forked from gitea/gitea
85 lines
2.3 KiB
Go
85 lines
2.3 KiB
Go
// Copyright 2019+ Klaus Post. All rights reserved.
|
|
// License information can be found in the LICENSE file.
|
|
// Based on work by Yann Collet, released under BSD License.
|
|
|
|
package zstd
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"runtime"
|
|
)
|
|
|
|
// DOption is an option for creating a decoder.
|
|
type DOption func(*decoderOptions) error
|
|
|
|
// options retains accumulated state of multiple options.
|
|
type decoderOptions struct {
|
|
lowMem bool
|
|
concurrent int
|
|
maxDecodedSize uint64
|
|
dicts []dict
|
|
}
|
|
|
|
func (o *decoderOptions) setDefault() {
|
|
*o = decoderOptions{
|
|
// use less ram: true for now, but may change.
|
|
lowMem: true,
|
|
concurrent: runtime.GOMAXPROCS(0),
|
|
}
|
|
o.maxDecodedSize = 1 << 63
|
|
}
|
|
|
|
// WithDecoderLowmem will set whether to use a lower amount of memory,
|
|
// but possibly have to allocate more while running.
|
|
func WithDecoderLowmem(b bool) DOption {
|
|
return func(o *decoderOptions) error { o.lowMem = b; return nil }
|
|
}
|
|
|
|
// WithDecoderConcurrency will set the concurrency,
|
|
// meaning the maximum number of decoders to run concurrently.
|
|
// The value supplied must be at least 1.
|
|
// By default this will be set to GOMAXPROCS.
|
|
func WithDecoderConcurrency(n int) DOption {
|
|
return func(o *decoderOptions) error {
|
|
if n <= 0 {
|
|
return fmt.Errorf("Concurrency must be at least 1")
|
|
}
|
|
o.concurrent = n
|
|
return nil
|
|
}
|
|
}
|
|
|
|
// WithDecoderMaxMemory allows to set a maximum decoded size for in-memory
|
|
// non-streaming operations or maximum window size for streaming operations.
|
|
// This can be used to control memory usage of potentially hostile content.
|
|
// For streaming operations, the maximum window size is capped at 1<<30 bytes.
|
|
// Maximum and default is 1 << 63 bytes.
|
|
func WithDecoderMaxMemory(n uint64) DOption {
|
|
return func(o *decoderOptions) error {
|
|
if n == 0 {
|
|
return errors.New("WithDecoderMaxMemory must be at least 1")
|
|
}
|
|
if n > 1<<63 {
|
|
return fmt.Errorf("WithDecoderMaxmemory must be less than 1 << 63")
|
|
}
|
|
o.maxDecodedSize = n
|
|
return nil
|
|
}
|
|
}
|
|
|
|
// WithDecoderDicts allows to register one or more dictionaries for the decoder.
|
|
// If several dictionaries with the same ID is provided the last one will be used.
|
|
func WithDecoderDicts(dicts ...[]byte) DOption {
|
|
return func(o *decoderOptions) error {
|
|
for _, b := range dicts {
|
|
d, err := loadDict(b)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
o.dicts = append(o.dicts, *d)
|
|
}
|
|
return nil
|
|
}
|
|
}
|