Skip to content

Commit

Permalink
fix sorting
Browse files Browse the repository at this point in the history
  • Loading branch information
@pyshx
pyshx committed Aug 7, 2024
1 parent eeb7f65 commit af577db
Showing 1 changed file with 82 additions and 38 deletions.
120 changes: 82 additions & 38 deletions mongox/pagination.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,7 @@ import (
)

func (c *Collection) Paginate(ctx context.Context, rawFilter any, s *usecasex.Sort, p *usecasex.Pagination, consumer Consumer, opts ...*options.FindOptions) (*usecasex.PageInfo, error) {
if p == nil || p.Cursor == nil && p.Offset == nil {
if p == nil || (p.Cursor == nil && p.Offset == nil) {
return nil, nil
}

Expand All @@ -39,16 +39,27 @@ func (c *Collection) Paginate(ctx context.Context, rawFilter any, s *usecasex.So
return nil, rerror.ErrInternalByWithContext(ctx, fmt.Errorf("failed to count: %w", err))
}

startCursor, endCursor, hasMore, err := consume(ctx, cursor, limit(*p), consumer)
items, startCursor, endCursor, hasMore, err := consume(ctx, cursor, limit(*p))
if err != nil {
return nil, err
}

hasNextPage, hasPreviousPage := pageInfo(p, hasMore)
if p.Cursor != nil && p.Cursor.Last != nil {
reverse(items)
}

for _, item := range items {
if err := consumer.Consume(item); err != nil {
return nil, err
}
}

hasNextPage, hasPreviousPage := pageInfo(p, hasMore, len(items))

return usecasex.NewPageInfo(count, startCursor, endCursor, hasNextPage, hasPreviousPage), nil
}


func (c *Collection) PaginateAggregation(ctx context.Context, pipeline []any, s *usecasex.Sort, p *usecasex.Pagination, consumer Consumer, opts ...*options.AggregateOptions) (*usecasex.PageInfo, error) {
if p == nil || p.Cursor == nil && p.Offset == nil {
return nil, nil
Expand All @@ -74,53 +85,84 @@ func (c *Collection) PaginateAggregation(ctx context.Context, pipeline []any, s
return nil, rerror.ErrInternalByWithContext(ctx, fmt.Errorf("failed to count: %w", err))
}

startCursor, endCursor, hasMore, err := consume(ctx, cursor, limit(*p), consumer)
items, startCursor, endCursor, hasMore, err := consume(ctx, cursor, limit(*p))
if err != nil {
return nil, err
}

hasNextPage, hasPreviousPage := pageInfo(p, hasMore)
if p.Cursor != nil && p.Cursor.Last != nil {
reverse(items)
}

for _, item := range items {
if err := consumer.Consume(item); err != nil {
return nil, err
}
}

hasNextPage, hasPreviousPage := pageInfo(p, hasMore, len(items))

return usecasex.NewPageInfo(count, startCursor, endCursor, hasNextPage, hasPreviousPage), nil
}

func pageInfo(p *usecasex.Pagination, hasMore bool) (bool, bool) {
// ref: https://facebook.github.io/relay/graphql/connections.htm#sec-undefined.PageInfo.Fields
// If first is set, false can be returned unless it can be efficiently determined whether or not a previous page exists.
// If last is set, false can be returned unless it can be efficiently determined whether or not a next page exists.
// Returning absolutely false because the existing implementation cannot determine it efficiently.
hasNextPage := (p.Cursor != nil && p.Cursor.First != nil || p.Offset != nil) && hasMore
hasPreviousPage := (p.Cursor != nil && p.Cursor.Last != nil) && hasMore
func pageInfo(p *usecasex.Pagination, hasMore bool, itemCount int) (bool, bool) {
hasNextPage := false
hasPreviousPage := false

if p.Cursor != nil {
if p.Cursor.First != nil {
hasNextPage = hasMore
hasPreviousPage = p.Cursor.After != nil
} else if p.Cursor.Last != nil {
hasNextPage = p.Cursor.Before != nil
hasPreviousPage = hasMore
}
} else if p.Offset != nil {
hasNextPage = itemCount == int(limit(*p)) - 1
hasPreviousPage = p.Offset.Offset > 0
}

return hasNextPage, hasPreviousPage
}

func consume(ctx context.Context, cursor *mongo.Cursor, limit int64, consumer Consumer) (*usecasex.Cursor, *usecasex.Cursor, bool, error) {
func consume(ctx context.Context, cursor *mongo.Cursor, limit int64) ([]bson.Raw, *usecasex.Cursor, *usecasex.Cursor, bool, error) {
i := int64(0)
var startCursor, endCursor *usecasex.Cursor
var items []bson.Raw

for cursor.Next(ctx) {
if i < limit-1 {
cur, err := getCursor(cursor.Current)
var item bson.Raw
if err := cursor.Decode(&item); err != nil {
return nil, nil, nil, false, rerror.ErrInternalByWithContext(ctx, fmt.Errorf("failed to decode item: %w", err))
}

cur, err := getCursor(item)
if err != nil {
return nil, nil, false, rerror.ErrInternalByWithContext(ctx, fmt.Errorf("failed to get cursor: %w", err))
return nil, nil, nil, false, rerror.ErrInternalByWithContext(ctx, fmt.Errorf("failed to get cursor: %w", err))
}

if startCursor == nil {
startCursor = cur
}
endCursor = cur

if err := consumer.Consume(cursor.Current); err != nil {
return nil, nil, false, err
}
items = append(items, item)
}

i++
}

if err := cursor.Err(); err != nil {
return nil, nil, false, rerror.ErrInternalByWithContext(ctx, fmt.Errorf("failed to read cursor: %w", err))
return nil, nil, nil, false, rerror.ErrInternalByWithContext(ctx, fmt.Errorf("failed to read cursor: %w", err))
}
return items, startCursor, endCursor, i == limit, nil
}

func reverse(items []bson.Raw) {
for i, j := 0, len(items)-1; i < j; i, j = i+1, j-1 {
items[i], items[j] = items[j], items[i]
}
return startCursor, endCursor, i == limit, nil
}

func (c *Collection) findFilter(ctx context.Context, p usecasex.Pagination, s *usecasex.Sort) (any, *options.FindOptions, error) {
Expand Down Expand Up @@ -164,12 +206,7 @@ func findOptionsFromPagination(p usecasex.Pagination, s *usecasex.Sort) *options
o = o.SetSkip(p.Offset.Offset)
}

sortFilter := sortFilter(p, s)
if sortFilter != nil {
o = o.SetSort(sortFilter)
}

return o.SetCollation(&options.Collation{Strength: 1, Locale: "simple"})
return o.SetCollation(&options.Collation{Strength: 1, Locale: "simple"}).SetSort(sortFilter(p, s))
}

func aggregateOptionsFromPagination(_ usecasex.Pagination, _ *usecasex.Sort) *options.AggregateOptions {
Expand Down Expand Up @@ -211,7 +248,7 @@ func (c *Collection) pageFilter(ctx context.Context, p usecasex.Pagination, s *u
}

if cursorDoc[*sortKey] == nil {
return nil, fmt.Errorf("invalid sort key")
return nil, fmt.Errorf("invalied sort key")
}

paginationFilter = bson.M{
Expand All @@ -229,18 +266,11 @@ func (c *Collection) pageFilter(ctx context.Context, p usecasex.Pagination, s *u
}

func sortFilter(p usecasex.Pagination, s *usecasex.Sort) bson.D {
var sortOrder int
if p.Cursor != nil && p.Cursor.Last != nil {
sortOrder = -1
} else {
sortOrder = 1
var sortOptions bson.D
if s != nil && s.Key != "" && s.Key != idKey {
sortOptions = append(sortOptions, bson.E{Key: s.Key, Value: sortDirection(p, s)})
}

if s != nil && s.Key != "" {
return bson.D{{Key: s.Key, Value: sortOrder}, {Key: idKey, Value: sortOrder}}
}

return bson.D{{Key: idKey, Value: sortOrder}}
return append(sortOptions, bson.E{Key: idKey, Value: sortDirection(p, s)})
}

func limit(p usecasex.Pagination) int64 {
Expand All @@ -264,3 +294,17 @@ func limit(p usecasex.Pagination) int64 {

return defaultLimit + 1
}

func sortDirection(p usecasex.Pagination, s *usecasex.Sort) int {
reverted := false
if s != nil {
reverted = s.Reverted
}

reverted = reverted || (p.Cursor != nil && p.Cursor.Last != nil)

if reverted {
return -1
}
return 1
}

0 comments on commit af577db

Please sign in to comment.