storj/private/dbutil/pgutil/schema.go
paul cannon 378b863b2b private,satellite: unite all the "temp db schema" things
first, so that they all work the same way, because it's getting
complicated, and second, so that we can do the appropriate thing
instead of CREATE SCHEMA for cockroachdb.

Change-Id: I27fbaeeb6223a3e06d97bcf692a2d014b31465f7
2019-12-05 15:36:59 +00:00

92 lines
2.5 KiB
Go

// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.
// Package pgutil contains utilities for postgres
package pgutil
import (
"database/sql"
"encoding/hex"
"math/rand"
"net/url"
"strings"
"github.com/lib/pq"
)
// CreateRandomTestingSchemaName creates a random schema name string.
func CreateRandomTestingSchemaName(n int) string {
data := make([]byte, n)
// math/rand.Read() always returns a nil error so there's no need to handle the error.
_, _ = rand.Read(data)
return hex.EncodeToString(data)
}
// ConnstrWithSchema adds schema to a connection string
func ConnstrWithSchema(connstr, schema string) string {
if strings.Contains(connstr, "?") {
connstr += "&options="
} else {
connstr += "?options="
}
return connstr + url.QueryEscape("--search_path="+pq.QuoteIdentifier(schema))
}
// ParseSchemaFromConnstr returns the name of the schema parsed from the
// connection string if one is provided
func ParseSchemaFromConnstr(connstr string) (string, error) {
url, err := url.Parse(connstr)
if err != nil {
return "", err
}
queryValues := url.Query()
// this is the Proper™ way to encode search_path in a pq connection string
options := queryValues["options"]
for _, option := range options {
if strings.HasPrefix(option, "--search_path=") {
return UnquoteIdentifier(option[len("--search_path="):]), nil
}
}
// this is another way we've used before; supported brokenly as a kludge in github.com/lib/pq
schema := queryValues["search_path"]
if len(schema) > 0 {
return UnquoteIdentifier(schema[0]), nil
}
return "", nil
}
// QuoteSchema quotes schema name for
func QuoteSchema(schema string) string {
return pq.QuoteIdentifier(schema)
}
// Execer is for executing sql
type Execer interface {
Exec(query string, args ...interface{}) (sql.Result, error)
}
// CreateSchema creates a schema if it doesn't exist.
func CreateSchema(db Execer, schema string) (err error) {
for try := 0; try < 5; try++ {
_, err = db.Exec(`create schema if not exists ` + QuoteSchema(schema) + `;`)
// Postgres `CREATE SCHEMA IF NOT EXISTS` may return "duplicate key value violates unique constraint".
// In that case, we will retry rather than doing anything more complicated.
//
// See more in: https://stackoverflow.com/a/29908840/192220
if IsConstraintError(err) {
continue
}
return err
}
return err
}
// DropSchema drops the named schema
func DropSchema(db Execer, schema string) error {
_, err := db.Exec(`drop schema ` + QuoteSchema(schema) + ` cascade;`)
return err
}