pkg/buffer: Remove dependency to safemem, code no longer used

PiperOrigin-RevId: 373846881

3 files changed, 0 insertions, 310 deletions

diff --git a/pkg/buffer/BUILD b/pkg/buffer/BUILD
index 2a2e3d1aa..19cd28a32 100644
--- a/pkg/buffer/BUILD
+++ b/pkg/buffer/BUILD
@@ -21,7 +21,6 @@ go_library(
         "buffer.go",
         "buffer_list.go",
         "pool.go",
-        "safemem.go",
         "view.go",
         "view_unsafe.go",
     ],
@@ -29,8 +28,6 @@ go_library(
     deps = [
         "//pkg/context",
         "//pkg/log",
-        "//pkg/safemem",
-        "//pkg/usermem",
     ],
 )
 
@@ -40,12 +37,10 @@ go_test(
     srcs = [
         "buffer_test.go",
         "pool_test.go",
-        "safemem_test.go",
         "view_test.go",
     ],
     library = ":buffer",
     deps = [
-        "//pkg/safemem",
         "//pkg/state",
     ],
 )
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))
-			}
-		})
-	}
-}