diff options
Diffstat (limited to 'pkg/buffer')
| -rw-r--r-- | pkg/buffer/BUILD | 50 | ||||
| -rw-r--r-- | pkg/buffer/buffer.go | 77 | ||||
| -rw-r--r-- | pkg/buffer/pool.go | 83 | ||||
| -rw-r--r-- | pkg/buffer/pool_test.go | 51 | ||||
| -rw-r--r-- | pkg/buffer/safemem.go | 133 | ||||
| -rw-r--r-- | pkg/buffer/safemem_test.go | 172 | ||||
| -rw-r--r-- | pkg/buffer/view.go | 391 | ||||
| -rw-r--r-- | pkg/buffer/view_test.go | 544 | ||||
| -rw-r--r-- | pkg/buffer/view_unsafe.go | 25 |
9 files changed, 0 insertions, 1526 deletions
diff --git a/pkg/buffer/BUILD b/pkg/buffer/BUILD deleted file mode 100644 index 1186f788e..000000000 --- a/pkg/buffer/BUILD +++ /dev/null @@ -1,50 +0,0 @@ -load("//tools:defs.bzl", "go_library", "go_test") -load("//tools/go_generics:defs.bzl", "go_template_instance") - -package(licenses = ["notice"]) - -go_template_instance( - name = "buffer_list", - out = "buffer_list.go", - package = "buffer", - prefix = "buffer", - template = "//pkg/ilist:generic_list", - types = { - "Element": "*buffer", - "Linker": "*buffer", - }, -) - -go_library( - name = "buffer", - srcs = [ - "buffer.go", - "buffer_list.go", - "pool.go", - "safemem.go", - "view.go", - "view_unsafe.go", - ], - visibility = ["//visibility:public"], - deps = [ - "//pkg/context", - "//pkg/log", - "//pkg/safemem", - "//pkg/usermem", - ], -) - -go_test( - name = "buffer_test", - size = "small", - srcs = [ - "pool_test.go", - "safemem_test.go", - "view_test.go", - ], - library = ":buffer", - deps = [ - "//pkg/safemem", - "//pkg/state", - ], -) diff --git a/pkg/buffer/buffer.go b/pkg/buffer/buffer.go deleted file mode 100644 index 311808ae9..000000000 --- a/pkg/buffer/buffer.go +++ /dev/null @@ -1,77 +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 provides the implementation of a buffer view. -// -// A view is an flexible buffer, supporting the safecopy operations natively as -// well as the ability to grow via either prepend or append, as well as shrink. -package buffer - -// buffer encapsulates a queueable byte buffer. -// -// +stateify savable -type buffer struct { - data []byte - read int - write int - bufferEntry -} - -// init performs in-place initialization for zero value. -func (b *buffer) init(size int) { - b.data = make([]byte, size) -} - -// Reset resets read and write locations, effectively emptying the buffer. -func (b *buffer) Reset() { - b.read = 0 - b.write = 0 -} - -// Full indicates the buffer is full. -// -// This indicates there is no capacity left to write. -func (b *buffer) Full() bool { - return b.write == len(b.data) -} - -// ReadSize returns the number of bytes available for reading. -func (b *buffer) ReadSize() int { - return b.write - b.read -} - -// ReadMove advances the read index by the given amount. -func (b *buffer) ReadMove(n int) { - b.read += n -} - -// ReadSlice returns the read slice for this buffer. -func (b *buffer) ReadSlice() []byte { - return b.data[b.read:b.write] -} - -// WriteSize returns the number of bytes available for writing. -func (b *buffer) WriteSize() int { - return len(b.data) - b.write -} - -// WriteMove advances the write index by the given amount. -func (b *buffer) WriteMove(n int) { - b.write += n -} - -// WriteSlice returns the write slice for this buffer. -func (b *buffer) WriteSlice() []byte { - return b.data[b.write:] -} diff --git a/pkg/buffer/pool.go b/pkg/buffer/pool.go deleted file mode 100644 index 7ad6132ab..000000000 --- a/pkg/buffer/pool.go +++ /dev/null @@ -1,83 +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 - -const ( - // embeddedCount is the number of buffer structures embedded in the pool. It - // is also the number for overflow allocations. - embeddedCount = 8 - - // defaultBufferSize is the default size for each underlying storage buffer. - // - // It is slightly less than two pages. This is done intentionally to ensure - // that the buffer object aligns with runtime internals. This two page size - // will effectively minimize internal fragmentation, but still have a large - // enough chunk to limit excessive segmentation. - defaultBufferSize = 8144 -) - -// pool allocates buffer. -// -// It contains an embedded buffer storage for fast path when the number of -// buffers needed is small. -// -// +stateify savable -type pool struct { - bufferSize int - avail []buffer `state:"nosave"` - embeddedStorage [embeddedCount]buffer `state:"wait"` -} - -// get gets a new buffer from p. -func (p *pool) get() *buffer { - if p.avail == nil { - p.avail = p.embeddedStorage[:] - } - if len(p.avail) == 0 { - p.avail = make([]buffer, embeddedCount) - } - if p.bufferSize <= 0 { - p.bufferSize = defaultBufferSize - } - buf := &p.avail[0] - buf.init(p.bufferSize) - p.avail = p.avail[1:] - return buf -} - -// put releases buf. -func (p *pool) put(buf *buffer) { - // Remove reference to the underlying storage, allowing it to be garbage - // collected. - buf.data = nil -} - -// setBufferSize sets the size of underlying storage buffer for future -// allocations. It can be called at any time. -func (p *pool) setBufferSize(size int) { - p.bufferSize = size -} - -// afterLoad is invoked by stateify. -func (p *pool) afterLoad() { - // S/R does not save subslice into embeddedStorage correctly. Restore - // available portion of embeddedStorage manually. Restore as nil if none used. - for i := len(p.embeddedStorage); i > 0; i-- { - if p.embeddedStorage[i-1].data != nil { - p.avail = p.embeddedStorage[i:] - break - } - } -} diff --git a/pkg/buffer/pool_test.go b/pkg/buffer/pool_test.go deleted file mode 100644 index 8584bac89..000000000 --- a/pkg/buffer/pool_test.go +++ /dev/null @@ -1,51 +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 ( - "testing" -) - -func TestGetDefaultBufferSize(t *testing.T) { - var p pool - for i := 0; i < embeddedCount*2; i++ { - buf := p.get() - if got, want := len(buf.data), defaultBufferSize; got != want { - t.Errorf("#%d len(buf.data) = %d, want %d", i, got, want) - } - } -} - -func TestGetCustomBufferSize(t *testing.T) { - const size = 100 - - var p pool - p.setBufferSize(size) - for i := 0; i < embeddedCount*2; i++ { - buf := p.get() - if got, want := len(buf.data), size; got != want { - t.Errorf("#%d len(buf.data) = %d, want %d", i, got, want) - } - } -} - -func TestPut(t *testing.T) { - var p pool - buf := p.get() - p.put(buf) - if buf.data != nil { - t.Errorf("buf.data = %x, want nil", buf.data) - } -} 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()) -} diff --git a/pkg/buffer/safemem_test.go b/pkg/buffer/safemem_test.go deleted file mode 100644 index 721cc5934..000000000 --- a/pkg/buffer/safemem_test.go +++ /dev/null @@ -1,172 +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 ( - "bytes" - "strings" - "testing" - - "gvisor.dev/gvisor/pkg/safemem" -) - -func TestSafemem(t *testing.T) { - const bufferSize = defaultBufferSize - - testCases := []struct { - name string - input string - output string - readLen int - op func(*View) - }{ - // Basic coverage. - { - name: "short", - input: "010", - output: "010", - }, - { - name: "long", - input: "0" + strings.Repeat("1", bufferSize) + "0", - output: "0" + strings.Repeat("1", bufferSize) + "0", - }, - { - name: "short-read", - input: "0", - readLen: 100, // > size. - output: "0", - }, - { - name: "zero-read", - input: "0", - output: "", - }, - { - name: "read-empty", - input: "", - readLen: 1, // > size. - output: "", - }, - - // Ensure offsets work. - { - name: "offsets-short", - input: "012", - output: "2", - op: func(v *View) { - v.TrimFront(2) - }, - }, - { - name: "offsets-long0", - input: "0" + strings.Repeat("1", bufferSize) + "0", - output: strings.Repeat("1", bufferSize) + "0", - op: func(v *View) { - v.TrimFront(1) - }, - }, - { - name: "offsets-long1", - input: "0" + strings.Repeat("1", bufferSize) + "0", - output: strings.Repeat("1", bufferSize-1) + "0", - op: func(v *View) { - v.TrimFront(2) - }, - }, - { - name: "offsets-long2", - input: "0" + strings.Repeat("1", bufferSize) + "0", - output: "10", - op: func(v *View) { - v.TrimFront(bufferSize) - }, - }, - - // Ensure truncation works. - { - name: "truncate-short", - input: "012", - output: "01", - op: func(v *View) { - v.Truncate(2) - }, - }, - { - name: "truncate-long0", - input: "0" + strings.Repeat("1", bufferSize) + "0", - output: "0" + strings.Repeat("1", bufferSize), - op: func(v *View) { - v.Truncate(bufferSize + 1) - }, - }, - { - name: "truncate-long1", - input: "0" + strings.Repeat("1", bufferSize) + "0", - output: "0" + strings.Repeat("1", bufferSize-1), - op: func(v *View) { - v.Truncate(bufferSize) - }, - }, - { - name: "truncate-long2", - input: "0" + strings.Repeat("1", bufferSize) + "0", - output: "01", - op: func(v *View) { - v.Truncate(2) - }, - }, - } - - for _, tc := range testCases { - t.Run(tc.name, func(t *testing.T) { - // Construct the new view. - var view View - bs := safemem.BlockSeqOf(safemem.BlockFromSafeSlice([]byte(tc.input))) - n, err := view.WriteFromBlocks(bs) - if err != nil { - t.Errorf("expected err nil, got %v", err) - } - if n != uint64(len(tc.input)) { - t.Errorf("expected %d bytes, got %d", len(tc.input), n) - } - - // Run the operation. - if tc.op != nil { - tc.op(&view) - } - - // Read and validate. - readLen := tc.readLen - if readLen == 0 { - readLen = len(tc.output) // Default. - } - out := make([]byte, readLen) - bs = safemem.BlockSeqOf(safemem.BlockFromSafeSlice(out)) - n, err = view.ReadToBlocks(bs) - if err != nil { - t.Errorf("expected nil, got %v", err) - } - if n != uint64(len(tc.output)) { - t.Errorf("expected %d bytes, got %d", len(tc.output), n) - } - - // Ensure the contents are correct. - if !bytes.Equal(out[:n], []byte(tc.output[:n])) { - t.Errorf("contents are wrong: expected %q, got %q", tc.output, string(out)) - } - }) - } -} diff --git a/pkg/buffer/view.go b/pkg/buffer/view.go deleted file mode 100644 index 00652d675..000000000 --- a/pkg/buffer/view.go +++ /dev/null @@ -1,391 +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 ( - "fmt" - "io" -) - -// View is a non-linear buffer. -// -// All methods are thread compatible. -// -// +stateify savable -type View struct { - data bufferList - size int64 - pool pool -} - -// TrimFront removes the first count bytes from the buffer. -func (v *View) TrimFront(count int64) { - if count >= v.size { - v.advanceRead(v.size) - } else { - v.advanceRead(count) - } -} - -// ReadAt implements io.ReaderAt.ReadAt. -func (v *View) ReadAt(p []byte, offset int64) (int, error) { - var ( - skipped int64 - done int64 - ) - for buf := v.data.Front(); buf != nil && done < int64(len(p)); buf = buf.Next() { - needToSkip := int(offset - skipped) - if sz := buf.ReadSize(); sz <= needToSkip { - skipped += int64(sz) - continue - } - - // Actually read data. - n := copy(p[done:], buf.ReadSlice()[needToSkip:]) - skipped += int64(needToSkip) - done += int64(n) - } - if int(done) < len(p) || offset+done == v.size { - return int(done), io.EOF - } - return int(done), nil -} - -// advanceRead advances the view's read index. -// -// Precondition: there must be sufficient bytes in the buffer. -func (v *View) advanceRead(count int64) { - for buf := v.data.Front(); buf != nil && count > 0; { - sz := int64(buf.ReadSize()) - if sz > count { - // There is still data for reading. - buf.ReadMove(int(count)) - v.size -= count - count = 0 - break - } - - // Consume the whole buffer. - oldBuf := buf - buf = buf.Next() // Iterate. - v.data.Remove(oldBuf) - oldBuf.Reset() - v.pool.put(oldBuf) - - // Update counts. - count -= sz - v.size -= sz - } - if count > 0 { - panic(fmt.Sprintf("advanceRead still has %d bytes remaining", count)) - } -} - -// Truncate truncates the view to the given bytes. -// -// This will not grow the view, only shrink it. If a length is passed that is -// greater than the current size of the view, then nothing will happen. -// -// Precondition: length must be >= 0. -func (v *View) Truncate(length int64) { - if length < 0 { - panic("negative length provided") - } - if length >= v.size { - return // Nothing to do. - } - for buf := v.data.Back(); buf != nil && v.size > length; buf = v.data.Back() { - sz := int64(buf.ReadSize()) - if after := v.size - sz; after < length { - // Truncate the buffer locally. - left := (length - after) - buf.write = buf.read + int(left) - v.size = length - break - } - - // Drop the buffer completely; see above. - v.data.Remove(buf) - buf.Reset() - v.pool.put(buf) - v.size -= sz - } -} - -// Grow grows the given view to the number of bytes, which will be appended. If -// zero is true, all these bytes will be zero. If zero is false, then this is -// the caller's responsibility. -// -// Precondition: length must be >= 0. -func (v *View) Grow(length int64, zero bool) { - if length < 0 { - panic("negative length provided") - } - for v.size < length { - buf := v.data.Back() - - // Is there some space in the last buffer? - if buf == nil || buf.Full() { - buf = v.pool.get() - v.data.PushBack(buf) - } - - // Write up to length bytes. - sz := buf.WriteSize() - if int64(sz) > length-v.size { - sz = int(length - v.size) - } - - // Zero the written section; note that this pattern is - // specifically recognized and optimized by the compiler. - if zero { - for i := buf.write; i < buf.write+sz; i++ { - buf.data[i] = 0 - } - } - - // Advance the index. - buf.WriteMove(sz) - v.size += int64(sz) - } -} - -// Prepend prepends the given data. -func (v *View) Prepend(data []byte) { - // Is there any space in the first buffer? - if buf := v.data.Front(); buf != nil && buf.read > 0 { - // Fill up before the first write. - avail := buf.read - bStart := 0 - dStart := len(data) - avail - if avail > len(data) { - bStart = avail - len(data) - dStart = 0 - } - n := copy(buf.data[bStart:], data[dStart:]) - data = data[:dStart] - v.size += int64(n) - buf.read -= n - } - - for len(data) > 0 { - // Do we need an empty buffer? - buf := v.pool.get() - v.data.PushFront(buf) - - // The buffer is empty; copy last chunk. - avail := len(buf.data) - bStart := 0 - dStart := len(data) - avail - if avail > len(data) { - bStart = avail - len(data) - dStart = 0 - } - - // We have to put the data at the end of the current - // buffer in order to ensure that the next prepend will - // correctly fill up the beginning of this buffer. - n := copy(buf.data[bStart:], data[dStart:]) - data = data[:dStart] - v.size += int64(n) - buf.read = len(buf.data) - n - buf.write = len(buf.data) - } -} - -// Append appends the given data. -func (v *View) Append(data []byte) { - for done := 0; done < len(data); { - buf := v.data.Back() - - // Ensure there's a buffer with space. - if buf == nil || buf.Full() { - buf = v.pool.get() - v.data.PushBack(buf) - } - - // Copy in to the given buffer. - n := copy(buf.WriteSlice(), data[done:]) - done += n - buf.WriteMove(n) - v.size += int64(n) - } -} - -// Flatten returns a flattened copy of this data. -// -// This method should not be used in any performance-sensitive paths. It may -// allocate a fresh byte slice sufficiently large to contain all the data in -// the buffer. This is principally for debugging. -// -// N.B. Tee data still belongs to this view, as if there is a single buffer -// present, then it will be returned directly. This should be used for -// temporary use only, and a reference to the given slice should not be held. -func (v *View) Flatten() []byte { - if buf := v.data.Front(); buf == nil { - return nil // No data at all. - } else if buf.Next() == nil { - return buf.ReadSlice() // Only one buffer. - } - data := make([]byte, 0, v.size) // Need to flatten. - for buf := v.data.Front(); buf != nil; buf = buf.Next() { - // Copy to the allocated slice. - data = append(data, buf.ReadSlice()...) - } - return data -} - -// Size indicates the total amount of data available in this view. -func (v *View) Size() int64 { - return v.size -} - -// Copy makes a strict copy of this view. -func (v *View) Copy() (other View) { - for buf := v.data.Front(); buf != nil; buf = buf.Next() { - other.Append(buf.ReadSlice()) - } - return -} - -// Apply applies the given function across all valid data. -func (v *View) Apply(fn func([]byte)) { - for buf := v.data.Front(); buf != nil; buf = buf.Next() { - fn(buf.ReadSlice()) - } -} - -// Merge merges the provided View with this one. -// -// The other view will be appended to v, and other will be empty after this -// operation completes. -func (v *View) Merge(other *View) { - // Copy over all buffers. - for buf := other.data.Front(); buf != nil; buf = other.data.Front() { - other.data.Remove(buf) - v.data.PushBack(buf) - } - - // Adjust sizes. - v.size += other.size - other.size = 0 -} - -// WriteFromReader writes to the buffer from an io.Reader. -// -// A minimum read size equal to unsafe.Sizeof(unintptr) is enforced, -// provided that count is greater than or equal to unsafe.Sizeof(uintptr). -func (v *View) WriteFromReader(r io.Reader, count int64) (int64, error) { - var ( - done int64 - n int - err error - ) - for done < count { - buf := v.data.Back() - - // Ensure we have an empty buffer. - if buf == nil || buf.Full() { - buf = v.pool.get() - v.data.PushBack(buf) - } - - // Is this less than the minimum batch? - if buf.WriteSize() < minBatch && (count-done) >= int64(minBatch) { - tmp := make([]byte, minBatch) - n, err = r.Read(tmp) - v.Append(tmp[:n]) - done += int64(n) - if err != nil { - break - } - continue - } - - // Limit the read, if necessary. - sz := buf.WriteSize() - if left := count - done; int64(sz) > left { - sz = int(left) - } - - // Pass the relevant portion of the buffer. - n, err = r.Read(buf.WriteSlice()[:sz]) - buf.WriteMove(n) - done += int64(n) - v.size += int64(n) - if err == io.EOF { - err = nil // Short write allowed. - break - } else if err != nil { - break - } - } - return done, err -} - -// ReadToWriter reads from the buffer into an io.Writer. -// -// N.B. This does not consume the bytes read. TrimFront should -// be called appropriately after this call in order to do so. -// -// A minimum write size equal to unsafe.Sizeof(unintptr) is enforced, -// provided that count is greater than or equal to unsafe.Sizeof(uintptr). -func (v *View) ReadToWriter(w io.Writer, count int64) (int64, error) { - var ( - done int64 - n int - err error - ) - offset := 0 // Spill-over for batching. - for buf := v.data.Front(); buf != nil && done < count; buf = buf.Next() { - // Has this been consumed? Skip it. - sz := buf.ReadSize() - if sz <= offset { - offset -= sz - continue - } - sz -= offset - - // Is this less than the minimum batch? - left := count - done - if sz < minBatch && left >= int64(minBatch) && (v.size-done) >= int64(minBatch) { - tmp := make([]byte, minBatch) - n, err = v.ReadAt(tmp, done) - w.Write(tmp[:n]) - done += int64(n) - offset = n - sz // Reset below. - if err != nil { - break - } - continue - } - - // Limit the write if necessary. - if int64(sz) >= left { - sz = int(left) - } - - // Perform the actual write. - n, err = w.Write(buf.ReadSlice()[offset : offset+sz]) - done += int64(n) - if err != nil { - break - } - - // Reset spill-over. - offset = 0 - } - return done, err -} diff --git a/pkg/buffer/view_test.go b/pkg/buffer/view_test.go deleted file mode 100644 index 839af0223..000000000 --- a/pkg/buffer/view_test.go +++ /dev/null @@ -1,544 +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 ( - "bytes" - "context" - "io" - "strings" - "testing" - - "gvisor.dev/gvisor/pkg/state" -) - -const bufferSize = defaultBufferSize - -func fillAppend(v *View, data []byte) { - v.Append(data) -} - -func fillAppendEnd(v *View, data []byte) { - v.Grow(bufferSize-1, false) - v.Append(data) - v.TrimFront(bufferSize - 1) -} - -func fillWriteFromReader(v *View, data []byte) { - b := bytes.NewBuffer(data) - v.WriteFromReader(b, int64(len(data))) -} - -func fillWriteFromReaderEnd(v *View, data []byte) { - v.Grow(bufferSize-1, false) - b := bytes.NewBuffer(data) - v.WriteFromReader(b, int64(len(data))) - v.TrimFront(bufferSize - 1) -} - -var fillFuncs = map[string]func(*View, []byte){ - "append": fillAppend, - "appendEnd": fillAppendEnd, - "writeFromReader": fillWriteFromReader, - "writeFromReaderEnd": fillWriteFromReaderEnd, -} - -func BenchmarkReadAt(b *testing.B) { - b.ReportAllocs() - var v View - v.Append(make([]byte, 100)) - - buf := make([]byte, 10) - for i := 0; i < b.N; i++ { - v.ReadAt(buf, 0) - } -} - -func BenchmarkWriteRead(b *testing.B) { - b.ReportAllocs() - var v View - sz := 1000 - wbuf := make([]byte, sz) - rbuf := bytes.NewBuffer(make([]byte, sz)) - for i := 0; i < b.N; i++ { - v.Append(wbuf) - rbuf.Reset() - v.ReadToWriter(rbuf, int64(sz)) - } -} - -func testReadAt(t *testing.T, v *View, offset int64, n int, wantStr string, wantErr error) { - t.Helper() - d := make([]byte, n) - n, err := v.ReadAt(d, offset) - if n != len(wantStr) { - t.Errorf("got %d, want %d", n, len(wantStr)) - } - if err != wantErr { - t.Errorf("got err %v, want %v", err, wantErr) - } - if !bytes.Equal(d[:n], []byte(wantStr)) { - t.Errorf("got %q, want %q", string(d[:n]), wantStr) - } -} - -func TestView(t *testing.T) { - testCases := []struct { - name string - input string - output string - op func(*testing.T, *View) - }{ - // Preconditions. - { - name: "truncate-check", - input: "hello", - output: "hello", // Not touched. - op: func(t *testing.T, v *View) { - defer func() { - if r := recover(); r == nil { - t.Errorf("Truncate(-1) did not panic") - } - }() - v.Truncate(-1) - }, - }, - { - name: "grow-check", - input: "hello", - output: "hello", // Not touched. - op: func(t *testing.T, v *View) { - defer func() { - if r := recover(); r == nil { - t.Errorf("Grow(-1) did not panic") - } - }() - v.Grow(-1, false) - }, - }, - { - name: "advance-check", - input: "hello", - output: "", // Consumed. - op: func(t *testing.T, v *View) { - defer func() { - if r := recover(); r == nil { - t.Errorf("advanceRead(Size()+1) did not panic") - } - }() - v.advanceRead(v.Size() + 1) - }, - }, - - // Prepend. - { - name: "prepend", - input: "world", - output: "hello world", - op: func(t *testing.T, v *View) { - v.Prepend([]byte("hello ")) - }, - }, - { - name: "prepend-backfill-full", - input: "hello world", - output: "jello world", - op: func(t *testing.T, v *View) { - v.TrimFront(1) - v.Prepend([]byte("j")) - }, - }, - { - name: "prepend-backfill-under", - input: "hello world", - output: "hola world", - op: func(t *testing.T, v *View) { - v.TrimFront(5) - v.Prepend([]byte("hola")) - }, - }, - { - name: "prepend-backfill-over", - input: "hello world", - output: "smello world", - op: func(t *testing.T, v *View) { - v.TrimFront(1) - v.Prepend([]byte("sm")) - }, - }, - { - name: "prepend-fill", - input: strings.Repeat("1", bufferSize-1), - output: "0" + strings.Repeat("1", bufferSize-1), - op: func(t *testing.T, v *View) { - v.Prepend([]byte("0")) - }, - }, - { - name: "prepend-overflow", - input: strings.Repeat("1", bufferSize), - output: "0" + strings.Repeat("1", bufferSize), - op: func(t *testing.T, v *View) { - v.Prepend([]byte("0")) - }, - }, - { - name: "prepend-multiple-buffers", - input: strings.Repeat("1", bufferSize-1), - output: strings.Repeat("0", bufferSize*3) + strings.Repeat("1", bufferSize-1), - op: func(t *testing.T, v *View) { - v.Prepend([]byte(strings.Repeat("0", bufferSize*3))) - }, - }, - - // Append and write. - { - name: "append", - input: "hello", - output: "hello world", - op: func(t *testing.T, v *View) { - v.Append([]byte(" world")) - }, - }, - { - name: "append-fill", - input: strings.Repeat("1", bufferSize-1), - output: strings.Repeat("1", bufferSize-1) + "0", - op: func(t *testing.T, v *View) { - v.Append([]byte("0")) - }, - }, - { - name: "append-overflow", - input: strings.Repeat("1", bufferSize), - output: strings.Repeat("1", bufferSize) + "0", - op: func(t *testing.T, v *View) { - v.Append([]byte("0")) - }, - }, - { - name: "append-multiple-buffers", - input: strings.Repeat("1", bufferSize-1), - output: strings.Repeat("1", bufferSize-1) + strings.Repeat("0", bufferSize*3), - op: func(t *testing.T, v *View) { - v.Append([]byte(strings.Repeat("0", bufferSize*3))) - }, - }, - - // Truncate. - { - name: "truncate", - input: "hello world", - output: "hello", - op: func(t *testing.T, v *View) { - v.Truncate(5) - }, - }, - { - name: "truncate-noop", - input: "hello world", - output: "hello world", - op: func(t *testing.T, v *View) { - v.Truncate(v.Size() + 1) - }, - }, - { - name: "truncate-multiple-buffers", - input: strings.Repeat("1", bufferSize*2), - output: strings.Repeat("1", bufferSize*2-1), - op: func(t *testing.T, v *View) { - v.Truncate(bufferSize*2 - 1) - }, - }, - { - name: "truncate-multiple-buffers-to-one", - input: strings.Repeat("1", bufferSize*2), - output: "11111", - op: func(t *testing.T, v *View) { - v.Truncate(5) - }, - }, - - // TrimFront. - { - name: "trim", - input: "hello world", - output: "world", - op: func(t *testing.T, v *View) { - v.TrimFront(6) - }, - }, - { - name: "trim-too-large", - input: "hello world", - output: "", - op: func(t *testing.T, v *View) { - v.TrimFront(v.Size() + 1) - }, - }, - { - name: "trim-multiple-buffers", - input: strings.Repeat("1", bufferSize*2), - output: strings.Repeat("1", bufferSize*2-1), - op: func(t *testing.T, v *View) { - v.TrimFront(1) - }, - }, - { - name: "trim-multiple-buffers-to-one-buffer", - input: strings.Repeat("1", bufferSize*2), - output: "1", - op: func(t *testing.T, v *View) { - v.TrimFront(bufferSize*2 - 1) - }, - }, - - // Grow. - { - name: "grow", - input: "hello world", - output: "hello world", - op: func(t *testing.T, v *View) { - v.Grow(1, true) - }, - }, - { - name: "grow-from-zero", - output: strings.Repeat("\x00", 1024), - op: func(t *testing.T, v *View) { - v.Grow(1024, true) - }, - }, - { - name: "grow-from-non-zero", - input: strings.Repeat("1", bufferSize), - output: strings.Repeat("1", bufferSize) + strings.Repeat("\x00", bufferSize), - op: func(t *testing.T, v *View) { - v.Grow(bufferSize*2, true) - }, - }, - - // Copy. - { - name: "copy", - input: "hello", - output: "hello", - op: func(t *testing.T, v *View) { - other := v.Copy() - bs := other.Flatten() - want := []byte("hello") - if !bytes.Equal(bs, want) { - t.Errorf("expected %v, got %v", want, bs) - } - }, - }, - { - name: "copy-large", - input: strings.Repeat("1", bufferSize+1), - output: strings.Repeat("1", bufferSize+1), - op: func(t *testing.T, v *View) { - other := v.Copy() - bs := other.Flatten() - want := []byte(strings.Repeat("1", bufferSize+1)) - if !bytes.Equal(bs, want) { - t.Errorf("expected %v, got %v", want, bs) - } - }, - }, - - // Merge. - { - name: "merge", - input: "hello", - output: "hello world", - op: func(t *testing.T, v *View) { - var other View - other.Append([]byte(" world")) - v.Merge(&other) - if sz := other.Size(); sz != 0 { - t.Errorf("expected 0, got %d", sz) - } - }, - }, - { - name: "merge-large", - input: strings.Repeat("1", bufferSize+1), - output: strings.Repeat("1", bufferSize+1) + strings.Repeat("0", bufferSize+1), - op: func(t *testing.T, v *View) { - var other View - other.Append([]byte(strings.Repeat("0", bufferSize+1))) - v.Merge(&other) - if sz := other.Size(); sz != 0 { - t.Errorf("expected 0, got %d", sz) - } - }, - }, - - // ReadAt. - { - name: "readat", - input: "hello", - output: "hello", - op: func(t *testing.T, v *View) { testReadAt(t, v, 0, 6, "hello", io.EOF) }, - }, - { - name: "readat-long", - input: "hello", - output: "hello", - op: func(t *testing.T, v *View) { testReadAt(t, v, 0, 8, "hello", io.EOF) }, - }, - { - name: "readat-short", - input: "hello", - output: "hello", - op: func(t *testing.T, v *View) { testReadAt(t, v, 0, 3, "hel", nil) }, - }, - { - name: "readat-offset", - input: "hello", - output: "hello", - op: func(t *testing.T, v *View) { testReadAt(t, v, 2, 3, "llo", io.EOF) }, - }, - { - name: "readat-long-offset", - input: "hello", - output: "hello", - op: func(t *testing.T, v *View) { testReadAt(t, v, 2, 8, "llo", io.EOF) }, - }, - { - name: "readat-short-offset", - input: "hello", - output: "hello", - op: func(t *testing.T, v *View) { testReadAt(t, v, 2, 2, "ll", nil) }, - }, - { - name: "readat-skip-all", - input: "hello", - output: "hello", - op: func(t *testing.T, v *View) { testReadAt(t, v, bufferSize+1, 1, "", io.EOF) }, - }, - { - name: "readat-second-buffer", - input: strings.Repeat("0", bufferSize+1) + "12", - output: strings.Repeat("0", bufferSize+1) + "12", - op: func(t *testing.T, v *View) { testReadAt(t, v, bufferSize+1, 1, "1", nil) }, - }, - { - name: "readat-second-buffer-end", - input: strings.Repeat("0", bufferSize+1) + "12", - output: strings.Repeat("0", bufferSize+1) + "12", - op: func(t *testing.T, v *View) { testReadAt(t, v, bufferSize+1, 2, "12", io.EOF) }, - }, - } - - for _, tc := range testCases { - for fillName, fn := range fillFuncs { - t.Run(fillName+"/"+tc.name, func(t *testing.T) { - // Construct & fill the view. - var view View - fn(&view, []byte(tc.input)) - - // Run the operation. - if tc.op != nil { - tc.op(t, &view) - } - - // Flatten and validate. - out := view.Flatten() - if !bytes.Equal([]byte(tc.output), out) { - t.Errorf("expected %q, got %q", tc.output, string(out)) - } - - // Ensure the size is correct. - if len(out) != int(view.Size()) { - t.Errorf("size is wrong: expected %d, got %d", len(out), view.Size()) - } - - // Calculate contents via apply. - var appliedOut []byte - view.Apply(func(b []byte) { - appliedOut = append(appliedOut, b...) - }) - if len(appliedOut) != len(out) { - t.Errorf("expected %d, got %d", len(out), len(appliedOut)) - } - if !bytes.Equal(appliedOut, out) { - t.Errorf("expected %v, got %v", out, appliedOut) - } - - // Calculate contents via ReadToWriter. - var b bytes.Buffer - n, err := view.ReadToWriter(&b, int64(len(out))) - if n != int64(len(out)) { - t.Errorf("expected %d, got %d", len(out), n) - } - if err != nil { - t.Errorf("expected nil, got %v", err) - } - if !bytes.Equal(b.Bytes(), out) { - t.Errorf("expected %v, got %v", out, b.Bytes()) - } - }) - } - } -} - -func doSaveAndLoad(t *testing.T, toSave, toLoad *View) { - t.Helper() - var buf bytes.Buffer - ctx := context.Background() - if _, err := state.Save(ctx, &buf, toSave); err != nil { - t.Fatal("state.Save:", err) - } - if _, err := state.Load(ctx, bytes.NewReader(buf.Bytes()), toLoad); err != nil { - t.Fatal("state.Load:", err) - } -} - -func TestSaveRestoreViewEmpty(t *testing.T) { - var toSave View - var v View - doSaveAndLoad(t, &toSave, &v) - - if got := v.pool.avail; got != nil { - t.Errorf("pool is not in zero state: v.pool.avail = %v, want nil", got) - } - if got := v.Flatten(); len(got) != 0 { - t.Errorf("v.Flatten() = %x, want []", got) - } -} - -func TestSaveRestoreView(t *testing.T) { - // Create data that fits 2.5 slots. - data := bytes.Join([][]byte{ - bytes.Repeat([]byte{1, 2}, defaultBufferSize), - bytes.Repeat([]byte{3}, defaultBufferSize/2), - }, nil) - - var toSave View - toSave.Append(data) - - var v View - doSaveAndLoad(t, &toSave, &v) - - // Next available slot at index 3; 0-2 slot are used. - i := 3 - if got, want := &v.pool.avail[0], &v.pool.embeddedStorage[i]; got != want { - t.Errorf("next available buffer points to %p, want %p (&v.pool.embeddedStorage[%d])", got, want, i) - } - if got := v.Flatten(); !bytes.Equal(got, data) { - t.Errorf("v.Flatten() = %x, want %x", got, data) - } -} diff --git a/pkg/buffer/view_unsafe.go b/pkg/buffer/view_unsafe.go deleted file mode 100644 index d1ef39b26..000000000 --- a/pkg/buffer/view_unsafe.go +++ /dev/null @@ -1,25 +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 ( - "unsafe" -) - -// minBatch is the smallest Read or Write operation that the -// WriteFromReader and ReadToWriter functions will use. -// -// This is defined as the size of a native pointer. -const minBatch = int(unsafe.Sizeof(uintptr(0))) |