open-vault/vendor/github.com/nwaples/rardecode/bit_reader.go
Calvin Leung Huang d2dbb8c963
Vault Debug (#7375)
* cli: initial work on debug; server-status target

* debug: add metrics capture target (#7376)

* check against DR secondary

* debug: add compression

* refactor check into preflight func

* debug: set short test time on tests, fix exit code bug

* debug: use temp dir for output on tests

* debug: use mholt/archiver for compression

* first pass on adding pprof

* use logger for output

* refactor polling target capture logic

* debug: poll and collect replication status

* debug: poll and collect host-info; rename output files and collection refactor

* fix comments

* add archive test; fix bugs found

* rename flag name to singular target

* add target output test; scaffold other tests cases

* debug/test: add pprof and index file tests

* debug/test: add min timing check tests

* debug: fix index gen race and collection goroutine race

* debug: extend archive tests, handle race between program exit and polling goroutines

* update docstring

* debug: correctly add to pollingWg

* debug: add config target support

* debug: don't wait on interrupt shutdown; add file exists unit tests

* move pprof bits into its goroutine

* debug: skip empty metrics and some pprof file creation if permission denied, add matching unit test

* address comments and feedback

* Vault debug using run.Group (#7658)

* debug: switch to use oklog/run.Group

* debug: use context to cancel requests and interrupt rungroups.

* debug: trigger the first interval properly

* debug: metrics collection should use metrics interval

* debug: add missing continue on metrics error

* debug: remove the use of buffered chan to trigger first interval

* debug: don't shadow BaseCommand's client, properly block on interval capture failures

* debug: actually use c.cachedClient everywhere

* go mod vendor

* debug: run all pprof in goroutines; bump pprof timings in tests to reduce flakiness

* debug: update help text
2019-10-15 15:39:19 -07:00

120 lines
2.4 KiB
Go

package rardecode
import "io"
type bitReader interface {
readBits(n uint) (int, error) // read n bits of data
unreadBits(n uint) // revert the reading of the last n bits read
}
type limitedBitReader struct {
br bitReader
n int
err error // error to return if br returns EOF before all n bits have been read
}
// limitBitReader returns a bitReader that reads from br and stops with io.EOF after n bits.
// If br returns an io.EOF before reading n bits, err is returned.
func limitBitReader(br bitReader, n int, err error) bitReader {
return &limitedBitReader{br, n, err}
}
func (l *limitedBitReader) readBits(n uint) (int, error) {
if int(n) > l.n {
return 0, io.EOF
}
v, err := l.br.readBits(n)
if err == nil {
l.n -= int(n)
} else if err == io.EOF {
err = l.err
}
return v, err
}
func (l *limitedBitReader) unreadBits(n uint) {
l.n += int(n)
l.br.unreadBits(n)
}
// rarBitReader wraps an io.ByteReader to perform various bit and byte
// reading utility functions used in RAR file processing.
type rarBitReader struct {
r io.ByteReader
v int
n uint
}
func (r *rarBitReader) reset(br io.ByteReader) {
r.r = br
r.n = 0
r.v = 0
}
func (r *rarBitReader) readBits(n uint) (int, error) {
for n > r.n {
c, err := r.r.ReadByte()
if err != nil {
return 0, err
}
r.v = r.v<<8 | int(c)
r.n += 8
}
r.n -= n
return (r.v >> r.n) & ((1 << n) - 1), nil
}
func (r *rarBitReader) unreadBits(n uint) {
r.n += n
}
// alignByte aligns the current bit reading input to the next byte boundary.
func (r *rarBitReader) alignByte() {
r.n -= r.n % 8
}
// readUint32 reads a RAR V3 encoded uint32
func (r *rarBitReader) readUint32() (uint32, error) {
n, err := r.readBits(2)
if err != nil {
return 0, err
}
if n != 1 {
n, err = r.readBits(4 << uint(n))
return uint32(n), err
}
n, err = r.readBits(4)
if err != nil {
return 0, err
}
if n == 0 {
n, err = r.readBits(8)
n |= -1 << 8
return uint32(n), err
}
nlow, err := r.readBits(4)
n = n<<4 | nlow
return uint32(n), err
}
func (r *rarBitReader) ReadByte() (byte, error) {
n, err := r.readBits(8)
return byte(n), err
}
// readFull reads len(p) bytes into p. If fewer bytes are read an error is returned.
func (r *rarBitReader) readFull(p []byte) error {
for i := range p {
c, err := r.ReadByte()
if err != nil {
return err
}
p[i] = c
}
return nil
}
func newRarBitReader(r io.ByteReader) *rarBitReader {
return &rarBitReader{r: r}
}