Documentation
¶
Overview ¶
Package ecc implements common support for error correction in sharded blob providers
Index ¶
- Constants
- func CreateAlgorithm(opts *Options) (encryption.Encryptor, error)
- func CreateEncryptor(p Parameters) (encryption.Encryptor, error)
- func RegisterAlgorithm(name string, createFunc CreateECCFunc)
- func SupportedAlgorithms() []string
- type CreateECCFunc
- type Options
- type Parameters
- type ReedSolomonCrcECC
Constants ¶
const (
// AlgorithmReedSolomonWithCrc32 is the name of an implemented algorithm.
AlgorithmReedSolomonWithCrc32 = "REED-SOLOMON-CRC32"
)
const DefaultAlgorithm = AlgorithmReedSolomonWithCrc32
DefaultAlgorithm is the name of the default ecc algorithm.
Variables ¶
This section is empty.
Functions ¶
func CreateAlgorithm ¶
func CreateAlgorithm(opts *Options) (encryption.Encryptor, error)
CreateAlgorithm returns new encryption.Encryptor with error correction.
func CreateEncryptor ¶
func CreateEncryptor(p Parameters) (encryption.Encryptor, error)
CreateEncryptor returns new encryption.Encryptor with error correction.
func RegisterAlgorithm ¶
func RegisterAlgorithm(name string, createFunc CreateECCFunc)
RegisterAlgorithm registers new ecc algorithm.
func SupportedAlgorithms ¶
func SupportedAlgorithms() []string
SupportedAlgorithms returns the names of the supported ecc methods.
Types ¶
type CreateECCFunc ¶
type CreateECCFunc func(opts *Options) (encryption.Encryptor, error)
CreateECCFunc creates an ECC for given parameters.
type Options ¶
type Options struct {
// Algorithm name to be used. Leave empty to disable error correction.
Algorithm string `json:"algorithm,omitempty"`
// OverheadPercent is how much more space can be used for ECC, in percentage.
// Between 0 and 100. 0 means disable ECC.
OverheadPercent int `json:"overheadPercent,omitempty"`
// MaxShardSize represents the max shard size before splitting in blocks.
// Use 0 to compute based on file size.
MaxShardSize int `json:"maxShardSize,omitempty"`
// Only set to true during benchmark tests
DeleteFirstShardForTests bool
}
Options represents the configuration for all ECC algorithms.
type Parameters ¶
Parameters encapsulates all ECC parameters.
type ReedSolomonCrcECC ¶
type ReedSolomonCrcECC struct {
Options
DataShards int
ParityShards int
ThresholdParityInput int
ThresholdParityOutput int
ThresholdBlocksInput int
ThresholdBlocksOutput int
// contains filtered or unexported fields
}
ReedSolomonCrcECC implements Reed-Solomon error codes with CRC32 error detection.
func (*ReedSolomonCrcECC) Decrypt ¶
func (r *ReedSolomonCrcECC) Decrypt(input gather.Bytes, _ []byte, output *gather.WriteBuffer) error
Decrypt corrects the data from input based on the ECC data. See Encrypt comments for a description of the layout.
func (*ReedSolomonCrcECC) Encrypt ¶
func (r *ReedSolomonCrcECC) Encrypt(input gather.Bytes, _ []byte, output *gather.WriteBuffer) error
Encrypt creates ECC for the bytes in input. The bytes in output are stored in with the layout: ([CRC32][Parity shard])+ ([CRC32][Data shard])+ With one detail: the length of the original data is prepended to the data itself, so that we can know it when storing also the padding. All shards must be of the same size, so it may be needed to pad the input data. The parity data comes first so we can avoid storing the padding needed for the data shards, and instead compute the padded size based on the input length. All parity shards are always stored.
func (*ReedSolomonCrcECC) Overhead ¶
func (r *ReedSolomonCrcECC) Overhead() int
Overhead should not be called. It's just implemented because it is in the interface.
Source Files