not, resume wait.
select {
case <-options.Terminator:
return
default:
}
}
}
// Check whether user channel access has changed while waiting:
var err error
userChangeCount, addedChannels, err = db.checkForUserUpdates(userChangeCount, changeWaiter)
if err != nil {
change := makeErrorEntry("User not found during reload - terminating changes feed")
base.LogTo("Changes+", "User not found during reload - terminating changes feed with entry %+v", change)
output <- &change
return
}
// Clean up inactive lateSequenceFeeds (because user has lost access to the channel)
for channel, lateFeed := range lateSequenceFeeds {
if !lateFeed.active {
db.closeLateFeed(lateFeed)
delete(lateSequenceFeeds, channel)
} else {
lateFeed.active = false
}
}
}
}()
return output, nil
}