go-judge/envexec/file_collect.go
2021-06-05 20:24:08 -07:00

90 lines
1.7 KiB
Go

package envexec
import (
"bytes"
"errors"
"fmt"
"io"
"os"
"sync"
"github.com/criyle/go-sandbox/runner"
"golang.org/x/sync/errgroup"
)
// copyOutAndCollect reads file and pipes in parallel from container
func copyOutAndCollect(m Environment, c *Cmd, ptc []pipeCollector) (map[string][]byte, error) {
var (
g errgroup.Group
l sync.Mutex
)
rt := make(map[string][]byte)
put := func(f []byte, n string) {
l.Lock()
defer l.Unlock()
rt[n] = f
}
// copy out
for _, n := range c.CopyOut {
n := n
g.Go(func() error {
cf, err := m.Open(n.Name, os.O_RDONLY, 0777)
if err != nil {
if errors.Is(err, os.ErrNotExist) && n.Optional {
return nil
}
return err
}
defer cf.Close()
stat, err := cf.Stat()
if err != nil {
return err
}
// check regular file
if stat.Mode()&os.ModeType != 0 {
return fmt.Errorf("%s: not a regular file %d", n.Name, stat.Mode()&os.ModeType)
}
// check size limit
s := stat.Size()
if c.CopyOutMax > 0 && s > int64(c.CopyOutMax) {
return fmt.Errorf("%s: size (%d) exceeded the limit (%d)", n.Name, s, c.CopyOutMax)
}
var buf bytes.Buffer
buf.Grow(int(s))
// Ensure not copy over file size
_, err = buf.ReadFrom(io.LimitReader(cf, s))
if err != nil {
return err
}
put(buf.Bytes(), n.Name)
return nil
})
}
// collect pipe
for _, p := range ptc {
p := p
g.Go(func() error {
<-p.done
if int64(p.buffer.Len()) > int64(p.limit) {
return runner.StatusOutputLimitExceeded
}
put(p.buffer.Bytes(), p.name)
return nil
})
}
// copy out dir
if c.CopyOutDir != "" {
g.Go(func() error {
return copyDir(m.WorkDir(), c.CopyOutDir)
})
}
err := g.Wait()
return rt, err
}