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runner.go
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runner.go
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package proteus
import (
"context"
"fmt"
"reflect"
"strings"
"database/sql"
"github.com/jonbodner/proteus/logger"
"github.com/jonbodner/proteus/mapper"
"github.com/jonbodner/stackerr"
)
func buildQueryArgs(c context.Context, funcArgs []reflect.Value, paramOrder []paramInfo) ([]interface{}, error) {
//walk through the rest of the input parameters and build a slice for args
var out []interface{}
for _, v := range paramOrder {
val, err := mapper.Extract(c, funcArgs[v.posInParams].Interface(), strings.Split(v.name, "."))
if err != nil {
return nil, err
}
if v.isSlice {
curSlice := reflect.ValueOf(val)
for i := 0; i < curSlice.Len(); i++ {
out = append(out, curSlice.Index(i).Interface())
}
} else {
out = append(out, val)
}
}
return out, nil
}
var (
errType = reflect.TypeOf((*error)(nil)).Elem()
errZero = reflect.Zero(errType)
zeroInt64 = reflect.ValueOf(int64(0))
zeroSQLResult = reflect.ValueOf((sql.Result)(nil))
sqlResultType = reflect.TypeOf((*sql.Result)(nil)).Elem()
)
func makeContextExecutorImplementation(c context.Context, funcType reflect.Type, query queryHolder, paramOrder []paramInfo) func(args []reflect.Value) []reflect.Value {
buildRetVals := makeExecutorReturnVals(funcType)
return func(args []reflect.Value) []reflect.Value {
executor := args[1].Interface().(ContextExecutor)
ctx := args[0].Interface().(context.Context)
// if the passed-in context doesn't contain any logging settings, use the one that were supplied
// at build time
if _, ok := logger.LevelFromContext(ctx); !ok {
if defaultLevel, ok := logger.LevelFromContext(c); ok {
ctx = logger.WithLevel(ctx, defaultLevel)
}
}
// copy over any logging values that were supplied at build time
if defaultVals, ok := logger.ValuesFromContext(c); ok {
ctx = logger.WithValues(ctx, defaultVals...)
}
var result sql.Result
finalQuery, err := query.finalize(ctx, args)
if err != nil {
return buildRetVals(result, err)
}
queryArgs, err := buildQueryArgs(ctx, args, paramOrder)
if err != nil {
return buildRetVals(result, err)
}
logger.Log(ctx, logger.DEBUG, fmt.Sprintln("calling", finalQuery, "with params", queryArgs))
result, err = executor.ExecContext(ctx, finalQuery, queryArgs...)
return buildRetVals(result, err)
}
}
func makeExecutorImplementation(c context.Context, funcType reflect.Type, query queryHolder, paramOrder []paramInfo) func(args []reflect.Value) []reflect.Value {
buildRetVals := makeExecutorReturnVals(funcType)
return func(args []reflect.Value) []reflect.Value {
executor := args[0].Interface().(Executor)
var result sql.Result
finalQuery, err := query.finalize(c, args)
if err != nil {
return buildRetVals(result, err)
}
queryArgs, err := buildQueryArgs(c, args, paramOrder)
if err != nil {
return buildRetVals(result, err)
}
logger.Log(c, logger.DEBUG, fmt.Sprintln("calling", finalQuery, "with params", queryArgs))
result, err = executor.Exec(finalQuery, queryArgs...)
return buildRetVals(result, err)
}
}
func makeExecutorReturnVals(funcType reflect.Type) func(sql.Result, error) []reflect.Value {
numOut := funcType.NumOut()
//handle the 0,1,2 out parameter cases
if numOut == 0 {
return func(sql.Result, error) []reflect.Value {
return []reflect.Value{}
}
}
sType := funcType.Out(0)
if numOut == 1 {
return func(result sql.Result, err error) []reflect.Value {
if err != nil {
if sType == sqlResultType {
return []reflect.Value{zeroSQLResult}
}
return []reflect.Value{zeroInt64}
}
if sType == sqlResultType {
return []reflect.Value{reflect.ValueOf(result)}
}
val, err := result.RowsAffected()
if err != nil {
return []reflect.Value{zeroInt64}
}
return []reflect.Value{reflect.ValueOf(val).Convert(sType)}
}
}
if numOut == 2 {
return func(result sql.Result, err error) []reflect.Value {
eType := funcType.Out(1)
if sType == sqlResultType {
if err != nil {
return []reflect.Value{zeroSQLResult, reflect.ValueOf(err).Convert(eType)}
}
return []reflect.Value{reflect.ValueOf(result), errZero}
}
if err != nil {
return []reflect.Value{zeroInt64, reflect.ValueOf(err).Convert(eType)}
}
val, err := result.RowsAffected()
if err != nil {
return []reflect.Value{zeroInt64, reflect.ValueOf(err).Convert(eType)}
}
return []reflect.Value{reflect.ValueOf(val).Convert(sType), errZero}
}
}
// impossible case since validation should happen first, but be safe
return func(result sql.Result, err error) []reflect.Value {
impossibleErr := reflect.ValueOf(stackerr.New("should never get here"))
if sType == sqlResultType {
return []reflect.Value{zeroSQLResult, impossibleErr}
}
return []reflect.Value{zeroInt64, impossibleErr}
}
}
func makeContextQuerierImplementation(c context.Context, funcType reflect.Type, query queryHolder, paramOrder []paramInfo) (func(args []reflect.Value) []reflect.Value, error) {
numOut := funcType.NumOut()
var builder mapper.Builder
var err error
if numOut > 0 {
builder, err = mapper.MakeBuilder(c, funcType.Out(0))
if err != nil {
return nil, err
}
}
buildRetVals := makeQuerierReturnVals(c, funcType, builder)
return func(args []reflect.Value) []reflect.Value {
querier := args[1].Interface().(ContextQuerier)
ctx := args[0].Interface().(context.Context)
// if the passed-in context doesn't contain any logging settings, use the one that were supplied
// at build time
if _, ok := logger.LevelFromContext(ctx); !ok {
if defaultLevel, ok := logger.LevelFromContext(c); ok {
ctx = logger.WithLevel(ctx, defaultLevel)
}
}
// copy over any logging values that were supplied at build time
if defaultVals, ok := logger.ValuesFromContext(c); ok {
ctx = logger.WithValues(ctx, defaultVals...)
}
var rows *sql.Rows
finalQuery, err := query.finalize(ctx, args)
if err != nil {
return buildRetVals(rows, err)
}
queryArgs, err := buildQueryArgs(ctx, args, paramOrder)
if err != nil {
return buildRetVals(rows, err)
}
logger.Log(ctx, logger.DEBUG, fmt.Sprintln("calling", finalQuery, "with params", queryArgs))
// going to work around the defective Go MySQL driver, which refuses to convert the text protocol properly.
// It is used when doing a query without parameters.
if len(queryArgs) == 0 {
type ContextPreparer interface {
PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
}
if cp, ok := querier.(ContextPreparer); ok {
var stmt *sql.Stmt
stmt, err = cp.PrepareContext(ctx, finalQuery)
if err != nil {
return buildRetVals(rows, err)
}
defer stmt.Close()
rows, err = stmt.QueryContext(ctx)
return buildRetVals(rows, err)
}
}
rows, err = querier.QueryContext(ctx, finalQuery, queryArgs...)
return buildRetVals(rows, err)
}, nil
}
func makeQuerierImplementation(c context.Context, funcType reflect.Type, query queryHolder, paramOrder []paramInfo) (func(args []reflect.Value) []reflect.Value, error) {
numOut := funcType.NumOut()
var builder mapper.Builder
var err error
if numOut > 0 {
builder, err = mapper.MakeBuilder(c, funcType.Out(0))
if err != nil {
return nil, err
}
}
buildRetVals := makeQuerierReturnVals(c, funcType, builder)
return func(args []reflect.Value) []reflect.Value {
querier := args[0].Interface().(Querier)
var rows *sql.Rows
finalQuery, err := query.finalize(c, args)
if err != nil {
return buildRetVals(rows, err)
}
queryArgs, err := buildQueryArgs(c, args, paramOrder)
if err != nil {
return buildRetVals(rows, err)
}
logger.Log(c, logger.DEBUG, fmt.Sprintln("calling", finalQuery, "with params", queryArgs))
// going to work around the defective Go MySQL driver, which refuses to convert the text protocol properly.
// It is used when doing a query without parameters.
if len(queryArgs) == 0 {
type Preparer interface {
Prepare(query string) (*sql.Stmt, error)
}
if cp, ok := querier.(Preparer); ok {
var stmt *sql.Stmt
stmt, err = cp.Prepare(finalQuery)
if err != nil {
return buildRetVals(rows, err)
}
defer stmt.Close()
rows, err = stmt.Query()
return buildRetVals(rows, err)
}
}
rows, err = querier.Query(finalQuery, queryArgs...)
return buildRetVals(rows, err)
}, nil
}
func makeQuerierReturnVals(c context.Context, funcType reflect.Type, builder mapper.Builder) func(*sql.Rows, error) []reflect.Value {
numOut := funcType.NumOut()
//handle the 0,1,2 out parameter cases
if numOut == 0 {
return func(*sql.Rows, error) []reflect.Value {
return []reflect.Value{}
}
}
sType := funcType.Out(0)
qZero := reflect.Zero(sType)
if numOut == 1 {
return func(rows *sql.Rows, err error) []reflect.Value {
if err != nil {
return []reflect.Value{qZero}
}
// handle mapping
val, err := handleMapping(c, sType, rows, builder)
if err != nil {
return []reflect.Value{qZero}
}
if val == nil {
return []reflect.Value{qZero}
}
return []reflect.Value{reflect.ValueOf(val).Convert(sType)}
}
}
if numOut == 2 {
return func(rows *sql.Rows, err error) []reflect.Value {
eType := funcType.Out(1)
if err != nil {
return []reflect.Value{qZero, reflect.ValueOf(err).Convert(eType)}
}
// handle mapping
val, err := handleMapping(c, sType, rows, builder)
var eVal reflect.Value
if err == nil {
eVal = errZero
} else {
eVal = reflect.ValueOf(err).Convert(eType)
}
if val == nil {
return []reflect.Value{qZero, eVal}
}
return []reflect.Value{reflect.ValueOf(val).Convert(sType), eVal}
}
}
// impossible case since validation should happen first, but be safe
return func(*sql.Rows, error) []reflect.Value {
return []reflect.Value{qZero, reflect.ValueOf(stackerr.New("should never get here!"))}
}
}
func handleMapping(c context.Context, sType reflect.Type, rows *sql.Rows, builder mapper.Builder) (interface{}, error) {
var val interface{}
var err error
if sType.Kind() == reflect.Slice {
s := reflect.MakeSlice(sType, 0, 0)
var result interface{}
for {
result, err = mapRows(c, rows, builder)
if err != nil {
return nil, err
}
if result == nil {
break
}
s = reflect.Append(s, reflect.ValueOf(result))
}
val = s.Interface()
} else {
val, err = mapRows(c, rows, builder)
}
rows.Close()
return val, err
}
// Map takes the next value from Rows and uses it to create a new instance of the specified type
// If the type is a primitive and there are more than 1 values in the current row, only the first value is used.
// If the type is a map of string to interface, then the column names are the keys in the map and the values are assigned
// If the type is a struct that has prop tags on its fields, then any matching tags will be associated with values with the associate columns
// Any non-associated values will be set to the zero value
// If any columns cannot be assigned to any types, then an error is returned
// If next returns false, then nil is returned for both the interface and the error
// If an error occurs while processing the current row, nil is returned for the interface and the error is non-nil
// If a value is successfully extracted from the current row, the instance is returned and the error is nil
func mapRows(c context.Context, rows *sql.Rows, builder mapper.Builder) (interface{}, error) {
//fmt.Println(sType)
if rows == nil {
return nil, stackerr.New("rows must be non-nil")
}
if !rows.Next() {
if err := rows.Err(); err != nil {
return nil, err
}
return nil, nil
}
cols, err := rows.Columns()
if err != nil {
return nil, err
}
if len(cols) == 0 {
return nil, stackerr.New("No values returned from query")
}
vals := make([]interface{}, len(cols))
colTypes, err := rows.ColumnTypes()
if err != nil {
return nil, err
}
for i := 0; i < len(vals); i++ {
newVal := reflect.New(colTypes[i].ScanType()).Interface()
vals[i] = &newVal
}
err = rows.Scan(vals...)
if err != nil {
logger.Log(c, logger.WARN, "scan failed")
return nil, err
}
return builder(cols, vals)
}