X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=internal%2Fhasher.go;fp=internal%2Fhasher.go;h=da54b7d519177b9674e483a56e9d136537301507;hb=be69a4fc0c240c2772a0f0bf0955b39783e4c48a;hp=0000000000000000000000000000000000000000;hpb=ce902a58a32f42801603475c67dd75da86d4502a;p=meta4ra.git

diff --git a/internal/hasher.go b/internal/hasher.go
new file mode 100644
index 0000000..da54b7d
--- /dev/null
+++ b/internal/hasher.go
@@ -0,0 +1,127 @@
+// meta4ra -- Metalink 4.0 utilities
+// Copyright (C) 2021-2024 Sergey Matveev <stargrave@stargrave.org>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, version 3 of the License.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package internal
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"os/exec"
+	"strings"
+)
+
+type Hasher struct {
+	Names []string
+	Cmds  []*exec.Cmd
+	Ins   []io.WriteCloser
+	Outs  []io.ReadCloser
+}
+
+func NewHasher(hashes string) (*Hasher, error) {
+	h := Hasher{}
+	for _, hc := range strings.Split(hashes, ",") {
+		cols := strings.SplitN(hc, ":", 2)
+		name, cmdline := cols[0], cols[1]
+		if cmdline == BuiltinCmd {
+			newHash, exists := BuiltinHashes[name]
+			if !exists {
+				return nil, errors.New("no builtin hash: " + name)
+			}
+			b := &BuiltinHasher{h: newHash()}
+			h.Names = append(h.Names, name)
+			h.Ins = append(h.Ins, b)
+			h.Outs = append(h.Outs, b)
+			h.Cmds = append(h.Cmds, nil)
+		} else {
+			cmd := exec.Command("/bin/sh", "-e", "-c", cmdline)
+			in, err := cmd.StdinPipe()
+			if err != nil {
+				return &h, err
+			}
+			out, err := cmd.StdoutPipe()
+			if err != nil {
+				return &h, err
+			}
+			h.Names = append(h.Names, name)
+			h.Ins = append(h.Ins, in)
+			h.Outs = append(h.Outs, out)
+			h.Cmds = append(h.Cmds, cmd)
+		}
+	}
+	return &h, nil
+}
+
+func (h *Hasher) Start() (err error) {
+	for _, cmd := range h.Cmds {
+		if cmd == nil {
+			continue
+		}
+		err = cmd.Start()
+		if err != nil {
+			return
+		}
+	}
+	return nil
+}
+
+func (h *Hasher) Stop() {
+	for _, cmd := range h.Cmds {
+		if cmd == nil || cmd.Process == nil {
+			continue
+		}
+		cmd.Process.Kill()
+		cmd.Process.Release()
+	}
+}
+
+func (h *Hasher) Write(p []byte) (n int, rerr error) {
+	errs := make(chan error)
+	for _, in := range h.Ins {
+		go func(in io.WriteCloser) {
+			_, err := io.Copy(in, bytes.NewReader(p))
+			errs <- err
+		}(in)
+	}
+	for i := 0; i < len(h.Names); i++ {
+		if err := <-errs; err != nil {
+			rerr = err
+		}
+	}
+	n = len(p)
+	return
+}
+
+func (h *Hasher) Sums() (sums []Hash, err error) {
+	sums = make([]Hash, 0, len(h.Names))
+	for i, name := range h.Names {
+		if err = h.Ins[i].Close(); err != nil {
+			return
+		}
+		var out []byte
+		out, err = io.ReadAll(h.Outs[i])
+		if err != nil {
+			return
+		}
+		if cmd := h.Cmds[i]; cmd != nil {
+			if err = h.Cmds[i].Wait(); err != nil {
+				return
+			}
+		}
+		cols := strings.Fields(strings.TrimSuffix(string(out), "\n"))
+		sums = append(sums, Hash{Type: name, Hash: cols[0]})
+	}
+	return
+}