// Package filename provides utilities for encoder.package filenameimport ( "encoding/base64" "sync" "github.com/klauspost/compress/huff0")// encodeURL is base64 url encoding values.const encodeURL = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"// decodeMap will return x = decodeMap[encodeURL[byte(x)]] - 1 if x >= 0 and x < 64, otherwise -1 is returned.var decodeMap [256]byte// maxLength is the maximum length that will be attempted to be compressed.const maxLength = 256var ( initOnce sync.Once // Used to control init of tables. encTables [64]*huff0.Scratch // Encoders. encTableLocks [64]sync.Mutex // Temporary locks for encoders since they are stateful. decTables [64]*huff0.Decoder // Stateless decoders.)const ( tableUncompressed = 0 tableSCSU = 59 tableSCSUPlain = 60 tableRLE = 61 tableCustom = 62 tableReserved = 63)// predefined tables as base64 URL encoded string.var tablesData = [64]string{ // Uncompressed tableUncompressed: "", // ncw home directory 1: "MRDIEtAAMAzDMAzDSjX_ybu0w97bb-L3b2mR-rUl5LXW3lZII43kIDMzM1NXu3okgQs=", // ncw images 2: "IhDIAEAA______-Pou_4Sf5z-uS-39MVWjullFLKM7EBECs=", // ncw Google Drive: 3: "JxDQAIIBMDMzMwOzbv7nJJCyd_m_9D2llCarnQX33nvvlFKEhUxAAQ==", // Hex 4: "ExDoSTD___-tfXfhJ0hKSkryTxU=", // Base64 5: "JRDIcQf_______8PgIiIiIgINkggARHlkQwSSCCBxHFYINHdfXI=", // Hex plus a bit... 6: "E5CxwAHm9sYcAlmWZVvMHA4Y5jw=", // Hex, upper case letters. 7: "FICxgAMMAGC3YwMthe3DWM_wDAAQ", // Special tables: // SCSU and a fairly generic table: tableSCSU: "UxAgZmEB-RYPU8hrnAk6uMgpTNQMB5MGRBx0D3T0JjyUyY-yOi5CoGgktbAktSh7d36HtPTFu7SXJ7FYw_AYmA74ZH2vWgc8O6Z5jLnWnsFqU_4B", // SCSU with no table... tableSCSUPlain: "", // Compressed data has its own table. tableCustom: "", // Reserved for extension. tableReserved: "",}func initCoders() { initOnce.Do(func() { // Init base 64 decoder. for i, v := range encodeURL { decodeMap[v] = byte(i) + 1 } // Initialize encoders and decoders. for i, dataString := range tablesData { if len(dataString) == 0 { continue } data, err := base64.URLEncoding.DecodeString(dataString) if err != nil { panic(err) } s, _, err := huff0.ReadTable(data, nil) if err != nil { panic(err) } // We want to save at least len(in) >> 5 s.WantLogLess = 5 s.Reuse = huff0.ReusePolicyMust encTables[i] = s decTables[i] = s.Decoder() } // Add custom table type. var s huff0.Scratch s.Reuse = huff0.ReusePolicyNone encTables[tableCustom] = &s decTables[tableCustom] = nil })}
// Package filename provides utilities for encoder.
package filename
import (
"encoding/base64"
"sync"
"github.com/klauspost/compress/huff0"
)
// encodeURL is base64 url encoding values.
const encodeURL = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"
// decodeMap will return x = decodeMap[encodeURL[byte(x)]] - 1 if x >= 0 and x < 64, otherwise -1 is returned.
var decodeMap [256]byte
// maxLength is the maximum length that will be attempted to be compressed.
const maxLength = 256
var (
initOnce sync.Once // Used to control init of tables.
encTables [64]*huff0.Scratch // Encoders.
encTableLocks [64]sync.Mutex // Temporary locks for encoders since they are stateful.
decTables [64]*huff0.Decoder // Stateless decoders.
)
const (
tableUncompressed = 0
tableSCSU = 59
tableSCSUPlain = 60
tableRLE = 61
tableCustom = 62
tableReserved = 63
)
// predefined tables as base64 URL encoded string.
var tablesData = [64]string{
// Uncompressed
tableUncompressed: "",
// ncw home directory
1: "MRDIEtAAMAzDMAzDSjX_ybu0w97bb-L3b2mR-rUl5LXW3lZII43kIDMzM1NXu3okgQs=",
// ncw images
2: "IhDIAEAA______-Pou_4Sf5z-uS-39MVWjullFLKM7EBECs=",
// ncw Google Drive:
3: "JxDQAIIBMDMzMwOzbv7nJJCyd_m_9D2llCarnQX33nvvlFKEhUxAAQ==",
// Hex
4: "ExDoSTD___-tfXfhJ0hKSkryTxU=",
// Base64
5: "JRDIcQf_______8PgIiIiIgINkggARHlkQwSSCCBxHFYINHdfXI=",
// Hex plus a bit...
6: "E5CxwAHm9sYcAlmWZVvMHA4Y5jw=",
// Hex, upper case letters.
7: "FICxgAMMAGC3YwMthe3DWM_wDAAQ",
// Special tables:
// SCSU and a fairly generic table:
tableSCSU: "UxAgZmEB-RYPU8hrnAk6uMgpTNQMB5MGRBx0D3T0JjyUyY-yOi5CoGgktbAktSh7d36HtPTFu7SXJ7FYw_AYmA74ZH2vWgc8O6Z5jLnWnsFqU_4B",
// SCSU with no table...
tableSCSUPlain: "",
// Compressed data has its own table.
tableCustom: "",
// Reserved for extension.
tableReserved: "",
}
func initCoders() {
initOnce.Do(func() {
// Init base 64 decoder.
for i, v := range encodeURL {
decodeMap[v] = byte(i) + 1
}
// Initialize encoders and decoders.
for i, dataString := range tablesData {
if len(dataString) == 0 {
continue
}
data, err := base64.URLEncoding.DecodeString(dataString)
if err != nil {
panic(err)
}
s, _, err := huff0.ReadTable(data, nil)
if err != nil {
panic(err)
}
// We want to save at least len(in) >> 5
s.WantLogLess = 5
s.Reuse = huff0.ReusePolicyMust
encTables[i] = s
decTables[i] = s.Decoder()
}
// Add custom table type.
var s huff0.Scratch
s.Reuse = huff0.ReusePolicyNone
encTables[tableCustom] = &s
decTables[tableCustom] = nil
})
}