Optimise reading of only Build metainformation

[goredo.git] / dep.go

diff --git a/dep.go b/dep.go
index d819440a18b57909e05e387941030fc84482aa95..40245196c4b7a7a649eeabdbbac6c2ac9fe2cbaf 100644 (file)
--- a/dep.go
+++ b/dep.go
@@ -1,6 +1,6 @@
 /*
 goredo -- djb's redo implementation on pure Go
-Copyright (C) 2020-2022 Sergey Matveev <stargrave@stargrave.org>
+Copyright (C) 2020-2023 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
@@ -26,7 +26,6 @@ import (
        "io"
        "os"
        "path"
-       "path/filepath"
 
        "go.cypherpunks.ru/recfile"
        "lukechampine.com/blake3"
@@ -90,24 +89,20 @@ func depWrite(fdDep *os.File, cwd, tgt, hsh string) error {
        tracef(CDebug, "ifchange: %s <- %s", fdDep.Name(), tgt)
        fd, err := os.Open(path.Join(cwd, tgt))
        if err != nil {
-               return err
+               return ErrLine(err)
        }
        defer fd.Close()
-       fi, err := fd.Stat()
+       inode, isDir, err := inodeFromFileByFd(fd)
        if err != nil {
-               return err
+               return ErrLine(err)
        }
-       if fi.IsDir() {
+       if isDir {
                return nil
        }
-       inode, err := inodeFromFileByFd(fd)
-       if err != nil {
-               return err
-       }
        if hsh == "" {
                hsh, err = fileHash(fd)
                if err != nil {
-                       return err
+                       return ErrLine(err)
                }
        }
        fields := []recfile.Field{
@@ -124,22 +119,17 @@ func depsWrite(fdDep *os.File, tgts []string) error {
                tracef(CDebug, "no opened fdDep: %s", tgts)
                return nil
        }
+       var err error
        for _, tgt := range tgts {
-               tgtAbs, err := filepath.Abs(tgt)
-               if err != nil {
-                       panic(err)
-               }
+               tgtAbs := mustAbs(tgt)
                cwd := Cwd
                if DepCwd != "" && Cwd != DepCwd {
                        cwd = DepCwd
                }
                tgtDir := path.Join(cwd, DirPrefix)
-               tgtRel, err := filepath.Rel(tgtDir, tgtAbs)
-               if err != nil {
-                       panic(err)
-               }
+               tgtRel := mustRel(tgtDir, tgtAbs)
                if _, errStat := os.Stat(tgt); errStat == nil {
-                       err = depWrite(fdDep, tgtDir, tgtRel, "")
+                       err = ErrLine(depWrite(fdDep, tgtDir, tgtRel, ""))
                } else {
                        tracef(CDebug, "ifchange: %s <- %s (non-existing)", fdDep.Name(), tgtRel)
                        fields := []recfile.Field{
@@ -148,7 +138,7 @@ func depsWrite(fdDep *os.File, tgts []string) error {
                        }
                        inodeDummy := Inode{}
                        fields = append(fields, inodeDummy.RecfileFields()...)
-                       err = recfileWrite(fdDep, fields...)
+                       err = ErrLine(recfileWrite(fdDep, fields...))
                }
                if err != nil {
                        return err
@@ -165,6 +155,8 @@ type DepInfo struct {
        ifchanges []map[string]string
 }
 
+var missingBuild = errors.New(".rec missing Build:")
+
 func depRead(fdDep io.Reader) (*DepInfo, error) {
        r := recfile.NewReader(fdDep)
        m, err := r.NextMap()
@@ -174,7 +166,7 @@ func depRead(fdDep io.Reader) (*DepInfo, error) {
        depInfo := DepInfo{}
        b := m["Build"]
        if b == "" {
-               return nil, errors.New(".rec missing Build:")
+               return nil, missingBuild
        }
        depInfo.build = b
        for {
@@ -209,3 +201,21 @@ func depRead(fdDep io.Reader) (*DepInfo, error) {
        }
        return &depInfo, nil
 }
+
+func depReadBuild(pth string) (string, error) {
+       fd, err := os.Open(pth)
+       if err != nil {
+               return "", err
+       }
+       r := recfile.NewReader(fd)
+       m, err := r.NextMap()
+       fd.Close()
+       if err != nil {
+               return "", err
+       }
+       build := m["Build"]
+       if build == "" {
+               err = missingBuild
+       }
+       return build, err
+}