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Diffstat (limited to 'pkg/buffer/safemem.go')
-rw-r--r-- | pkg/buffer/safemem.go | 133 |
1 files changed, 0 insertions, 133 deletions
diff --git a/pkg/buffer/safemem.go b/pkg/buffer/safemem.go deleted file mode 100644 index 8b42575b4..000000000 --- a/pkg/buffer/safemem.go +++ /dev/null @@ -1,133 +0,0 @@ -// Copyright 2020 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package buffer - -import ( - "gvisor.dev/gvisor/pkg/safemem" -) - -// WriteBlock returns this buffer as a write Block. -func (b *buffer) WriteBlock() safemem.Block { - return safemem.BlockFromSafeSlice(b.WriteSlice()) -} - -// ReadBlock returns this buffer as a read Block. -func (b *buffer) ReadBlock() safemem.Block { - return safemem.BlockFromSafeSlice(b.ReadSlice()) -} - -// WriteFromSafememReader writes up to count bytes from r to v and advances the -// write index by the number of bytes written. It calls r.ReadToBlocks() at -// most once. -func (v *View) WriteFromSafememReader(r safemem.Reader, count uint64) (uint64, error) { - if count == 0 { - return 0, nil - } - - var ( - dst safemem.BlockSeq - blocks []safemem.Block - ) - - // Need at least one buffer. - firstBuf := v.data.Back() - if firstBuf == nil { - firstBuf = v.pool.get() - v.data.PushBack(firstBuf) - } - - // Does the last block have sufficient capacity alone? - if l := uint64(firstBuf.WriteSize()); l >= count { - dst = safemem.BlockSeqOf(firstBuf.WriteBlock().TakeFirst64(count)) - } else { - // Append blocks until sufficient. - count -= l - blocks = append(blocks, firstBuf.WriteBlock()) - for count > 0 { - emptyBuf := v.pool.get() - v.data.PushBack(emptyBuf) - block := emptyBuf.WriteBlock().TakeFirst64(count) - count -= uint64(block.Len()) - blocks = append(blocks, block) - } - dst = safemem.BlockSeqFromSlice(blocks) - } - - // Perform I/O. - n, err := r.ReadToBlocks(dst) - v.size += int64(n) - - // Update all indices. - for left := n; left > 0; firstBuf = firstBuf.Next() { - if l := firstBuf.WriteSize(); left >= uint64(l) { - firstBuf.WriteMove(l) // Whole block. - left -= uint64(l) - } else { - firstBuf.WriteMove(int(left)) // Partial block. - left = 0 - } - } - - return n, err -} - -// WriteFromBlocks implements safemem.Writer.WriteFromBlocks. It advances the -// write index by the number of bytes written. -func (v *View) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error) { - return v.WriteFromSafememReader(&safemem.BlockSeqReader{srcs}, srcs.NumBytes()) -} - -// ReadToSafememWriter reads up to count bytes from v to w. It does not advance -// the read index. It calls w.WriteFromBlocks() at most once. -func (v *View) ReadToSafememWriter(w safemem.Writer, count uint64) (uint64, error) { - if count == 0 { - return 0, nil - } - - var ( - src safemem.BlockSeq - blocks []safemem.Block - ) - - firstBuf := v.data.Front() - if firstBuf == nil { - return 0, nil // No EOF. - } - - // Is all the data in a single block? - if l := uint64(firstBuf.ReadSize()); l >= count { - src = safemem.BlockSeqOf(firstBuf.ReadBlock().TakeFirst64(count)) - } else { - // Build a list of all the buffers. - count -= l - blocks = append(blocks, firstBuf.ReadBlock()) - for buf := firstBuf.Next(); buf != nil && count > 0; buf = buf.Next() { - block := buf.ReadBlock().TakeFirst64(count) - count -= uint64(block.Len()) - blocks = append(blocks, block) - } - src = safemem.BlockSeqFromSlice(blocks) - } - - // Perform I/O. As documented, we don't advance the read index. - return w.WriteFromBlocks(src) -} - -// ReadToBlocks implements safemem.Reader.ReadToBlocks. It does not advance the -// read index by the number of bytes read, such that it's only safe to call if -// the caller guarantees that ReadToBlocks will only be called once. -func (v *View) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) { - return v.ReadToSafememWriter(&safemem.BlockSeqWriter{dsts}, dsts.NumBytes()) -} |