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author | Daniel J Walsh <dwalsh@redhat.com> | 2018-07-08 07:55:30 -0400 |
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committer | Atomic Bot <atomic-devel@projectatomic.io> | 2018-07-19 18:43:32 +0000 |
commit | 98703eb204923f06555605c648fc165a55214520 (patch) | |
tree | a407bae8b3489d4f9b0f0d0f228658bbfe95a38e /vendor/github.com/ulikunitz/xz/lzma/treecodecs.go | |
parent | c020db8cd21cb221cfbe36b264e0ec02999596ed (diff) | |
download | podman-98703eb204923f06555605c648fc165a55214520.tar.gz podman-98703eb204923f06555605c648fc165a55214520.tar.bz2 podman-98703eb204923f06555605c648fc165a55214520.zip |
Vendor in latest code for storage,image, buildah
vendor in containers/storage
vendor in containers/image
vendor in projectatomic/buildah
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Closes: #1114
Approved by: mheon
Diffstat (limited to 'vendor/github.com/ulikunitz/xz/lzma/treecodecs.go')
-rw-r--r-- | vendor/github.com/ulikunitz/xz/lzma/treecodecs.go | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/vendor/github.com/ulikunitz/xz/lzma/treecodecs.go b/vendor/github.com/ulikunitz/xz/lzma/treecodecs.go new file mode 100644 index 000000000..504b3d78e --- /dev/null +++ b/vendor/github.com/ulikunitz/xz/lzma/treecodecs.go @@ -0,0 +1,133 @@ +// Copyright 2014-2017 Ulrich Kunitz. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package lzma + +// treeCodec encodes or decodes values with a fixed bit size. It is using a +// tree of probability value. The root of the tree is the most-significant bit. +type treeCodec struct { + probTree +} + +// makeTreeCodec makes a tree codec. The bits value must be inside the range +// [1,32]. +func makeTreeCodec(bits int) treeCodec { + return treeCodec{makeProbTree(bits)} +} + +// deepcopy initializes tc as a deep copy of the source. +func (tc *treeCodec) deepcopy(src *treeCodec) { + tc.probTree.deepcopy(&src.probTree) +} + +// Encode uses the range encoder to encode a fixed-bit-size value. +func (tc *treeCodec) Encode(e *rangeEncoder, v uint32) (err error) { + m := uint32(1) + for i := int(tc.bits) - 1; i >= 0; i-- { + b := (v >> uint(i)) & 1 + if err := e.EncodeBit(b, &tc.probs[m]); err != nil { + return err + } + m = (m << 1) | b + } + return nil +} + +// Decodes uses the range decoder to decode a fixed-bit-size value. Errors may +// be caused by the range decoder. +func (tc *treeCodec) Decode(d *rangeDecoder) (v uint32, err error) { + m := uint32(1) + for j := 0; j < int(tc.bits); j++ { + b, err := d.DecodeBit(&tc.probs[m]) + if err != nil { + return 0, err + } + m = (m << 1) | b + } + return m - (1 << uint(tc.bits)), nil +} + +// treeReverseCodec is another tree codec, where the least-significant bit is +// the start of the probability tree. +type treeReverseCodec struct { + probTree +} + +// deepcopy initializes the treeReverseCodec as a deep copy of the +// source. +func (tc *treeReverseCodec) deepcopy(src *treeReverseCodec) { + tc.probTree.deepcopy(&src.probTree) +} + +// makeTreeReverseCodec creates treeReverseCodec value. The bits argument must +// be in the range [1,32]. +func makeTreeReverseCodec(bits int) treeReverseCodec { + return treeReverseCodec{makeProbTree(bits)} +} + +// Encode uses range encoder to encode a fixed-bit-size value. The range +// encoder may cause errors. +func (tc *treeReverseCodec) Encode(v uint32, e *rangeEncoder) (err error) { + m := uint32(1) + for i := uint(0); i < uint(tc.bits); i++ { + b := (v >> i) & 1 + if err := e.EncodeBit(b, &tc.probs[m]); err != nil { + return err + } + m = (m << 1) | b + } + return nil +} + +// Decodes uses the range decoder to decode a fixed-bit-size value. Errors +// returned by the range decoder will be returned. +func (tc *treeReverseCodec) Decode(d *rangeDecoder) (v uint32, err error) { + m := uint32(1) + for j := uint(0); j < uint(tc.bits); j++ { + b, err := d.DecodeBit(&tc.probs[m]) + if err != nil { + return 0, err + } + m = (m << 1) | b + v |= b << j + } + return v, nil +} + +// probTree stores enough probability values to be used by the treeEncode and +// treeDecode methods of the range coder types. +type probTree struct { + probs []prob + bits byte +} + +// deepcopy initializes the probTree value as a deep copy of the source. +func (t *probTree) deepcopy(src *probTree) { + if t == src { + return + } + t.probs = make([]prob, len(src.probs)) + copy(t.probs, src.probs) + t.bits = src.bits +} + +// makeProbTree initializes a probTree structure. +func makeProbTree(bits int) probTree { + if !(1 <= bits && bits <= 32) { + panic("bits outside of range [1,32]") + } + t := probTree{ + bits: byte(bits), + probs: make([]prob, 1<<uint(bits)), + } + for i := range t.probs { + t.probs[i] = probInit + } + return t +} + +// Bits provides the number of bits for the values to de- or encode. +func (t *probTree) Bits() int { + return int(t.bits) +} |