diff options
Diffstat (limited to 'vendor/golang.org/x/tools/internal/modindex/index.go')
| -rw-r--r-- | vendor/golang.org/x/tools/internal/modindex/index.go | 287 |
1 files changed, 0 insertions, 287 deletions
diff --git a/vendor/golang.org/x/tools/internal/modindex/index.go b/vendor/golang.org/x/tools/internal/modindex/index.go deleted file mode 100644 index c41d1dd90..000000000 --- a/vendor/golang.org/x/tools/internal/modindex/index.go +++ /dev/null @@ -1,287 +0,0 @@ -// Copyright 2024 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package modindex - -import ( - "bufio" - "crypto/sha256" - "encoding/csv" - "fmt" - "io" - "log" - "os" - "path/filepath" - "strconv" - "strings" - "testing" - "time" -) - -/* -The on-disk index ("payload") is a text file. -The first 3 lines are header information containing CurrentVersion, -the value of GOMODCACHE, and the validity date of the index. -(This is when the code started building the index.) -Following the header are sections of lines, one section for each -import path. These sections are sorted by package name. -The first line of each section, marked by a leading :, contains -the package name, the import path, the name of the directory relative -to GOMODCACHE, and its semantic version. -The rest of each section consists of one line per exported symbol. -The lines are sorted by the symbol's name and contain the name, -an indication of its lexical type (C, T, V, F), and if it is the -name of a function, information about the signature. - -The fields in the section header lines are separated by commas, and -in the unlikely event this would be confusing, the csv package is used -to write (and read) them. - -In the lines containing exported names, C=const, V=var, T=type, F=func. -If it is a func, the next field is the number of returned values, -followed by pairs consisting of formal parameter names and types. -All these fields are separated by spaces. Any spaces in a type -(e.g., chan struct{}) are replaced by $s on the disk. The $s are -turned back into spaces when read. - -Here is an index header (the comments are not part of the index): -0 // version (of the index format) -/usr/local/google/home/pjw/go/pkg/mod // GOMODCACHE -2024-09-11 18:55:09 // validity date of the index - -Here is an index section: -:yaml,gopkg.in/yaml.v1,gopkg.in/yaml.v1@v1.0.0-20140924161607-9f9df34309c0,v1.0.0-20140924161607-9f9df34309c0 -Getter T -Marshal F 2 in interface{} -Setter T -Unmarshal F 1 in []byte out interface{} - -The package name is yaml, the import path is gopkg.in/yaml.v1. -Getter and Setter are types, and Marshal and Unmarshal are functions. -The latter returns one value and has two arguments, 'in' and 'out' -whose types are []byte and interface{}. -*/ - -// CurrentVersion tells readers about the format of the index. -const CurrentVersion int = 0 - -// Index is returned by [Read]. -type Index struct { - Version int - GOMODCACHE string // absolute path of Go module cache dir - ValidAt time.Time // moment at which the index was up to date - Entries []Entry -} - -func (ix *Index) String() string { - return fmt.Sprintf("Index(%s v%d has %d entries at %v)", - ix.GOMODCACHE, ix.Version, len(ix.Entries), ix.ValidAt) -} - -// An Entry contains information for an import path. -type Entry struct { - Dir string // package directory relative to GOMODCACHE; uses OS path separator - ImportPath string - PkgName string - Version string - Names []string // exported names and information -} - -// IndexDir is where the module index is stored. -// Each logical index entry consists of a pair of files: -// -// - the "payload" (index-VERSION-XXX), whose name is -// randomized, holds the actual index; and -// - the "link" (index-name-VERSION-HASH), -// whose name is predictable, contains the -// name of the payload file. -// -// Since the link file is small (<512B), -// reads and writes to it may be assumed atomic. -var IndexDir string = func() string { - var dir string - if testing.Testing() { - dir = os.TempDir() - } else { - var err error - dir, err = os.UserCacheDir() - // shouldn't happen, but TempDir is better than - // creating ./go/imports - if err != nil { - dir = os.TempDir() - } - } - dir = filepath.Join(dir, "goimports") - if err := os.MkdirAll(dir, 0777); err != nil { - log.Printf("failed to create modcache index dir: %v", err) - } - return dir -}() - -// Read reads the latest version of the on-disk index -// for the specified Go module cache directory. -// If there is no index, it returns a nil Index and an fs.ErrNotExist error. -func Read(gomodcache string) (*Index, error) { - gomodcache, err := filepath.Abs(gomodcache) - if err != nil { - return nil, err - } - - // Read the "link" file for the specified gomodcache directory. - // It names the payload file. - content, err := os.ReadFile(filepath.Join(IndexDir, linkFileBasename(gomodcache))) - if err != nil { - return nil, err - } - payloadFile := filepath.Join(IndexDir, string(content)) - - // Read the index out of the payload file. - f, err := os.Open(payloadFile) - if err != nil { - return nil, err - } - defer f.Close() - return readIndexFrom(gomodcache, bufio.NewReader(f)) -} - -func readIndexFrom(gomodcache string, r io.Reader) (*Index, error) { - scan := bufio.NewScanner(r) - - // version - if !scan.Scan() { - return nil, fmt.Errorf("unexpected scan error: %v", scan.Err()) - } - version, err := strconv.Atoi(scan.Text()) - if err != nil { - return nil, err - } - if version != CurrentVersion { - return nil, fmt.Errorf("got version %d, expected %d", version, CurrentVersion) - } - - // gomodcache - if !scan.Scan() { - return nil, fmt.Errorf("scanner error reading module cache dir: %v", scan.Err()) - } - // TODO(pjw): need to check that this is the expected cache dir - // so the tag should be passed in to this function - if dir := string(scan.Text()); dir != gomodcache { - return nil, fmt.Errorf("index file GOMODCACHE mismatch: got %q, want %q", dir, gomodcache) - } - - // changed - if !scan.Scan() { - return nil, fmt.Errorf("scanner error reading index creation time: %v", scan.Err()) - } - changed, err := time.ParseInLocation(time.DateTime, scan.Text(), time.Local) - if err != nil { - return nil, err - } - - // entries - var ( - curEntry *Entry - entries []Entry - ) - for scan.Scan() { - v := scan.Text() - if v[0] == ':' { - if curEntry != nil { - entries = append(entries, *curEntry) - } - // as directories may contain commas and quotes, they need to be read as csv. - rdr := strings.NewReader(v[1:]) - cs := csv.NewReader(rdr) - flds, err := cs.Read() - if err != nil { - return nil, err - } - if len(flds) != 4 { - return nil, fmt.Errorf("header contains %d fields, not 4: %q", len(v), v) - } - curEntry = &Entry{ - PkgName: flds[0], - ImportPath: flds[1], - Dir: relative(gomodcache, flds[2]), - Version: flds[3], - } - continue - } - curEntry.Names = append(curEntry.Names, v) - } - if err := scan.Err(); err != nil { - return nil, fmt.Errorf("scanner failed while reading modindex entry: %v", err) - } - if curEntry != nil { - entries = append(entries, *curEntry) - } - - return &Index{ - Version: version, - GOMODCACHE: gomodcache, - ValidAt: changed, - Entries: entries, - }, nil -} - -// write writes the index file and updates the index directory to refer to it. -func write(gomodcache string, ix *Index) error { - // Write the index into a payload file with a fresh name. - f, err := os.CreateTemp(IndexDir, fmt.Sprintf("index-%d-*", CurrentVersion)) - if err != nil { - return err // e.g. disk full, or index dir deleted - } - if err := writeIndexToFile(ix, bufio.NewWriter(f)); err != nil { - _ = f.Close() // ignore error - return err - } - if err := f.Close(); err != nil { - return err - } - - // Write the name of the payload file into a link file. - indexDirFile := filepath.Join(IndexDir, linkFileBasename(gomodcache)) - content := []byte(filepath.Base(f.Name())) - return os.WriteFile(indexDirFile, content, 0666) -} - -func writeIndexToFile(x *Index, w *bufio.Writer) error { - fmt.Fprintf(w, "%d\n", x.Version) - fmt.Fprintf(w, "%s\n", x.GOMODCACHE) - tm := x.ValidAt.Truncate(time.Second) // round the time down - fmt.Fprintf(w, "%s\n", tm.Format(time.DateTime)) - for _, e := range x.Entries { - if e.ImportPath == "" { - continue // shouldn't happen - } - // PJW: maybe always write these headers as csv? - if strings.ContainsAny(string(e.Dir), ",\"") { - cw := csv.NewWriter(w) - cw.Write([]string{":" + e.PkgName, e.ImportPath, string(e.Dir), e.Version}) - cw.Flush() - } else { - fmt.Fprintf(w, ":%s,%s,%s,%s\n", e.PkgName, e.ImportPath, e.Dir, e.Version) - } - for _, x := range e.Names { - fmt.Fprintf(w, "%s\n", x) - } - } - return w.Flush() -} - -// linkFileBasename returns the base name of the link file in the -// index directory that holds the name of the payload file for the -// specified (absolute) Go module cache dir. -func linkFileBasename(gomodcache string) string { - // Note: coupled to logic in ./gomodindex/cmd.go. TODO: factor. - h := sha256.Sum256([]byte(gomodcache)) // collision-resistant hash - return fmt.Sprintf("index-name-%d-%032x", CurrentVersion, h) -} - -func relative(base, file string) string { - if rel, err := filepath.Rel(base, file); err == nil { - return rel - } - return file -} |