werf/werf

package gitdata

import (
    "encoding/json"
    "fmt"
    "io/ioutil"
    "os"
    "path/filepath"
    "strings"
    "time"
)

type GitPatchDesc struct {
    MetadataPath  string
    PatchPath     string
    Metadata      *PatchMetadata
    Size          uint64
    CacheBasePath string
}

func (entry *GitPatchDesc) GetPaths() []string {
    return []string{entry.MetadataPath, entry.PatchPath}
}

func (entry *GitPatchDesc) GetSize() uint64 {
    return entry.Size
}

func (entry *GitPatchDesc) GetLastAccessAt() time.Time {
    return time.Unix(entry.Metadata.LastAccessTimestamp, 0)
}

func (entry *GitPatchDesc) GetCacheBasePath() string {
    return entry.CacheBasePath
}

func GetExistingGitPatches(cacheVersionRoot string) ([]*GitPatchDesc, error) {
    var res []*GitPatchDesc

    if _, err := os.Stat(cacheVersionRoot); os.IsNotExist(err) {
        return nil, nil
    } else if err != nil {
        return nil, fmt.Errorf("error accessing dir %q: %w", cacheVersionRoot, err)
    }

    files, err := ioutil.ReadDir(cacheVersionRoot)
    if err != nil {
        return nil, fmt.Errorf("error reading dir %q: %w", cacheVersionRoot, err)
    }

    for _, finfo := range files {
        repoPatchesRootDir := filepath.Join(cacheVersionRoot, finfo.Name())

        if !finfo.IsDir() {
            if err := os.RemoveAll(repoPatchesRootDir); err != nil {
                return nil, fmt.Errorf("unable to remove %q: %w", repoPatchesRootDir, err)
            }
        }

        hashDirs, err := ioutil.ReadDir(repoPatchesRootDir)
        if err != nil {
            return nil, fmt.Errorf("error reading repo archives dir %q: %w", repoPatchesRootDir, err)
        }

        for _, finfo := range hashDirs {
            hashDir := filepath.Join(repoPatchesRootDir, finfo.Name())

            if !finfo.IsDir() {
                if err := os.RemoveAll(hashDir); err != nil {
                    return nil, fmt.Errorf("unable to remove %q: %w", hashDir, err)
                }
            }

            patchesFiles, err := ioutil.ReadDir(hashDir)
            if err != nil {
                return nil, fmt.Errorf("error reading repo patches from dir %q: %w", hashDir, err)
            }

            for _, finfo := range patchesFiles {
                path := filepath.Join(hashDir, finfo.Name())

                if finfo.IsDir() {
                    if err := os.RemoveAll(path); err != nil {
                        return nil, fmt.Errorf("unable to remove %q: %w", path, err)
                    }
                }

                if !strings.HasSuffix(finfo.Name(), ".meta.json") {
                    continue
                }

                desc := &GitPatchDesc{MetadataPath: path}
                res = append(res, desc)

                if data, err := ioutil.ReadFile(path); err != nil {
                    return nil, fmt.Errorf("error reading metadata file %q: %w", path, err)
                } else {
                    if err := json.Unmarshal(data, &desc.Metadata); err != nil {
                        return nil, fmt.Errorf("error unmarshalling json from %q: %w", path, err)
                    }
                }

                patchPath := filepath.Join(hashDir, fmt.Sprintf("%s.patch", strings.TrimSuffix(finfo.Name(), ".meta.json")))

                patchInfo, err := os.Stat(patchPath)
                if err != nil {
                    if os.IsNotExist(err) {
                        continue
                    }

                    return nil, fmt.Errorf("error accessing %q: %w", patchPath, err)
                }

                desc.PatchPath = patchPath
                desc.Size = uint64(patchInfo.Size())
            }
        }
    }

    return res, nil
}