Initialize module and dependencies

2026-01-04 20:57:40 +00:00
commit a3b390c008
514 changed files with 310495 additions and 0 deletions
--- a/vendor/golang.org/x/tools/internal/modindex/index.go
+++ b/vendor/golang.org/x/tools/internal/modindex/index.go
@@ -0,0 +1,287 @@
+// 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
+}