Skip to content

use AppendFormat to format time values #615

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
Jun 10, 2017
Merged

use AppendFormat to format time values #615

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
c184106
use AppendFormat to format time values
Jun 10, 2017
a82205e
Merge pull request #1 from achille-roussel/optimize-time-format
achille-roussel Jun 10, 2017
cfbb03b
Merge remote-tracking branch 'upstream/master'
Jun 10, 2017
bfd41ad
drop support for Go 1.4
Jun 10, 2017
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 0 additions & 1 deletion .travis.yml
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,6 @@
sudo: false
language: go
go:
- 1.4
- 1.5
- 1.6
- 1.7
Expand Down
1 change: 1 addition & 0 deletions AUTHORS
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@
# Individual Persons

Aaron Hopkins <go-sql-driver at die.net>
Achille Roussel <achille.roussel at gmail.com>
Arne Hormann <arnehormann at gmail.com>
Asta Xie <xiemengjun at gmail.com>
Bulat Gaifullin <gaifullinbf at gmail.com>
Expand Down
2 changes: 1 addition & 1 deletion README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -39,7 +39,7 @@ A MySQL-Driver for Go's [database/sql](https://golang.org/pkg/database/sql/) pac
* Optional placeholder interpolation

## Requirements
* Go 1.4 or higher
* Go 1.5 or higher
* MySQL (4.1+), MariaDB, Percona Server, Google CloudSQL or Sphinx (2.2.3+)

---------------------------------------
Expand Down
12 changes: 7 additions & 5 deletions packets.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1078,17 +1078,19 @@ func (stmt *mysqlStmt) writeExecutePacket(args []driver.Value) error {
paramTypes[i+i] = fieldTypeString
paramTypes[i+i+1] = 0x00

var val []byte
var a [64]byte
var b = a[:0]
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Sorry for commenting on old piece of code but I came here from an article and I can't help but wonder, why this wasn't done by make([]byte, 0, 64). Isn't it the same?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think the compiler can optimize “make” to be stack allocated if possible, so the end result is the same whether we use make or declare an array, it’s just a style decision.

The optimization doesn’t come from the use of an array, it comes from writing directly into a pre-allocated buffer instead of working with intermediary heap allocated values.


if v.IsZero() {
val = []byte("0000-00-00")
b = append(b, "0000-00-00"...)
} else {
val = []byte(v.In(mc.cfg.Loc).Format(timeFormat))
b = v.In(mc.cfg.Loc).AppendFormat(b, timeFormat)
}

paramValues = appendLengthEncodedInteger(paramValues,
uint64(len(val)),
uint64(len(b)),
)
paramValues = append(paramValues, val...)
paramValues = append(paramValues, b...)

default:
return fmt.Errorf("can not convert type: %T", arg)
Expand Down