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postgres_collection.go
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postgres_collection.go
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package collection
import (
"context"
"crypto/md5"
"database/sql"
"fmt"
"strings"
"time"
"github.com/gogo/protobuf/proto"
"github.com/jackc/pgerrcode"
"github.com/jmoiron/sqlx"
"github.com/lib/pq"
etcd "go.etcd.io/etcd/client/v3"
"github.com/pachyderm/pachyderm/v2/src/internal/dbutil"
"github.com/pachyderm/pachyderm/v2/src/internal/errors"
"github.com/pachyderm/pachyderm/v2/src/internal/errutil"
"github.com/pachyderm/pachyderm/v2/src/internal/pachsql"
"github.com/pachyderm/pachyderm/v2/src/internal/pctx"
"github.com/pachyderm/pachyderm/v2/src/internal/watch"
"github.com/pachyderm/pachyderm/v2/src/version"
)
const (
defaultListBufferCapacity = 1000
)
type postgresCollection struct {
table string
db *pachsql.DB
listener PostgresListener
template proto.Message
indexes []*Index
keyGen func(interface{}) (string, error)
keyCheck func(string) error
notFound func(interface{}) string
exists func(interface{}) string
listBufferCapacity int
putHook func(*pachsql.Tx, interface{}) error
}
func indexFieldName(idx *Index) string {
return "idx_" + idx.Name
}
type model struct {
CreatedAt time.Time
UpdatedAt time.Time
Version string
Key string
Proto []byte
}
type Option func(collection *postgresCollection)
func WithKeyCheck(check func(string) error) Option {
return func(c *postgresCollection) {
c.keyCheck = check
}
}
func WithKeyGen(gen func(interface{}) (string, error)) Option {
return func(c *postgresCollection) {
c.keyGen = gen
}
}
func WithExistsMessage(format func(interface{}) string) Option {
return func(c *postgresCollection) {
c.exists = format
}
}
func WithNotFoundMessage(format func(interface{}) string) Option {
return func(c *postgresCollection) {
c.notFound = format
}
}
func WithListBufferCapacity(cap int) Option {
return func(c *postgresCollection) {
c.listBufferCapacity = cap
}
}
func WithPutHook(putHook func(*pachsql.Tx, interface{}) error) Option {
return func(c *postgresCollection) {
c.putHook = putHook
}
}
// NewPostgresCollection creates a new collection backed by postgres.
func NewPostgresCollection(name string, db *pachsql.DB, listener PostgresListener, template proto.Message, indexes []*Index, opts ...Option) PostgresCollection {
col := &postgresCollection{
table: name,
db: db,
listener: listener,
template: template,
indexes: indexes,
listBufferCapacity: defaultListBufferCapacity,
}
for _, opt := range opts {
opt(col)
}
return col
}
// Indexes passed into queries are required to be the same object used at
// construction time to ensure that their Name field and Extract method are
// identical.
func (c *postgresCollection) validateIndex(index *Index) error {
found := false
for _, idx := range c.indexes {
if idx == index {
found = true
break
}
}
if !found {
return errors.Errorf("Unknown collection index: %s", index.Name)
}
return nil
}
func (c *postgresCollection) tableWatchChannel() string {
return "pwc_" + c.table
}
func (c *postgresCollection) indexWatchChannel(field string, value string) string {
data := fmt.Sprintf("%s %s", field, value)
return c.tableWatchChannel() + "_" + fmt.Sprintf("%x", md5.Sum([]byte(data)))
}
func (c *postgresCollection) ReadOnly(ctx context.Context) PostgresReadOnlyCollection {
return &postgresReadOnlyCollection{c, ctx}
}
func (c *postgresCollection) ReadWrite(tx *pachsql.Tx) PostgresReadWriteCollection {
return &postgresReadWriteCollection{c, tx}
}
// NewDryrunSQLTx is identical to NewSQLTx except it will always roll back the
// transaction instead of committing it.
func NewDryrunSQLTx(ctx context.Context, db *pachsql.DB, apply func(*pachsql.Tx) error) error {
err := dbutil.WithTx(ctx, db, func(tx *pachsql.Tx) error {
if err := apply(tx); err != nil {
return err
}
return errors.EnsureStack(tx.Rollback())
})
if errors.Is(err, sql.ErrTxDone) {
err = nil
}
return err
}
func (c *postgresCollection) Claim(ctx context.Context, key string, val proto.Message, f func(context.Context) error) error {
return errors.New("Claim is not supported on postgres collections")
}
func isDuplicateKeyError(err error) bool {
pqerr := &pq.Error{}
if errors.As(err, pqerr) {
return pqerr.Code == pgerrcode.UniqueViolation
}
return false
}
func (c *postgresCollection) mapSQLError(err error, key string) error {
if err != nil {
if errors.Is(err, sql.ErrNoRows) {
return errors.WithStack(ErrNotFound{Type: c.table, Key: key})
} else if isDuplicateKeyError(err) {
return errors.WithStack(ErrExists{Type: c.table, Key: key})
}
return errors.EnsureStack(err)
}
return nil
}
type postgresReadOnlyCollection struct {
*postgresCollection
ctx context.Context
}
func (c *postgresCollection) get(ctx context.Context, key string, q sqlx.QueryerContext) (*model, error) {
result := &model{}
queryString := fmt.Sprintf("select proto, updatedat from collections.%s where key = $1;", c.table)
if err := sqlx.GetContext(ctx, q, result, queryString, key); err != nil {
return nil, c.mapSQLError(err, key)
}
return result, nil
}
func (c *postgresReadOnlyCollection) Get(key interface{}, val proto.Message) error {
var result *model
var err error
err = c.withKey(key, func(rawKey string) error {
result, err = c.get(c.ctx, rawKey, c.db)
return err
})
if err != nil {
return err
}
return errors.EnsureStack(proto.Unmarshal(result.Proto, val))
}
func (c *postgresCollection) withKey(key interface{}, query func(string) error) error {
if str, ok := key.(string); ok {
return query(str)
}
rawKey, err := c.keyGen(key)
if err != nil {
return err
}
err = query(rawKey)
if err != nil {
var notFound ErrNotFound
var exists ErrExists
if c.notFound != nil && errors.As(err, ¬Found) {
notFound.customMessage = c.notFound(key)
return errors.EnsureStack(notFound)
}
if c.exists != nil && errors.As(err, &exists) {
exists.customMessage = c.exists(key)
return errors.EnsureStack(exists)
}
return err
}
return nil
}
func (c *postgresCollection) getByIndex(ctx context.Context, q sqlx.ExtContext, index *Index, indexVal string, val proto.Message, opts *Options, f func(string) error) error {
if err := c.validateIndex(index); err != nil {
return err
}
return c.list(ctx, map[string]string{indexFieldName(index): indexVal}, opts, q, func(m *model) error {
if err := proto.Unmarshal(m.Proto, val); err != nil {
return errors.Wrapf(err, "getByIndex unmarshal proto")
}
return f(m.Key)
})
}
// NOTE: Internally, GetByIndex scans the collection over multiple transactions,
// making this method susceptible to inconsistent reads
func (c *postgresReadOnlyCollection) GetByIndex(index *Index, indexVal string, val proto.Message, opts *Options, f func(string) error) error {
return c.getByIndex(c.ctx, c.db, index, indexVal, val, opts, f)
}
// NOTE: Internally, GetByIndex scans the collection using multiple queries,
// making this method susceptible to inconsistent reads
func (c *postgresReadWriteCollection) GetByIndex(index *Index, indexVal string, val proto.Message, opts *Options, f func(string) error) error {
return c.getByIndex(context.Background(), c.tx, index, indexVal, val, opts, f)
}
func (c *postgresCollection) getUniqueByIndex(ctx context.Context, q sqlx.ExtContext, index *Index, indexVal string, val proto.Message) error {
found := false
if err := c.getByIndex(ctx, q, index, indexVal, val, DefaultOptions(), func(string) error {
if found {
return ErrNotUnique{Type: c.table, Index: index.Name, Value: indexVal}
}
found = true
return nil
}); err != nil {
return err
}
if !found {
return ErrNotFound{Type: c.table, Key: indexVal}
}
return nil
}
func (c *postgresReadOnlyCollection) GetUniqueByIndex(index *Index, indexVal string, val proto.Message) error {
return c.getUniqueByIndex(c.ctx, c.db, index, indexVal, val)
}
func (c *postgresReadWriteCollection) GetUniqueByIndex(index *Index, indexVal string, val proto.Message) error {
return c.getUniqueByIndex(context.Background(), c.tx, index, indexVal, val)
}
func orderToSQL(order etcd.SortOrder) (string, error) {
switch order {
case SortAscend:
return "asc", nil
case SortDescend:
return "desc", nil
}
return "", errors.Errorf("unsupported sort order: %d", order)
}
func targetToSQL(target etcd.SortTarget) (string, error) {
switch target {
case SortByCreateRevision:
return "createdat", nil
case SortByModRevision:
return "updatedat", nil
case SortByKey:
return "key", nil
}
return "", errors.Errorf("unsupported sort target for postgres collections: %d", target)
}
func sortTargetValue(m *model, target SortTarget) (interface{}, error) {
switch target {
case SortByCreateRevision:
return m.CreatedAt, nil
case SortByModRevision:
return m.UpdatedAt, nil
case SortByKey:
return m.Key, nil
}
return "", errors.Errorf("unsupported sort target for postgres collections: %d", target)
}
func sortOrderOperator(order SortOrder) string {
if order == SortDescend {
return "<"
}
// SortAscend + SortNone
return ">"
}
func (c *postgresCollection) listQueryStr(ctx context.Context, withFields map[string]string, opts *Options, last *model, offset int) (string, []interface{}, error) {
query := fmt.Sprintf("select key, createdat, updatedat, proto from collections.%s", c.table)
var args []interface{}
if len(withFields) > 0 {
fields := []string{}
i := 1
for k, v := range withFields {
fields = append(fields, fmt.Sprintf("%s = $%d", k, i))
args = append(args, v)
i++
}
query += " where " + strings.Join(fields, " and ")
}
afterCondition := func(t SortTarget, ord SortOrder) (string, error) {
ts, err := targetToSQL(t)
if err != nil {
return "", err
}
afterSortVal, err := sortTargetValue(last, t)
if err != nil {
return "", err
}
args = append(args, afterSortVal)
// condition ends up including:
// where ... (<TARGET> <OP> <VALUE> or (<TARGET> = <VALUE> and key > '<PKEY>'))
// This covers the case where we only want to return rows following a certain offset value.
// We handle the case where multiple rows have the same sort value (when it isn't sorted by primary key)
// by including "or (<TARGET> = <VALUE> and key > '<PKEY>')" and also ordering by Primary Key as a tie breaker
cond := fmt.Sprintf("(%s %s $%d or (%s = $%d and key > '%s'))", ts, sortOrderOperator(ord), len(args), ts, len(args), last.Key)
if len(withFields) > 0 {
return " and " + cond, nil
} else {
return " where " + cond, nil
}
}
st := opts.Target
so := opts.Order
if opts.Order == SortNone { // defaults if to "order by key asc" if no sort specified
st = SortByKey
so = SortAscend
}
if order, err := orderToSQL(so); err != nil {
return "", nil, err
} else if target, err := targetToSQL(st); err != nil {
return "", nil, err
} else {
if last != nil {
ac, err := afterCondition(st, so)
if err != nil {
return "", nil, err
}
query += ac
}
if st == SortByKey {
query += fmt.Sprintf(" order by key %s", order)
} else {
query += fmt.Sprintf(" order by %s %s, key asc", target, order)
}
}
if batchLimit := opts.Limit - offset; opts.Limit > 0 && batchLimit < c.listBufferCapacity {
query += fmt.Sprintf(" limit %d", batchLimit)
} else {
query += fmt.Sprintf(" limit %d", c.listBufferCapacity)
}
return query, args, nil
}
func (c *postgresCollection) list(
ctx context.Context,
withFields map[string]string,
opts *Options,
q sqlx.ExtContext,
f func(*model) error,
) (retErr error) {
// To avoid holding a transaction open (which holds a DB connection) for an unknown duration
// dictated by the client's callback, we:
// (1) query a limited count of SQL rows into a buffer
// (2) apply f(), the client's callback, to results in the buffer
// (3) if the buffer was full, re-execute the query, offset by key, and repeat (1)
bufferResults := func(last *model, offset int) ([]*model, bool, error) {
query, args, err := c.listQueryStr(ctx, withFields, opts, last, offset)
if err != nil {
return nil, false, err
}
rs, err := q.QueryxContext(ctx, query, args...)
if err != nil {
return nil, false, errors.Wrapf(c.mapSQLError(err, ""), "list query into buffer with offset %v", offset)
}
defer func() {
if err := rs.Close(); err != nil {
retErr = errors.Join(
retErr,
errors.Wrapf(c.mapSQLError(err, ""), "closing rows for list query buffer with offset %v", offset),
)
}
}()
var rowCnt int
rowsBuffer := make([]*model, 0, c.listBufferCapacity)
for rs.Next() && rowCnt < c.listBufferCapacity {
result := &model{}
if err := rs.StructScan(result); err != nil {
return nil, false, errors.Wrapf(c.mapSQLError(err, ""), "scan row in list query with offset %v", offset)
}
rowsBuffer = append(rowsBuffer, result)
rowCnt++
}
if err := rs.Err(); err != nil {
return nil, false, errors.Wrapf(err, "list query error with offset %v", offset)
}
return rowsBuffer, rowCnt == c.listBufferCapacity, nil
}
var last *model
var offset int
for {
rowsBuffer, fullBuffer, err := bufferResults(last, offset)
if err != nil {
return err
}
for _, v := range rowsBuffer {
if err := f(v); err != nil {
if errors.Is(err, errutil.ErrBreak) {
return nil
}
return errors.Wrap(err, "apply function to list row element")
}
last = v
offset++
}
if !fullBuffer {
break
}
}
return nil
}
func (c *postgresReadOnlyCollection) list(withFields map[string]string, opts *Options, f func(*model) error) error {
return c.postgresCollection.list(c.ctx, withFields, opts, c.db, f)
}
// NOTE: Internally, List scans the collection over multiple transactions,
// making this method susceptible to inconsistent reads
func (c *postgresReadOnlyCollection) List(val proto.Message, opts *Options, f func(string) error) error {
return c.list(nil, opts, func(m *model) error {
if err := proto.Unmarshal(m.Proto, val); err != nil {
return errors.EnsureStack(err)
}
return f(m.Key)
})
}
// NOTE: Internally, List scans the collection using multiple queries,
// making this method susceptible to inconsistent reads
func (c *postgresReadWriteCollection) List(val proto.Message, opts *Options, f func(string) error) error {
ctx, cf := pctx.WithCancel(context.Background())
defer cf()
return c.postgresCollection.list(ctx, nil, opts, c.tx, func(m *model) error {
if err := proto.Unmarshal(m.Proto, val); err != nil {
return errors.EnsureStack(err)
}
return f(m.Key)
})
}
func (c *postgresReadOnlyCollection) listRev(withFields map[string]string, val proto.Message, opts *Options, f func(string, int64) error) error {
fakeRev := int64(0)
lastTimestamp := time.Time{}
updateRev := func(t time.Time) {
if t.After(lastTimestamp) {
lastTimestamp = t
fakeRev++
}
}
return c.list(withFields, opts, func(m *model) error {
if err := proto.Unmarshal(m.Proto, val); err != nil {
return errors.EnsureStack(err)
}
if opts.Target == SortByCreateRevision {
updateRev(m.CreatedAt)
} else if opts.Target == SortByModRevision {
updateRev(m.UpdatedAt)
}
return f(m.Key, fakeRev)
})
}
// ListRev emulates the behavior of etcd collection's ListRev, but doesn't
// reproduce it exactly. The revisions returned are not from the database -
// postgres uses 32-bit transaction ids and doesn't include one for the creating
// transaction of a row. So, we fake a revision id by sorting rows by their
// create/update timestamp and incrementing a fake revision id every time the
// timestamp changes. Note that the etcd implementation always returns the
// create revision, but that only works here if you also sort by the create
// revision.
func (c *postgresReadOnlyCollection) ListRev(val proto.Message, opts *Options, f func(string, int64) error) error {
return c.listRev(nil, val, opts, f)
}
// GetRevByIndex is identical to ListRev except that it filters the results
// according to a predicate on the given index.
func (c *postgresReadOnlyCollection) GetRevByIndex(index *Index, indexVal string, val proto.Message, opts *Options, f func(string, int64) error) error {
if err := c.validateIndex(index); err != nil {
return err
}
return c.listRev(map[string]string{indexFieldName(index): indexVal}, val, opts, f)
}
func (c *postgresReadOnlyCollection) Count() (int64, error) {
query := fmt.Sprintf("select count(*) from collections.%s", c.table)
row := c.db.QueryRowContext(c.ctx, query)
var result int64
err := row.Scan(&result)
return result, c.mapSQLError(err, "")
}
// This blocking function sends watch events to the client. It first sends a list of the existing elements
// in the collection, followed by new events.
func (c *postgresReadOnlyCollection) watchRoutine(watcher *postgresWatcher, options watch.WatchOptions, withFields map[string]string) {
// Do a list of the collection to get the initial state
val := cloneProtoMsg(c.template)
lastTimestamp := func(m *model, target etcd.SortTarget) time.Time {
if target == SortByModRevision {
return m.UpdatedAt
}
return m.CreatedAt
}
var bufEvent *postgresEvent
// Since list is not a snapshot of the DB, we break out early and hand-off
// event emition to the watcher if we encounter a listed record that is
// in the future of a buffered event
if err := c.list(withFields, &Options{Target: options.SortTarget, Order: etcd.SortAscend}, func(m *model) error {
if err := proto.Unmarshal(m.Proto, val); err != nil {
return errors.EnsureStack(err)
}
if bufEvent == nil {
select {
case eventData := <-watcher.buf:
bufEvent = eventData
default:
}
}
if bufEvent != nil && bufEvent.time.Before(lastTimestamp(m, options.SortTarget)) {
return errutil.ErrBreak
}
return watcher.sendInitial(c.ctx, &watch.Event{
Key: []byte(m.Key),
Value: m.Proto,
Type: watch.EventPut,
Template: c.template,
Rev: m.UpdatedAt.Unix(),
})
}); err != nil && !errors.Is(err, errutil.ErrBreak) {
// use a background context in case we failed with context cancelled
watcher.sendInitial(context.Background(), &watch.Event{Type: watch.EventError, Err: err}) //nolint:errcheck // already sending the error from c.list()
watcher.listener.Unregister(watcher) //nolint:errcheck
return
}
if bufEvent != nil {
if err := watcher.sendInitial(c.ctx, bufEvent.WatchEvent(c.ctx, watcher.db, watcher.template)); err != nil {
watcher.sendInitial(context.Background(), &watch.Event{Type: watch.EventError, Err: err}) //nolint:errcheck
watcher.listener.Unregister(watcher) //nolint:errcheck
return
}
}
// Forward all buffered notifications until the watcher is closed
watcher.forwardNotifications(c.ctx)
}
// NOTE: Internally, Watch scans the collection's initial state over multiple transactions,
// making this method susceptible to inconsistent reads
func (c *postgresReadOnlyCollection) Watch(opts ...watch.Option) (watch.Watcher, error) {
options := watch.SumOptions(opts...)
if options.SortOrder == SortDescend {
return nil, errors.New("Watches cannot have a descending sort order.")
}
watcher, err := newPostgresWatcher(c.db, c.listener, c.tableWatchChannel(), c.template, nil, nil, options)
if err != nil {
return nil, err
}
go c.watchRoutine(watcher, options, nil)
return watcher, nil
}
// NOTE: Internally, WatchF scans the collection's initial state over multiple transactions,
// making this method susceptible to inconsistent reads
func (c *postgresReadOnlyCollection) WatchF(f func(*watch.Event) error, opts ...watch.Option) error {
watcher, err := c.Watch(opts...)
if err != nil {
return err
}
defer watcher.Close()
return watchF(c.ctx, watcher, f)
}
func (c *postgresReadOnlyCollection) WatchOne(key interface{}, opts ...watch.Option) (watch.Watcher, error) {
var watcher watch.Watcher
var err error
err = c.withKey(key, func(rawKey string) error {
watcher, err = c.watchOne(rawKey, opts...)
return err
})
return watcher, err
}
func (c *postgresReadOnlyCollection) watchOne(key string, opts ...watch.Option) (watch.Watcher, error) {
options := watch.SumOptions(opts...)
watcher, err := newPostgresWatcher(c.db, c.listener, c.indexWatchChannel("key", key), c.template, nil, nil, options)
if err != nil {
return nil, err
}
withFields := map[string]string{"key": key}
go c.watchRoutine(watcher, options, withFields)
return watcher, nil
}
func (c *postgresReadOnlyCollection) WatchOneF(key interface{}, f func(*watch.Event) error, opts ...watch.Option) error {
watcher, err := c.WatchOne(key, opts...)
if err != nil {
return err
}
defer watcher.Close()
return watchF(c.ctx, watcher, f)
}
// NOTE: Internally, WatchByIndex scans the collection's initial state over multiple transactions,
// making this method susceptible to inconsistent reads
func (c *postgresReadOnlyCollection) WatchByIndex(index *Index, indexVal string, opts ...watch.Option) (watch.Watcher, error) {
if err := c.validateIndex(index); err != nil {
return nil, err
}
options := watch.SumOptions(opts...)
if options.SortOrder == SortDescend {
return nil, errors.New("Watches cannot have a descending sort order.")
}
channelName := c.indexWatchChannel(indexFieldName(index), indexVal)
watcher, err := newPostgresWatcher(c.db, c.listener, channelName, c.template, nil, nil, options)
if err != nil {
return nil, err
}
withFields := map[string]string{indexFieldName(index): indexVal}
go c.watchRoutine(watcher, options, withFields)
return watcher, nil
}
// NOTE: Internally, WatchByIndexF scans the collection's initial state over multiple transactions,
// making this method susceptible to inconsistent reads
func (c *postgresReadOnlyCollection) WatchByIndexF(index *Index, indexVal string, f func(*watch.Event) error, opts ...watch.Option) error {
watcher, err := c.WatchByIndex(index, indexVal, opts...)
if err != nil {
return err
}
defer watcher.Close()
return watchF(c.ctx, watcher, f)
}
type postgresReadWriteCollection struct {
*postgresCollection
tx *pachsql.Tx
}
func (c *postgresReadWriteCollection) Get(key interface{}, val proto.Message) error {
var result *model
var err error
err = c.withKey(key, func(rawKey string) error {
result, err = c.get(context.Background(), rawKey, c.tx)
return err
})
if err != nil {
return err
}
return errors.EnsureStack(proto.Unmarshal(result.Proto, val))
}
func (c *postgresReadWriteCollection) Put(key interface{}, val proto.Message) error {
return c.withKey(key, func(rawKey string) error {
return c.insert(rawKey, val, true)
})
}
func (c *postgresReadWriteCollection) getWriteParams(key string, val proto.Message) (map[string]interface{}, error) {
data, err := proto.Marshal(val)
if err != nil {
return nil, errors.EnsureStack(err)
}
params := map[string]interface{}{
"version": version.PrettyVersion(),
"key": key,
"proto": data,
}
for _, idx := range c.indexes {
params[indexFieldName(idx)] = idx.Extract(val)
}
return params, nil
}
func (c *postgresReadWriteCollection) Update(key interface{}, val proto.Message, f func() error) error {
if err := c.Get(key, val); err != nil {
return err
}
if err := f(); err != nil {
return err
}
return c.withKey(key, func(rawKey string) error {
params, err := c.getWriteParams(rawKey, val)
if err != nil {
return err
}
updateFields := []string{}
for k := range params {
updateFields = append(updateFields, fmt.Sprintf("%s = :%s", k, k))
}
query := fmt.Sprintf("update collections.%s set %s where key = :key", c.table, strings.Join(updateFields, ", "))
_, err = c.tx.NamedExec(query, params)
return c.mapSQLError(err, rawKey)
})
}
func (c *postgresReadWriteCollection) insert(key string, val proto.Message, upsert bool) error {
if c.keyCheck != nil {
if err := c.keyCheck(key); err != nil {
return errors.Wrap(err, "bad key")
}
}
paramMap, err := c.getWriteParams(key, val)
if err != nil {
return errors.Wrap(err, "could not get write params")
}
columns := []string{}
paramNames := []string{}
params := []interface{}{}
for k, v := range paramMap {
columns = append(columns, k)
paramNames = append(paramNames, fmt.Sprintf("$%d", len(paramNames)+1))
params = append(params, v)
}
columnList := strings.Join(columns, ", ")
paramList := strings.Join(paramNames, ", ")
query := fmt.Sprintf("insert into collections.%s (%s) values (%s)", c.table, columnList, paramList)
if upsert {
query = fmt.Sprintf("%s on conflict (key) do update set (%s) = (%s)", query, columnList, paramList)
} else {
// On a normal insert, an error would invalidate the transaction, so do
// nothing and check the number of rows affected afterwards.
query += " on conflict do nothing"
}
result, err := c.tx.Exec(query, params...)
if err != nil {
return c.mapSQLError(err, key)
}
if c.putHook != nil {
if err := c.putHook(c.tx, val); err != nil {
return c.mapSQLError(err, key)
}
}
if !upsert {
count, err := result.RowsAffected()
if err != nil {
return errors.Wrap(c.mapSQLError(err, key), "insert failed")
}
if count != int64(1) {
return errors.WithStack(ErrExists{Type: c.table, Key: key})
}
}
return nil
}
func (c *postgresReadWriteCollection) Upsert(key interface{}, val proto.Message, f func() error) error {
if err := c.Get(key, val); err != nil && !IsErrNotFound(err) {
return err
}
if err := f(); err != nil {
return err
}
return c.Put(key, val)
}
func (c *postgresReadWriteCollection) Create(key interface{}, val proto.Message) error {
return c.withKey(key, func(rawKey string) error {
return c.insert(rawKey, val, false)
})
}
func (c *postgresReadWriteCollection) Delete(key interface{}) error {
return c.withKey(key, func(rawKey string) error {
return c.delete(rawKey)
})
}
func (c *postgresReadWriteCollection) delete(key string) error {
query := fmt.Sprintf("delete from collections.%s where key = $1", c.table)
res, err := c.tx.Exec(query, key)
if err != nil {
return c.mapSQLError(err, key)
}
if count, err := res.RowsAffected(); err != nil {
return c.mapSQLError(err, key)
} else if count == 0 {
return errors.WithStack(ErrNotFound{Type: c.table, Key: key})
}
return nil
}
func (c *postgresReadWriteCollection) DeleteAll() error {
query := fmt.Sprintf("delete from collections.%s", c.table)
_, err := c.tx.Exec(query)
return c.mapSQLError(err, "")
}
func (c *postgresReadWriteCollection) DeleteByIndex(index *Index, indexVal string) error {
if err := c.validateIndex(index); err != nil {
return err
}
query := fmt.Sprintf("delete from collections.%s where %s = $1", c.table, indexFieldName(index))
_, err := c.tx.Exec(query, indexVal)
return c.mapSQLError(err, "")
}