diff options
Diffstat (limited to 'pkg/fspath')
| -rw-r--r-- | pkg/fspath/BUILD | 29 | ||||
| -rw-r--r-- | pkg/fspath/builder.go | 104 | ||||
| -rw-r--r-- | pkg/fspath/builder_test.go | 58 | ||||
| -rw-r--r-- | pkg/fspath/builder_unsafe.go | 27 | ||||
| -rw-r--r-- | pkg/fspath/fspath.go | 182 | ||||
| -rw-r--r-- | pkg/fspath/fspath_test.go | 143 |
6 files changed, 0 insertions, 543 deletions
diff --git a/pkg/fspath/BUILD b/pkg/fspath/BUILD deleted file mode 100644 index 0c5f50397..000000000 --- a/pkg/fspath/BUILD +++ /dev/null @@ -1,29 +0,0 @@ -load("//tools/go_stateify:defs.bzl", "go_library") -load("@io_bazel_rules_go//go:def.bzl", "go_test") - -package( - default_visibility = ["//visibility:public"], - licenses = ["notice"], -) - -go_library( - name = "fspath", - srcs = [ - "builder.go", - "builder_unsafe.go", - "fspath.go", - ], - importpath = "gvisor.dev/gvisor/pkg/fspath", - deps = ["//pkg/syserror"], -) - -go_test( - name = "fspath_test", - size = "small", - srcs = [ - "builder_test.go", - "fspath_test.go", - ], - embed = [":fspath"], - deps = ["//pkg/syserror"], -) diff --git a/pkg/fspath/builder.go b/pkg/fspath/builder.go deleted file mode 100644 index 7ddb36826..000000000 --- a/pkg/fspath/builder.go +++ /dev/null @@ -1,104 +0,0 @@ -// Copyright 2019 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 fspath - -import ( - "fmt" -) - -// Builder is similar to strings.Builder, but is used to produce pathnames -// given path components in reverse order (from leaf to root). This is useful -// in the common case where a filesystem is represented by a tree of named -// nodes, and the path to a given node must be produced by walking upward from -// that node to a given root. -type Builder struct { - buf []byte - start int - needSep bool -} - -// Reset resets the Builder to be empty. -func (b *Builder) Reset() { - b.start = len(b.buf) - b.needSep = false -} - -// Len returns the number of accumulated bytes. -func (b *Builder) Len() int { - return len(b.buf) - b.start -} - -func (b *Builder) needToGrow(n int) bool { - return b.start < n -} - -func (b *Builder) grow(n int) { - newLen := b.Len() + n - var newCap int - if len(b.buf) == 0 { - newCap = 64 // arbitrary - } else { - newCap = 2 * len(b.buf) - } - for newCap < newLen { - newCap *= 2 - if newCap == 0 { - panic(fmt.Sprintf("required length (%d) causes buffer size to overflow", newLen)) - } - } - newBuf := make([]byte, newCap) - copy(newBuf[newCap-b.Len():], b.buf[b.start:]) - b.start += newCap - len(b.buf) - b.buf = newBuf -} - -// PrependComponent prepends the given path component to b's buffer. A path -// separator is automatically inserted if appropriate. -func (b *Builder) PrependComponent(pc string) { - if b.needSep { - b.PrependByte('/') - } - b.PrependString(pc) - b.needSep = true -} - -// PrependString prepends the given string to b's buffer. -func (b *Builder) PrependString(str string) { - if b.needToGrow(len(str)) { - b.grow(len(str)) - } - b.start -= len(str) - copy(b.buf[b.start:], str) -} - -// PrependByte prepends the given byte to b's buffer. -func (b *Builder) PrependByte(c byte) { - if b.needToGrow(1) { - b.grow(1) - } - b.start-- - b.buf[b.start] = c -} - -// AppendString appends the given string to b's buffer. -func (b *Builder) AppendString(str string) { - if b.needToGrow(len(str)) { - b.grow(len(str)) - } - oldStart := b.start - b.start -= len(str) - copy(b.buf[b.start:], b.buf[oldStart:]) - copy(b.buf[len(b.buf)-len(str):], str) -} diff --git a/pkg/fspath/builder_test.go b/pkg/fspath/builder_test.go deleted file mode 100644 index 22f890273..000000000 --- a/pkg/fspath/builder_test.go +++ /dev/null @@ -1,58 +0,0 @@ -// Copyright 2019 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 fspath - -import ( - "testing" -) - -func TestBuilder(t *testing.T) { - type testCase struct { - pcs []string // path components in reverse order - after string - want string - } - tests := []testCase{ - { - // Empty case. - }, - { - pcs: []string{"foo"}, - want: "foo", - }, - { - pcs: []string{"foo", "bar", "baz"}, - want: "baz/bar/foo", - }, - { - pcs: []string{"foo", "bar"}, - after: " (deleted)", - want: "bar/foo (deleted)", - }, - } - - for _, test := range tests { - t.Run(test.want, func(t *testing.T) { - var b Builder - for _, pc := range test.pcs { - b.PrependComponent(pc) - } - b.AppendString(test.after) - if got := b.String(); got != test.want { - t.Errorf("got %q, wanted %q", got, test.want) - } - }) - } -} diff --git a/pkg/fspath/builder_unsafe.go b/pkg/fspath/builder_unsafe.go deleted file mode 100644 index 75606808d..000000000 --- a/pkg/fspath/builder_unsafe.go +++ /dev/null @@ -1,27 +0,0 @@ -// Copyright 2019 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 fspath - -import ( - "unsafe" -) - -// String returns the accumulated string. No other methods should be called -// after String. -func (b *Builder) String() string { - bs := b.buf[b.start:] - // Compare strings.Builder.String(). - return *(*string)(unsafe.Pointer(&bs)) -} diff --git a/pkg/fspath/fspath.go b/pkg/fspath/fspath.go deleted file mode 100644 index f68752560..000000000 --- a/pkg/fspath/fspath.go +++ /dev/null @@ -1,182 +0,0 @@ -// Copyright 2019 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 fspath provides efficient tools for working with file paths in -// Linux-compatible filesystem implementations. -package fspath - -import ( - "strings" - - "gvisor.dev/gvisor/pkg/syserror" -) - -const pathSep = '/' - -// Parse parses a pathname as described by path_resolution(7). -func Parse(pathname string) (Path, error) { - if len(pathname) == 0 { - // "... POSIX decrees that an empty pathname must not be resolved - // successfully. Linux returns ENOENT in this case." - - // path_resolution(7) - return Path{}, syserror.ENOENT - } - // Skip leading path separators. - i := 0 - for pathname[i] == pathSep { - i++ - if i == len(pathname) { - // pathname consists entirely of path separators. - return Path{ - Absolute: true, - Dir: true, - }, nil - } - } - // Skip trailing path separators. This is required by Iterator.Next. This - // loop is guaranteed to terminate with j >= 0 because otherwise the - // pathname would consist entirely of path separators, so we would have - // returned above. - j := len(pathname) - 1 - for pathname[j] == pathSep { - j-- - } - // Find the end of the first path component. - firstEnd := i + 1 - for firstEnd != len(pathname) && pathname[firstEnd] != pathSep { - firstEnd++ - } - return Path{ - Begin: Iterator{ - partialPathname: pathname[i : j+1], - end: firstEnd - i, - }, - Absolute: i != 0, - Dir: j != len(pathname)-1, - }, nil -} - -// Path contains the information contained in a pathname string. -// -// Path is copyable by value. -type Path struct { - // Begin is an iterator to the first path component in the relative part of - // the path. - // - // Path doesn't store information about path components after the first - // since this would require allocation. - Begin Iterator - - // If true, the path is absolute, such that lookup should begin at the - // filesystem root. If false, the path is relative, such that where lookup - // begins is unspecified. - Absolute bool - - // If true, the pathname contains trailing path separators, so the last - // path component must exist and resolve to a directory. - Dir bool -} - -// String returns a pathname string equivalent to p. Note that the returned -// string is not necessarily equal to the string p was parsed from; in -// particular, redundant path separators will not be present. -func (p Path) String() string { - var b strings.Builder - if p.Absolute { - b.WriteByte(pathSep) - } - sep := false - for pit := p.Begin; pit.Ok(); pit = pit.Next() { - if sep { - b.WriteByte(pathSep) - } - b.WriteString(pit.String()) - sep = true - } - // Don't return "//" for Parse("/"). - if p.Dir && p.Begin.Ok() { - b.WriteByte(pathSep) - } - return b.String() -} - -// An Iterator represents either a path component in a Path or a terminal -// iterator indicating that the end of the path has been reached. -// -// Iterator is immutable and copyable by value. The zero value of Iterator is -// valid, and represents a terminal iterator. -type Iterator struct { - // partialPathname is a substring of the original pathname beginning at the - // start of the represented path component and ending immediately after the - // end of the last path component in the pathname. If partialPathname is - // empty, the PathnameIterator is terminal. - // - // See TestParseIteratorPartialPathnames in fspath_test.go for a worked - // example. - partialPathname string - - // end is the offset into partialPathname of the first byte after the end - // of the represented path component. - end int -} - -// Ok returns true if it is not terminal. -func (it Iterator) Ok() bool { - return len(it.partialPathname) != 0 -} - -// String returns the path component represented by it. -// -// Preconditions: it.Ok(). -func (it Iterator) String() string { - return it.partialPathname[:it.end] -} - -// Next returns an iterator to the path component after it. If it is the last -// component in the path, Next returns a terminal iterator. -// -// Preconditions: it.Ok(). -func (it Iterator) Next() Iterator { - if it.end == len(it.partialPathname) { - // End of the path. - return Iterator{} - } - // Skip path separators. Since Parse trims trailing path separators, if we - // aren't at the end of the path, there is definitely another path - // component. - i := it.end + 1 - for { - if it.partialPathname[i] != pathSep { - break - } - i++ - } - nextPartialPathname := it.partialPathname[i:] - // Find the end of this path component. - nextEnd := 1 - for nextEnd < len(nextPartialPathname) && nextPartialPathname[nextEnd] != pathSep { - nextEnd++ - } - return Iterator{ - partialPathname: nextPartialPathname, - end: nextEnd, - } -} - -// NextOk is equivalent to it.Next().Ok(), but is faster. -// -// Preconditions: it.Ok(). -func (it Iterator) NextOk() bool { - return it.end != len(it.partialPathname) -} diff --git a/pkg/fspath/fspath_test.go b/pkg/fspath/fspath_test.go deleted file mode 100644 index 215b35622..000000000 --- a/pkg/fspath/fspath_test.go +++ /dev/null @@ -1,143 +0,0 @@ -// Copyright 2019 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 fspath - -import ( - "reflect" - "strings" - "testing" - - "gvisor.dev/gvisor/pkg/syserror" -) - -func TestParseIteratorPartialPathnames(t *testing.T) { - path, err := Parse("/foo//bar///baz////") - if err != nil { - t.Fatalf("Parse failed: %v", err) - } - // Parse strips leading slashes, and records their presence as - // Path.Absolute. - if !path.Absolute { - t.Errorf("Path.Absolute: got false, wanted true") - } - // Parse strips trailing slashes, and records their presence as Path.Dir. - if !path.Dir { - t.Errorf("Path.Dir: got false, wanted true") - } - // The first Iterator.partialPathname is the input pathname, with leading - // and trailing slashes stripped. - it := path.Begin - if want := "foo//bar///baz"; it.partialPathname != want { - t.Errorf("first Iterator.partialPathname: got %q, wanted %q", it.partialPathname, want) - } - // Successive Iterator.partialPathnames remove the leading path component - // and following slashes, until we run out of path components and get a - // terminal Iterator. - it = it.Next() - if want := "bar///baz"; it.partialPathname != want { - t.Errorf("second Iterator.partialPathname: got %q, wanted %q", it.partialPathname, want) - } - it = it.Next() - if want := "baz"; it.partialPathname != want { - t.Errorf("third Iterator.partialPathname: got %q, wanted %q", it.partialPathname, want) - } - it = it.Next() - if want := ""; it.partialPathname != want { - t.Errorf("fourth Iterator.partialPathname: got %q, wanted %q", it.partialPathname, want) - } - if it.Ok() { - t.Errorf("fourth Iterator.Ok(): got true, wanted false") - } -} - -func TestParse(t *testing.T) { - type testCase struct { - pathname string - relpath []string - abs bool - dir bool - } - tests := []testCase{ - { - pathname: "/", - relpath: []string{}, - abs: true, - dir: true, - }, - { - pathname: "//", - relpath: []string{}, - abs: true, - dir: true, - }, - } - for _, sep := range []string{"/", "//"} { - for _, abs := range []bool{false, true} { - for _, dir := range []bool{false, true} { - for _, pcs := range [][]string{ - // single path component - {"foo"}, - // multiple path components, including non-UTF-8 - {".", "foo", "..", "\xe6", "bar"}, - } { - prefix := "" - if abs { - prefix = sep - } - suffix := "" - if dir { - suffix = sep - } - tests = append(tests, testCase{ - pathname: prefix + strings.Join(pcs, sep) + suffix, - relpath: pcs, - abs: abs, - dir: dir, - }) - } - } - } - } - - for _, test := range tests { - t.Run(test.pathname, func(t *testing.T) { - p, err := Parse(test.pathname) - if err != nil { - t.Fatalf("failed to parse pathname %q: %v", test.pathname, err) - } - t.Logf("pathname %q => path %q", test.pathname, p) - if p.Absolute != test.abs { - t.Errorf("path absoluteness: got %v, wanted %v", p.Absolute, test.abs) - } - if p.Dir != test.dir { - t.Errorf("path must resolve to a directory: got %v, wanted %v", p.Dir, test.dir) - } - pcs := []string{} - for pit := p.Begin; pit.Ok(); pit = pit.Next() { - pcs = append(pcs, pit.String()) - } - if !reflect.DeepEqual(pcs, test.relpath) { - t.Errorf("relative path: got %v, wanted %v", pcs, test.relpath) - } - }) - } -} - -func TestParseEmptyPathname(t *testing.T) { - p, err := Parse("") - if err != syserror.ENOENT { - t.Errorf("parsing empty pathname: got (%v, %v), wanted (<unspecified>, ENOENT)", p, err) - } -} |