From 51cc4c07b2a2b6345b1496baac865f5faf955e7d Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Fri, 20 Jan 2017 00:52:56 +0000 Subject: Switch from database/sql to sqlx --- vendor/github.com/jmoiron/sqlx/bind.go | 186 +++++++++++++++++++++++++++++++++ 1 file changed, 186 insertions(+) create mode 100644 vendor/github.com/jmoiron/sqlx/bind.go (limited to 'vendor/github.com/jmoiron/sqlx/bind.go') diff --git a/vendor/github.com/jmoiron/sqlx/bind.go b/vendor/github.com/jmoiron/sqlx/bind.go new file mode 100644 index 0000000..53659bc --- /dev/null +++ b/vendor/github.com/jmoiron/sqlx/bind.go @@ -0,0 +1,186 @@ +package sqlx + +import ( + "bytes" + "errors" + "reflect" + "strconv" + "strings" + + "github.com/jmoiron/sqlx/reflectx" +) + +// Bindvar types supported by Rebind, BindMap and BindStruct. +const ( + UNKNOWN = iota + QUESTION + DOLLAR + NAMED +) + +// BindType returns the bindtype for a given database given a drivername. +func BindType(driverName string) int { + switch driverName { + case "postgres", "pgx": + return DOLLAR + case "mysql": + return QUESTION + case "sqlite3": + return QUESTION + case "oci8", "ora", "goracle": + return NAMED + } + return UNKNOWN +} + +// FIXME: this should be able to be tolerant of escaped ?'s in queries without +// losing much speed, and should be to avoid confusion. + +// Rebind a query from the default bindtype (QUESTION) to the target bindtype. +func Rebind(bindType int, query string) string { + switch bindType { + case QUESTION, UNKNOWN: + return query + } + + qb := []byte(query) + // Add space enough for 10 params before we have to allocate + rqb := make([]byte, 0, len(qb)+10) + j := 1 + for _, b := range qb { + if b == '?' { + switch bindType { + case DOLLAR: + rqb = append(rqb, '$') + case NAMED: + rqb = append(rqb, ':', 'a', 'r', 'g') + } + for _, b := range strconv.Itoa(j) { + rqb = append(rqb, byte(b)) + } + j++ + } else { + rqb = append(rqb, b) + } + } + return string(rqb) +} + +// Experimental implementation of Rebind which uses a bytes.Buffer. The code is +// much simpler and should be more resistant to odd unicode, but it is twice as +// slow. Kept here for benchmarking purposes and to possibly replace Rebind if +// problems arise with its somewhat naive handling of unicode. +func rebindBuff(bindType int, query string) string { + if bindType != DOLLAR { + return query + } + + b := make([]byte, 0, len(query)) + rqb := bytes.NewBuffer(b) + j := 1 + for _, r := range query { + if r == '?' { + rqb.WriteRune('$') + rqb.WriteString(strconv.Itoa(j)) + j++ + } else { + rqb.WriteRune(r) + } + } + + return rqb.String() +} + +// In expands slice values in args, returning the modified query string +// and a new arg list that can be executed by a database. The `query` should +// use the `?` bindVar. The return value uses the `?` bindVar. +func In(query string, args ...interface{}) (string, []interface{}, error) { + // argMeta stores reflect.Value and length for slices and + // the value itself for non-slice arguments + type argMeta struct { + v reflect.Value + i interface{} + length int + } + + var flatArgsCount int + var anySlices bool + + meta := make([]argMeta, len(args)) + + for i, arg := range args { + v := reflect.ValueOf(arg) + t := reflectx.Deref(v.Type()) + + if t.Kind() == reflect.Slice { + meta[i].length = v.Len() + meta[i].v = v + + anySlices = true + flatArgsCount += meta[i].length + + if meta[i].length == 0 { + return "", nil, errors.New("empty slice passed to 'in' query") + } + } else { + meta[i].i = arg + flatArgsCount++ + } + } + + // don't do any parsing if there aren't any slices; note that this means + // some errors that we might have caught below will not be returned. + if !anySlices { + return query, args, nil + } + + newArgs := make([]interface{}, 0, flatArgsCount) + + var arg, offset int + var buf bytes.Buffer + + for i := strings.IndexByte(query[offset:], '?'); i != -1; i = strings.IndexByte(query[offset:], '?') { + if arg >= len(meta) { + // if an argument wasn't passed, lets return an error; this is + // not actually how database/sql Exec/Query works, but since we are + // creating an argument list programmatically, we want to be able + // to catch these programmer errors earlier. + return "", nil, errors.New("number of bindVars exceeds arguments") + } + + argMeta := meta[arg] + arg++ + + // not a slice, continue. + // our questionmark will either be written before the next expansion + // of a slice or after the loop when writing the rest of the query + if argMeta.length == 0 { + offset = offset + i + 1 + newArgs = append(newArgs, argMeta.i) + continue + } + + // write everything up to and including our ? character + buf.WriteString(query[:offset+i+1]) + + newArgs = append(newArgs, argMeta.v.Index(0).Interface()) + + for si := 1; si < argMeta.length; si++ { + buf.WriteString(", ?") + newArgs = append(newArgs, argMeta.v.Index(si).Interface()) + } + + // slice the query and reset the offset. this avoids some bookkeeping for + // the write after the loop + query = query[offset+i+1:] + offset = 0 + } + + buf.WriteString(query) + + if arg < len(meta) { + return "", nil, errors.New("number of bindVars less than number arguments") + } + + return buf.String(), newArgs, nil +} -- cgit v1.2.3