dendrite/vendor/src/github.com/gchaincl/sqlhooks/README.md
2017-12-13 10:37:28 +00:00

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# sqlhooks [![Build Status](https://travis-ci.org/gchaincl/sqlhooks.svg)](https://travis-ci.org/gchaincl/sqlhooks) [![Coverage Status](https://coveralls.io/repos/github/gchaincl/sqlhooks/badge.svg?branch=master)](https://coveralls.io/github/gchaincl/sqlhooks?branch=master) [![Go Report Card](https://goreportcard.com/badge/github.com/gchaincl/sqlhooks)](https://goreportcard.com/report/github.com/gchaincl/sqlhooks)
Attach hooks to any database/sql driver.
The purpose of sqlhooks is to provide a way to instrument your sql statements, making really easy to log queries or measure execution time without modifying your actual code.
# Install
```bash
go get github.com/gchaincl/sqlhooks
```
## Breaking changes
`V1` isn't backward compatible with previous versions, if you want to fetch old versions, you can get them from [gopkg.in](http://gopkg.in/)
```bash
go get gopkg.in/gchaincl/sqlhooks.v0
```
# Usage [![GoDoc](https://godoc.org/github.com/gchaincl/dotsql?status.svg)](https://godoc.org/github.com/gchaincl/sqlhooks)
```go
// This example shows how to instrument sql queries in order to display the time that they consume
package main
import (
"context"
"database/sql"
"fmt"
"time"
"github.com/gchaincl/sqlhooks"
"github.com/mattn/go-sqlite3"
)
// Hooks satisfies the sqlhook.Hooks interface
type Hooks struct {}
// Before hook will print the query with it's args and return the context with the timestamp
func (h *Hooks) Before(ctx context.Context, query string, args ...interface{}) (context.Context, error) {
fmt.Printf("> %s %q", query, args)
return context.WithValue(ctx, "begin", time.Now()), nil
}
// After hook will get the timestamp registered on the Before hook and print the elapsed time
func (h *Hooks) After(ctx context.Context, query string, args ...interface{}) (context.Context, error) {
begin := ctx.Value("begin").(time.Time)
fmt.Printf(". took: %s\n", time.Since(begin))
return ctx, nil
}
func main() {
// First, register the wrapper
sql.Register("sqlite3WithHooks", sqlhooks.Wrap(&sqlite3.SQLiteDriver{}, &Hooks{}))
// Connect to the registered wrapped driver
db, _ := sql.Open("sqlite3WithHooks", ":memory:")
// Do you're stuff
db.Exec("CREATE TABLE t (id INTEGER, text VARCHAR(16))")
db.Exec("INSERT into t (text) VALUES(?), (?)", "foo", "bar")
db.Query("SELECT id, text FROM t")
}
/*
Output should look like:
> CREATE TABLE t (id INTEGER, text VARCHAR(16)) []. took: 121.238µs
> INSERT into t (text) VALUES(?), (?) ["foo" "bar"]. took: 36.364µs
> SELECT id, text FROM t []. took: 4.653µs
*/
```
# Benchmarks
```
go test -bench=. -benchmem
BenchmarkSQLite3/Without_Hooks-4 200000 8572 ns/op 627 B/op 16 allocs/op
BenchmarkSQLite3/With_Hooks-4 200000 10231 ns/op 738 B/op 18 allocs/op
BenchmarkMySQL/Without_Hooks-4 10000 108421 ns/op 437 B/op 10 allocs/op
BenchmarkMySQL/With_Hooks-4 10000 226085 ns/op 597 B/op 13 allocs/op
BenchmarkPostgres/Without_Hooks-4 10000 125718 ns/op 649 B/op 17 allocs/op
BenchmarkPostgres/With_Hooks-4 5000 354831 ns/op 1122 B/op 27 allocs/op
PASS
ok github.com/gchaincl/sqlhooks 11.713s
```