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 | 262 |
1 files changed, 0 insertions, 262 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 27b6dd832..000000000 --- a/vendor/golang.org/x/tools/internal/modindex/index.go +++ /dev/null @@ -1,262 +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" - "encoding/csv" - "errors" - "fmt" - "hash/crc64" - "io" - "io/fs" - "log" - "os" - "path/filepath" - "strconv" - "strings" - "time" -) - -/* -The on-disk index 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 ReadIndex(). -type Index struct { - Version int - Cachedir Abspath // The directory containing the module cache - Changed time.Time // The index is up to date as of Changed - Entries []Entry -} - -// An Entry contains information for an import path. -type Entry struct { - Dir Relpath // directory in modcache - ImportPath string - PkgName string - Version string - //ModTime STime // is this useful? - Names []string // exported names and information -} - -// ReadIndex reads the latest version of the on-disk index -// for the cache directory cd. -// It returns (nil, nil) if there is no index, but returns -// a non-nil error if the index exists but could not be read. -func ReadIndex(cachedir string) (*Index, error) { - cachedir, err := filepath.Abs(cachedir) - if err != nil { - return nil, err - } - cd := Abspath(cachedir) - dir, err := IndexDir() - if err != nil { - return nil, err - } - base := indexNameBase(cd) - iname := filepath.Join(dir, base) - buf, err := os.ReadFile(iname) - if err != nil { - if errors.Is(err, fs.ErrNotExist) { - return nil, nil - } - return nil, fmt.Errorf("cannot read %s: %w", iname, err) - } - fname := filepath.Join(dir, string(buf)) - fd, err := os.Open(fname) - if err != nil { - return nil, err - } - defer fd.Close() - r := bufio.NewReader(fd) - ix, err := readIndexFrom(cd, r) - if err != nil { - return nil, err - } - return ix, nil -} - -func readIndexFrom(cd Abspath, bx io.Reader) (*Index, error) { - b := bufio.NewScanner(bx) - var ans Index - // header - ok := b.Scan() - if !ok { - return nil, fmt.Errorf("unexpected scan error") - } - l := b.Text() - var err error - ans.Version, err = strconv.Atoi(l) - if err != nil { - return nil, err - } - if ans.Version != CurrentVersion { - return nil, fmt.Errorf("got version %d, expected %d", ans.Version, CurrentVersion) - } - if ok := b.Scan(); !ok { - return nil, fmt.Errorf("scanner error reading cachedir") - } - ans.Cachedir = Abspath(b.Text()) - if ok := b.Scan(); !ok { - return nil, fmt.Errorf("scanner error reading index creation time") - } - // TODO(pjw): need to check that this is the expected cachedir - // so the tag should be passed in to this function - ans.Changed, err = time.ParseInLocation(time.DateTime, b.Text(), time.Local) - if err != nil { - return nil, err - } - var curEntry *Entry - for b.Scan() { - v := b.Text() - if v[0] == ':' { - if curEntry != nil { - ans.Entries = append(ans.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: toRelpath(cd, flds[2]), Version: flds[3]} - continue - } - curEntry.Names = append(curEntry.Names, v) - } - if curEntry != nil { - ans.Entries = append(ans.Entries, *curEntry) - } - if err := b.Err(); err != nil { - return nil, fmt.Errorf("scanner failed %v", err) - } - return &ans, nil -} - -// write the index as a text file -func writeIndex(cachedir Abspath, ix *Index) error { - dir, err := IndexDir() - if err != nil { - return err - } - ipat := fmt.Sprintf("index-%d-*", CurrentVersion) - fd, err := os.CreateTemp(dir, ipat) - if err != nil { - return err // can this happen? - } - defer fd.Close() - if err := writeIndexToFile(ix, fd); err != nil { - return err - } - content := fd.Name() - content = filepath.Base(content) - base := indexNameBase(cachedir) - nm := filepath.Join(dir, base) - err = os.WriteFile(nm, []byte(content), 0666) - if err != nil { - return err - } - return nil -} - -func writeIndexToFile(x *Index, fd *os.File) error { - cnt := 0 - w := bufio.NewWriter(fd) - fmt.Fprintf(w, "%d\n", x.Version) - fmt.Fprintf(w, "%s\n", x.Cachedir) - // round the time down - tm := x.Changed.Add(-time.Second / 2) - 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), ",\"") { - log.Printf("DIR: %s", 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) - cnt++ - } - } - if err := w.Flush(); err != nil { - return err - } - return nil -} - -// tests can override this -var IndexDir = indexDir - -// IndexDir computes the directory containing the index -func indexDir() (string, error) { - dir, err := os.UserCacheDir() - if err != nil { - return "", fmt.Errorf("cannot open UserCacheDir, %w", err) - } - return filepath.Join(dir, "go", "imports"), nil -} - -// return the base name of the file containing the name of the current index -func indexNameBase(cachedir Abspath) string { - // crc64 is a way to convert path names into 16 hex digits. - h := crc64.Checksum([]byte(cachedir), crc64.MakeTable(crc64.ECMA)) - fname := fmt.Sprintf("index-name-%d-%016x", CurrentVersion, h) - return fname -} |