Giant blob of minor changes

[dotfiles/.git] / .config / coc / extensions / coc-go-data / tools / pkg / mod / golang.org / x / mod@v0.3.0 / sumdb / dirhash / hash.go

diff --git a/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/mod@v0.3.0/sumdb/dirhash/hash.go b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/mod@v0.3.0/sumdb/dirhash/hash.go
new file mode 100644 (file)
index 0000000..ef5df6f
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+++ b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/mod@v0.3.0/sumdb/dirhash/hash.go
@@ -0,0 +1,132 @@
+// Copyright 2018 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 dirhash defines hashes over directory trees.
+// These hashes are recorded in go.sum files and in the Go checksum database,
+// to allow verifying that a newly-downloaded module has the expected content.
+package dirhash
+
+import (
+       "archive/zip"
+       "crypto/sha256"
+       "encoding/base64"
+       "errors"
+       "fmt"
+       "io"
+       "os"
+       "path/filepath"
+       "sort"
+       "strings"
+)
+
+// DefaultHash is the default hash function used in new go.sum entries.
+var DefaultHash Hash = Hash1
+
+// A Hash is a directory hash function.
+// It accepts a list of files along with a function that opens the content of each file.
+// It opens, reads, hashes, and closes each file and returns the overall directory hash.
+type Hash func(files []string, open func(string) (io.ReadCloser, error)) (string, error)
+
+// Hash1 is the "h1:" directory hash function, using SHA-256.
+//
+// Hash1 is "h1:" followed by the base64-encoded SHA-256 hash of a summary
+// prepared as if by the Unix command:
+//
+//     find . -type f | sort | sha256sum
+//
+// More precisely, the hashed summary contains a single line for each file in the list,
+// ordered by sort.Strings applied to the file names, where each line consists of
+// the hexadecimal SHA-256 hash of the file content,
+// two spaces (U+0020), the file name, and a newline (U+000A).
+//
+// File names with newlines (U+000A) are disallowed.
+func Hash1(files []string, open func(string) (io.ReadCloser, error)) (string, error) {
+       h := sha256.New()
+       files = append([]string(nil), files...)
+       sort.Strings(files)
+       for _, file := range files {
+               if strings.Contains(file, "\n") {
+                       return "", errors.New("dirhash: filenames with newlines are not supported")
+               }
+               r, err := open(file)
+               if err != nil {
+                       return "", err
+               }
+               hf := sha256.New()
+               _, err = io.Copy(hf, r)
+               r.Close()
+               if err != nil {
+                       return "", err
+               }
+               fmt.Fprintf(h, "%x  %s\n", hf.Sum(nil), file)
+       }
+       return "h1:" + base64.StdEncoding.EncodeToString(h.Sum(nil)), nil
+}
+
+// HashDir returns the hash of the local file system directory dir,
+// replacing the directory name itself with prefix in the file names
+// used in the hash function.
+func HashDir(dir, prefix string, hash Hash) (string, error) {
+       files, err := DirFiles(dir, prefix)
+       if err != nil {
+               return "", err
+       }
+       osOpen := func(name string) (io.ReadCloser, error) {
+               return os.Open(filepath.Join(dir, strings.TrimPrefix(name, prefix)))
+       }
+       return hash(files, osOpen)
+}
+
+// DirFiles returns the list of files in the tree rooted at dir,
+// replacing the directory name dir with prefix in each name.
+// The resulting names always use forward slashes.
+func DirFiles(dir, prefix string) ([]string, error) {
+       var files []string
+       dir = filepath.Clean(dir)
+       err := filepath.Walk(dir, func(file string, info os.FileInfo, err error) error {
+               if err != nil {
+                       return err
+               }
+               if info.IsDir() {
+                       return nil
+               }
+               rel := file
+               if dir != "." {
+                       rel = file[len(dir)+1:]
+               }
+               f := filepath.Join(prefix, rel)
+               files = append(files, filepath.ToSlash(f))
+               return nil
+       })
+       if err != nil {
+               return nil, err
+       }
+       return files, nil
+}
+
+// HashZip returns the hash of the file content in the named zip file.
+// Only the file names and their contents are included in the hash:
+// the exact zip file format encoding, compression method,
+// per-file modification times, and other metadata are ignored.
+func HashZip(zipfile string, hash Hash) (string, error) {
+       z, err := zip.OpenReader(zipfile)
+       if err != nil {
+               return "", err
+       }
+       defer z.Close()
+       var files []string
+       zfiles := make(map[string]*zip.File)
+       for _, file := range z.File {
+               files = append(files, file.Name)
+               zfiles[file.Name] = file
+       }
+       zipOpen := func(name string) (io.ReadCloser, error) {
+               f := zfiles[name]
+               if f == nil {
+                       return nil, fmt.Errorf("file %q not found in zip", name) // should never happen
+               }
+               return f.Open()
+       }
+       return hash(files, zipOpen)
+}