traefik/vendor/gopkg.in/mgo.v2/bulk.go

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2017-02-07 21:33:23 +00:00
package mgo
import (
"bytes"
"sort"
"gopkg.in/mgo.v2/bson"
)
// Bulk represents an operation that can be prepared with several
// orthogonal changes before being delivered to the server.
//
// MongoDB servers older than version 2.6 do not have proper support for bulk
// operations, so the driver attempts to map its API as much as possible into
// the functionality that works. In particular, in those releases updates and
// removals are sent individually, and inserts are sent in bulk but have
// suboptimal error reporting compared to more recent versions of the server.
// See the documentation of BulkErrorCase for details on that.
//
// Relevant documentation:
//
// http://blog.mongodb.org/post/84922794768/mongodbs-new-bulk-api
//
type Bulk struct {
c *Collection
opcount int
actions []bulkAction
ordered bool
}
type bulkOp int
const (
bulkInsert bulkOp = iota + 1
bulkUpdate
bulkUpdateAll
bulkRemove
)
type bulkAction struct {
op bulkOp
docs []interface{}
idxs []int
}
type bulkUpdateOp []interface{}
type bulkDeleteOp []interface{}
// BulkResult holds the results for a bulk operation.
type BulkResult struct {
Matched int
Modified int // Available only for MongoDB 2.6+
// Be conservative while we understand exactly how to report these
// results in a useful and convenient way, and also how to emulate
// them with prior servers.
private bool
}
// BulkError holds an error returned from running a Bulk operation.
// Individual errors may be obtained and inspected via the Cases method.
type BulkError struct {
ecases []BulkErrorCase
}
func (e *BulkError) Error() string {
if len(e.ecases) == 0 {
return "invalid BulkError instance: no errors"
}
if len(e.ecases) == 1 {
return e.ecases[0].Err.Error()
}
msgs := make([]string, 0, len(e.ecases))
seen := make(map[string]bool)
for _, ecase := range e.ecases {
msg := ecase.Err.Error()
if !seen[msg] {
seen[msg] = true
msgs = append(msgs, msg)
}
}
if len(msgs) == 1 {
return msgs[0]
}
var buf bytes.Buffer
buf.WriteString("multiple errors in bulk operation:\n")
for _, msg := range msgs {
buf.WriteString(" - ")
buf.WriteString(msg)
buf.WriteByte('\n')
}
return buf.String()
}
type bulkErrorCases []BulkErrorCase
func (slice bulkErrorCases) Len() int { return len(slice) }
func (slice bulkErrorCases) Less(i, j int) bool { return slice[i].Index < slice[j].Index }
func (slice bulkErrorCases) Swap(i, j int) { slice[i], slice[j] = slice[j], slice[i] }
// BulkErrorCase holds an individual error found while attempting a single change
// within a bulk operation, and the position in which it was enqueued.
//
// MongoDB servers older than version 2.6 do not have proper support for bulk
// operations, so the driver attempts to map its API as much as possible into
// the functionality that works. In particular, only the last error is reported
// for bulk inserts and without any positional information, so the Index
// field is set to -1 in these cases.
type BulkErrorCase struct {
Index int // Position of operation that failed, or -1 if unknown.
Err error
}
// Cases returns all individual errors found while attempting the requested changes.
//
// See the documentation of BulkErrorCase for limitations in older MongoDB releases.
func (e *BulkError) Cases() []BulkErrorCase {
return e.ecases
}
// Bulk returns a value to prepare the execution of a bulk operation.
func (c *Collection) Bulk() *Bulk {
return &Bulk{c: c, ordered: true}
}
// Unordered puts the bulk operation in unordered mode.
//
// In unordered mode the indvidual operations may be sent
// out of order, which means latter operations may proceed
// even if prior ones have failed.
func (b *Bulk) Unordered() {
b.ordered = false
}
func (b *Bulk) action(op bulkOp, opcount int) *bulkAction {
var action *bulkAction
if len(b.actions) > 0 && b.actions[len(b.actions)-1].op == op {
action = &b.actions[len(b.actions)-1]
} else if !b.ordered {
for i := range b.actions {
if b.actions[i].op == op {
action = &b.actions[i]
break
}
}
}
if action == nil {
b.actions = append(b.actions, bulkAction{op: op})
action = &b.actions[len(b.actions)-1]
}
for i := 0; i < opcount; i++ {
action.idxs = append(action.idxs, b.opcount)
b.opcount++
}
return action
}
// Insert queues up the provided documents for insertion.
func (b *Bulk) Insert(docs ...interface{}) {
action := b.action(bulkInsert, len(docs))
action.docs = append(action.docs, docs...)
}
// Remove queues up the provided selectors for removing matching documents.
// Each selector will remove only a single matching document.
func (b *Bulk) Remove(selectors ...interface{}) {
action := b.action(bulkRemove, len(selectors))
for _, selector := range selectors {
if selector == nil {
selector = bson.D{}
}
action.docs = append(action.docs, &deleteOp{
Collection: b.c.FullName,
Selector: selector,
Flags: 1,
Limit: 1,
})
}
}
// RemoveAll queues up the provided selectors for removing all matching documents.
// Each selector will remove all matching documents.
func (b *Bulk) RemoveAll(selectors ...interface{}) {
action := b.action(bulkRemove, len(selectors))
for _, selector := range selectors {
if selector == nil {
selector = bson.D{}
}
action.docs = append(action.docs, &deleteOp{
Collection: b.c.FullName,
Selector: selector,
Flags: 0,
Limit: 0,
})
}
}
// Update queues up the provided pairs of updating instructions.
// The first element of each pair selects which documents must be
// updated, and the second element defines how to update it.
// Each pair matches exactly one document for updating at most.
func (b *Bulk) Update(pairs ...interface{}) {
if len(pairs)%2 != 0 {
panic("Bulk.Update requires an even number of parameters")
}
action := b.action(bulkUpdate, len(pairs)/2)
for i := 0; i < len(pairs); i += 2 {
selector := pairs[i]
if selector == nil {
selector = bson.D{}
}
action.docs = append(action.docs, &updateOp{
Collection: b.c.FullName,
Selector: selector,
Update: pairs[i+1],
})
}
}
// UpdateAll queues up the provided pairs of updating instructions.
// The first element of each pair selects which documents must be
// updated, and the second element defines how to update it.
// Each pair updates all documents matching the selector.
func (b *Bulk) UpdateAll(pairs ...interface{}) {
if len(pairs)%2 != 0 {
panic("Bulk.UpdateAll requires an even number of parameters")
}
action := b.action(bulkUpdate, len(pairs)/2)
for i := 0; i < len(pairs); i += 2 {
selector := pairs[i]
if selector == nil {
selector = bson.D{}
}
action.docs = append(action.docs, &updateOp{
Collection: b.c.FullName,
Selector: selector,
Update: pairs[i+1],
Flags: 2,
Multi: true,
})
}
}
// Upsert queues up the provided pairs of upserting instructions.
// The first element of each pair selects which documents must be
// updated, and the second element defines how to update it.
// Each pair matches exactly one document for updating at most.
func (b *Bulk) Upsert(pairs ...interface{}) {
if len(pairs)%2 != 0 {
panic("Bulk.Update requires an even number of parameters")
}
action := b.action(bulkUpdate, len(pairs)/2)
for i := 0; i < len(pairs); i += 2 {
selector := pairs[i]
if selector == nil {
selector = bson.D{}
}
action.docs = append(action.docs, &updateOp{
Collection: b.c.FullName,
Selector: selector,
Update: pairs[i+1],
Flags: 1,
Upsert: true,
})
}
}
// Run runs all the operations queued up.
//
// If an error is reported on an unordered bulk operation, the error value may
// be an aggregation of all issues observed. As an exception to that, Insert
// operations running on MongoDB versions prior to 2.6 will report the last
// error only due to a limitation in the wire protocol.
func (b *Bulk) Run() (*BulkResult, error) {
var result BulkResult
var berr BulkError
var failed bool
for i := range b.actions {
action := &b.actions[i]
var ok bool
switch action.op {
case bulkInsert:
ok = b.runInsert(action, &result, &berr)
case bulkUpdate:
ok = b.runUpdate(action, &result, &berr)
case bulkRemove:
ok = b.runRemove(action, &result, &berr)
default:
panic("unknown bulk operation")
}
if !ok {
failed = true
if b.ordered {
break
}
}
}
if failed {
sort.Sort(bulkErrorCases(berr.ecases))
return nil, &berr
}
return &result, nil
}
func (b *Bulk) runInsert(action *bulkAction, result *BulkResult, berr *BulkError) bool {
op := &insertOp{b.c.FullName, action.docs, 0}
if !b.ordered {
op.flags = 1 // ContinueOnError
}
lerr, err := b.c.writeOp(op, b.ordered)
return b.checkSuccess(action, berr, lerr, err)
}
func (b *Bulk) runUpdate(action *bulkAction, result *BulkResult, berr *BulkError) bool {
lerr, err := b.c.writeOp(bulkUpdateOp(action.docs), b.ordered)
if lerr != nil {
result.Matched += lerr.N
result.Modified += lerr.modified
}
return b.checkSuccess(action, berr, lerr, err)
}
func (b *Bulk) runRemove(action *bulkAction, result *BulkResult, berr *BulkError) bool {
lerr, err := b.c.writeOp(bulkDeleteOp(action.docs), b.ordered)
if lerr != nil {
result.Matched += lerr.N
result.Modified += lerr.modified
}
return b.checkSuccess(action, berr, lerr, err)
}
func (b *Bulk) checkSuccess(action *bulkAction, berr *BulkError, lerr *LastError, err error) bool {
if lerr != nil && len(lerr.ecases) > 0 {
for i := 0; i < len(lerr.ecases); i++ {
// Map back from the local error index into the visible one.
ecase := lerr.ecases[i]
idx := ecase.Index
if idx >= 0 {
idx = action.idxs[idx]
}
berr.ecases = append(berr.ecases, BulkErrorCase{idx, ecase.Err})
}
return false
} else if err != nil {
for i := 0; i < len(action.idxs); i++ {
berr.ecases = append(berr.ecases, BulkErrorCase{action.idxs[i], err})
}
return false
}
return true
}