Skip to content

GODRIVER-3533 Optimize value reader and writer #2022

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 6 commits into
base: master
Choose a base branch
from
Open

GODRIVER-3533 Optimize value reader and writer #2022

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
70c4fbb
GODRIVER-3533 Optimize value reader and writer
prestonvasquez Apr 16, 2025
20145ad
GODRIVER-3533 Remove uncessary additions to vr
prestonvasquez Apr 16, 2025
e0f81a0
GODRIVER-3533 Account for full buffer in appending next ele
prestonvasquez Apr 16, 2025
8848df3
GODRIVER-3533 Revert valueReader struct changes
prestonvasquez Apr 16, 2025
3afc6f8
GODRIVER-3533 Use document-specific pool for encoding
prestonvasquez Apr 16, 2025
ecb98ce
GODRIVER-3533 Remove mem.perf file
prestonvasquez Apr 17, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 4 additions & 1 deletion bson/marshal.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -74,7 +74,10 @@ func Marshal(val interface{}) ([]byte, error) {
}
}()
sw.Reset()
vw := NewDocumentWriter(sw)

vw := getDocumentWriter(sw)
defer putDocumentWriter(vw)

enc := encPool.Get().(*Encoder)
defer encPool.Put(enc)
enc.Reset(vw)
Expand Down
2 changes: 2 additions & 0 deletions bson/unmarshal.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,8 @@ type ValueUnmarshaler interface {
// pointer, the pointer is set to nil without calling UnmarshalBSONValue.
func Unmarshal(data []byte, val interface{}) error {
vr := newDocumentReader(bytes.NewReader(data))
defer releaseDocumentReader(vr)

if l, err := vr.peekLength(); err != nil {
return err
} else if int(l) != len(data) {
Expand Down
65 changes: 53 additions & 12 deletions bson/value_reader.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@ import (
"fmt"
"io"
"math"
"sync"
)

var _ ValueReader = &valueReader{}
Expand All @@ -29,6 +30,20 @@ type vrState struct {
end int64
}

var bufioReaderPool = sync.Pool{
New: func() interface{} {
return bufio.NewReader(nil)
},
}

var vrPool = sync.Pool{
New: func() interface{} {
return &valueReader{
stack: make([]vrState, 1, 5),
}
},
}

// valueReader is for reading BSON values.
type valueReader struct {
r *bufio.Reader
Expand Down Expand Up @@ -57,14 +72,26 @@ func newValueReader(t Type, r io.Reader) ValueReader {
}

func newDocumentReader(r io.Reader) *valueReader {
stack := make([]vrState, 1, 5)
stack[0] = vrState{
mode: mTopLevel,
}
return &valueReader{
r: bufio.NewReader(r),
stack: stack,
}
vr := vrPool.Get().(*valueReader)

vr.offset = 0
vr.frame = 0

vr.stack = vr.stack[:1]
vr.stack[0].mode = mTopLevel

br := bufioReaderPool.Get().(*bufio.Reader)
br.Reset(r)
vr.r = br

return vr
}

func releaseDocumentReader(vr *valueReader) {
bufioReaderPool.Put(vr.r)
vr.r = nil

vrPool.Put(vr)
}

func (vr *valueReader) advanceFrame() {
Expand Down Expand Up @@ -253,14 +280,28 @@ func (vr *valueReader) appendNextElement(dst []byte) ([]byte, error) {
return nil, err
}

buf := make([]byte, length)
_, err = io.ReadFull(vr.r, buf)
buf, err := vr.r.Peek(int(length))
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Peek only allocates once for the bufio's internal buffer, we can borrow views of it with Peek without touching the heap. And append makes the copy.

if err != nil {
if err == bufio.ErrBufferFull {
temp := make([]byte, length)
if _, err = io.ReadFull(vr.r, temp); err != nil {
return nil, err
}
dst = append(dst, temp...)
vr.offset += int64(len(temp))
return dst, nil
}

return nil, err
}

dst = append(dst, buf...)
vr.offset += int64(len(buf))
return dst, err
if _, err = vr.r.Discard(int(length)); err != nil {
return nil, err
}

vr.offset += int64(length)
return dst, nil
}

func (vr *valueReader) readValueBytes(dst []byte) (Type, []byte, error) {
Expand Down
23 changes: 23 additions & 0 deletions bson/value_writer.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,29 @@ func putValueWriter(vw *valueWriter) {
}
}

var documentWriterPool = sync.Pool{
New: func() interface{} {
return NewDocumentWriter(nil)
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Can we call newDocumentWriter() because it returns a *valueWriter for syntactic clarity?

},
}

func getDocumentWriter(w io.Writer) *valueWriter {
vw := documentWriterPool.Get().(*valueWriter)

vw.reset(vw.buf)
vw.buf = vw.buf[:0]
vw.w = w

return vw
}

func putDocumentWriter(vw *valueWriter) {
if vw != nil {
vw.w = nil // don't leak the writer
documentWriterPool.Put(vw)
}
}

// This is here so that during testing we can change it and not require
// allocating a 4GB slice.
var maxSize = math.MaxInt32
Expand Down
Loading