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Diffstat (limited to 'gcc-4.8.1/libgo/go/encoding/binary/varint.go')
-rw-r--r--gcc-4.8.1/libgo/go/encoding/binary/varint.go134
1 files changed, 0 insertions, 134 deletions
diff --git a/gcc-4.8.1/libgo/go/encoding/binary/varint.go b/gcc-4.8.1/libgo/go/encoding/binary/varint.go
deleted file mode 100644
index 7035529f2..000000000
--- a/gcc-4.8.1/libgo/go/encoding/binary/varint.go
+++ /dev/null
@@ -1,134 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package binary
-
-// This file implements "varint" encoding of 64-bit integers.
-// The encoding is:
-// - unsigned integers are serialized 7 bits at a time, starting with the
-// least significant bits
-// - the most significant bit (msb) in each output byte indicates if there
-// is a continuation byte (msb = 1)
-// - signed integers are mapped to unsigned integers using "zig-zag"
-// encoding: Positive values x are written as 2*x + 0, negative values
-// are written as 2*(^x) + 1; that is, negative numbers are complemented
-// and whether to complement is encoded in bit 0.
-//
-// Design note:
-// At most 10 bytes are needed for 64-bit values. The encoding could
-// be more dense: a full 64-bit value needs an extra byte just to hold bit 63.
-// Instead, the msb of the previous byte could be used to hold bit 63 since we
-// know there can't be more than 64 bits. This is a trivial improvement and
-// would reduce the maximum encoding length to 9 bytes. However, it breaks the
-// invariant that the msb is always the "continuation bit" and thus makes the
-// format incompatible with a varint encoding for larger numbers (say 128-bit).
-
-import (
- "errors"
- "io"
-)
-
-// MaxVarintLenN is the maximum length of a varint-encoded N-bit integer.
-const (
- MaxVarintLen16 = 3
- MaxVarintLen32 = 5
- MaxVarintLen64 = 10
-)
-
-// PutUvarint encodes a uint64 into buf and returns the number of bytes written.
-// If the buffer is too small, PutUvarint will panic.
-func PutUvarint(buf []byte, x uint64) int {
- i := 0
- for x >= 0x80 {
- buf[i] = byte(x) | 0x80
- x >>= 7
- i++
- }
- buf[i] = byte(x)
- return i + 1
-}
-
-// Uvarint decodes a uint64 from buf and returns that value and the
-// number of bytes read (> 0). If an error occurred, the value is 0
-// and the number of bytes n is <= 0 meaning:
-//
-// n == 0: buf too small
-// n < 0: value larger than 64 bits (overflow)
-// and -n is the number of bytes read
-//
-func Uvarint(buf []byte) (uint64, int) {
- var x uint64
- var s uint
- for i, b := range buf {
- if b < 0x80 {
- if i > 9 || i == 9 && b > 1 {
- return 0, -(i + 1) // overflow
- }
- return x | uint64(b)<<s, i + 1
- }
- x |= uint64(b&0x7f) << s
- s += 7
- }
- return 0, 0
-}
-
-// PutVarint encodes an int64 into buf and returns the number of bytes written.
-// If the buffer is too small, PutVarint will panic.
-func PutVarint(buf []byte, x int64) int {
- ux := uint64(x) << 1
- if x < 0 {
- ux = ^ux
- }
- return PutUvarint(buf, ux)
-}
-
-// Varint decodes an int64 from buf and returns that value and the
-// number of bytes read (> 0). If an error occurred, the value is 0
-// and the number of bytes n is <= 0 with the following meaning:
-//
-// n == 0: buf too small
-// n < 0: value larger than 64 bits (overflow)
-// and -n is the number of bytes read
-//
-func Varint(buf []byte) (int64, int) {
- ux, n := Uvarint(buf) // ok to continue in presence of error
- x := int64(ux >> 1)
- if ux&1 != 0 {
- x = ^x
- }
- return x, n
-}
-
-var overflow = errors.New("binary: varint overflows a 64-bit integer")
-
-// ReadUvarint reads an encoded unsigned integer from r and returns it as a uint64.
-func ReadUvarint(r io.ByteReader) (uint64, error) {
- var x uint64
- var s uint
- for i := 0; ; i++ {
- b, err := r.ReadByte()
- if err != nil {
- return x, err
- }
- if b < 0x80 {
- if i > 9 || i == 9 && b > 1 {
- return x, overflow
- }
- return x | uint64(b)<<s, nil
- }
- x |= uint64(b&0x7f) << s
- s += 7
- }
- panic("unreachable")
-}
-
-// ReadVarint reads an encoded signed integer from r and returns it as an int64.
-func ReadVarint(r io.ByteReader) (int64, error) {
- ux, err := ReadUvarint(r) // ok to continue in presence of error
- x := int64(ux >> 1)
- if ux&1 != 0 {
- x = ^x
- }
- return x, err
-}