[hw-8] add: repo layer

comments/infra/db/postgres/tx.go

@@ -0,0 +1,87 @@
+package postgres
+
+// From https://gitlab.ozon.dev/go/classroom-18/students/week-4-workshop/-/blob/master/internal/infra/postgres/tx.go
+
+import (
+	"context"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/opentracing/opentracing-go"
+)
+
+// Tx транзакция.
+type Tx pgx.Tx
+
+type txKey struct{}
+
+func ctxWithTx(ctx context.Context, tx pgx.Tx) context.Context {
+	return context.WithValue(ctx, txKey{}, tx)
+}
+
+func TxFromCtx(ctx context.Context) (pgx.Tx, bool) {
+	tx, ok := ctx.Value(txKey{}).(pgx.Tx)
+
+	return tx, ok
+}
+
+type TxManager struct {
+	write *pgxpool.Pool
+	read  *pgxpool.Pool
+}
+
+func NewTxManager(write, read *pgxpool.Pool) *TxManager {
+	return &TxManager{
+		write: write,
+		read:  read,
+	}
+}
+
+// WithTransaction выполняет fn в транзакции с дефолтным уровнем изоляции.
+func (m *TxManager) WriteWithTransaction(ctx context.Context, fn func(ctx context.Context) error) (err error) {
+	return m.withTx(ctx, m.write, pgx.TxOptions{}, fn)
+}
+
+func (m *TxManager) ReadWithTransaction(ctx context.Context, fn func(ctx context.Context) error) (err error) {
+	return m.withTx(ctx, m.read, pgx.TxOptions{}, fn)
+}
+
+// WithTransaction выполняет fn в транзакции с уровнем изоляции RepeatableRead.
+func (m *TxManager) WriteWithRepeatableRead(ctx context.Context, fn func(ctx context.Context) error) (err error) {
+	return m.withTx(ctx, m.write, pgx.TxOptions{IsoLevel: pgx.RepeatableRead}, fn)
+}
+
+func (m *TxManager) ReadWithRepeatableRead(ctx context.Context, fn func(ctx context.Context) error) (err error) {
+	return m.withTx(ctx, m.read, pgx.TxOptions{IsoLevel: pgx.RepeatableRead}, fn)
+}
+
+// WithTx выполняет fn в транзакции.
+func (m *TxManager) withTx(ctx context.Context, pool *pgxpool.Pool, options pgx.TxOptions, fn func(ctx context.Context) error) (err error) {
+	var span opentracing.Span
+	span, ctx = opentracing.StartSpanFromContext(ctx, "Transaction")
+	defer span.Finish()
+
+	tx, err := pool.BeginTx(ctx, options)
+	if err != nil {
+		return
+	}
+	ctx = ctxWithTx(ctx, tx)
+
+	defer func() {
+		if p := recover(); p != nil {
+			// a panic occurred, rollback and repanic
+			_ = tx.Rollback(ctx)
+			panic(p)
+		} else if err != nil {
+			// something went wrong, rollback
+			_ = tx.Rollback(ctx)
+		} else {
+			// all good, commit
+			err = tx.Commit(ctx)
+		}
+	}()
+
+	err = fn(ctx)
+
+	return
+}

comments/infra/repository/sqlc/db.go

@@ -0,0 +1,32 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.29.0
+
+package sqlc
+
+import (
+	"context"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgconn"
+)
+
+type DBTX interface {
+	Exec(context.Context, string, ...interface{}) (pgconn.CommandTag, error)
+	Query(context.Context, string, ...interface{}) (pgx.Rows, error)
+	QueryRow(context.Context, string, ...interface{}) pgx.Row
+}
+
+func New(db DBTX) *Queries {
+	return &Queries{db: db}
+}
+
+type Queries struct {
+	db DBTX
+}
+
+func (q *Queries) WithTx(tx pgx.Tx) *Queries {
+	return &Queries{
+		db: tx,
+	}
+}

comments/infra/repository/sqlc/models.go

@@ -0,0 +1,17 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.29.0
+
+package sqlc
+
+import (
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+type Comment struct {
+	ID        int64
+	UserID    int64
+	Sku       int64
+	Text      string
+	CreatedAt pgtype.Timestamp
+}

comments/infra/repository/sqlc/querier.go

@@ -0,0 +1,19 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.29.0
+
+package sqlc
+
+import (
+	"context"
+)
+
+type Querier interface {
+	GetCommentByID(ctx context.Context, id int64) (*Comment, error)
+	InsertComment(ctx context.Context, arg *InsertCommentParams) (*Comment, error)
+	ListCommentsBySku(ctx context.Context, sku int64) ([]*Comment, error)
+	ListCommentsByUser(ctx context.Context, userID int64) ([]*Comment, error)
+	UpdateComment(ctx context.Context, arg *UpdateCommentParams) (*Comment, error)
+}
+
+var _ Querier = (*Queries)(nil)

comments/infra/repository/sqlc/query.sql

@@ -0,0 +1,24 @@
+-- name: InsertComment :one
+INSERT INTO comments (user_id, sku, text) VALUES ($1, $2, $3)
+RETURNING id, user_id, sku, text, created_at;
+
+-- name: GetCommentByID :one
+SELECT id, user_id, sku, text, created_at FROM comments WHERE id = $1;
+
+-- name: UpdateComment :one
+UPDATE comments
+SET text = $2
+WHERE id = $1
+RETURNING id, user_id, sku, text, created_at;
+
+-- name: ListCommentsBySku :many
+SELECT id, user_id, sku, text, created_at
+FROM comments
+WHERE sku = $1
+ORDER BY created_at DESC, user_id ASC;
+
+-- name: ListCommentsByUser :many
+SELECT id, user_id, sku, text, created_at
+FROM comments
+WHERE user_id = $1
+ORDER BY created_at DESC;

comments/infra/repository/sqlc/query.sql.go

@@ -0,0 +1,142 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.29.0
+// source: query.sql
+
+package sqlc
+
+import (
+	"context"
+)
+
+const getCommentByID = `-- name: GetCommentByID :one
+SELECT id, user_id, sku, text, created_at FROM comments WHERE id = $1
+`
+
+func (q *Queries) GetCommentByID(ctx context.Context, id int64) (*Comment, error) {
+	row := q.db.QueryRow(ctx, getCommentByID, id)
+	var i Comment
+	err := row.Scan(
+		&i.ID,
+		&i.UserID,
+		&i.Sku,
+		&i.Text,
+		&i.CreatedAt,
+	)
+	return &i, err
+}
+
+const insertComment = `-- name: InsertComment :one
+INSERT INTO comments (user_id, sku, text) VALUES ($1, $2, $3)
+RETURNING id, user_id, sku, text, created_at
+`
+
+type InsertCommentParams struct {
+	UserID int64
+	Sku    int64
+	Text   string
+}
+
+func (q *Queries) InsertComment(ctx context.Context, arg *InsertCommentParams) (*Comment, error) {
+	row := q.db.QueryRow(ctx, insertComment, arg.UserID, arg.Sku, arg.Text)
+	var i Comment
+	err := row.Scan(
+		&i.ID,
+		&i.UserID,
+		&i.Sku,
+		&i.Text,
+		&i.CreatedAt,
+	)
+	return &i, err
+}
+
+const listCommentsBySku = `-- name: ListCommentsBySku :many
+SELECT id, user_id, sku, text, created_at
+FROM comments
+WHERE sku = $1
+ORDER BY created_at DESC, user_id ASC
+`
+
+func (q *Queries) ListCommentsBySku(ctx context.Context, sku int64) ([]*Comment, error) {
+	rows, err := q.db.Query(ctx, listCommentsBySku, sku)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []*Comment
+	for rows.Next() {
+		var i Comment
+		if err := rows.Scan(
+			&i.ID,
+			&i.UserID,
+			&i.Sku,
+			&i.Text,
+			&i.CreatedAt,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, &i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+const listCommentsByUser = `-- name: ListCommentsByUser :many
+SELECT id, user_id, sku, text, created_at
+FROM comments
+WHERE user_id = $1
+ORDER BY created_at DESC
+`
+
+func (q *Queries) ListCommentsByUser(ctx context.Context, userID int64) ([]*Comment, error) {
+	rows, err := q.db.Query(ctx, listCommentsByUser, userID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []*Comment
+	for rows.Next() {
+		var i Comment
+		if err := rows.Scan(
+			&i.ID,
+			&i.UserID,
+			&i.Sku,
+			&i.Text,
+			&i.CreatedAt,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, &i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+const updateComment = `-- name: UpdateComment :one
+UPDATE comments
+SET text = $2
+WHERE id = $1
+RETURNING id, user_id, sku, text, created_at
+`
+
+type UpdateCommentParams struct {
+	ID   int64
+	Text string
+}
+
+func (q *Queries) UpdateComment(ctx context.Context, arg *UpdateCommentParams) (*Comment, error) {
+	row := q.db.QueryRow(ctx, updateComment, arg.ID, arg.Text)
+	var i Comment
+	err := row.Scan(
+		&i.ID,
+		&i.UserID,
+		&i.Sku,
+		&i.Text,
+		&i.CreatedAt,
+	)
+	return &i, err
+}

comments/infra/repository/sqlc/repository.go

@@ -0,0 +1,148 @@
+package sqlc
+
+import (
+	"context"
+	"errors"
+	"sort"
+
+	"route256/comments/internal/domain/entity"
+	"route256/comments/internal/domain/model"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/rs/zerolog/log"
+)
+
+type commentsRepo struct {
+	shard1 *pgxpool.Pool
+	shard2 *pgxpool.Pool
+}
+
+func NewCommentsRepository(shard1, shard2 *pgxpool.Pool) *commentsRepo {
+	return &commentsRepo{
+		shard1: shard1,
+		shard2: shard2,
+	}
+}
+
+func (r *commentsRepo) pickShard(sku int64) *pgxpool.Pool {
+	if sku%2 == 0 {
+		return r.shard1
+	}
+
+	return r.shard2
+}
+
+func (r *commentsRepo) GetCommentByID(ctx context.Context, id int64) (*Comment, error) {
+	q1 := New(r.shard1)
+	c, err := q1.GetCommentByID(ctx, id)
+	switch {
+	case err == nil:
+		return c, nil
+	case errors.Is(err, pgx.ErrNoRows):
+		log.Trace().Msgf("comment with id %d not found in shard 1", id)
+	default:
+		return nil, err
+	}
+
+	q2 := New(r.shard2)
+	c2, err2 := q2.GetCommentByID(ctx, id)
+	switch {
+	case err2 == nil:
+		return c2, nil
+	case errors.Is(err2, pgx.ErrNoRows):
+		return nil, model.ErrCommentNotFound
+	default:
+		return nil, err2
+	}
+}
+
+func (r *commentsRepo) InsertComment(ctx context.Context, comment *entity.Comment) (*Comment, error) {
+	shard := r.pickShard(comment.SKU)
+	q := New(shard)
+
+	req := &InsertCommentParams{
+		UserID: comment.UserID,
+		Sku:    comment.SKU,
+		Text:   comment.Text,
+	}
+
+	c, err := q.InsertComment(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+
+	return c, nil
+}
+
+func (r *commentsRepo) ListCommentsBySku(ctx context.Context, sku int64) ([]*Comment, error) {
+	shard := r.pickShard(sku)
+	q := New(shard)
+
+	list, err := q.ListCommentsBySku(ctx, sku)
+	if err != nil {
+		return nil, err
+	}
+
+	out := make([]*Comment, len(list))
+	copy(out, list)
+
+	return out, nil
+}
+
+func (r *commentsRepo) ListCommentsByUser(ctx context.Context, userID int64) ([]*Comment, error) {
+	q1 := New(r.shard1)
+	l1, err1 := q1.ListCommentsByUser(ctx, userID)
+	if err1 != nil {
+		return nil, err1
+	}
+
+	q2 := New(r.shard2)
+	l2, err2 := q2.ListCommentsByUser(ctx, userID)
+	if err2 != nil {
+		return nil, err2
+	}
+
+	merged := make([]*Comment, 0, len(l1)+len(l2))
+	merged = append(merged, l1...)
+	merged = append(merged, l2...)
+
+	sort.Slice(merged, func(i, j int) bool {
+		if merged[i].CreatedAt.Time.Equal(merged[j].CreatedAt.Time) {
+			return merged[i].UserID < merged[j].UserID
+		}
+
+		return merged[i].CreatedAt.Time.After(merged[j].CreatedAt.Time)
+	})
+
+	return merged, nil
+}
+
+func (r *commentsRepo) UpdateComment(ctx context.Context, comment *entity.Comment) (*Comment, error) {
+	req := &UpdateCommentParams{
+		ID:   comment.ID,
+		Text: comment.Text,
+	}
+
+	q1 := New(r.shard1)
+	c, err := q1.UpdateComment(ctx, req)
+	switch {
+	case err == nil:
+		return c, nil
+	case errors.Is(err, pgx.ErrNoRows):
+		log.Trace().Msgf("comment with id %d not found in shard 1", req.ID)
+	default:
+		return nil, err
+	}
+
+	q2 := New(r.shard2)
+	c2, err2 := q2.UpdateComment(ctx, req)
+	switch {
+	case err2 == nil:
+		return c2, nil
+	case errors.Is(err2, pgx.ErrNoRows):
+		return nil, model.ErrCommentNotFound
+	default:
+		return nil, err2
+	}
+}