12882779193

Committed 21 Jan 2025 08:19AM UTC coverage: 79.891% (-0.06%) from 79.953%

Build # 12882779193

Build Type

push

github

Committed by

web-flow

Commit Message

Merge pull request #1928 from Permify/feat-add-cursor-pagination-limit

refactor: update dataReader.go for improved pagination and limit hand…

Run Details

24 of 43 new or added lines in 3 files covered. (55.81%)

2 existing lines in 1 file now uncovered.

8184 of 10244 relevant lines covered (79.89%)

122.03 hits per line

Source File
Press 'n' to go to next uncovered line, 'b' for previous

78.14

/internal/storage/postgres/dataReader.go

package postgres

import (
        "context"
        "errors"
        "log/slog"
        "strconv"
        "strings"

        "github.com/jackc/pgx/v5"

        "github.com/Masterminds/squirrel"
        "github.com/golang/protobuf/jsonpb"
        "google.golang.org/protobuf/types/known/anypb"

        "github.com/Permify/permify/internal"
        "github.com/Permify/permify/internal/storage"
        "github.com/Permify/permify/internal/storage/postgres/snapshot"
        "github.com/Permify/permify/internal/storage/postgres/types"
        "github.com/Permify/permify/internal/storage/postgres/utils"
        "github.com/Permify/permify/pkg/database"
        db "github.com/Permify/permify/pkg/database/postgres"
        base "github.com/Permify/permify/pkg/pb/base/v1"
        "github.com/Permify/permify/pkg/token"
)

// DataReader is a struct which holds a reference to the database, transaction options and a logger.
// It is responsible for reading data from the database.
type DataReader struct {
        database  *db.Postgres  // database is an instance of the PostgreSQL database
        txOptions pgx.TxOptions // txOptions specifies the isolation level for database transaction and sets it as read only
}

// NewDataReader is a constructor function for DataReader.
// It initializes a new DataReader with a given database, a logger, and sets transaction options to be read-only with Repeatable Read isolation level.
func NewDataReader(database *db.Postgres) *DataReader {
        return &DataReader{
                database:  database,                                                             // Set the database to the passed in PostgreSQL instance
                txOptions: pgx.TxOptions{IsoLevel: pgx.ReadCommitted, AccessMode: pgx.ReadOnly}, // Set the transaction options
        }
}

// QueryRelationships reads relation tuples from the storage based on the given filter.
func (r *DataReader) QueryRelationships(ctx context.Context, tenantID string, filter *base.TupleFilter, snap string, pagination database.CursorPagination) (it *database.TupleIterator, err error) {
        // Start a new trace span and end it when the function exits.
        ctx, span := internal.Tracer.Start(ctx, "data-reader.query-relationships")
        defer span.End()

        slog.DebugContext(ctx, "querying relationships for tenant_id", slog.String("tenant_id", tenantID))

        // Decode the snapshot value.
        var st token.SnapToken
        st, err = snapshot.EncodedToken{Value: snap}.Decode()
        if err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)
        }

        // Build the relationships query based on the provided filter and snapshot value.
        var args []interface{}
        builder := r.database.Builder.Select("entity_type, entity_id, relation, subject_type, subject_id, subject_relation").From(RelationTuplesTable).Where(squirrel.Eq{"tenant_id": tenantID})
        builder = utils.TuplesFilterQueryForSelectBuilder(builder, filter)
        builder = utils.SnapshotQuery(builder, st.(snapshot.Token).Value.Uint)

        if pagination.Cursor() != "" {
                var t database.ContinuousToken
                t, err = utils.EncodedContinuousToken{Value: pagination.Cursor()}.Decode()
                if err != nil {
                        return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INVALID_CONTINUOUS_TOKEN)
                }
                builder = builder.Where(squirrel.GtOrEq{pagination.Sort(): t.(utils.ContinuousToken).Value})
        }

        if pagination.Sort() != "" {
                builder = builder.OrderBy(pagination.Sort())
        }

        // Apply limit if specified in pagination
        limit := pagination.Limit()
        if limit > 0 {
                builder = builder.Limit(uint64(limit))
        }

        // Generate the SQL query and arguments.
        var query string
        query, args, err = builder.ToSql()
        if err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)
        }

        slog.DebugContext(ctx, "generated sql query", slog.String("query", query), "with args", slog.Any("arguments", args))

        // Execute the SQL query and retrieve the result rows.
        var rows pgx.Rows
        rows, err = r.database.ReadPool.Query(ctx, query, args...)
        if err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_EXECUTION)
        }
        defer rows.Close()

        // Process the result rows and store the relationships in a TupleCollection.
        collection := database.NewTupleCollection()
        for rows.Next() {
                rt := storage.RelationTuple{}
                err = rows.Scan(&rt.EntityType, &rt.EntityID, &rt.Relation, &rt.SubjectType, &rt.SubjectID, &rt.SubjectRelation)
                if err != nil {
                        return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
                }
                collection.Add(rt.ToTuple())
        }
        if err = rows.Err(); err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
        }

        slog.DebugContext(ctx, "successfully retrieved relation tuples from the database")

        // Return a TupleIterator created from the TupleCollection.
        return collection.CreateTupleIterator(), nil
}

// ReadRelationships reads relation tuples from the storage based on the given filter and pagination.
func (r *DataReader) ReadRelationships(ctx context.Context, tenantID string, filter *base.TupleFilter, snap string, pagination database.Pagination) (collection *database.TupleCollection, ct database.EncodedContinuousToken, err error) {
        // Start a new trace span and end it when the function exits.
        ctx, span := internal.Tracer.Start(ctx, "data-reader.read-relationships")
        defer span.End()

        slog.DebugContext(ctx, "reading relationships for tenant_id", slog.String("tenant_id", tenantID))

        // Decode the snapshot value.
        var st token.SnapToken
        st, err = snapshot.EncodedToken{Value: snap}.Decode()
        if err != nil {
                return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)
        }

        // Build the relationships query based on the provided filter, snapshot value, and pagination settings.
        builder := r.database.Builder.Select("id, entity_type, entity_id, relation, subject_type, subject_id, subject_relation").From(RelationTuplesTable).Where(squirrel.Eq{"tenant_id": tenantID})
        builder = utils.TuplesFilterQueryForSelectBuilder(builder, filter)
        builder = utils.SnapshotQuery(builder, st.(snapshot.Token).Value.Uint)

        // Apply the pagination token and limit to the query.
        if pagination.Token() != "" {
                var t database.ContinuousToken
                t, err = utils.EncodedContinuousToken{Value: pagination.Token()}.Decode()
                if err != nil {
                        return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INVALID_CONTINUOUS_TOKEN)
                }
                var v uint64
                v, err = strconv.ParseUint(t.(utils.ContinuousToken).Value, 10, 64)
                if err != nil {
                        return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INVALID_CONTINUOUS_TOKEN)
                }
                builder = builder.Where(squirrel.GtOrEq{"id": v})
        }

        builder = builder.OrderBy("id")

        if pagination.PageSize() != 0 {
                builder = builder.Limit(uint64(pagination.PageSize() + 1))
        }

        // Generate the SQL query and arguments.
        var query string
        var args []interface{}
        query, args, err = builder.ToSql()
        if err != nil {
                return nil, database.NewNoopContinuousToken().Encode(), utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)
        }

        slog.DebugContext(ctx, "generated sql query", slog.String("query", query), "with args", slog.Any("arguments", args))

        // Execute the query and retrieve the rows.
        var rows pgx.Rows
        rows, err = r.database.ReadPool.Query(ctx, query, args...)
        if err != nil {
                return nil, database.NewNoopContinuousToken().Encode(), utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_EXECUTION)
        }
        defer rows.Close()

        var lastID uint64

        // Iterate through the rows and scan the result into a RelationTuple struct.
        tuples := make([]*base.Tuple, 0, pagination.PageSize()+1)
        for rows.Next() {
                rt := storage.RelationTuple{}
                err = rows.Scan(&rt.ID, &rt.EntityType, &rt.EntityID, &rt.Relation, &rt.SubjectType, &rt.SubjectID, &rt.SubjectRelation)
                if err != nil {
                        return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
                }
                lastID = rt.ID
                tuples = append(tuples, rt.ToTuple())
        }
        // Check for any errors during iteration.
        if err = rows.Err(); err != nil {
                return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
        }

        slog.DebugContext(ctx, "successfully read relation tuples from database")

        // Return the results and encoded continuous token for pagination.
        if pagination.PageSize() != 0 && len(tuples) > int(pagination.PageSize()) {
                return database.NewTupleCollection(tuples[:pagination.PageSize()]...), utils.NewContinuousToken(strconv.FormatUint(lastID, 10)).Encode(), nil
        }

        return database.NewTupleCollection(tuples...), database.NewNoopContinuousToken().Encode(), nil
}

// QuerySingleAttribute retrieves a single attribute from the storage based on the given filter.
func (r *DataReader) QuerySingleAttribute(ctx context.Context, tenantID string, filter *base.AttributeFilter, snap string) (attribute *base.Attribute, err error) {
        // Start a new trace span and end it when the function exits.
        ctx, span := internal.Tracer.Start(ctx, "data-reader.query-single-attribute")
        defer span.End()

        slog.DebugContext(ctx, "querying single attribute for tenant_id", slog.String("tenant_id", tenantID))

        // Decode the snapshot value.
        var st token.SnapToken
        st, err = snapshot.EncodedToken{Value: snap}.Decode()
        if err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)
        }

        // Build the relationships query based on the provided filter and snapshot value.
        var args []interface{}
        builder := r.database.Builder.Select("entity_type, entity_id, attribute, value").From(AttributesTable).Where(squirrel.Eq{"tenant_id": tenantID})
        builder = utils.AttributesFilterQueryForSelectBuilder(builder, filter)
        builder = utils.SnapshotQuery(builder, st.(snapshot.Token).Value.Uint)

        // Generate the SQL query and arguments.
        var query string
        query, args, err = builder.ToSql()
        if err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)
        }

        slog.DebugContext(ctx, "generated sql query", slog.String("query", query), "with args", slog.Any("arguments", args))

        row := r.database.ReadPool.QueryRow(ctx, query, args...)

        rt := storage.Attribute{}

        // Suppose you have a struct `rt` with a field `Value` of type `*anypb.Any`.
        var valueStr string

        // Scan the row from the database into the fields of `rt` and `valueStr`.
        err = row.Scan(&rt.EntityType, &rt.EntityID, &rt.Attribute, &valueStr)
        if err != nil {
                if errors.Is(err, pgx.ErrNoRows) {
                        return nil, nil
                } else {
                        return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
                }
        }

        // Unmarshal the JSON data from `valueStr` into `rt.Value`.
        rt.Value = &anypb.Any{}
        unmarshaler := &jsonpb.Unmarshaler{}
        err = unmarshaler.Unmarshal(strings.NewReader(valueStr), rt.Value)
        if err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)
        }

        slog.DebugContext(ctx, "successfully retrieved Single attribute from the database")

        return rt.ToAttribute(), nil
}

// QueryAttributes reads multiple attributes from the storage based on the given filter.
func (r *DataReader) QueryAttributes(ctx context.Context, tenantID string, filter *base.AttributeFilter, snap string, pagination database.CursorPagination) (it *database.AttributeIterator, err error) {
        // Start a new trace span and end it when the function exits.
        ctx, span := internal.Tracer.Start(ctx, "data-reader.query-attributes")
        defer span.End()

        slog.DebugContext(ctx, "querying Attributes for tenant_id", slog.String("tenant_id", tenantID))

        // Decode the snapshot value.
        var st token.SnapToken
        st, err = snapshot.EncodedToken{Value: snap}.Decode()
        if err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)
        }

        // Build the attributes query based on the provided filter and snapshot value.
        var args []interface{}
        builder := r.database.Builder.Select("entity_type, entity_id, attribute, value").From(AttributesTable).Where(squirrel.Eq{"tenant_id": tenantID})
        builder = utils.AttributesFilterQueryForSelectBuilder(builder, filter)
        builder = utils.SnapshotQuery(builder, st.(snapshot.Token).Value.Uint)

        if pagination.Cursor() != "" {
                var t database.ContinuousToken
                t, err = utils.EncodedContinuousToken{Value: pagination.Cursor()}.Decode()
                if err != nil {
                        return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INVALID_CONTINUOUS_TOKEN)
                }
                builder = builder.Where(squirrel.GtOrEq{pagination.Sort(): t.(utils.ContinuousToken).Value})
        }

        if pagination.Sort() != "" {
                builder = builder.OrderBy(pagination.Sort())
        }

        // Apply limit if specified in pagination
        limit := pagination.Limit()
        if limit > 0 {
                builder = builder.Limit(uint64(limit))
        }

        // Generate the SQL query and arguments.
        var query string
        query, args, err = builder.ToSql()
        if err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)
        }

        slog.DebugContext(ctx, "generated sql query", slog.String("query", query), "with args", slog.Any("arguments", args))

        // Execute the SQL query and retrieve the result rows.
        var rows pgx.Rows
        rows, err = r.database.ReadPool.Query(ctx, query, args...)
        if err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_EXECUTION)
        }
        defer rows.Close()

        // Process the result rows and store the attributes in an AttributeCollection.
        collection := database.NewAttributeCollection()
        for rows.Next() {
                rt := storage.Attribute{}

                // Suppose you have a struct `rt` with a field `Value` of type `*anypb.Any`.
                var valueStr string

                // Scan the row from the database into the fields of `rt` and `valueStr`.
                err := rows.Scan(&rt.EntityType, &rt.EntityID, &rt.Attribute, &valueStr)
                if err != nil {
                        return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
                }

                // Unmarshal the JSON data from `valueStr` into `rt.Value`.
                rt.Value = &anypb.Any{}
                unmarshaler := &jsonpb.Unmarshaler{}
                err = unmarshaler.Unmarshal(strings.NewReader(valueStr), rt.Value)
                if err != nil {
                        return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)
                }

                collection.Add(rt.ToAttribute())
        }
        if err = rows.Err(); err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
        }

        slog.DebugContext(ctx, "successfully retrieved attributes tuples from the database")

        // Return an AttributeIterator created from the AttributeCollection.
        return collection.CreateAttributeIterator(), nil
}

// ReadAttributes reads multiple attributes from the storage based on the given filter and pagination.
func (r *DataReader) ReadAttributes(ctx context.Context, tenantID string, filter *base.AttributeFilter, snap string, pagination database.Pagination) (collection *database.AttributeCollection, ct database.EncodedContinuousToken, err error) {
        // Start a new trace span and end it when the function exits.
        ctx, span := internal.Tracer.Start(ctx, "data-reader.read-attributes")
        defer span.End()

        slog.DebugContext(ctx, "reading attributes for tenant_id", slog.String("tenant_id", tenantID))

        // Decode the snapshot value.
        var st token.SnapToken
        st, err = snapshot.EncodedToken{Value: snap}.Decode()
        if err != nil {
                return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)
        }

        // Build the relationships query based on the provided filter, snapshot value, and pagination settings.
        builder := r.database.Builder.Select("id, entity_type, entity_id, attribute, value").From(AttributesTable).Where(squirrel.Eq{"tenant_id": tenantID})
        builder = utils.AttributesFilterQueryForSelectBuilder(builder, filter)
        builder = utils.SnapshotQuery(builder, st.(snapshot.Token).Value.Uint)

        // Apply the pagination token and limit to the query.
        if pagination.Token() != "" {
                var t database.ContinuousToken
                t, err = utils.EncodedContinuousToken{Value: pagination.Token()}.Decode()
                if err != nil {
                        return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INVALID_CONTINUOUS_TOKEN)
                }
                var v uint64
                v, err = strconv.ParseUint(t.(utils.ContinuousToken).Value, 10, 64)
                if err != nil {
                        return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INVALID_CONTINUOUS_TOKEN)
                }
                builder = builder.Where(squirrel.GtOrEq{"id": v})
        }

        builder = builder.OrderBy("id")

        if pagination.PageSize() != 0 {
                builder = builder.Limit(uint64(pagination.PageSize() + 1))
        }

        // Generate the SQL query and arguments.
        var query string
        var args []interface{}
        query, args, err = builder.ToSql()
        if err != nil {
                return nil, database.NewNoopContinuousToken().Encode(), utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)
        }

        slog.DebugContext(ctx, "generated sql query", slog.String("query", query), "with args", slog.Any("arguments", args))

        // Execute the query and retrieve the rows.
        var rows pgx.Rows
        rows, err = r.database.ReadPool.Query(ctx, query, args...)
        if err != nil {
                return nil, database.NewNoopContinuousToken().Encode(), utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_EXECUTION)
        }
        defer rows.Close()

        var lastID uint64

        // Iterate through the rows and scan the result into a RelationTuple struct.
        attributes := make([]*base.Attribute, 0, pagination.PageSize()+1)
        for rows.Next() {
                rt := storage.Attribute{}

                // Suppose you have a struct `rt` with a field `Value` of type `*anypb.Any`.
                var valueStr string

                // Scan the row from the database into the fields of `rt` and `valueStr`.
                err := rows.Scan(&rt.ID, &rt.EntityType, &rt.EntityID, &rt.Attribute, &valueStr)
                if err != nil {
                        return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
                }
                lastID = rt.ID

                // Unmarshal the JSON data from `valueStr` into `rt.Value`.
                rt.Value = &anypb.Any{}
                unmarshaler := &jsonpb.Unmarshaler{}
                err = unmarshaler.Unmarshal(strings.NewReader(valueStr), rt.Value)
                if err != nil {
                        return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)
                }

                attributes = append(attributes, rt.ToAttribute())
        }
        // Check for any errors during iteration.
        if err = rows.Err(); err != nil {
                return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
        }

        slog.DebugContext(ctx, "successfully read attributes from the database")

        // Return the results and encoded continuous token for pagination.
        if len(attributes) > int(pagination.PageSize()) {
                return database.NewAttributeCollection(attributes[:pagination.PageSize()]...), utils.NewContinuousToken(strconv.FormatUint(lastID, 10)).Encode(), nil
        }

        return database.NewAttributeCollection(attributes...), database.NewNoopContinuousToken().Encode(), nil
}

// QueryUniqueSubjectReferences reads unique subject references from the storage based on the given filter and pagination.
func (r *DataReader) QueryUniqueSubjectReferences(ctx context.Context, tenantID string, subjectReference *base.RelationReference, excluded []string, snap string, pagination database.Pagination) (ids []string, ct database.EncodedContinuousToken, err error) {
        // Start a new trace span and end it when the function exits.
        ctx, span := internal.Tracer.Start(ctx, "data-reader.query-unique-subject-reference")
        defer span.End()

        slog.DebugContext(ctx, "querying unique subject references for tenant_id", slog.String("tenant_id", tenantID))

        // Decode the snapshot value.
        var st token.SnapToken
        st, err = snapshot.EncodedToken{Value: snap}.Decode()
        if err != nil {
                return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)
        }

        // Build the relationships query based on the provided filter, snapshot value, and pagination settings.
        builder := r.database.Builder.
                Select("subject_id"). // This will pick the smallest `id` for each unique `subject_id`.
                From(RelationTuplesTable).
                Where(squirrel.Eq{"tenant_id": tenantID}).
                GroupBy("subject_id")

        // Apply subject filter
        builder = utils.TuplesFilterQueryForSelectBuilder(builder, &base.TupleFilter{
                Subject: &base.SubjectFilter{
                        Type:     subjectReference.GetType(),
                        Relation: subjectReference.GetRelation(),
                },
        })

        // Apply snapshot filter
        builder = utils.SnapshotQuery(builder, st.(snapshot.Token).Value.Uint)

        // Apply exclusion if the list is not empty
        if len(excluded) > 0 {
                builder = builder.Where(squirrel.NotEq{"subject_id": excluded})
        }

        // Apply the pagination token and limit to the query.
        if pagination.Token() != "" {
                var t database.ContinuousToken
                t, err = utils.EncodedContinuousToken{Value: pagination.Token()}.Decode()
                if err != nil {
                        return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INVALID_CONTINUOUS_TOKEN)
                }
                builder = builder.Where(squirrel.GtOrEq{"subject_id": t.(utils.ContinuousToken).Value})
        }

        builder = builder.OrderBy("subject_id")

        if pagination.PageSize() != 0 {
                builder = builder.Limit(uint64(pagination.PageSize() + 1))
        }

        // Generate the SQL query and arguments.
        var query string
        var args []interface{}
        query, args, err = builder.ToSql()
        if err != nil {
                return nil, database.NewNoopContinuousToken().Encode(), utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)
        }

        slog.DebugContext(ctx, "generated sql query", slog.String("query", query), "with args", slog.Any("arguments", args))

        // Execute the query and retrieve the rows.
        var rows pgx.Rows
        rows, err = r.database.ReadPool.Query(ctx, query, args...)
        if err != nil {
                return nil, database.NewNoopContinuousToken().Encode(), utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_EXECUTION)
        }
        defer rows.Close()

        var lastID string

        // Iterate through the rows and scan the result into a RelationTuple struct.
        subjectIDs := make([]string, 0, pagination.PageSize()+1)
        for rows.Next() {
                var subjectID string
                err = rows.Scan(&subjectID)
                if err != nil {
                        return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_INTERNAL)
                }

                subjectIDs = append(subjectIDs, subjectID)
                lastID = subjectID
        }
        // Check for any errors during iteration.
        if err = rows.Err(); err != nil {
                return nil, nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
        }

        slog.DebugContext(ctx, "successfully retrieved unique subject references from the database")

        // Return the results and encoded continuous token for pagination.
        if pagination.PageSize() != 0 && len(subjectIDs) > int(pagination.PageSize()) {
                return subjectIDs[:pagination.PageSize()], utils.NewContinuousToken(lastID).Encode(), nil
        }

        return subjectIDs, database.NewNoopContinuousToken().Encode(), nil
}

// HeadSnapshot retrieves the latest snapshot token associated with the tenant.
func (r *DataReader) HeadSnapshot(ctx context.Context, tenantID string) (token.SnapToken, error) {
        // Start a new trace span and end it when the function exits.
        ctx, span := internal.Tracer.Start(ctx, "data-reader.head-snapshot")
        defer span.End()

        slog.DebugContext(ctx, "getting head snapshot for tenant_id", slog.String("tenant_id", tenantID))

        var xid types.XID8

        // Build the query to find the highest transaction ID associated with the tenant.
        builder := r.database.Builder.Select("id").From(TransactionsTable).Where(squirrel.Eq{"tenant_id": tenantID}).OrderBy("id DESC").Limit(1)
        query, args, err := builder.ToSql()
        if err != nil {
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SQL_BUILDER)
        }

        // TODO: To optimize this query, create the following index concurrently to avoid table locks:
        // CREATE INDEX CONCURRENTLY idx_transactions_tenant_id_id ON transactions(tenant_id, id DESC);

        // Execute the query and retrieve the highest transaction ID.
        err = r.database.ReadPool.QueryRow(ctx, query, args...).Scan(&xid)
        if err != nil {
                // If no rows are found, return a snapshot token with a value of 0.
                if errors.Is(err, pgx.ErrNoRows) {
                        return snapshot.Token{Value: types.XID8{Uint: 0}}, nil
                }
                return nil, utils.HandleError(ctx, span, err, base.ErrorCode_ERROR_CODE_SCAN)
        }

        slog.DebugContext(ctx, "successfully retrieved latest snapshot token")

        // Return the latest snapshot token associated with the tenant.
        return snapshot.Token{Value: xid}, nil
}

Permify / permify / 12882779193

Source File Press 'n' to go to next uncovered line, 'b' for previous

Source File
Press 'n' to go to next uncovered line, 'b' for previous